feat: Allow automatic project actions on events (#30205)

This PR introduces project workflows, allowing users to configure
event-based automations directly from the UI.
Users can define filters and actions for each workflow event, and
duplicate existing events when needed.

### Concepts

Every workflow is composed of `event`, `filters`, and `actions`.

- **Event** - An Event defines when a workflow should be triggered. It
represents specific activities such as an issue being added to the
project, a pull request being merged, or a project column being changed.
- **Filter** - A Filter refines when an event should take effect. It
allows users to specify conditions like issue type, labels, or project
columns to ensure actions only run in targeted scenarios.
- **Action** - An Action defines what happens when the event and filters
match. It performs operations such as adding labels, moving issues
between columns, or changing the issue or pull request state.

### Available Events

Currently, the following eight events are supported:

- On issues/pull requests closed
- On issues/pull requests reopened
- On issues/pull requests was added to the project, including when
created in it
- On issues/pull requests was removed from the project
- On issues/pull requests' column was changed
- On code changes requested
- On code review approved
- On pull request merged

Each event type supports its own set of filters and actions.

### Available Filters

There are four types of filters that can be configured for an event:

- **Apply to** - Specify the target type: `issues only`, `pull requests
only`, or `issues and pull requests`.
- **Labels** - Trigger the event only if the issue or pull request
contains one or more specified labels.
- **Move from column** - Filter events based on the original project
column.
- **Move to column** - Filter events based on the destination project
column.

### Available Actions

There are four types of actions that can be executed when an event is
triggered:

- **Add labels** - Automatically add one or more labels to the issue or
pull request.
- **Remove labels** - Remove one or more specified labels.
- **Move to column** - Move the issue or pull request to a designated
project column.
- **Issue state** - Close or reopen the issue. Pull requests can only be
closed.

### Enable/Disable an event workflow

Each event workflow can be individually enabled or disabled. When
disabled, the workflow will be ignored even if the event occurs. This
feature is useful when you want to temporarily stop certain automated
actions without deleting the workflow configuration. Workflows of closed
projects don't run either.

### Clone an event workflow

When you need multiple workflows for the same event, you can clone an
existing event to create a new one with different filters and actions.
This allows you to customize how the same event behaves under different
conditions, making workflows more flexible and powerful.

### Permissions

Permissions are checked when workflows are managed, not when they run:

- Viewing a project's workflows needs read access to the project
- Managing them needs write access to the project plus write access to
both issues and pull requests of a repository project's repository,
being an owner of an organization project's organization or a site
administrator, or being the user of a user project. Tokens limited to
public repositories can't manage owner-level projects' workflows
- A workflow runs when its event happens to an item of an open project
that can hold the item's repository, unless that repository is archived,
no matter who caused the event, and applies its actions without further
permission checks. Pull requests are never reopened
- Changes show as made by "Project workflow" on behalf of the user who
triggered the event and don't trigger other workflows
- Only users who can read an item can put it on a board or move its card

The management rule is also documented on `CanManageWorkflows` in
`services/projects/workflow.go`.

Fixes:  #14359
Fixes: #26704
Fixes: #27990
Replaces:  #28745
Documentation PR: https://gitea.com/gitea/docs/pulls/308
Co-authored-by: bircni <bircni@icloud.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Giteabot <teabot@gitea.io>

routers/api/v1/api.go

@@ -775,6 +775,8 @@ func addProjectRoutes(m *web.Router, writeChecks ...any) {
 			m.Get("", shared.GetProjectColumn)
 			m.Get("/issues", shared.ListProjectColumnIssues)
 		})
+		m.Get("/workflows", shared.ListProjectWorkflows)
+		m.Get("/workflows/{workflow_id}", shared.GetProjectWorkflow)
 	})
 	m.Group("", func() {
 		m.Post("", bind(api.CreateProjectOption{}), shared.CreateProject)
@@ -791,6 +793,11 @@ func addProjectRoutes(m *web.Router, writeChecks ...any) {
 				m.Delete("/issues/{issue_id}", shared.RemoveIssueFromProjectColumn)
 			})
 			m.Post("/issues/{issue_id}/move", bind(api.MoveProjectIssueOption{}), shared.MoveProjectIssue)
+			m.Post("/workflows", bind(api.CreateProjectWorkflowOption{}), shared.CreateProjectWorkflow)
+			m.Group("/workflows/{workflow_id}", func() {
+				m.Patch("", bind(api.EditProjectWorkflowOption{}), shared.EditProjectWorkflow)
+				m.Delete("", shared.DeleteProjectWorkflow)
+			})
 		})
 	}, writeChecks...)
 }

