Block IPv6 encapsulation and CGNAT ranges in SSRF guard

Add NAT64 (64:ff9b::/96), 6to4 (2002::/16), and CGNAT shared address space (100.64.0.0/10) to the private-network guard. These ranges can smuggle requests toward internal networks and were not covered by the existing predicates, leaving an SSRF bypass. Introduce DISALLOWED_RANGES and OR it into private_ip?, preserving LOCAL_IP behavior. Ref: weekend run #3873122 (IPv6 encapsulation SSRF ranges)
2026-10-28 00:16:48 +09:00 · 2026-07-20 02:17:12 -07:00
142 changed files with 735 additions and 3336 deletions
@@ -50,6 +50,3 @@

 # Ignore test files
 /test/
-
-# Agent session state — worktrees under .claude/ are whole extra checkouts of this repo
-.claude
@@ -20,12 +20,13 @@ updates:
      semver-minor-days: 3
      semver-patch-days: 2
      default-days: 7
-      exclude:
-        - "brakeman"

-  # No docker ecosystem. Our base image tag is a build arg
-  # (`FROM ruby:$RUBY_VERSION-slim`), which the updater cannot read, so the
-  # entry only ever matched nothing — worse than no entry, because it looked
-  # like coverage. Ruby base image bumps are a manual, reviewed step here, as
-  # they are across the rest of the fleet. Keep Dockerfile, Dockerfile-export
-  # and .ruby-version on the same version by hand.
+  - package-ecosystem: docker
+    directory: "/"
+    schedule:
+      interval: weekly
+    cooldown:
+      semver-major-days: 7
+      semver-minor-days: 3
+      semver-patch-days: 2
+      default-days: 7
@@ -16,12 +16,12 @@ jobs:

    steps:
      - name: Checkout code
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
        with:
          persist-credentials: false

      - name: Set up Ruby
-        uses: ruby/setup-ruby@a0102e0972be65f351c307e2d64b9314a57c8073 # v1.324.0
+        uses: ruby/setup-ruby@319994f95fa847cf3fb3cd3dbe89f6dcde9f178f # v1.295.0
        with:
          ruby-version: .ruby-version
          bundler-cache: true
@@ -35,12 +35,12 @@ jobs:
      contents: read
    steps:
      - name: Checkout code
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
        with:
          persist-credentials: false

      - name: Set up Ruby
-        uses: ruby/setup-ruby@a0102e0972be65f351c307e2d64b9314a57c8073 # v1.324.0
+        uses: ruby/setup-ruby@319994f95fa847cf3fb3cd3dbe89f6dcde9f178f # v1.295.0
        with:
          ruby-version: .ruby-version
          bundler-cache: true
@@ -55,15 +55,15 @@ jobs:
      contents: read

    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
        with:
          persist-credentials: false

      - name: Run actionlint
-        uses: rhysd/actionlint@914e7df21a07ef503a81201c76d2b11c789d3fca # v1.7.12
+        uses: rhysd/actionlint@393031adb9afb225ee52ae2ccd7a5af5525e03e8 # v1.7.11

      - name: Run zizmor
-        uses: zizmorcore/zizmor-action@cc914d7f3750a2d13d75c7f184a1060aa0e9d482 # v0.6.4
+        uses: zizmorcore/zizmor-action@71321a20a9ded102f6e9ce5718a2fcec2c4f70d8 # v0.5.2
        with:
          advanced-security: false

@@ -82,12 +82,12 @@ jobs:
        run: sudo apt-get update && sudo apt-get install --no-install-recommends -y libsqlite3-0 libvips curl ffmpeg

      - name: Checkout code
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
        with:
          persist-credentials: false

      - name: Set up Ruby
-        uses: ruby/setup-ruby@a0102e0972be65f351c307e2d64b9314a57c8073 # v1.324.0
+        uses: ruby/setup-ruby@319994f95fa847cf3fb3cd3dbe89f6dcde9f178f # v1.295.0
        env:
          REDIS_URL: redis://localhost:6379/0
        with:
@@ -112,12 +112,12 @@ jobs:
        run: sudo apt-get update && sudo apt-get install --no-install-recommends -y libsqlite3-0 libvips curl ffmpeg

      - name: Checkout code
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
        with:
          persist-credentials: false

      - name: Set up Ruby
-        uses: ruby/setup-ruby@a0102e0972be65f351c307e2d64b9314a57c8073 # v1.324.0
+        uses: ruby/setup-ruby@319994f95fa847cf3fb3cd3dbe89f6dcde9f178f # v1.295.0
        env:
          REDIS_URL: redis://localhost:6379/0
        with:
@@ -44,15 +44,15 @@ jobs:
      IMAGE_NAME: ${{ github.repository }}
    steps:
      - name: Checkout
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
        with:
          persist-credentials: false

      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@f87e5991a6d7451dcb8d9637bfbc97413f497069 # v4.4.1
+        uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1

      - name: Log in to GHCR
-        uses: docker/login-action@dbcb813823bdd20940b903addbd779551569679f # v4.6.0
+        uses: docker/login-action@184bdaa0721073962dff0199f1fb9940f07167d1 # v3.5.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
@@ -67,20 +67,9 @@ jobs:
          CANONICAL_IMAGE="${REGISTRY}/${IMAGE_REF,,}"
          echo "canonical=${CANONICAL_IMAGE}" >> "$GITHUB_OUTPUT"

-      - name: Compute app version
-        id: version
-        shell: bash
-        run: |
-          set -eu
-          if [[ "${GITHUB_REF}" == refs/tags/v* ]]; then
-            echo "version=${GITHUB_REF#refs/tags/v}" >> "$GITHUB_OUTPUT"
-          else
-            echo "version=${GITHUB_SHA::7}" >> "$GITHUB_OUTPUT"
-          fi
-
      - name: Extract Docker metadata (tags, labels) with arch suffix
        id: meta
-        uses: docker/metadata-action@dc802804100637a589fabce1cb79ff13a1411302 # v6.2.0
+        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5.8.0
        with:
          images: ${{ steps.vars.outputs.canonical }}
          tags: |
@@ -98,15 +87,13 @@ jobs:

      - name: Build and push (${{ matrix.platform }})
        id: build
-        uses: docker/build-push-action@c3c9e263c25d99ce0380d002d59b67737d91b0dc # v7.4.0
+        uses: docker/build-push-action@263435318d21b8e681c14492fe198d362a7d2c83 # v6.18.0
        with:
          context: .
          file: Dockerfile
          build-args: |
            OCI_SOURCE=${{ env.SOURCE_URL }}
            OCI_DESCRIPTION=${{ env.IMAGE_DESCRIPTION }}
-            APP_VERSION=${{ steps.version.outputs.version }}
-            GIT_REVISION=${{ github.sha }}
          platforms: ${{ matrix.platform }}
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
@@ -118,7 +105,7 @@ jobs:

      - name: Attest image provenance (per-arch)
        if: github.event_name != 'pull_request'
-        uses: actions/attest-build-provenance@4d101475d8b20a2381f78447822ac1eab6504dd8 # v4.2.2
+        uses: actions/attest-build-provenance@977bb373ede98d70efdf65b84cb5f73e068dcc2a # v3.0.0
        with:
          subject-name: ${{ steps.vars.outputs.canonical }}
          subject-digest: ${{ steps.build.outputs.digest }}
@@ -139,10 +126,10 @@ jobs:
      IMAGE_NAME: ${{ github.repository }}
    steps:
      - name: Set up Docker Buildx (for imagetools)
-        uses: docker/setup-buildx-action@f87e5991a6d7451dcb8d9637bfbc97413f497069 # v4.4.1
+        uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1

      - name: Log in to GHCR
-        uses: docker/login-action@dbcb813823bdd20940b903addbd779551569679f # v4.6.0
+        uses: docker/login-action@184bdaa0721073962dff0199f1fb9940f07167d1 # v3.5.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
@@ -159,7 +146,7 @@ jobs:

      - name: Compute base tags (no suffix)
        id: meta
-        uses: docker/metadata-action@dc802804100637a589fabce1cb79ff13a1411302 # v6.2.0
+        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5.8.0
        with:
          images: ${{ steps.vars.outputs.canonical }}
          tags: |
@@ -207,7 +194,7 @@ jobs:
          done <<< "$tags"

      - name: Install Cosign
-        uses: sigstore/cosign-installer@6f9f17788090df1f26f669e9d70d6ae9567deba6 # v4.1.2
+        uses: sigstore/cosign-installer@d58896d6a1865668819e1d91763c7751a165e159 # v3.9.2

      - name: Cosign sign all tags (keyless OIDC)
        shell: bash
@@ -1 +1 @@
-3.4.10
+3.4.5
@@ -1,7 +1,7 @@
 # syntax = docker/dockerfile:1

 # Make sure it matches the Ruby version in .ruby-version and Gemfile
-ARG RUBY_VERSION=3.4.10
+ARG RUBY_VERSION=3.4.5
 FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base

 # Rails app lives here
@@ -66,9 +66,6 @@ ENV HTTP_WRITE_TIMEOUT=300
 COPY --from=build --chown=rails:rails /usr/local/bundle /usr/local/bundle
 COPY --from=build --chown=rails:rails /rails /rails

-# Install ONCE backup/restore hooks
-COPY --chmod=755 hooks /hooks
-
 # Set version and revision
 ARG APP_VERSION
 ENV APP_VERSION=$APP_VERSION
@@ -1,7 +1,7 @@
 # syntax = docker/dockerfile:1

 # Make sure it matches the Ruby version in .ruby-version and Gemfile
-ARG RUBY_VERSION=3.4.10
+ARG RUBY_VERSION=3.4.7
 FROM ruby:$RUBY_VERSION-slim as base

 # Install the tools we need
@@ -26,9 +26,6 @@ gem "importmap-rails", github: "rails/importmap-rails"
 gem "turbo-rails", github: "hotwired/turbo-rails"
 gem "stimulus-rails"

-# Rich text
-gem "lexxy", "~> 0.9.24"
-
 # Media handling
 gem "image_processing", ">= 1.2"

@@ -44,7 +41,6 @@ gem "rails_autolink"
 gem "geared_pagination"
 gem "jbuilder"
 gem "net-http-persistent"
-gem "surfguard", github: "basecamp/surfguard" # The SSRF address policy behind RestrictedHTTP
 gem "kredis"
 gem "platform_agent"
 gem "thruster"
@@ -1,9 +1,3 @@
-GIT
-  remote: https://github.com/basecamp/surfguard.git
-  revision: 59e278c01a537755f22791429051891949231ead
-  specs:
-    surfguard (0.2.0)
-
 GIT
  remote: https://github.com/hotwired/turbo-rails.git
  revision: 30cd8fcc6f82c1ad4edd1ed6069ba878f21f02b3
@@ -143,7 +137,7 @@ GEM
    bcrypt (3.1.22)
    benchmark (0.5.0)
    bigdecimal (3.3.1)
-    brakeman (8.0.6)
+    brakeman (8.0.5)
      racc
    builder (3.3.0)
    bundler-audit (0.9.3)
@@ -174,7 +168,6 @@ GEM
    erubi (1.13.1)
    faker (3.5.2)
      i18n (>= 1.8.11, < 2)
-    ffi (1.17.2)
    ffi (1.17.2-aarch64-linux-gnu)
    ffi (1.17.2-arm64-darwin)
    ffi (1.17.2-x86_64-darwin)
@@ -198,7 +191,7 @@ GEM
    jbuilder (2.14.1)
      actionview (>= 7.0.0)
      activesupport (>= 7.0.0)
-    json (2.21.2)
+    json (2.20.0)
    jwt (3.2.0)
      base64
    kredis (1.8.0)
@@ -206,14 +199,12 @@ GEM
      activesupport (>= 6.0.0)
      redis (>= 4.2, < 6)
    language_server-protocol (3.17.0.5)
-    lexxy (0.9.24)
-      rails (>= 8.0.2)
    lint_roller (1.1.0)
    logger (1.7.0)
    loofah (2.25.2)
      crass (~> 1.0.2)
      nokogiri (>= 1.12.0)
-    mail (2.9.1)
+    mail (2.9.0)
      logger
      mini_mime (>= 0.1.1)
      net-imap
@@ -225,7 +216,7 @@ GEM
      logger
    mini_mime (1.1.5)
    minitest (5.26.2)
-    mocha (3.1.0)
+    mocha (2.7.1)
      ruby2_keywords (>= 0.0.5)
    mono_logger (1.1.2)
    multi_json (1.17.0)
@@ -251,7 +242,7 @@ GEM
      racc (~> 1.4)
    nokogiri (1.19.4-x86_64-linux-gnu)
      racc (~> 1.4)
-    openssl (4.0.2)
+    openssl (3.3.0)
    ostruct (0.6.3)
    parallel (1.27.0)
    parser (3.3.9.0)
@@ -355,7 +346,7 @@ GEM
      ffi (~> 1.12)
      logger
    ruby2_keywords (0.0.5)
-    rubyzip (3.4.0)
+    rubyzip (3.0.2)
    securerandom (0.4.1)
    selenium-webdriver (4.35.0)
      base64 (~> 0.2)
@@ -376,18 +367,18 @@ GEM
      rack-protection (= 4.2.1)
      rack-session (>= 2.0.0, < 3)
      tilt (~> 2.0)
-    sqlite3 (2.9.6-aarch64-linux-gnu)
-    sqlite3 (2.9.6-arm64-darwin)
-    sqlite3 (2.9.6-x86_64-darwin)
-    sqlite3 (2.9.6-x86_64-linux-gnu)
+    sqlite3 (2.9.5-aarch64-linux-gnu)
+    sqlite3 (2.9.5-arm64-darwin)
+    sqlite3 (2.9.5-x86_64-darwin)
+    sqlite3 (2.9.5-x86_64-linux-gnu)
    stimulus-rails (1.3.4)
      railties (>= 6.0.0)
    stringio (3.1.8)
    thor (1.4.0)
-    thruster (0.1.23-aarch64-linux)
-    thruster (0.1.23-arm64-darwin)
-    thruster (0.1.23-x86_64-darwin)
-    thruster (0.1.23-x86_64-linux)
+    thruster (0.1.15-aarch64-linux)
+    thruster (0.1.15-arm64-darwin)
+    thruster (0.1.15-x86_64-darwin)
+    thruster (0.1.15-x86_64-linux)
    tilt (2.6.1)
    timeout (0.6.1)
    tsort (0.2.0)
@@ -398,9 +389,9 @@ GEM
    unicode-emoji (4.2.0)
    uri (1.1.1)
    useragent (0.16.11)
-    web-push (3.1.0)
+    web-push (3.0.2)
      jwt (~> 3.0)
-      openssl (>= 3.0)
+      openssl (~> 3.0)
    webmock (3.25.1)
      addressable (>= 2.8.0)
      crack (>= 0.3.2)
@@ -433,7 +424,6 @@ DEPENDENCIES
  importmap-rails!
  jbuilder
  kredis
-  lexxy (~> 0.9.24)
  mocha
  net-http-persistent
  ostruct
@@ -452,7 +442,6 @@ DEPENDENCIES
  sentry-ruby
  sqlite3
  stimulus-rails
-  surfguard!
  thruster
  turbo-rails!
  web-push
@@ -53,7 +53,3 @@ If you'd rather run the Docker image yourself, you can read more about that in t

 You are welcome - and encouraged - to modify Campfire to your liking.
 Please see our [development guide](docs/development.md) for how to get Campfire set up for local development.
-
-## Security
-
-See [SECURITY.md](SECURITY.md) for how to report a vulnerability and a description of our trust model.
@@ -1,22 +0,0 @@
-# Security
-
-Report vulnerabilities through our [HackerOne program](https://hackerone.com/basecamp) or at
-https://github.com/basecamp/once-campfire/security. Note that Campfire is in scope for our security
-program, but is not bounty eligible.
-
-## Trust model
-
-Campfire is self-hosted and single-tenant, so the administrator is the server operator,
-with shell, network, and database access already. Anything requiring the administrator
-role grants nothing they do not already have, and is not a vulnerability.
-
-We do want reports of anything a **non-administrator** can reach, and of any credential or
-network path held by the Campfire process but not by the operator's own shell.
-
-## Intentional behavior
-
-Bot webhook URLs are unrestricted: an administrator can point one at any address,
-including internal ones, because operators legitimately wire bots to their own services.
-Link unfurling is different because any member can trigger it by pasting a URL, so it
-validates destinations through `RestrictedHTTP::PrivateNetworkGuard`. The difference is who
-picks the destination.
@@ -1,160 +1,165 @@
-/* Resolve Lexxy's palette to Campfire's, in the editor and in rendered messages,
-   so everything follows Campfire's light/dark color scheme */
-.lexxy-content {
-  --lexxy-color-canvas: transparent;
-  --lexxy-color-text: var(--color-text);
-  --lexxy-color-text-subtle: var(--color-text);
-  --lexxy-color-link: var(--color-link);
-  --lexxy-color-ink: var(--color-text);
-  --lexxy-color-ink-inverted: var(--color-text-reversed);
-  --lexxy-color-ink-medium: var(--color-text);
-  --lexxy-color-ink-lighter: var(--color-border-darker);
-  --lexxy-color-ink-lightest: var(--color-bg);
-  --lexxy-color-selected: var(--color-selected, var(--color-bg));
-  --lexxy-color-code-bg: var(--color-bg);
+trix-toolbar {
+  display: none;
+  inset: auto 0 0 0;
+  min-width: 0;
+  position: sticky;
+  z-index: 3;

-  /* Campfire's message lines stack without extra block margins */
-  --lexxy-content-margin: 0;
+  .trix-dialog {
+    bottom: 3rem !important;
+    top: auto !important;
+  }
+
+  .trix-button--icon {
+    height: auto !important;
+  }
+
+  .trix-dialog {
+    background-color: var(--color-bg) !important;
+    border-radius: 1rem !important;
+    border: 2px solid var(--color-text) !important;
+    box-shadow: none !important;
+    color: var(--color-text) !important;
+    gap: var(--inline-space);
+    padding: 0 !important;
+    overflow: clip;
+
+    .trix-input {
+      background: transparent !important;
+      border: 0 !important;
+      color: var(--color-text) !important;
+      font-size: max(16px, 1em) !important;
+      padding: var(--input-padding, 0.5em 0.8em) !important;
+    }
+
+    .trix-button {
+      color: var(--color-text) !important;
+    }
+  }
+
+  .trix-dialog--link {
+    .trix-dialog__link-fields {
+      align-items: center;
+      padding-right: 0.3em;
+    }
+
+    [value="Link"],
+    [value="Unlink"] {
+      width: 2.6em;
+      aspect-ratio: 1 / 1;
+      background-position: center center;
+      background-repeat: no-repeat;
+      text-indent: -9999%;
+      padding: 0;
+    }
+
+    [value="Link"] { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' fill='none'%3E%3Cpath fill='%23000' fill-rule='evenodd' d='M18.948 5.258a4.337 4.337 0 0 0-6.108 0L11.217 6.87a.993.993 0 0 0 0 1.41c.392.39 1.027.39 1.418 0l1.623-1.613a2.323 2.323 0 0 1 3.271 0 2.29 2.29 0 0 1 0 3.251l-2.393 2.38a3.021 3.021 0 0 1-4.255 0l-.05-.049a1.007 1.007 0 0 0-1.418 0 .993.993 0 0 0 0 1.41l.05.049a5.036 5.036 0 0 0 7.091 0l2.394-2.38a4.275 4.275 0 0 0 0-6.072Zm-13.683 13.6a4.337 4.337 0 0 0 6.108 0l1.262-1.255a.993.993 0 0 0 0-1.41 1.007 1.007 0 0 0-1.418 0L9.954 17.45a2.323 2.323 0 0 1-3.27 0 2.29 2.29 0 0 1 0-3.251l2.344-2.331a2.579 2.579 0 0 1 3.631 0c.392.39 1.027.39 1.419 0a.993.993 0 0 0 0-1.41 4.593 4.593 0 0 0-6.468 0l-2.345 2.33a4.275 4.275 0 0 0 0 6.072Z' clip-rule='evenodd'/%3E%3C/svg%3E"); }
+
+    [value="Unlink"] {
+      background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' fill='none'%3E%3Cpath fill='%23000' fill-rule='evenodd' d='M18.954 5.264a3.58 3.58 0 0 0-5.04 0l-2.157 2.144a.993.993 0 0 0 0 1.41c.392.39 1.027.39 1.418 0l2.157-2.144a1.565 1.565 0 0 1 2.204 0c.607.603.609 1.58.005 2.186l-2.348 2.355a.993.993 0 0 0 .006 1.41 1.007 1.007 0 0 0 1.419-.007l2.347-2.354a3.528 3.528 0 0 0-.01-5ZM5.257 18.852a3.59 3.59 0 0 0 5.041.015l2.6-2.554a.993.993 0 0 0 .01-1.41 1.007 1.007 0 0 0-1.419-.009l-2.6 2.554c-.615.603-1.603.6-2.214-.006a1.554 1.554 0 0 1-.012-2.195l2.539-2.58a.993.993 0 0 0-.016-1.41 1.007 1.007 0 0 0-1.418.015l-2.539 2.58a3.54 3.54 0 0 0 .028 5Z' clip-rule='evenodd'/%3E%3Cpath stroke='%23000' stroke-linecap='round' stroke-width='2' d='M10.233 5.78V3.769M5.968 9.802H4.21M7.343 7.107 5.968 5.781M14.348 17.523v2.013M18.613 13.502h1.758M17.238 16.196l1.375 1.327'/%3E%3C/svg%3E%0A");
+      border-top-right-radius: 1em !important;
+      border-bottom-right-radius: 1em !important;
+    }
+  }
 }

-lexxy-editor {
+trix-editor {
  &.input {
-    --lexxy-editor-padding: 0;
-
-    /* One line high when empty. Lexxy derives this from attr(rows lh, 8lh),
-       whose resolution differs between Chrome versions — pin it instead of
-       risking the 8-line fallback */
-    --lexxy-editor-rows: 1lh;
-
-    background: transparent;
-    border: 0;
-    border-radius: 0;
    min-height: 24px;
  }

  .attachment--content {
    margin: 0;
    display: inline-flex;
-  }
-}

-/* The mentions menu needs a solid surface — the editor's transparent canvas
-   would let messages show through it */
-.lexxy-prompt-menu {
-  --lexxy-color-canvas: var(--color-bg);
-
-  border: 1px solid var(--color-border-dark);
-}
-
-/* Same for the code block language picker: with a transparent canvas the
-   native dropdown renders white-on-white in dark mode */
-lexxy-editor lexxy-code-language-picker select {
-  background-color: var(--color-bg);
-  color: var(--color-text);
-
-  option {
-    background-color: var(--color-bg);
-    color: var(--color-text);
-  }
-}
-
-/* The toolbar only shows when rich text mode is toggled on (see composer.css) */
-lexxy-toolbar {
-  /* Wide, airy button spacing like the Trix toolbar */
-  --lexxy-toolbar-gap: 1.3em;
-
-  /* Match the compact size of the Trix toolbar buttons */
-  --lexxy-toolbar-button-size: 1.7em;
-  --lexxy-toolbar-icon-size: 1.125em;
-
-  display: none;
-  border-block-end: 0;
-  min-width: 0;
-  z-index: 3;
-
-  /* Tools Campfire doesn't offer, matching the Trix toolbar: underline,
-     color highlights, tables, dividers and undo/redo (history tools were
-     hidden under Trix as well) */
-  button[name="underline"],
-  button[name="table"],
-  button[name="divider"],
-  button[name="undo"],
-  button[name="redo"],
-  lexxy-highlight-dropdown {
-    display: none !important;
-  }
-
-  /* No group separator pipes, like the Trix toolbar */
-  .lexxy-editor__toolbar-button.lexxy-editor__toolbar-group-end::after {
-    display: none;
-  }
-
-  /* Dropdown panels: a solid surface with a uniform radius. Lexxy derives
-     the panel's radius and gap from --lexxy-toolbar-gap, which Campfire
-     repurposes for button spacing */
-  .lexxy-editor__toolbar-dropdown [data-dropdown-panel] {
-    --lexxy-color-canvas: var(--color-bg);
-    --lexxy-color-ink-lightest: var(--color-message-bg);
-    --lexxy-color-selected: var(--color-selected);
-    --lexxy-color-selected-hover: var(--color-message-bg);
-
-    border: 1px solid var(--color-border-dark);
-    border-radius: 0.5em;
-    gap: 0.25em;
-    padding: 0.25em;
-  }
-
-  .lexxy-editor__toolbar-dropdown > .lexxy-editor__toolbar-button[aria-expanded="true"] {
-    border-radius: var(--lexxy-radius);
-  }
-}
-
-/* Attachment markup contains formatting whitespace that must not turn into
-   line breaks under the editor's white-space: pre-wrap */
-lexxy-editor action-text-attachment {
-  white-space: normal;
-}
-
-action-text-attachment[content-type~="application/vnd.campfire.mention"] {
-  display: inline-flex;
-  margin: 0;
-  padding: 0;
-  position: relative;
-}
-
-action-text-attachment[content-type~="application/vnd.actiontext.opengraph-embed"] {
-  lexxy-editor & {
-    display: block;
-    inline-size: fit-content;
-    max-inline-size: 100%;
-  }
-
-  /* No selection background — it peeks through the card's rounded corners.
-     The lexxy-editor prefix out-specifies Lexxy's own selection rule. */
-  lexxy-editor &.node--selected {
-    --lexxy-attachment-bg-color: transparent;
-  }
-
-  /* A prominent remove button on the card's top edge, horizontally
-     centered, like the Trix one. The lexxy-editor prefix out-specifies
-     Lexxy's own placement rules. */
-  lexxy-editor & lexxy-node-delete-button {
-    inset-block-start: 0;
-    inset-inline-start: 50%;
-    inset-inline-end: auto;
-    transform: translate(-50%, -50%);
-
-    .lexxy-floating-controls__group {
-      --button-size: 2.2em;
-
-      background-color: var(--color-negative);
-      border-radius: 50%;
-      color: white;
+    .attachment__toolbar {
+      top: 0;
+      z-index: 2;
    }
  }
 }

-.lexxy-content {
+.trix-button-group--file-tools,
+.trix-button-group--history-tools {
+  display: none !important;
+}
+
+.trix-button-group,
+.trix-button {
+  border: 0 !important;
+  margin: 0 !important;
+  border-radius: 0.3em !important;
+  box-shadow: none;
+
+  &::before {
+    opacity: 1 !important;
+  }
+
+  @media (prefers-color-scheme: dark) {
+    &::before {
+      filter: invert(100);
+    }
+  }
+
+  &.trix-active {
+    background-color: var(--color-text) !important;
+
+    &::before {
+      filter: invert(100);
+    }
+
+    @media (prefers-color-scheme: dark) {
+      &::before {
+        filter: invert(0);
+      }
+    }
+  }
+
+  &.trix-button--remove {
+    background-color: var(--color-negative);
+    border-radius: 1.8em !important;
+
+    &::before {
+      filter: invert(100);
+      background-size: 70%;
+      background-image: url("minus.svg");
+    }
+  }
+}
+
+[data-trix-content-type~='application/vnd.campfire.mention'] {
+  .trix-button-group {
+    display: inline;
+  }
+}
+
+[data-trix-content-type~="application/vnd.actiontext.opengraph-embed"] {
+  * {
+    text-decoration: none;
+  }
+
+  trix-editor & {
+    display: block;
+    inline-size: fit-content;
+    max-inline-size: 100%;
+  }
+}
+
+.trix-button:not(.trix-button--remove) {
+  @media (any-hover: hover) {
+    &:where(:not(:active):hover) {
+      filter: brightness(0.9);
+      background-color: var(--color-bg);
+    }
+  }
+
+  &:disabled {
+    opacity: 0.33;
+  }
+}
+
+trix-editor,
+.trix-content {
  pre {
    background-color: var(--color-bg) !important;
    border-radius: 0.5em;
@@ -174,13 +179,11 @@ action-text-attachment[content-type~="application/vnd.actiontext.opengraph-embed
  blockquote {
    border: 0 solid var(--color-border-darker) !important;
    border-inline-start-width: var(--blockquote-border) !important;
-    font-style: normal;
    margin: 0 var(--blockquote-margin) !important;
    padding-inline-start: var(--blockquote-padding) !important;
  }

  cite {
-    display: block;
    margin-inline-start: calc(var(--blockquote-padding));
    font-style: normal;
    font-size: 0.8rem;
@@ -196,14 +199,13 @@ action-text-attachment[content-type~="application/vnd.actiontext.opengraph-embed
    color: var(--color-link);
  }