routers/api/v1/repo/issue.go

@@ -616,8 +616,9 @@ func CreateIssue(ctx *context.APIContext) {
 			return
 		}
 	} else {
-		// setting labels is not allowed if user is not a writer
+		// setting labels and projects is not allowed if user is not a writer
 		form.Labels = make([]int64, 0)
+		form.Projects = nil
 	}
 
 	if err := issue_service.NewIssue(ctx, ctx.Repo.Repository, issue, form.Labels, nil, assigneeIDs, form.Projects); err != nil {
@@ -631,7 +632,15 @@ func CreateIssue(ctx *context.APIContext) {
 		return
 	}
 
-	if form.Closed {
+	// Refetch from database to assign some automatic values and project workflow changes
+	var err error
+	issue, err = issues_model.GetIssueByID(ctx, issue.ID)
+	if err != nil {
+		ctx.APIErrorInternal(err)
+		return
+	}
+
+	if form.Closed && !issue.IsClosed {
 		if err := issue_service.CloseIssue(ctx, issue, ctx.Doer, ""); err != nil {
 			if issues_model.IsErrDependenciesLeft(err) {
 				ctx.APIError(http.StatusPreconditionFailed, "cannot close this issue because it still has open dependencies")
@@ -641,14 +650,6 @@ func CreateIssue(ctx *context.APIContext) {
 			return
 		}
 	}
-
-	// Refetch from database to assign some automatic values
-	var err error
-	issue, err = issues_model.GetIssueByID(ctx, issue.ID)
-	if err != nil {
-		ctx.APIErrorInternal(err)
-		return
-	}
 	ctx.JSON(http.StatusCreated, convert.ToAPIIssue(ctx, ctx.Doer, issue))
 }
 
@@ -824,7 +825,7 @@ func EditIssue(ctx *context.APIContext) {
 
 	// Update projects if provided
 	if canWrite && form.Projects != nil {
-		if err := issues_model.IssueAssignOrRemoveProject(ctx, issue, ctx.Doer, *form.Projects); err != nil {
+		if err := issue_service.AssignOrRemoveProjects(ctx, issue, ctx.Doer, *form.Projects); err != nil {
 			if errors.Is(err, util.ErrPermissionDenied) || errors.Is(err, util.ErrNotExist) {
 				ctx.APIError(http.StatusBadRequest, err.Error())
 			} else {

routers/api/v1/shared/project.go

@@ -109,8 +109,8 @@ func (s projectScope) findColumnIssue(ctx *context.APIContext) (*project_model.C
 	return column, s.findIssue(ctx)
 }
 
-// findIssue resolves an issue addressable within this scope. Owner-level boards span
-// repositories, so the issue is looked up globally and gated on the doer's read access.
+// findIssue resolves an issue addressable within this scope, gated on the doer's read access.
+// Owner-level boards span repositories, so the issue is looked up globally there.
 func (s projectScope) findIssue(ctx *context.APIContext) *issues_model.Issue {
 	issueID := ctx.PathParamInt64("issue_id")
 	var issue *issues_model.Issue
@@ -124,26 +124,24 @@ func (s projectScope) findIssue(ctx *context.APIContext) *issues_model.Issue {
 		ctx.APIErrorAuto(err)
 		return nil
 	}
-	if s.Repo == nil {
-		if err := issue.LoadRepo(ctx); err != nil {
-			ctx.APIErrorInternal(err)
-			return nil
-		}
-		perm, err := access_model.GetDoerRepoPermission(ctx, issue.Repo, ctx.Doer)
-		if err != nil {
-			ctx.APIErrorInternal(err)
-			return nil
-		}
-		// hide the issue's existence rather than reporting it as forbidden
-		if !perm.CanReadIssuesOrPulls(issue.IsPull) {
-			ctx.APIErrorNotFound()
-			return nil
-		}
-		// the repo route group has mustNotBeArchived, owner boards have to check per issue
-		if issue.Repo.IsArchived {
-			ctx.APIError(http.StatusLocked, "repo is archived")
-			return nil
-		}
+	if err := issue.LoadRepo(ctx); err != nil {
+		ctx.APIErrorInternal(err)
+		return nil
+	}
+	perm, err := access_model.GetDoerRepoPermission(ctx, issue.Repo, ctx.Doer)
+	if err != nil {
+		ctx.APIErrorInternal(err)
+		return nil
+	}
+	// hide the issue's existence rather than reporting it as forbidden
+	if !perm.CanReadIssuesOrPulls(issue.IsPull) {
+		ctx.APIErrorNotFound()
+		return nil
+	}
+	// the repo route group has mustNotBeArchived, owner boards have to check per issue
+	if issue.Repo.IsArchived {
+		ctx.APIError(http.StatusLocked, "repo is archived")
+		return nil
 	}
 	return issue
 }