-  /* The composer's mention menu is a list inside the editor too, and keeps Lexxy's own spacing */
-  ul:not(.lexxy-prompt-menu),
+  ul,
  ol {
    margin: 0 !important;
    padding: 0 !important;
  }

-  li:not(.lexxy-prompt-menu__item) {
+  li {
    margin: 0 0 0 var(--inline-space-double) !important;
    padding: 0 !important;
  }
@@ -33,7 +33,7 @@
  }
 }

-action-text-attachment[content-type~='application/vnd.campfire.mention'] {
+[data-trix-content-type~='application/vnd.campfire.mention'] {
  display: inline-flex;
  margin: 0;
  padding: 0;
@@ -100,42 +100,16 @@
  }

  .composer--rich-text {
-    lexxy-toolbar {
-      display: flex;
+    trix-toolbar {
+      display: block;
    }

-    lexxy-editor.input {
+    trix-editor.input {
      margin-block-start: var(--block-space-half);
    }
  }

-  /* In the message composer the toolbar goes below the text, on the same
-     row as the surrounding action buttons, like the Trix toolbar did.
-     The edit composer keeps it on top. */
-  #composer.composer--rich-text lexxy-editor.input {
-    display: flex;
-    flex-direction: column;
-
-    /* Sit the toolbar row on the same baseline as the composer's round
-       buttons, which pull themselves down with negative margins */
-    margin-block-end: -0.25em;
-
-    .lexxy-editor__content {
-      order: -1;
-    }
-
-    lexxy-toolbar {
-      margin-block-start: 0.4em;
-
-      /* Dropdowns open upward — the toolbar sits at the bottom of the screen */
-      [data-dropdown-panel] {
-        inset-block-start: auto;
-        inset-block-end: 100%;
-      }
-    }
-  }
-
-  .composer--edit lexxy-toolbar {
+  .composer--edit trix-toolbar {
    border-block-end: 1px solid var(--color-border);
    margin-inline: -0.8em;
    padding-inline: 0.3em;
@@ -143,16 +117,6 @@
  }
 }

-/* The editor's container-type prevents it from sizing the message bubble by
-   its content, so give the bubble the full available width while editing */
-.message__body:has(.composer--edit) {
-  inline-size: 100%;
-
-  .message__body-content--editing {
-    flex-grow: 1;
-  }
-}
-
 /* Typing indicator */
 .typing-indicator {
  inset-block-start: var(--indicator-position, 0.15rem);
@@ -1,5 +1,5 @@
-
-.lexxy-content {
+trix-editor,
+.trix-content {
  .og-embed {
    background: var(--color-bg);
    border: 1px solid var(--color-border-dark);
@@ -15,7 +15,7 @@
      flex-direction: row;
    }

-    &.og-embed--twitter-avatar {
+    .cf-twitter-avatar & {
      flex-direction: row;
    }
  }
@@ -35,11 +35,10 @@

  .og-embed__title {
    font-weight: 600;
+    text-decoration: underline;

-    /* Underline the link itself so the line is link-colored */
    a {
      color: var(--color-link);
-      text-decoration: underline;
    }
  }

@@ -54,11 +53,7 @@
      inline-size: 15dvw;
    }

-    /* block-size/border-radius guard against Lexxy's 1em round avatar
-       styling for custom attachment images */
    > * {
-      block-size: auto;
-      border-radius: 0;
      object-position: top right;
      inline-size: 100%;
      object-fit: contain;
@@ -68,7 +63,7 @@
      }
    }

-    .og-embed--twitter-avatar & {
+    .cf-twitter-avatar & {
      aspect-ratio: 1;
      border-radius: 50%;
      inline-size: 2lh;
@@ -537,7 +537,7 @@ img.message__attachment {
    padding: var(--content-padding-block) 0 var(--content-padding-block) var(--content-padding-inline);
    text-shadow: 0 0 3px var(--color-text-reversed);

-    .lexxy-content {
+    .trix-content {
      font-size: 2.4em;
      line-height: 1.4;
    }
@@ -1,13 +0,0 @@
-# Prepended onto Turbo::StreamsChannel. The subscriber names the channel it wants, so
-# authorizing room messages only in RoomMessagesChannel would leave the stock channel as
-# a way around it: same signed stream name, no membership check. Turn those names away
-# here and RoomMessagesChannel becomes the only door.
-module RoomStreamsAreAuthorized
-  def subscribed
-    if RoomMessagesChannel.guarded_stream?(verified_stream_name_from_params)
-      reject
-    else
-      super
-    end
-  end
-end
@@ -1,55 +0,0 @@
-# Authorizes the room message stream when the subscription is made, so that revoking a
-# membership actually stops delivery.
-#
-# Turbo's stock channel verifies only the signature on the stream name. That name carries
-# no expiry and no binding to a user, so one harvested while a member keeps working after
-# the membership is gone. Reconnecting makes it worse rather than better: revoking a
-# membership disconnects the user with reconnect: true, and the client then replays its
-# subscriptions on the fresh socket.
-#
-# The room is derived from the verified stream name rather than taken as a parameter, so
-# there's nothing for a subscriber to point somewhere else. The subscriber also doesn't
-# get to choose the channel: Turbo::StreamsChannel turns these stream names away, so this
-# is the only way onto them. See config/initializers/turbo_streams_authorization.rb.
-class RoomMessagesChannel < ApplicationCable::Channel
-  extend  Turbo::Streams::StreamName
-  include Turbo::Streams::StreamName::ClassMethods
-
-  STREAM_SUFFIX = "messages"
-
-  class << self
-    # True for the stream names this channel exists to guard, whoever is asking.
-    def guarded_stream?(stream_name)
-      stream_name.to_s.split(":", 2).second == STREAM_SUFFIX
-    end
-
-    def subscribable_room(user, stream_name)
-      gid_param, suffix = stream_name.to_s.split(":", 2)
-
-      if suffix == STREAM_SUFFIX && room = room_from(gid_param)
-        user.rooms.find_by(id: room.id)
-      end
-    end
-
-    private
-      def room_from(gid_param)
-        GlobalID::Locator.locate gid_param, only: Room
-      rescue ActiveRecord::RecordNotFound
-        nil
-      end
-  end
-
-  def subscribed
-    if stream_name = authorized_stream_name
-      stream_from stream_name
-    else
-      reject
-    end
-  end
-
-  private
-    def authorized_stream_name
-      stream_name = verified_stream_name_from_params
-      stream_name if stream_name.present? && self.class.subscribable_room(current_user, stream_name)
-    end
-end
@@ -1,12 +1,5 @@
 class UnreadRoomsChannel < ApplicationCable::Channel
-  # Scoped per user, like ReadRoomsChannel. A single global stream would tell every
-  # authenticated connection when any room on the account is active, including closed
-  # rooms and direct conversations they're not part of.
-  def self.stream_name_for(user_id)
-    "user_#{user_id}_unreads"
-  end
-
  def subscribed
-    stream_from self.class.stream_name_for(current_user.id)
+    stream_from "unread_rooms"
  end
 end
@@ -8,8 +8,9 @@ class Accounts::LogosController < ApplicationController
    if stale?(etag: Current.account)
      expires_in 5.minutes, public: true, stale_while_revalidate: 1.week

-      if (logo_variant = Current.account&.logo_variant(logo_size))
-        send_png_file ActiveStorage::Blob.service.path_for(logo_variant.key)
+      if Current.account&.logo&.attached?
+        logo = Current.account.logo.variant(logo_variant).processed
+        send_png_file ActiveStorage::Blob.service.path_for(logo.key)
      else
        send_stock_icon
      end
@@ -22,6 +23,9 @@ class Accounts::LogosController < ApplicationController
  end

  private
+    LARGE_SQUARE_PNG_VARIANT = { resize_to_limit: [ 512, 512 ], format: :png }
+    SMALL_SQUARE_PNG_VARIANT = { resize_to_limit: [ 192, 192 ], format: :png }
+
    def send_png_file(path)
      send_file path, content_type: "image/png", disposition: :inline
    end
@@ -34,8 +38,8 @@ class Accounts::LogosController < ApplicationController
      end
    end

-    def logo_size
-      small_logo? ? :small : :large
+    def logo_variant
+      small_logo? ? SMALL_SQUARE_PNG_VARIANT : LARGE_SQUARE_PNG_VARIANT
    end

    def small_logo?
@@ -1,26 +1,11 @@
 class Autocompletable::UsersController < ApplicationController
  def index
    set_page_and_extract_portion_from find_autocompletable_users.with_attached_avatar.ordered, per_page: 20
-
-    respond_to do |format|
-      format.html { render layout: false } # <lexxy-prompt-item> elements for the mentions prompt
-      format.json
-    end
  end

  private
    def find_autocompletable_users
-      if query.present?
-        users_scope.active.filtered_by(query)
-      else
-        users_scope.active
-      end
-    end
-
-    # The rich text editor's mentions prompt filters with `filter`, the
-    # autocomplete inputs with `query`
-    def query
-      params[:filter].presence || params[:query].presence
+      params[:query].present? ? users_scope.active.filtered_by(params[:query]) : users_scope.active
    end

    def users_scope
@@ -1,9 +0,0 @@
-module ActiveStorageAuthentication
-  extend ActiveSupport::Concern
-  include Authentication::SessionLookup
-
-  private
-    def require_active_storage_authentication
-      head :unauthorized unless find_session_by_cookie
-    end
-end
@@ -71,13 +71,6 @@ module Authentication
      Current.session&.destroy!
      reset_session
      remove_authentication_cookie
-      disconnect_remote_connections
-    end
-
-    def disconnect_remote_connections
-      Current.user&.reset_remote_connections
-    rescue => error
-      Rails.logger.warn "Could not disconnect remote connections on sign out: #{error.class}"
    end

    def authenticated_as(session)
@@ -1,12 +0,0 @@
-module RawRequestBody
-  extend ActiveSupport::Concern
-
-  private
-
-  def raw_request_body
-    request.body.rewind
-    request.body.read.force_encoding("UTF-8")
-  ensure
-    request.body.rewind
-  end
-end
@@ -1,39 +0,0 @@
-class Messages::Boosts::ByBotsController < Messages::BoostsController
-  include RawRequestBody
-
-  allow_bot_access only: %i[ create destroy ]
-
-  before_action :ensure_content_present, only: :create
-
-  def create
-    @boost = @message.boosts.create!(boost_params)
-
-    broadcast_create
-    render :show, status: :created
-  end
-
-  private
-    def set_message
-      if room = Current.user.rooms.find_by(id: params[:room_id])
-        @message = room.messages.find_by(id: params[:message_id])
-      end
-
-      head :not_found unless @message
-    end
-
-    def set_boost
-      super
-    rescue ActiveRecord::RecordNotFound
-      head :not_found
-    end
-
-    def ensure_content_present
-      if raw_request_body.blank?
-        head :unprocessable_content
-      end
-    end
-
-    def boost_params
-      { content: raw_request_body }
-    end
-end
@@ -1,6 +1,5 @@
 class Messages::BoostsController < ApplicationController
  before_action :set_message
-  before_action :set_boost, only: :destroy

  def index
  end
@@ -16,6 +15,7 @@ class Messages::BoostsController < ApplicationController
  end

  def destroy
+    @boost = Current.user.boosts.find(params[:id])
    @boost.destroy!

    broadcast_remove
@@ -26,10 +26,6 @@ class Messages::BoostsController < ApplicationController
      @message = Current.user.reachable_messages.find(params[:message_id])
    end

-    def set_boost
-      @boost = @message.boosts.find_by!(id: params[:id], booster: Current.user)
-    end
-
    def boost_params
      params.require(:boost).permit(:content)
    end
@@ -1,64 +1,24 @@
 class Messages::ByBotsController < MessagesController
-  include RawRequestBody
-
-  allow_bot_access only: %i[ index create update destroy ]
-
-  before_action :set_room
-  before_action :set_message, only: %i[ update destroy ]
-  before_action :ensure_can_administer, only: %i[ update destroy ]
-  before_action :ensure_body_or_attachment_present, only: :create
-
-  def index
-    @messages = find_paged_messages
-    set_pagination_headers
-  end
+  allow_bot_access only: :create

  def create
    super
    head :created, location: message_url(@message)
  end

-  def destroy
-    super
-    head :no_content
-  end
-
  private
-    def set_room
-      @room = Current.user.rooms.find_by(id: params[:room_id])
-
-      head :not_found unless @room
-    end
-
-    def ensure_body_or_attachment_present
-      if params[:attachment].blank? && raw_request_body.blank?
-        head :unprocessable_content
-      end
-    end
-
-    def set_pagination_headers
-      headers["X-Total-Count"] = @room.messages.count.to_s
-
-      if next_page = next_page_params
-        headers["Link"] = %(<#{room_bot_messages_url(@room, params[:bot_key], **next_page)}>; rel="next")
-      end
-    end
-
-    def next_page_params
-      if @messages.any?
-        if params[:after].present?
-          { after: @messages.last.id } if @room.messages.after(@messages.last).exists?
-        else
-          { before: @messages.first.id } if @room.messages.before(@messages.first).exists?
-        end
-      end
-    end
-
    def message_params
      if params[:attachment]
        params.permit(:attachment)
      else
-        { body: raw_request_body }
+        reading(request.body) { |body| { body: body } }
      end
    end
+
+    def reading(io)
+      io.rewind
+      yield io.read.force_encoding("UTF-8")
+    ensure
+      io.rewind
+    end
 end
@@ -37,11 +37,7 @@ class MessagesController < ApplicationController
    @message.update!(message_params)

    @message.broadcast_replace_to @room, :messages, target: [ @message, :presentation ], partial: "messages/presentation", attributes: { maintain_scroll: true }
-
-    respond_to do |format|
-      format.html { redirect_to room_message_url(@room, @message) }
-      format.json { render :show }
-    end
+    redirect_to room_message_url(@room, @message)
  end

  def destroy
@@ -42,12 +42,6 @@ class Rooms::ClosedsController < RoomsController
      @room = @room.becomes!(Rooms::Closed)
    end

-    # Open and closed rooms convert into each other, so both are in reach here. Direct
-    # rooms never are: converting one would let its creator revise who's in it.
-    def room_scope
-      Current.user.rooms.without_directs
-    end
-
    def grantees
      User.where(id: grantee_ids)
    end
@@ -29,13 +29,8 @@ class Rooms::DirectsController < RoomsController
      end
    end

-    # All users in a direct room can administer it. Only direct rooms, though: this
-    # relaxation is why room_scope below has to keep every other type out of reach.
+    # All users in a direct room can administer it
    def ensure_can_administer
      true
    end
-
-    def room_scope
-      Current.user.rooms.directs
-    end
 end
@@ -40,12 +40,6 @@ class Rooms::OpensController < RoomsController
      @room = @room.becomes!(Rooms::Open)
    end

-    # Open and closed rooms convert into each other, so both are in reach here. Direct
-    # rooms never are: promoting one would republish its history to the whole account.
-    def room_scope
-      Current.user.rooms.without_directs
-    end
-
    def broadcast_create_room(room)
      broadcast_prepend_to :rooms, target: :shared_rooms, partial: "users/sidebars/rooms/shared", locals: { room: room }
    end
@@ -20,19 +20,13 @@ class RoomsController < ApplicationController

  private
    def set_room
-      if room = room_scope.find_by(id: params[:room_id] || params[:id])
+      if room = Current.user.rooms.find_by(id: params[:room_id] || params[:id])
        @room = room
      else
        redirect_to root_url, alert: "Room not found or inaccessible"
      end
    end

-    # Subclasses narrow this to the room types they're allowed to act on, so that one
-    # room namespace can't be used to reach another's rooms.
-    def room_scope
-      Current.user.rooms
-    end
-
    def ensure_can_administer
      head :forbidden unless Current.user.can_administer?(@room)
    end
@@ -9,7 +9,8 @@ class Users::AvatarsController < ApplicationController
    if stale?(etag: @user)
      expires_in 30.minutes, public: true, stale_while_revalidate: 1.week

-      if (avatar_variant = @user.avatar_variant)
+      if @user.avatar.attached?
+        avatar_variant = @user.avatar.variant(SQUARE_WEBP_VARIANT).processed
        send_webp_blob_file avatar_variant.key
      elsif @user.bot?
        render_default_bot
@@ -25,6 +26,8 @@ class Users::AvatarsController < ApplicationController
  end

  private
+    SQUARE_WEBP_VARIANT = { resize_to_limit: [ 512, 512 ], format: :webp }
+
    def send_webp_blob_file(key)
      send_file ActiveStorage::Blob.service.path_for(key), content_type: "image/webp", disposition: :inline
    end
@@ -6,17 +6,12 @@ class Users::PushSubscriptionsController < ApplicationController

  def create
    if subscription = @push_subscriptions.find_by(push_subscription_params)
-      # Existing endpoints must pass current validations
-      if subscription.valid?
-        subscription.touch
-        head :ok
-      else
-        head :unprocessable_entity
-      end
+      subscription.touch
    else
-      subscription = @push_subscriptions.create push_subscription_params.merge(user_agent: request.user_agent)
-      head subscription.persisted? ? :ok : :unprocessable_entity
+      @push_subscriptions.create! push_subscription_params.merge(user_agent: request.user_agent)
    end
+
+    head :ok
  end

  def destroy
@@ -1,13 +1,3 @@
 module ContentFilters
-  # Formatting the rich text editor produces that Rails' sanitizers don't
-  # allow by default. A message passes through three sanitization layers on
-  # its way to the screen, and each builds on this list:
-  #
-  #   * SanitizeTags strips disallowed markup from the message body
-  #   * Action Text sanitizes the rendered content (lib/rails_ext/action_text_allowed_tags.rb)
-  #   * auto_link re-sanitizes the final html (MessagesHelper#message_presentation)
-  EDITOR_FORMATTING_TAGS = %w[ s u mark table thead tbody tfoot tr th td ]
-  EDITOR_FORMATTING_ATTRIBUTES = %w[ data-language ]
-
-  TextMessagePresentationFilters = ActionText::Content::Filters.new(RemoveSoloUnfurledLinkText, SanitizeTags, SanitizeAttributes)
+  TextMessagePresentationFilters = ActionText::Content::Filters.new(RemoveSoloUnfurledLinkText, StyleUnfurledTwitterAvatars, SanitizeTags)
 end
@@ -1,22 +1,18 @@
 class ContentFilters::RemoveSoloUnfurledLinkText < ActionText::Content::Filter
-  TWITTER_DOMAINS = %w[ x.com twitter.com ]
-  TWITTER_DOMAIN_MAPPING = { "x.com" => "twitter.com" }
-
  def applicable?
    normalize_tweet_url(solo_unfurled_url) == normalize_tweet_url(content.to_plain_text)
  end

  def apply
-    if trix_body?
-      remove_link_text_from_wrapping_div
-    else
-      remove_link_paragraphs
-    end
+    fragment.replace("div") { |node| node.tap { |n| n.inner_html = unfurled_links.first.to_s } }
  end

  private
+    TWITTER_DOMAINS = %w[ x.com twitter.com ]
+    TWITTER_DOMAIN_MAPPING = { "x.com" => "twitter.com" }
+
    def solo_unfurled_url
-      ActionText::Attachment::OpengraphEmbed.from_node(unfurled_links.first)&.href if unfurled_links.size == 1
+      unfurled_links.first["href"] if unfurled_links.size == 1
    end

    def unfurled_links
@@ -39,20 +35,4 @@ class ContentFilters::RemoveSoloUnfurledLinkText < ActionText::Content::Filter
    def twitter_url?(url)
      url.present? && TWITTER_DOMAINS.any? { |domain| url.strip.include?(domain) }
    end
-
-    def trix_body?
-      fragment.find_all("div").any?
-    end
-
-    def remove_link_text_from_wrapping_div
-      fragment.replace("div") { |node| node.tap { |n| n.inner_html = unfurled_links.first.to_s } }
-    end
-
-    def remove_link_paragraphs
-      fragment.replace("p") do |node|
-        if node.at_css("action-text-attachment")
-          node
-        end
-      end
-    end
 end
@@ -1,47 +0,0 @@
-class ContentFilters::SanitizeAttributes < ActionText::Content::Filter
-  def applicable?
-    true
-  end
-
-  # Scrub attributes on the tags that SanitizeTags allows, using Rails' safe-list
-  # sanitizer so unsafe URI schemes and event-handler attributes are stripped.
-  # Runs after SanitizeTags, so passing the same allowed tags makes the tag pass
-  # a no-op and only attributes are scrubbed.
-  def apply
-    sanitizer.sanitize fragment.to_html, tags: allowed_tags, attributes: allowed_attributes
-  end
-
-  private
-    # Presentation styling relies on class attributes (e.g. unfurled link embeds),
-    # which the standard ActionText set doesn't include.
-    EXTRA_ALLOWED_ATTRIBUTES = %w[ class ]
-
-    # ActionText::ContentHelper.sanitizer is a single process-wide instance, and
-    # rails-html-sanitizer reuses one mutable permit scrubber that it reconfigures
-    # from the tags/attributes on every #sanitize call. Sharing it here would race
-    # our stricter tag set against ActionText's default rendering on concurrent
-    # requests, so use a dedicated instance of the same sanitizer class to keep the
-    # scrubber isolated.
-    def sanitizer
-      sanitizer_class.new
-    end
-
-    def sanitizer_class
-      ActionText::ContentHelper.sanitizer.class
-    end
-
-    def allowed_tags
-      ContentFilters::SanitizeTags::ALLOWED_TAGS
-    end
-
-    def allowed_attributes
-      standard_allowed_attributes + EXTRA_ALLOWED_ATTRIBUTES
-    end
-
-    # Mirrors ActionText::ContentHelper#sanitizer_allowed_attributes, which isn't
-    # exposed at the module level.
-    def standard_allowed_attributes
-      ActionText::ContentHelper.allowed_attributes ||
-        (sanitizer_class.allowed_attributes + ActionText::Attachment::ATTRIBUTES).to_a
-    end
-end
@@ -1,8 +1,4 @@
 class ContentFilters::SanitizeTags < ActionText::Content::Filter
-  ALLOWED_TAGS = %w[ a abbr acronym address b big blockquote br cite code dd del dfn div dl dt em h1 h2 h3 h4 h5 h6 hr i ins kbd li ol
-    p pre samp small span strong sub sup time tt ul var ] + ContentFilters::EDITOR_FORMATTING_TAGS +
-    [ ActionText::Attachment.tag_name, "figure", "figcaption" ]
-
  def applicable?
    true
  end
@@ -12,6 +8,9 @@ class ContentFilters::SanitizeTags < ActionText::Content::Filter
  end

  private
+    ALLOWED_TAGS = %w[ a abbr acronym address b big blockquote br cite code dd del dfn div dl dt em h1 h2 h3 h4 h5 h6 hr i ins kbd li ol
+      p pre samp small span strong sub sup time tt ul var ] + [ ActionText::Attachment.tag_name, "figure", "figcaption" ]
+
    def not_allowed_tags_css_selector
      ALLOWED_TAGS.map { |tag| ":not(#{tag})" }.join("")
    end
@@ -0,0 +1,24 @@
+class ContentFilters::StyleUnfurledTwitterAvatars < ActionText::Content::Filter
+  def applicable?
+    unfurled_twitter_avatars.present?
+  end
+
+  def apply
+    fragment.update do |source|
+      div = source.at_css("div")
+      div["class"] = UNFURLED_TWITTER_AVATAR_CSS_CLASS
+    end
+  end
+
+  private
+    UNFURLED_TWITTER_AVATAR_CSS_CLASS = "cf-twitter-avatar"
+    TWITTER_AVATAR_URL_PREFIX = "https://pbs.twimg.com/profile_images"
+
+    def unfurled_twitter_avatars
+      fragment.find_all("#{opengraph_css_selector}[url*='#{TWITTER_AVATAR_URL_PREFIX}']")
+    end
+
+    def opengraph_css_selector
+      "action-text-attachment[@content-type='#{ActionText::Attachment::OpengraphEmbed::OPENGRAPH_EMBED_CONTENT_TYPE}']"
+    end
+end
@@ -1,9 +1,4 @@
 module MessagesHelper
-  # auto_link re-sanitizes with Rails' default safe list, which lacks the
-  # formatting the rich text editor produces
-  AUTO_LINK_ALLOWED_TAGS = Rails::HTML5::SafeListSanitizer.allowed_tags + ContentFilters::EDITOR_FORMATTING_TAGS
-  AUTO_LINK_ALLOWED_ATTRIBUTES = Rails::HTML5::SafeListSanitizer.allowed_attributes + ContentFilters::EDITOR_FORMATTING_ATTRIBUTES
-
  def message_area_tag(room, &)
    tag.div id: "message-area", class: "message-area", contents: true, data: {
      controller: "messages presence drop-target",
@@ -62,8 +57,7 @@ module MessagesHelper
    when "sound"
      message_sound_presentation(message)
    else
-      auto_link h(ContentFilters::TextMessagePresentationFilters.apply(message.body.body)),
-        html: { target: "_blank" }, sanitize_options: { tags: AUTO_LINK_ALLOWED_TAGS, attributes: AUTO_LINK_ALLOWED_ATTRIBUTES }
+      auto_link h(ContentFilters::TextMessagePresentationFilters.apply(message.body.body)), html: { target: "_blank" }
    end
  rescue Exception => e
    Sentry.capture_exception(e, extra: { message: message })
@@ -1,33 +1,11 @@
 module RichTextHelper
  def rich_text_data_actions
-    # submitByKeyboard runs in the capture phase so it can submit on Enter
-    # before the editor turns the keystroke into a newline
-    "lexxy:change->typing-notifications#start keydown->composer#submitByKeyboard:capture"
-  end
+    default_actions =
+      "trix-change->typing-notifications#start keydown->composer#submitByKeyboard"

-  def mention_prompt_tag(room)
-    tag.lexxy_prompt trigger: "@", name: "mention", src: autocompletable_users_path(room_id: room.id),
-      "remote-filtering": true, "empty-results": "No matches"
-  end
+    autocomplete_actions =
+      "trix-focus->rich-autocomplete#focus trix-change->rich-autocomplete#search trix-blur->rich-autocomplete#blur"

-  # The editor keeps an attachment's content as it finds it, so every
-  # attachment is rebuilt from its attachable before editing: a Trix-era
-  # embed carries its details as node attributes the editor doesn't
-  # round-trip, a mention edited under Trix carries the generic content type
-  # the editor doesn't permit, and a hand-written embed carries whatever
-  # markup the author put there.
-  def editable_body(message)
-    fragment = ActionText::Fragment.wrap(message.body.body_before_type_cast)
-
-    transformed = fragment.replace(ActionText::Attachment.tag_name) do |node|
-      attachment = ActionText::Attachment.from_node(node)
-
-      node.tap do |n|
-        n["content-type"] = attachment.attachable.attachable_content_type
-        n["content"] = render_action_text_attachment(attachment)
-      end
-    end
-
-    ActionText::RichText.new(body: transformed.to_html)
+    [ default_actions, autocomplete_actions ].join(" ")
  end
 end
@@ -73,12 +73,12 @@ module RoomsHelper
    def composer_data_actions
      drag_and_drop_actions = "drop-target:drop@window->composer#dropFiles"