routers/api/v1/shared/project_workflow.go

@@ -0,0 +1,588 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package shared
+
+import (
+	"net/http"
+
+	"gitea.dev/models/db"
+	project_model "gitea.dev/models/project"
+	api "gitea.dev/modules/structs"
+	"gitea.dev/modules/web"
+	"gitea.dev/routers/api/v1/utils"
+	"gitea.dev/services/context"
+	"gitea.dev/services/convert"
+	project_service "gitea.dev/services/projects"
+)
+
+func findWorkflow(ctx *context.APIContext, project *project_model.Project) *project_model.Workflow {
+	workflow, err := project_model.GetWorkflowByProjectAndID(ctx, project.ID, ctx.PathParamInt64("workflow_id"))
+	if err != nil {
+		ctx.APIErrorAuto(err)
+		return nil
+	}
+	return workflow
+}
+
+func ListProjectWorkflows(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/projects/{id}/workflows repository repoListProjectWorkflows
+	// ---
+	// summary: List a project's workflows
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: page
+	//   in: query
+	//   description: page number of results to return (1-based)
+	//   type: integer
+	// - name: limit
+	//   in: query
+	//   description: page size of results
+	//   type: integer
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ProjectWorkflowList"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	// swagger:operation GET /orgs/{org}/projects/{id}/workflows organization orgListProjectWorkflows
+	// ---
+	// summary: List a project's workflows
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: org
+	//   in: path
+	//   description: name of the organization
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: page
+	//   in: query
+	//   description: page number of results to return (1-based)
+	//   type: integer
+	// - name: limit
+	//   in: query
+	//   description: page size of results
+	//   type: integer
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ProjectWorkflowList"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	// swagger:operation GET /user/projects/{id}/workflows user userCurrentListProjectWorkflows
+	// ---
+	// summary: List a project's workflows
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: page
+	//   in: query
+	//   description: page number of results to return (1-based)
+	//   type: integer
+	// - name: limit
+	//   in: query
+	//   description: page size of results
+	//   type: integer
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ProjectWorkflowList"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	project := projectScopeFromContext(ctx).findProject(ctx)
+	if ctx.Written() {
+		return
+	}
+	listOptions := utils.GetListOptions(ctx)
+	workflows, total, err := db.FindAndCount[project_model.Workflow](ctx, project_model.FindWorkflowsOptions{ListOptions: listOptions, ProjectIDs: []int64{project.ID}})
+	if err != nil {
+		ctx.APIErrorInternal(err)
+		return
+	}
+	ctx.SetLinkHeader(total, listOptions.PageSize)
+	ctx.SetTotalCountHeader(total)
+	ctx.JSON(http.StatusOK, convert.ToProjectWorkflowList(workflows))
+}
+
+func GetProjectWorkflow(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/projects/{id}/workflows/{workflow_id} repository repoGetProjectWorkflow
+	// ---
+	// summary: Get a project workflow
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: workflow_id
+	//   in: path
+	//   description: id of the workflow
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ProjectWorkflow"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	// swagger:operation GET /orgs/{org}/projects/{id}/workflows/{workflow_id} organization orgGetProjectWorkflow
+	// ---
+	// summary: Get a project workflow
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: org
+	//   in: path
+	//   description: name of the organization
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: workflow_id
+	//   in: path
+	//   description: id of the workflow
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ProjectWorkflow"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	// swagger:operation GET /user/projects/{id}/workflows/{workflow_id} user userCurrentGetProjectWorkflow
+	// ---
+	// summary: Get a project workflow
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: workflow_id
+	//   in: path
+	//   description: id of the workflow