-      attachment_actions =
-        "lexxy:file-accept->composer#preventAttachment refresh-room:online@window->composer#online"
+      trix_attachment_actions =
+        "trix-file-accept->composer#preventAttachment refresh-room:online@window->composer#online"

      remaining_actions =
        "typing-notifications#stop paste->composer#pasteFiles turbo:submit-end->composer#submitEnd refresh-room:offline@window->composer#offline"

-      [ drop_target_actions, drag_and_drop_actions, attachment_actions, remaining_actions ].join(" ")
+      [ drop_target_actions, drag_and_drop_actions, trix_attachment_actions, remaining_actions ].join(" ")
    end
 end
@@ -1,4 +1,6 @@
 // Configure your import map in config/importmap.rb. Read more: https://github.com/rails/importmap-rails
 import "@hotwired/turbo-rails"
+import "trix"
+import "@rails/actiontext"
 import "initializers"
 import "controllers"
@@ -1,7 +1,7 @@
 import { Controller } from "@hotwired/stimulus"
 import FileUploader from "models/file_uploader"
 import { onNextEventLoopTick, nextFrame } from "helpers/timing_helpers"
-import { escapeHTML } from "helpers/string_helpers"
+import { escapeHTML } from "helpers/dom_helpers"

 export default class extends Controller {
  static classes = ["toolbar"]
@@ -12,21 +12,11 @@ export default class extends Controller {
  #files = []

  connect() {
-    this.#restoreDraft()
-
    if (!this.#usingTouchDevice) {
      onNextEventLoopTick(() => this.textTarget.focus())
    }
  }

-  saveDraft() {
-    if (this.textTarget.isBlank) {
-      localStorage.removeItem(this.#draftKey)
-    } else {
-      localStorage.setItem(this.#draftKey, this.textTarget.value)
-    }
-  }
-
  submit(event) {
    event.preventDefault()

@@ -54,20 +44,21 @@ export default class extends Controller {
  }

  replaceMessageContent(content) {
-    this.textTarget.value = content
-    this.textTarget.focus()
-    this.textTarget.selection.placeCursorAtTheEnd()
+    const editor = this.textTarget.editor
+
+    editor.recordUndoEntry("Format reply")
+    editor.setSelectedRange([0, editor.getDocument().toString().length])
+    editor.deleteInDirection("forward")
+    editor.insertHTML(content)
+    editor.setSelectedRange([editor.getDocument().toString().length - 1])
  }

  submitByKeyboard(event) {
-    if (event.key != "Enter" || this.textTarget.hasOpenPrompt) return
-
    const toolbarVisible = this.element.classList.contains(this.toolbarClass)
-    const metaEnter = event.metaKey || event.ctrlKey
-    const plainEnter = !event.shiftKey && !event.isComposing
+    const metaEnter = event.key == "Enter" && (event.metaKey || event.ctrlKey)
+    const plainEnter = event.keyCode == 13 && !event.shiftKey && !event.isComposing

    if (!this.#usingTouchDevice && (metaEnter || (plainEnter && !toolbarVisible))) {
-      event.stopPropagation()
      this.submit(event)
    }
  }
@@ -117,19 +108,6 @@ export default class extends Controller {
    this.fieldsTarget.disabled = true
  }

-  #restoreDraft() {
-    const draft = localStorage.getItem(this.#draftKey)
-
-    if (draft) {
-      this.textTarget.value = draft
-      this.textTarget.selection.placeCursorAtTheEnd()
-    }
-  }
-
-  get #draftKey() {
-    return `composer-draft-${this.roomIdValue}`
-  }
-
  get #usingTouchDevice() {
    return 'ontouchstart' in window || navigator.maxTouchPoints > 0 || navigator.msMaxTouchPoints > 0;
  }
@@ -148,7 +126,7 @@ export default class extends Controller {
  }

  #validInput() {
-    return !this.textTarget.isBlank
+    return this.textTarget.textContent.trim().length > 0
  }

  async #submitFiles() {
@@ -181,7 +159,6 @@ export default class extends Controller {

  #reset() {
    this.textTarget.value = ""
-    localStorage.removeItem(this.#draftKey)
  }

  #updateFileList() {
@@ -89,7 +89,7 @@ export default class extends Controller {
  }

  async editMyLastMessage() {
-    const editorEmpty = document.querySelector("#composer lexxy-editor").isBlank
+    const editorEmpty = document.querySelector("#composer trix-editor").matches(":empty")

    if (editorEmpty && this.#paginator.upToDate) {
      this.#myLastMessage?.querySelector(".message__edit-btn")?.click()
@@ -11,7 +11,7 @@ export default class extends Controller {
  }

  reply() {
-    const content = `<blockquote>${this.#bodyContent}</blockquote><cite>${this.authorTarget.innerHTML} ${this.#linkToOriginal}</cite><p><br></p>`
+    const content = `<blockquote>${this.#bodyContent}</blockquote><cite>${this.authorTarget.innerHTML} ${this.#linkToOriginal}</cite><br>`
    this.composerOutlet.replaceMessageContent(content)
  }

@@ -23,7 +23,7 @@ export default class extends Controller {
  }

  get #bodyContent() {
-    const body = this.bodyTarget.querySelector(".lexxy-content").cloneNode(true)
+    const body = this.bodyTarget.querySelector(".trix-content").cloneNode(true)
    return this.#stripMentionAttachments(this.#stripUnfurledAttachments(body)).innerHTML
  }

@@ -0,0 +1,46 @@
+import { Controller } from "@hotwired/stimulus"
+import MentionsAutocompleteHandler from "lib/autocomplete/mentions_autocomplete_handler"
+import { debounce } from "helpers/timing_helpers"
+
+export default class extends Controller {
+  static values = { url: String }
+
+  initialize() {
+    this.handlers = []
+    this.search = debounce(this.search.bind(this), 300)
+  }
+
+  connect() {
+    if (this.element == document.activeElement) {
+      this.#installHandlers()
+    }
+  }
+
+  focus(event) {
+    this.#installHandlers()
+  }
+
+  search(event) {
+    const content = this.editor.getDocument().toString()
+    const position = this.editor.getPosition()
+    this.handlers.forEach(handler => handler.updateWithContentAndPosition(content, position))
+  }
+
+  blur(event) {
+    this.#uninstallHandlers()
+  }
+
+  #installHandlers() {
+    this.#uninstallHandlers()
+    this.handlers = [ new MentionsAutocompleteHandler(this.element, this.urlValue) ]
+  }
+
+  #uninstallHandlers() {
+    this.handlers.forEach(handler => handler.destroy())
+    this.handlers = []
+  }
+
+  get editor() {
+    return this.element.editor
+  }
+}
@@ -1,84 +0,0 @@
-import { Controller } from "@hotwired/stimulus"
-import { post } from "@rails/request.js"
-import { escapeHTML, truncateString } from "helpers/string_helpers"
-
-const OPENGRAPH_EMBED_CONTENT_TYPE = "application/vnd.actiontext.opengraph-embed"
-
-const UNFURLED_TWITTER_AVATAR_CSS_CLASS = "og-embed--twitter-avatar"
-const TWITTER_AVATAR_URL_PREFIX = "https://pbs.twimg.com/profile_images"
-
-export default class extends Controller {
-  #abortController
-
-  disconnect() {
-    this.#abortController?.abort()
-  }
-
-  async unfurl(event) {
-    if (!this.element.permitsAttachmentContentType(OPENGRAPH_EMBED_CONTENT_TYPE)) return
-
-    const { url, insertBelowLink } = event.detail
-
-    const metadata = await this.#fetchOpengraphMetadata(url)
-
-    if (metadata) {
-      insertBelowLink(this.#opengraphEmbedHTML(metadata), { attachment: { contentType: OPENGRAPH_EMBED_CONTENT_TYPE } })
-    }
-  }
-
-  async #fetchOpengraphMetadata(url) {
-    this.#abortController?.abort()
-    this.#abortController = new AbortController()
-
-    try {
-      const response = await post("/unfurl_link", {
-        body: { url },
-        contentType: "application/json",
-        signal: this.#abortController.signal
-      })
-
-      if (response.ok && response.statusCode !== 204) {
-        const { title, url: href, image, description } = await response.json
-        if (title && href) return { title, href, image, description }
-      }
-    } catch {
-      // Ignore aborted and failed requests
-    }
-
-    return null
-  }
-
-  #opengraphEmbedHTML({ title, href, image, description }) {
-    return `<actiontext-opengraph-embed>
-      <div class="og-embed gap ${this.#embedClass(image)}">
-        <div class="og-embed__content">
-          <div class="og-embed__title">
-            <a href="${escapeHTML(href)}" rel="noreferrer" target="_blank">${escapeHTML(truncateString(title, 280))}</a>
-          </div>
-          <div class="og-embed__description">${escapeHTML(truncateString(description, 560))}</div>
-        </div>
-        ${this.#imageHTML(image)}
-      </div>
-    </actiontext-opengraph-embed>`
-  }
-
-  #embedClass(image) {
-    if (this.#isTwitterAvatar(image)) {
-      return UNFURLED_TWITTER_AVATAR_CSS_CLASS
-    } else {
-      return ""
-    }
-  }
-
-  #isTwitterAvatar(image) {
-    return Boolean(image) && image.startsWith(TWITTER_AVATAR_URL_PREFIX)
-  }
-
-  #imageHTML(image) {
-    if (image) {
-      return `<div class="og-embed__image"><img src="${escapeHTML(image)}" class="image center" alt="" /></div>`
-    } else {
-      return ""
-    }
-  }
-}
@@ -4,6 +4,12 @@ export function scrollToBottom(container) {
  container.scrollTop = container.scrollHeight
 }

+export function escapeHTML(html) {
+  const div = document.createElement("div")
+  div.textContent = html
+  return div.innerHTML
+}
+
 export function parseHTMLFragment(html) {
  const template = document.createElement("template")
  template.innerHTML = html
@@ -1,5 +1,3 @@
-const HTML_ESCAPES = { "&": "&amp;", "<": "&lt;", ">": "&gt;", "\"": "&quot;", "'": "&#39;" }
-
 export function truncateString(string, length, omission = "…") {
  if (string.length <= length) {
    return string
@@ -7,7 +5,3 @@ export function truncateString(string, length, omission = "…") {
    return string.slice(0, length - omission.length) + omission
  }
 }
-
-export function escapeHTML(string) {
-  return String(string ?? "").replace(/[&<>"']/g, character => HTML_ESCAPES[character])
-}
@@ -1,19 +1,10 @@
-import * as Lexxy from "lexxy"
-import CampfireRichTextExtension from "lib/rich_text/campfire_extension"
+import Unfurler from "lib/rich_text/unfurl/unfurler"

-Lexxy.configure({
-  global: {
-    // Keep the content type of mention attachments (application/vnd.campfire.mention)
-    // that Campfire has used since its Trix days
-    attachmentContentTypeNamespace: "campfire",
-    extensions: [ CampfireRichTextExtension ]
-  },
-  default: {
-    // Campfire sends files as separate messages via the composer's own
-    // attach button, never through the editor
-    toolbar: { attachments: false },
+// Support a `cite` block for attribution links
+Trix.config.blockAttributes.cite = {
+  tagName: "cite",
+  inheritable: false,
+}

-    // Trix offered a single heading level, rendered as h1
-    headings: [ "h1" ]
-  }
-})
+const unfurler = new Unfurler()
+unfurler.install()
@@ -0,0 +1,48 @@
+import BaseAutocompleteHandler from "lib/autocomplete/base_autocomplete_handler"
+import { PUNCTUATION_PATTERN } from "lib/autocomplete/constants"
+
+export default class extends BaseAutocompleteHandler {
+  get pattern() {
+    return new RegExp(`^@(.*?)(${PUNCTUATION_PATTERN.source}*)$`)
+  }
+
+  insertAutocompletable(autocompletable, range, terminator, options = {}) {
+    const attachment = this.#createAttachmentForAutocompletable(autocompletable)
+    this.#insertAttachmentAndTerminatorIntoEditorAtRange(attachment, terminator, range, options)
+  }
+
+  // Override to set selector's position relative to the cursor in the editor
+  getOffsetsAtPosition(position) {
+    return this.#getOffsetsFromEditorAtPosition(this.#editor, position)
+  }
+
+  #createAttachmentForAutocompletable(mentionable) {
+    const mention = `
+      <span class="mention" sgid=${mentionable.sgid}>
+        <img src="${mentionable.avatar_url}" class="avatar" alt="${mentionable.name}">
+        ${mentionable.name}
+      </span>
+    `
+
+    return new Trix.Attachment({
+      content: mention,
+      contentType: "application/vnd.campfire.mention",
+      sgid: mentionable.sgid
+    })
+  }
+
+  #insertAttachmentAndTerminatorIntoEditorAtRange(attachment, terminator, range) {
+    if (range) { this.#editor.setSelectedRange(range) }
+    this.#editor.insertAttachment(attachment)
+    this.#editor.insertString(terminator)
+  }
+
+  get #editor() {
+    return this.element.editor
+  }
+
+  #getOffsetsFromEditorAtPosition(editor, position) {
+    const rect = this.#editor.getClientRectAtPosition(position)
+    return rect ? rect : {}
+  }
+}
@@ -1,24 +0,0 @@
-import * as Lexxy from "lexxy"
-import CiteNode from "lib/rich_text/cite_node"
-
-export default class CampfireRichTextExtension extends Lexxy.Extension {
-  get allowedElements() {
-    return [
-      "cite",
-      "figure",
-      "figcaption",
-      "actiontext-opengraph-embed",
-      { tag: "div", attributes: [ "sgid" ] },
-      { tag: "span", attributes: [ "sgid" ] },
-      { tag: "img", attributes: [ "alt" ] },
-      { tag: "a", attributes: [ "rel", "target" ] }
-    ]
-  }
-
-  get lexicalExtension() {
-    return this.defineExtension({
-      name: "campfire/rich-text",
-      nodes: [ CiteNode ]
-    })
-  }
-}
@@ -1,39 +0,0 @@
-import * as Lexxy from "lexxy"
-
-const { ElementNode } = Lexxy.Lexical
-
-export default class CiteNode extends ElementNode {
-  static getType() {
-    return "cite"
-  }
-
-  static clone(node) {
-    return new CiteNode(node.__key)
-  }
-
-  static importJSON(serializedNode) {
-    return new CiteNode().updateFromJSON(serializedNode)
-  }
-
-  static importDOM() {
-    return {
-      cite: () => ({ conversion: () => ({ node: new CiteNode() }), priority: 1 })
-    }
-  }
-
-  exportJSON() {
-    return { ...super.exportJSON(), type: "cite" }
-  }
-
-  createDOM() {
-    return document.createElement("cite")
-  }
-
-  updateDOM() {
-    return false
-  }
-
-  exportDOM() {
-    return { element: document.createElement("cite") }
-  }
-}
@@ -0,0 +1,80 @@
+import { post } from "@rails/request.js"
+import { truncateString } from "helpers/string_helpers"
+
+const UNFURLED_TWITTER_AVATAR_CSS_CLASS = "cf-twitter-avatar"
+const TWITTER_AVATAR_URL_PREFIX = "https://pbs.twimg.com/profile_images"
+
+export default class OpengraphEmbedOperation {
+  constructor(paste) {
+    this.paste = paste
+    this.editor = this.paste.editor
+    this.url = this.paste.string
+
+    this.abortController = new AbortController()
+  }
+
+  perform() {
+    return this.#createOpenGraphMetadataRequest()
+      .then(response => response.json)
+      .then(this.#insertOpengraphAttachment.bind(this))
+      .catch(() => null)
+  }
+
+  abort() {
+    this.abortController.abort()
+  }
+
+  #createOpenGraphMetadataRequest() {
+    return post("/unfurl_link", {
+      body: { url: this.url },
+      contentType: "application/json",
+      signal: this.abortController.signal
+    })
+  }
+
+  #insertOpengraphAttachment(response) {
+    if (this.#shouldInsertOpengraphPreview) {
+      const currentRange = this.editor.getSelectedRange()
+      this.editor.setSelectedRange(this.editor.getSelectedRange())
+      this.editor.recordUndoEntry("Insert Opengraph preview for Pasted URL")
+      this.editor.insertAttachment(this.#createOpengraphAttachment(response))
+      this.editor.setSelectedRange(currentRange)
+    }
+  }
+
+  get #shouldInsertOpengraphPreview() {
+    return this.editor.getDocument().toString().includes(this.url)
+  }
+
+  #createOpengraphAttachment(response) {
+    const { title, url, image, description } = response
+    const html = this.#generateOpengraphEmbedHTML({ title, url, image, description })
+
+    return new Trix.Attachment({
+      contentType: "application/vnd.actiontext.opengraph-embed",
+      content: html,
+      filename: title,
+      href: url,
+      url: image,
+      caption: description
+    })
+  }
+
+  #generateOpengraphEmbedHTML(embed) {
+    return `<actiontext-opengraph-embed class="${this.#isTwitterAvatar(embed) ? UNFURLED_TWITTER_AVATAR_CSS_CLASS : ''}">
+      <div class="og-embed">
+        <div class="og-embed__content">
+          <div class="og-embed__title">${truncateString(embed.title, 560)}</div>
+          <div class="og-embed__description">${truncateString(embed.description, 560)}</div>
+        </div>
+        <div class="og-embed__image">
+          <img src="${embed.image}" class="image" alt="" />
+        </div>
+      </div>
+    </actiontext-opengraph-embed>`
+  }
+
+  #isTwitterAvatar(embed) {
+    return embed.image.startsWith(TWITTER_AVATAR_URL_PREFIX)
+  }
+}
@@ -0,0 +1,39 @@
+export default class Paste {
+  constructor(range, editor, document) {
+    this.range = range
+    this.editor = editor
+    this.document = document
+    if (this.document == null) { this.document = this.editor.getDocument() }
+    this.string = this.document.getStringAtRange(this.range)
+  }
+
+  isURL() {
+    return /^(?:[a-z0-9]+:\/\/|www\.)[^\s]+$/.test(this.string)
+  }
+
+  getPathname() {
+    const a = document.createElement("a")
+    a.href = this.string
+    return a.pathname
+  }
+
+  isLinked() {
+    const {href} = this.getCommonAttributes()
+    return (href != null) && (href !== this.string)
+  }
+
+  getCommonAttributes() {
+    return this.document.getCommonAttributesAtRange(this.range)
+  }
+
+  getSignificantPaste() {
+    return new this.constructor(this.getSignificantRange(), this.editor, this.document)
+  }
+
+  getSignificantRange() {
+    const significantString = this.string.trim()
+    const startOffset = this.range[0] + this.string.indexOf(significantString)
+    const endOffset = startOffset + significantString.length
+    return [startOffset, endOffset]
+  }
+}
@@ -0,0 +1,59 @@
+import OpengraphEmbedOperation from "lib/rich_text/unfurl/lib/opengraph_embed_operation"
+import Paste from "lib/rich_text/unfurl/lib/paste"
+
+const performOperation = (function() {
+  let operation = null
+  let requestId = null
+
+  return function(operationToPerform) {
+    operation?.abort()
+    cancelAnimationFrame(requestId)
+
+    requestId = requestAnimationFrame(function() {
+      operation = operationToPerform
+      operation.perform().then(() => operation = null)
+    })
+  }
+})()
+
+export default class Unfurler {
+  install() {
+    this.#addEventListeners()
+  }
+
+  #addEventListeners() {
+    addEventListener("trix-initialize", function(event) {
+      if (this.#editorElementPermitsAttribute(event.target, "href")) {
+        return event.target.addEventListener("trix-paste", this.#didPaste.bind(this))
+      }
+    }.bind(this))
+  }
+
+  #didPaste(event) {
+    const {range} = event.paste
+    const {editor} = event.target
+
+    if (range != null) {
+      const paste = new Paste(range, editor).getSignificantPaste()
+
+      if (paste.isURL()) {
+        if (this.#editorElementPermitsOpengraphAttachment(event.target)) {
+          performOperation(new OpengraphEmbedOperation(paste))
+        }
+      }
+    }
+  }
+
+  #editorElementPermitsAttribute(element, attributeName) {
+    if (element.hasAttribute("data-permitted-attributes")) {
+      return Array.from(element.getAttribute("data-permitted-attributes").split(" ")).includes(attributeName)
+    } else {
+      return true
+    }
+  }
+
+  #editorElementPermitsOpengraphAttachment(element) {
+    const permittedAttachmentTypes = element.getAttribute("data-permitted-attachment-types")
+    return permittedAttachmentTypes && permittedAttachmentTypes.includes("application/vnd.actiontext.opengraph-embed")
+  }
+}
@@ -18,7 +18,7 @@ export default class ClientMessage {
      body,
      messageTimestamp: Math.floor(now.getTime()),
      messageDatetime: now.toISOString(),
-      messageClasses: this.#messageClassesFromNode(node),
+      messageClasses: this.#containsOnlyEmoji(node.textContent) ? "message--emoji" : "",
    })
  }

@@ -52,37 +52,26 @@ export default class ClientMessage {
    }
  }

-  #messageClassesFromNode(node) {
-    if (this.#containsOnlyEmoji(this.#plainTextFromNode(node))) {
-      return "message--emoji"
-    } else {
-      return ""
-    }
-  }
-

  #isPlayCommand(node) {
    return this.#matchPlayCommand(node)
  }

  #matchPlayCommand(node) {
-    return this.#plainTextFromNode(node)?.match(new RegExp(`^/play (${SOUND_NAMES.join("|")})`))?.[1]
+    return this.#stripWrapperElement(node)?.match(new RegExp(`^/play (${SOUND_NAMES.join("|")})`))?.[1]
  }

-  #plainTextFromNode(node) {
-    if (this.#isRichText(node)) {
-      return node.toString().trim()
-    } else {
-      return node
-    }
+  #stripWrapperElement(node) {
+    return node.innerHTML?.replace(/<div>(?:<!--[\s\S]*?-->)*([\s\S]*?)<\/div>/i, '$1')
  }

+
  #isRichText(node) {
    return typeof(node) != "string"
  }

  #richTextContent(node) {
-    return `<div class="lexxy-content">${node.value}</div>`
+    return `<div class="trix-content">${node.innerHTML}</div>`
  }


@@ -76,21 +76,7 @@ export default class MessageFormatter {
  }

  #highlightCodeBlock(block) {
-    this.#normalizeLineBreaks(block)
-
-    if (this.#isPlainText(block)) {
-      const language = block.dataset.language
-      if (language && window.hljs.getLanguage(language)) {
-        block.classList.add(`language-${language}`)
-      }
-
-      window.hljs.highlightElement(block)
-    }
-  }
-
-  // Lexxy breaks code block lines with <br>, Trix-era blocks used newlines
-  #normalizeLineBreaks(block) {
-    block.querySelectorAll("br").forEach(br => br.replaceWith("\n"))
+    if (this.#isPlainText(block)) window.hljs.highlightElement(block)
  }

  #isPlainText(element) {
@@ -1,14 +1,6 @@
 class Account < ApplicationRecord
  include Joinable

-  has_one_attached :logo do |attachable|
-    attachable.variant :large, resize_to_limit: [ 512, 512 ], format: :png
-    attachable.variant :small, resize_to_limit: [ 192, 192 ], format: :png
-  end
-
+  has_one_attached :logo
  has_json :settings, restrict_room_creation_to_administrators: false
-
-  def logo_variant(size)
-    logo.variant(size).processed if logo.variable?
-  end
 end
@@ -1,19 +1,10 @@
 module Message::Broadcasts
  def broadcast_create
    broadcast_append_to room, :messages, target: [ room, :messages ]
-    broadcast_unread_room
+    ActionCable.server.broadcast("unread_rooms", { roomId: room.id })
  end

  def broadcast_remove
    broadcast_remove_to room, :messages
  end
-
-  private
-    # Fanned out to the room's members rather than published on one global stream, so
-    # that the timing of activity in a room only reaches people who are in it.
-    def broadcast_unread_room
-      room.memberships.pluck(:user_id).each do |user_id|
-        ActionCable.server.broadcast UnreadRoomsChannel.stream_name_for(user_id), { roomId: room.id }
-      end
-    end
 end
@@ -1,61 +1,7 @@
-require "restricted_http/private_network_guard"
-
 class Push::Subscription < ApplicationRecord
-  PERMITTED_ENDPOINT_HOSTS = %w[
-    jmt17.google.com
-    fcm.googleapis.com
-    updates.push.services.mozilla.com
-    web.push.apple.com
-    notify.windows.com
-  ].freeze
-
  belongs_to :user

-  validates :endpoint, presence: true
-  validate :validate_endpoint_url
-
  def notification(**params)
-    # Defer DNS lookup to the delivery worker to prevent rebinding
-    WebPush::Notification.new(**params, badge: user.memberships.unread.count, endpoint: endpoint, endpoint_ip_resolver: method(:resolved_endpoint_ip), p256dh_key: p256dh_key, auth_key: auth_key)
+    WebPush::Notification.new(**params, badge: user.memberships.unread.count, endpoint: endpoint, p256dh_key: p256dh_key, auth_key: auth_key)
  end
-
-  # Validate at point of use, not just when saved.
-  def resolved_endpoint_ip
-    RestrictedHTTP::PrivateNetworkGuard.resolve(endpoint_uri.host) if permitted_endpoint_uri?
-  rescue RestrictedHTTP::Violation, Surfguard::Unresolvable
-    nil
-  end
-
-  private
-    # Validate endpoint shape. Belt & suspenders.
-    def permitted_endpoint_uri?
-      endpoint_uri&.scheme == "https" && endpoint_uri.port == 443 && permitted_endpoint_host?
-    end
-
-    def endpoint_uri
-      URI.parse(endpoint) if endpoint.present?
-    rescue URI::InvalidURIError
-      nil
-    end
-
-    def validate_endpoint_url
-      if endpoint_uri.nil?
-        errors.add(:endpoint, "is not a valid URL")
-      elsif endpoint_uri.scheme != "https"
-        errors.add(:endpoint, "must use HTTPS")
-      elsif endpoint_uri.port != 443
-        errors.add(:endpoint, "must use the default HTTPS port")
-      elsif !permitted_endpoint_host?
-        errors.add(:endpoint, "is not a permitted push service")
-      elsif resolved_endpoint_ip.nil?
-        errors.add(:endpoint, "resolves to a private or invalid IP address")
-      end
-    end
-
-    def permitted_endpoint_host?
-      host = endpoint_uri&.host&.downcase
-      host.present? && PERMITTED_ENDPOINT_HOSTS.any? do |permitted|
-        host == permitted || host.end_with?(".#{permitted}")
-      end
-    end
 end
@@ -22,8 +22,6 @@ class Room < ApplicationRecord

  belongs_to :creator, class_name: "User", default: -> { Current.user }

-  validate :direct_rooms_keep_their_type, on: :update
-
  scope :opens,           -> { where(type: "Rooms::Open") }
  scope :closeds,         -> { where(type: "Rooms::Closed") }
  scope :directs,         -> { where(type: "Rooms::Direct") }
@@ -67,15 +65,6 @@ class Room < ApplicationRecord
  end

  private
-    # Open and closed rooms convert into each other freely. A direct room can't become
-    # either: its participants agreed to a private conversation, not to one whose
-    # audience someone else gets to widen afterwards.
-    def direct_rooms_keep_their_type
-      if type_changed? && type_was == "Rooms::Direct"
-        errors.add :type, "can't be changed for a direct room"
-      end
-    end
-
    def unread_memberships(message)
      memberships.visible.disconnected.where.not(user: message.creator).update_all(unread_at: message.created_at, updated_at: Time.current)
    end
@@ -2,9 +2,7 @@ module User::Avatar
  extend ActiveSupport::Concern

  included do
-    has_one_attached :avatar do |attachable|
-      attachable.variant :square, resize_to_limit: [ 512, 512 ], format: :webp
-    end
+    has_one_attached :avatar
  end

  class_methods do
@@ -16,8 +14,4 @@ module User::Avatar
  def avatar_token
    signed_id(purpose: :avatar)
  end
-
-  def avatar_variant
-    avatar.variant(:square).processed if avatar.variable?
-  end
 end
@@ -1,13 +1,11 @@
 module User::Mentionable
  include ActionText::Attachable