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ProjectWorkflow"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	project := projectScopeFromContext(ctx).findProject(ctx)
+	if ctx.Written() {
+		return
+	}
+	workflow := findWorkflow(ctx, project)
+	if ctx.Written() {
+		return
+	}
+	ctx.JSON(http.StatusOK, convert.ToProjectWorkflow(workflow))
+}
+
+func CreateProjectWorkflow(ctx *context.APIContext) {
+	// swagger:operation POST /repos/{owner}/{repo}/projects/{id}/workflows repository repoCreateProjectWorkflow
+	// ---
+	// summary: Create a project workflow
+	// consumes:
+	// - application/json
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: body
+	//   in: body
+	//   schema:
+	//     "$ref": "#/definitions/CreateProjectWorkflowOption"
+	// responses:
+	//   "201":
+	//     "$ref": "#/responses/ProjectWorkflow"
+	//   "403":
+	//     "$ref": "#/responses/forbidden"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	//   "422":
+	//     "$ref": "#/responses/validationError"
+	//   "423":
+	//     "$ref": "#/responses/repoArchivedError"
+
+	// swagger:operation POST /orgs/{org}/projects/{id}/workflows organization orgCreateProjectWorkflow
+	// ---
+	// summary: Create a project workflow
+	// consumes:
+	// - application/json
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: org
+	//   in: path
+	//   description: name of the organization
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: body
+	//   in: body
+	//   schema:
+	//     "$ref": "#/definitions/CreateProjectWorkflowOption"
+	// responses:
+	//   "201":
+	//     "$ref": "#/responses/ProjectWorkflow"
+	//   "403":
+	//     "$ref": "#/responses/forbidden"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	//   "422":
+	//     "$ref": "#/responses/validationError"
+
+	// swagger:operation POST /user/projects/{id}/workflows user userCurrentCreateProjectWorkflow
+	// ---
+	// summary: Create a project workflow
+	// consumes:
+	// - application/json
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: body
+	//   in: body
+	//   schema:
+	//     "$ref": "#/definitions/CreateProjectWorkflowOption"
+	// responses:
+	//   "201":
+	//     "$ref": "#/responses/ProjectWorkflow"
+	//   "403":
+	//     "$ref": "#/responses/forbidden"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	//   "422":
+	//     "$ref": "#/responses/validationError"
+
+	project := projectScopeFromContext(ctx).findOpenProject(ctx)
+	if ctx.Written() {
+		return
+	}
+	workflow, err := project_service.CreateWorkflow(ctx, ctx.Doer, project, web.GetForm[*api.CreateProjectWorkflowOption](ctx))
+	if err != nil {
+		ctx.APIErrorAuto(err)
+		return
+	}
+	ctx.JSON(http.StatusCreated, convert.ToProjectWorkflow(workflow))
+}
+
+func EditProjectWorkflow(ctx *context.APIContext) {
+	// swagger:operation PATCH /repos/{owner}/{repo}/projects/{id}/workflows/{workflow_id} repository repoEditProjectWorkflow
+	// ---
+	// summary: Edit a project workflow
+	// consumes:
+	// - application/json
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: workflow_id
+	//   in: path
+	//   description: id of the workflow
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: body
+	//   in: body
+	//   schema:
+	//     "$ref": "#/definitions/EditProjectWorkflowOption"
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ProjectWorkflow"
+	//   "403":
+	//     "$ref": "#/responses/forbidden"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	//   "422":
+	//     "$ref": "#/responses/validationError"
+	//   "423":
+	//     "$ref": "#/responses/repoArchivedError"
+
+	// swagger:operation PATCH /orgs/{org}/projects/{id}/workflows/{workflow_id} organization orgEditProjectWorkflow
+	// ---
+	// summary: Edit a project workflow
+	// consumes:
+	// - application/json
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: org
+	//   in: path
+	//   description: name of the organization
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: workflow_id
+	//   in: path
+	//   description: id of the workflow
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: body
+	//   in: body
+	//   schema:
+	//     "$ref": "#/definitions/EditProjectWorkflowOption"
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ProjectWorkflow"
+	//   "403":
+	//     "$ref": "#/responses/forbidden"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	//   "422":