-  MENTION_CONTENT_TYPE = "application/vnd.campfire.mention"
-
-  def attachable_content_type
-    MENTION_CONTENT_TYPE
+  def to_attachable_partial_path
+    "users/mention"
  end

-  def to_attachable_partial_path
+  def to_trix_content_attachment_partial_path
    "users/mention"
  end

@@ -24,8 +24,6 @@ class Webhook < ApplicationRecord
        Net::HTTP::Post.new(uri, "Content-Type" => "application/json").tap { |request| request.body = payload }
    end

-    # No PrivateNetworkGuard, unlike Opengraph::Fetch: only an administrator sets this URL,
-    # and operators legitimately point bots at their own internal services.
    def http
      Net::HTTP.new(uri.host, uri.port).tap do |http|
        http.use_ssl = (uri.scheme == "https")
@@ -1,11 +1,11 @@
 <figure class="attachment attachment--content attachment--og">
  <actiontext-opengraph-embed>
-    <div class="og-embed gap <%= "og-embed--twitter-avatar" if opengraph_embed.twitter_avatar? %>">
+    <div class="og-embed gap">
      <div class="og-embed__content">
        <div class="og-embed__title">
-          <%= link_to_if opengraph_embed.href.present?, truncate(opengraph_embed.filename, length: 280, omission: "…"), opengraph_embed.href, rel: "noreferrer", target: "_blank" %>
+          <%= link_to truncate(opengraph_embed.filename, length: 280, omission: "…"), opengraph_embed.href, rel: "noreferrer", target: "_blank" %>
        </div>
-        <div class="og-embed__description"><%= truncate(opengraph_embed.description.to_s, length: 560, omission: "…") %></div>
+        <div class="og-embed__description"><%= truncate(opengraph_embed.caption, length: 560, omission: "…").html_safe %></div>
      </div>
      <% if opengraph_embed.url %>
        <div class="og-embed__image">
@@ -1,11 +0,0 @@
-<lexxy-prompt-item search="<%= user.name %>" sgid="<%= user.attachable_sgid %>">
-  <template type="menu">
-    <span class="autocomplete__item flex align-center gap unpad">
-      <%= avatar_tag user %>
-      <span class="autocompletable__name"><%= user.name %></span>
-    </span>
-  </template>
-  <template type="editor">
-    <%= render "users/mention", user: user %>
-  </template>
-</lexxy-prompt-item>
@@ -1 +0,0 @@
-<%= render partial: "autocompletable/users/prompt_item", collection: @page.records, as: :user %>
@@ -1,3 +1,3 @@
-<div class="lexxy-content">
+<div class="trix-content">
  <%= yield -%>
 </div>
@@ -1,7 +1,6 @@
 <%# Be sure to check/update messages/_template.html.erb when changing this file %>

-<%# Bump this version when the message presentation filters change what they emit. Editing this line changes the template digest, which busts BOTH this fragment cache and the collection cache that keys on this partial's digest (helper Ruby changes alone don't). %>
-<% cache [ message, "presentation-v3" ] do %>
+<% cache message do %>
  <%= message_tag message do %>
    <h2 class="message__day-separator"><%= local_datetime_tag message.created_at, style: :date %></h2>

@@ -1,18 +0,0 @@
-json.cache! message do
-  json.(message, :id)
-
-  json.created_at message.created_at.utc
-
-  json.body do
-    json.plain_text message.plain_text_body
-    json.html message.body.to_s
-  end
-
-  json.creator message.creator, partial: "users/user", as: :user
-
-  json.room do
-    json.id message.room_id
-  end
-
-  json.url room_message_url(message.room, message)
-end
@@ -1,12 +0,0 @@
-json.cache! boost do
-  json.(boost, :id, :content)
-
-  json.created_at boost.created_at.utc
-
-  json.booster boost.booster, partial: "users/user", as: :user
-
-  json.message do
-    json.id boost.message_id
-    json.url room_message_url(boost.message.room, boost.message)
-  end
-end
@@ -1 +0,0 @@
-json.partial! "messages/boosts/boost", boost: @boost
@@ -1 +0,0 @@
-json.array! @messages, partial: "messages/message", as: :message
@@ -1 +0,0 @@
-json.partial! "messages/message", message: @message
@@ -14,18 +14,17 @@
      <% else %>
        <div class="composer--edit composer--rich-text">
          <%= form_with model: @message, url: room_message_path(@room, @message), id: dom_id(@message, :form), data: {
-                controller: "form", action: "lexxy:file-accept->form#preventAttachment keydown.esc->form#cancel keydown.ctrl+enter->form#submit:prevent keydown.meta+enter->form#submit:prevent" } do |form| %>
+                controller: "form", action: "trix-file-accept->form#preventAttachment keydown.esc->form#cancel keydown.ctrl+enter->form#submit:prevent keydown.meta+enter->form#submit:prevent" } do |form| %>
            <div class="full-width input input--actor min-width fill-white">
              <%= form.rich_text_area :body,
-                    value: editable_body(@message),
                    rows: 1,
-                    class: "input lexxy-content",
+                    class: "input",
                    aria: { multiline: "true", label: "Edit message" },
                    autofocus: true,
-                    "permitted-attachment-types": "application/vnd.campfire.mention application/vnd.actiontext.opengraph-embed",
-                    data: { action: rich_text_data_actions } do %>
-                <%= mention_prompt_tag @room %>
-              <% end %>
+                    data: {
+                      controller: "rich-autocomplete",
+                      action: rich_text_data_actions,
+                      rich_autocomplete_url_value: autocompletable_users_path(room_id: @room.id) } %>
            </div>

            <%= link_to "Close editor and discard changes", room_message_path(@room, @message), data: { form_target: "cancel" }, hidden: true %>
@@ -17,7 +17,7 @@
    <%= render partial: "messages/message", collection: @messages, cached: true %>
  <% end %>

-  <%= turbo_stream_from @room, :messages, channel: "RoomMessagesChannel" %>
+  <%= turbo_stream_from @room, :messages %>
  <%= button_to_jump_to_newest_message %>
 <% end %>

@@ -19,16 +19,15 @@
                <div class="flex flex-column flex-item-grow min-width gap">
                  <%= form.rich_text_area :body,
                        rows: 1,
-                        class: "input lexxy-content",
+                        class: "input",
                        style: "order: -1",
                        aria: { multiline: "true", label: "Write a message" },
-                        "permitted-attachment-types": "application/vnd.campfire.mention application/vnd.actiontext.opengraph-embed",
                        data: {
-                          controller: "unfurl",
-                          action: "#{rich_text_data_actions} lexxy:change->composer#saveDraft lexxy:insert-link->unfurl#unfurl",
-                          composer_target: "text" } do %>
-                    <%= mention_prompt_tag room %>
-                  <% end %>
+                          controller: "rich-autocomplete",
+                          action: rich_text_data_actions,
+                          rich_autocomplete_url_value: autocompletable_users_path(room_id: room.id),
+                          permitted_attachment_types: "application/vnd.actiontext.opengraph-embed",
+                          composer_target: "text" } %>
                </div>

                <label class="btn btn--borderless txt-small flex-item-no-shrink composer__attachment-btn input--file">
@@ -1,4 +1,4 @@
-<%# A span rather than a div: mentions render inline inside the <p> paragraphs
-    the editor produces, and block elements would make the browser split the
-    paragraph when parsing %>
-<span class="mention" sgid="<%= user.attachable_sgid %>"><%= avatar_tag user %> <%= user.name %></span>
+<div class="mention" sgid="<%= user.attachable_sgid %>">
+  <%= avatar_tag user %>
+  <%= user.name %>
+</div>
@@ -1,5 +0,0 @@
-json.cache! user do
-  json.(user, :id, :name, :role)
-
-  json.avatar_url fresh_user_avatar_url(user)
-end
@@ -2,6 +2,6 @@
 require "rubygems"
 require "bundler/setup"

-ARGV.unshift("--ensure-latest", "15")
+ARGV.unshift("--ensure-latest")

 load Gem.bin_path("brakeman", "brakeman")
@@ -15,11 +15,9 @@ include SSHKit::DSL
 ARCH = "linux/amd64,linux/arm64"
 BUILDER_NAME = "campfire-builder"
 GIT_SHA = `git rev-parse HEAD`.strip
-MANUAL_NOTES = ARGV.delete("--notes")
 VERSION = ARGV[0]

-DOCKER_REGISTRY = "registry.once.com"
-DOCKER_IMAGE_NAME = "#{DOCKER_REGISTRY}/campfire"
+DOCKER_IMAGE_NAME = "registry.once.com/campfire"
 DOCKER_LATEST_IMAGE_NAME = [ DOCKER_IMAGE_NAME, :latest ].join(":")
 DOCKER_TAGGED_IMAGE_NAME = [ DOCKER_IMAGE_NAME, GIT_SHA ].join(":")

@@ -30,7 +28,7 @@ EXPORT_REMOTE_USER = "app"
 EXPORT_DEPLOY_HOSTS = %w[ once-store-app-101 once-store-app-102 ]
 EXPORT_DEPLOY_LOCATION = "/local/app/product_releases/"

-abort "You must specify a version, e.g. `bin/release 1.0.0` (pass --notes to write release notes manually)" unless VERSION
+abort "You must specify a version, e.g. `bin/release 1.0.0`" unless VERSION

 current_branch = `git rev-parse --abbrev-ref HEAD`.strip
 if current_branch != "main"
@@ -48,18 +46,6 @@ def announcing(message)
  yield
 end

-announcing "Checking #{DOCKER_REGISTRY} login..." do
-  unless system "docker", "manifest", "inspect", DOCKER_LATEST_IMAGE_NAME, out: File::NULL, err: File::NULL
-    abort <<~MESSAGE
-      Not logged in to #{DOCKER_REGISTRY}. Run:
-
-        docker login #{DOCKER_REGISTRY}
-
-      The credentials are in the "chatinabox" entry in 1Password.
-    MESSAGE
-  end
-end
-
 on(:local) do
  builder_found = test :docker, :buildx, :inspect, BUILDER_NAME

@@ -71,25 +57,19 @@ on(:local) do
 end

 announcing "Creating GitHub release v#{VERSION}..." do
+  notes_file = "tmp/release_notes.md"
+
  on(:local) do
-    if MANUAL_NOTES
-      notes_file = "tmp/release_notes.md"
+    execute :mkdir, "-p", "tmp"

-      execute :mkdir, "-p", "tmp"
+    File.write(notes_file, "# What's Changed\n\n- \n")
+    system ENV["EDITOR"] || "vim", notes_file

-      File.write(notes_file, "# What's Changed\n\n- \n")
-      system ENV["EDITOR"] || "vim", notes_file
-
-      unless system "gh", "release", "create", "v#{VERSION}", "--title", "v#{VERSION}", "--notes-file", notes_file
-        abort "Failed to create release; check that the version doesn't already exist"
-      end
-
-      execute :rm, notes_file
-    else
-      unless system "gh", "release", "create", "v#{VERSION}", "--title", "v#{VERSION}", "--generate-notes"
-        abort "Failed to create release; check that the version doesn't already exist"
-      end
+    unless system "gh", "release", "create", "v#{VERSION}", "--title", "v#{VERSION}", "--notes-file", notes_file
+      abort "Failed to create release; check that the version doesn't already exist"
    end
+
+    execute :rm, notes_file
  end
 end

@@ -1,6 +1,6 @@
 default: &default
  adapter: redis
-  url: <%= ENV.fetch("REDIS_URL") { "redis://localhost:6379" } %>
+  url: redis://localhost:6379

 development:
  <<: *default
@@ -1,6 +1,5 @@
 require "active_support/core_ext/integer/time"
 require "active_support/core_ext/numeric/bytes"
-require_relative "../../lib/rails_ext/log_scrubbing_formatter"

 Rails.application.configure do
  # Settings specified here will take precedence over those in config/application.rb.
@@ -51,7 +50,7 @@ Rails.application.configure do

  # Log to STDOUT by default
  config.logger = ActiveSupport::Logger.new(STDOUT)
-    .tap  { |logger| logger.formatter = LogScrubbingFormatter.new }
+    .tap  { |logger| logger.formatter = ::Logger::Formatter.new }
    .then { |logger| ActiveSupport::TaggedLogging.new(logger) }

  # Prepend all log lines with the following tags.
@@ -5,7 +5,8 @@ pin "@hotwired/stimulus-loading", to: "stimulus-loading.js"
 pin "@hotwired/turbo-rails", to: "turbo.js"
 pin "@rails/actioncable", to: "actioncable.esm.js"
 pin "@rails/request.js", to: "@rails--request.js" # @0.0.8
-pin "lexxy", to: "lexxy.js"
+pin "trix", to: "trix.esm.min.js" # @2.1.19
+pin "@rails/actiontext", to: "actiontext.js"
 pin "highlight.js", to: "highlight.js/core.js"

 pin_all_from "app/javascript/initializers", under: "initializers"
@@ -1,15 +0,0 @@
-# Active Storage mounts its direct-upload write endpoints
-# (POST /rails/active_storage/direct_uploads and the disk-service PUT) on
-# framework controllers that inherit from ActiveStorage::BaseController, so
-# they never pass through ApplicationController's require_authentication.
-# Campfire uploads attachments through MessagesController instead and does not
-# use direct uploads at all, leaving these endpoints reachable by anyone who
-# can read the public login page. Require a valid Campfire session before an
-# anonymous caller can allocate a Blob or persist bytes to disk.
-Rails.application.config.to_prepare do
-  ActiveStorage::DirectUploadsController.include ActiveStorageAuthentication
-  ActiveStorage::DirectUploadsController.before_action :require_active_storage_authentication
-
-  ActiveStorage::DiskController.include ActiveStorageAuthentication
-  ActiveStorage::DiskController.before_action :require_active_storage_authentication, only: :update
-end
@@ -1 +0,0 @@
-Resque.redis = ENV.fetch("REDIS_URL") { "redis://localhost:6379" }
@@ -1,3 +0,0 @@
-Rails.application.config.to_prepare do
-  Turbo::StreamsChannel.prepend RoomStreamsAreAuthorized
-end
@@ -1,2 +1,2 @@
-Rails.application.config.app_version = ENV["APP_VERSION"].presence || ENV["GIT_REVISION"].presence || "0"
+Rails.application.config.app_version = ENV.fetch("APP_VERSION", "0")
 Rails.application.config.git_revision = ENV["GIT_REVISION"]
@@ -1,9 +0,0 @@
-# Disable unfuzzed libvips operations.
-#
-# To block loaders we need to call `Vips.block` after Rails and image_processing set their
-# defaults. Force the order of operations by autoloading the file now.
-ActiveStorage::Transformers::Vips
-Vips.block_untrusted(true)
-Vips.block("VipsForeignLoadOpenslide", true) # prevent sqlite segfault in forked parallel workers
-Rails.application.config.active_storage.variable_content_types -=
-    %w[ image/bmp image/vnd.microsoft.icon image/vnd.adobe.photoshop ]
@@ -17,25 +17,7 @@ end

 module WebPush::PersistentRequest
  def perform
-    if endpoint_ip = @options[:endpoint_ip]
-      # Pin the connection to the public IP resolved (and guarded) by
-      # Push::Subscription so delivery can't be rebound to a private address
-      # between resolution and connect. Bypasses the shared persistent pool,
-      # which would re-resolve the host itself.
-      #
-      # The explicit nil proxy address disables proxy discovery from
-      # http_proxy/https_proxy. An egress proxy would open the TCP connection
-      # itself and re-resolve the endpoint host, so http.ipaddr would no longer
-      # pin the destination and the DNS-rebinding guarantee would be lost. This
-      # path is already committed to a direct connection (it bypasses the pool);
-      # push delivery to public vendor endpoints goes direct.
-      http = Net::HTTP.new(uri.host, uri.port, nil)
-      http.ipaddr = endpoint_ip
-      http.use_ssl = true
-      http.ssl_timeout = @options[:ssl_timeout] unless @options[:ssl_timeout].nil?
-      http.open_timeout = @options[:open_timeout] unless @options[:open_timeout].nil?
-      http.read_timeout = @options[:read_timeout] unless @options[:read_timeout].nil?
-    elsif @options[:connection]
+    if @options[:connection]
      http = @options[:connection]
    else
      http = Net::HTTP.new(uri.host, uri.port, *proxy_options)
@@ -62,13 +62,7 @@ Rails.application.routes.draw do
  resources :rooms do
    resources :messages

-    nested do
-      scope path: ":bot_key", as: :bot, defaults: { format: :json } do
-        resources :messages, controller: "messages/by_bots", only: %i[ index create update destroy ] do
-          resources :boosts, controller: "messages/boosts/by_bots", only: %i[ create destroy ]
-        end
-      end
-    end
+    post ":bot_key/messages", to: "messages/by_bots#create", as: :bot_messages

    scope module: "rooms" do
      resource :refresh, only: :show
@@ -1,12 +0,0 @@
-#!/bin/bash
-set -euo pipefail
-
-db_name="${RAILS_ENV:-production}.sqlite3"
-snapshot="/rails/storage/backups/$db_name"
-db="/rails/storage/db/$db_name"
-
-if [ -f "$snapshot" ]; then
-  mkdir -p "$(dirname "$db")"
-  cp "$snapshot" "$db"
-  rm -f "$db-wal" "$db-shm"
-fi
@@ -1,2 +0,0 @@
-#!/bin/bash
-exec /rails/script/admin/prepare-backup
@@ -1,11 +0,0 @@
-# The rich text editor produces formatting that Rails' default Action Text
-# sanitizer strips on render. The additions are declared once in
-# ContentFilters, shared by every sanitization layer.
-Rails.application.config.to_prepare do
-  defaults = Class.new.include(ActionText::ContentHelper).new
-
-  ActionText::ContentHelper.allowed_tags =
-    (ActionText::ContentHelper.allowed_tags || defaults.sanitizer_allowed_tags) | ContentFilters::EDITOR_FORMATTING_TAGS
-  ActionText::ContentHelper.allowed_attributes =
-    (ActionText::ContentHelper.allowed_attributes || defaults.sanitizer_allowed_attributes) | ContentFilters::EDITOR_FORMATTING_ATTRIBUTES
-end
@@ -2,7 +2,6 @@ class ActionText::Attachment::OpengraphEmbed
  include ActiveModel::Model

  OPENGRAPH_EMBED_CONTENT_TYPE = "application/vnd.actiontext.opengraph-embed"
-  TWITTER_AVATAR_URL_PREFIX = "https://pbs.twimg.com/profile_images"

  class << self
    def from_node(node)
@@ -15,85 +14,18 @@ class ActionText::Attachment::OpengraphEmbed
    end

    private
-      # Trix serialized the embed's details as attributes of the
-      # <action-text-attachment> node. Lexxy only serializes the sgid, content
-      # and content-type, so newer attachments carry the details in their
-      # content markup instead.
      def attributes_from_node(node)
-        if node["filename"].present?
-          {
-            href: web_url(node["href"]),
-            url: web_url(node["url"]),
-            filename: node["filename"],
-            description: node["caption"]
-          }
-        else
-          attributes_from_content(node["content"].to_s)
-        end
-      end
-
-      def attributes_from_content(content)
-        fragment = Nokogiri::HTML.fragment(content)
-        title = fragment.at_css(".og-embed__title")
-        link = title&.at_css("a")
-
        {
-          href: web_url(link&.[]("href")),
-          url: web_url(fragment.at_css(".og-embed__image img")&.[]("src")),
-          filename: (link || title)&.text&.strip,
-          description: fragment.at_css(".og-embed__description")&.text&.strip
+          href: node["href"],
+          url: node["url"],
+          filename: node["filename"],
+          description: node["caption"]
        }
      end
-
-      # A link preview points at what we unfurled: an absolute http or https URL
-      # on some other host. Drop anything else a message body asks for, so it
-      # can't aim the preview's link or its image at this Campfire and have every
-      # reader's browser fetch it with their session attached.
-      def web_url(value)
-        return if value.blank?
-
-        parsed = URI.parse(value)
-        value if parsed.is_a?(URI::HTTP) && elsewhere?(parsed.host)
-      rescue URI::InvalidURIError
-        nil
-      end
-
-      # "https:/rooms/1" parses as HTTPS with no host at all, and a browser
-      # resolves both that and our own hostname against the origin Campfire is
-      # served from. A percent-escape hides our hostname from this comparison
-      # while a browser still unescapes it back to us, so an escaped host is out
-      # too, and neither case is anything an unfurl could have produced.
-      def elsewhere?(host)
-        return false unless named_host?(host)
-
-        canonical_host(host) != canonical_host(Current.request_host.to_s)
-      end
-
-      # A preview names a page on the public internet, so its host is a domain
-      # name, written plainly. A bare address is not one, and a browser rewrites
-      # the many spellings of an address ("2130706433", "0x7f.0.0.1") into a
-      # single one before it fetches, which is a race a comparison here loses.
-      def named_host?(host)
-        host.present? && host.exclude?("%") && host.include?(".") && domain_ending?(host.split(".").last)
-      end
-
-      # What keeps a name from reading as an address is its last label, which is
-      # a word: never a number, and never the hexadecimal spelling of one.
-      def domain_ending?(label)
-        label.match?(/[a-z]/i) && !label.match?(/\A0x/i)
-      end
-
-      def canonical_host(host)
-        host.downcase.delete_suffix(".")
-      end
  end

  attr_accessor :href, :url, :filename, :description

-  def twitter_avatar?
-    url.to_s.start_with?(TWITTER_AVATAR_URL_PREFIX)
-  end
-
  def attachable_content_type
    OPENGRAPH_EMBED_CONTENT_TYPE
  end
@@ -105,4 +37,8 @@ class ActionText::Attachment::OpengraphEmbed
  def to_partial_path
    "action_text/attachables/opengraph_embed"
  end
+
+  def to_trix_content_attachment_partial_path
+    "action_text/attachables/opengraph_embed"
+  end
 end
@@ -1,16 +0,0 @@
-# Bot requests carry the bot key as a URL path segment (/rooms/:room_id/:bot_key/...).
-# config.filter_parameters redacts query and form parameters but never path segments,
-# so the key would otherwise be written verbatim to the request log. Redact it wherever
-# it appears in a formatted log line.
-class LogScrubbingFormatter < ::Logger::Formatter
-  BOT_KEY_IN_PATH = %r{(/rooms/\d+/)\d+-[A-Za-z0-9]+}
-
-  def call(severity, time, progname, message)
-    scrub(super)
-  end
-
-  private
-    def scrub(line)
-      line.gsub(BOT_KEY_IN_PATH, '\1[FILTERED]')
-    end
-end
@@ -1,29 +1,33 @@
-require "surfguard"
+require "resolv"

 module RestrictedHTTP
  class Violation < StandardError; end

-  # The address policy lives in the surfguard gem so this app, Basecamp, HEY and
-  # Fizzy classify "internal" the same way instead of each keeping a copy that
-  # drifts. The callers here hand a bare hostname in and pin the address that
-  # comes back, so this stays a hostname-in, address-out shim.
  module PrivateNetworkGuard
    extend self

-    # A hostname that resolves to nothing (NXDOMAIN, timeout, empty answer)
-    # raises Surfguard::Unresolvable, which we let propagate as a lookup failure
-    # -- the same way the old Resolv.getaddress guard raised Resolv::ResolvError,
-    # and the callers here already treat it as a fetch failure. The Violation is
-    # reserved for a host that resolves to a blocked address (an empty list back
-    # from resolve_public_ips), so a transient DNS miss is never misreported as
-    # an SSRF attempt.
+    LOCAL_IP = IPAddr.new("0.0.0.0/8") # "This" network
+
+    # IPv6 transition/encapsulation and shared-address ranges that can smuggle
+    # requests toward internal networks and must never be reachable.
+    DISALLOWED_RANGES = [
+      IPAddr.new("64:ff9b::/96"),  # NAT64 (RFC 6052) — embeds IPv4 in IPv6
+      IPAddr.new("2002::/16"),     # 6to4 (RFC 3056) — embeds IPv4 in IPv6
+      IPAddr.new("100.64.0.0/10")  # CGNAT / shared address space (RFC 6598)
+    ]
+
    def resolve(hostname)
-      Surfguard.resolve_public_ips(hostname).first or
-        raise Violation.new("Attempt to access private IP via #{hostname}")
+      Resolv.getaddress(hostname).tap do |ip|
+        raise Violation.new("Attempt to access private IP via #{hostname}") if ip && private_ip?(ip)
+      end
    end

    def private_ip?(ip)
-      Surfguard.blocked_address?(ip)
+      IPAddr.new(ip).then do |ipaddr|
+        ipaddr.private? || ipaddr.loopback? || ipaddr.link_local? || ipaddr.ipv4_mapped? || ipaddr.ipv4_compat? || LOCAL_IP.include?(ipaddr) || DISALLOWED_RANGES.any? { |range| range.include?(ipaddr) }
+      end
+    rescue IPAddr::InvalidAddressError
+      true
    end
  end
 end
@@ -1,18 +1,16 @@
 class WebPush::Notification
-  def initialize(title:, body:, path:, badge:, endpoint:, endpoint_ip_resolver:, p256dh_key:, auth_key:)
+  def initialize(title:, body:, path:, badge:, endpoint:, p256dh_key:, auth_key:)
    @title, @body, @path, @badge = title, body, path, badge
-    @endpoint, @endpoint_ip_resolver, @p256dh_key, @auth_key = endpoint, endpoint_ip_resolver, p256dh_key, auth_key
+    @endpoint, @p256dh_key, @auth_key = endpoint, p256dh_key, auth_key
  end

  def deliver(connection: nil)
-    if endpoint_ip = @endpoint_ip_resolver.call
-      WebPush.payload_send \
-        message: encoded_message,
-        endpoint: @endpoint, endpoint_ip: endpoint_ip, p256dh: @p256dh_key, auth: @auth_key,
-        vapid: vapid_identification,
-        connection: connection,
-        urgency: "high"
-    end
+    WebPush.payload_send \
+      message: encoded_message,
+      endpoint: @endpoint, p256dh: @p256dh_key, auth: @auth_key,
+      vapid: vapid_identification,
+      connection: connection,
+      urgency: "high"
  end

  private
@@ -1 +1 @@
 .4.10
 .4.5
				`@@ -1 +0,0 @@`
				`<%= render partial: "autocompletable/users/prompt_item", collection: @page.records, as: :user %>`
				`@@ -1 +0,0 @@`
				`json.partial! "messages/boosts/boost", boost: @boost`
				`@@ -1 +0,0 @@`
				`json.array! @messages, partial: "messages/message", as: :message`
				`@@ -1 +0,0 @@`
				`json.partial! "messages/message", message: @message`
				`@@ -1 +0,0 @@`
				`Resque.redis = ENV.fetch("REDIS_URL") { "redis://localhost:6379" }`