+	//     "$ref": "#/responses/validationError"
+
+	// swagger:operation PATCH /user/projects/{id}/workflows/{workflow_id} user userCurrentEditProjectWorkflow
+	// ---
+	// summary: Edit a project workflow
+	// consumes:
+	// - application/json
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: workflow_id
+	//   in: path
+	//   description: id of the workflow
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: body
+	//   in: body
+	//   schema:
+	//     "$ref": "#/definitions/EditProjectWorkflowOption"
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ProjectWorkflow"
+	//   "403":
+	//     "$ref": "#/responses/forbidden"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	//   "422":
+	//     "$ref": "#/responses/validationError"
+
+	project := projectScopeFromContext(ctx).findOpenProject(ctx)
+	if ctx.Written() {
+		return
+	}
+	workflow := findWorkflow(ctx, project)
+	if ctx.Written() {
+		return
+	}
+	if err := project_service.UpdateWorkflow(ctx, ctx.Doer, project, workflow, web.GetForm[*api.EditProjectWorkflowOption](ctx)); err != nil {
+		ctx.APIErrorAuto(err)
+		return
+	}
+	ctx.JSON(http.StatusOK, convert.ToProjectWorkflow(workflow))
+}
+
+func DeleteProjectWorkflow(ctx *context.APIContext) {
+	// swagger:operation DELETE /repos/{owner}/{repo}/projects/{id}/workflows/{workflow_id} repository repoDeleteProjectWorkflow
+	// ---
+	// summary: Delete a project workflow
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: workflow_id
+	//   in: path
+	//   description: id of the workflow
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// responses:
+	//   "204":
+	//     "$ref": "#/responses/empty"
+	//   "403":
+	//     "$ref": "#/responses/forbidden"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	//   "423":
+	//     "$ref": "#/responses/repoArchivedError"
+
+	// swagger:operation DELETE /orgs/{org}/projects/{id}/workflows/{workflow_id} organization orgDeleteProjectWorkflow
+	// ---
+	// summary: Delete a project workflow
+	// parameters:
+	// - name: org
+	//   in: path
+	//   description: name of the organization
+	//   type: string
+	//   required: true
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: workflow_id
+	//   in: path
+	//   description: id of the workflow
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// responses:
+	//   "204":
+	//     "$ref": "#/responses/empty"
+	//   "403":
+	//     "$ref": "#/responses/forbidden"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	// swagger:operation DELETE /user/projects/{id}/workflows/{workflow_id} user userCurrentDeleteProjectWorkflow
+	// ---
+	// summary: Delete a project workflow
+	// parameters:
+	// - name: id
+	//   in: path
+	//   description: id of the project
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: workflow_id
+	//   in: path
+	//   description: id of the workflow
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// responses:
+	//   "204":
+	//     "$ref": "#/responses/empty"
+	//   "403":
+	//     "$ref": "#/responses/forbidden"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	project := projectScopeFromContext(ctx).findOpenProject(ctx)
+	if ctx.Written() {
+		return
+	}
+	workflow := findWorkflow(ctx, project)
+	if ctx.Written() {
+		return
+	}
+	if err := project_service.DeleteWorkflow(ctx, ctx.Doer, project, workflow); err != nil {
+		ctx.APIErrorAuto(err)
+		return
+	}
+	ctx.Status(http.StatusNoContent)
+}

routers/api/v1/swagger/options.go

@@ -256,6 +256,12 @@ type swaggerParameterBodies struct {
 	// in:body
 	MoveProjectIssueOption api.MoveProjectIssueOption
 
+	// in:body
+	CreateProjectWorkflowOption api.CreateProjectWorkflowOption
+
+	// in:body
+	EditProjectWorkflowOption api.EditProjectWorkflowOption
+
 	// in:body
 	MergeUpstreamRequest api.MergeUpstreamRequest
 }

routers/api/v1/swagger/project.go

@@ -34,3 +34,17 @@ type swaggerResponseProjectColumnList struct {
 	// in:body
 	Body []api.ProjectColumn `json:"body"`
 }
+
+// ProjectWorkflow
+// swagger:response ProjectWorkflow
+type swaggerResponseProjectWorkflow struct {
+	// in:body
+	Body api.ProjectWorkflow `json:"body"`
+}
+
+// ProjectWorkflowList
+// swagger:response ProjectWorkflowList
+type swaggerResponseProjectWorkflowList struct {
+	// in:body
+	Body []api.ProjectWorkflow `json:"body"`
+}