Allow multiple projects per issue and pull requests (#36784)

Add ability to add and remove multiple projects per issue
and pull request.

Resolve #12974

---------

Signed-off-by: Icy Avocado <avocado@ovacoda.com>
Co-authored-by: Tyrone Yeh <siryeh@gmail.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: OpenCode (gpt-5.2-codex) <opencode@openai.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>

modules/structs/issue.go

@@ -60,6 +60,7 @@ type Issue struct {
 	Attachments      []*Attachment `json:"assets"`
 	Labels           []*Label      `json:"labels"`
 	Milestone        *Milestone    `json:"milestone"`
+	Projects         []*Project    `json:"projects"`
 	// deprecated
 	Assignee  *User     `json:"assignee"`
 	Assignees []*User   `json:"assignees"`
@@ -100,7 +101,9 @@ type CreateIssueOption struct {
 	Milestone int64 `json:"milestone"`
 	// list of label ids
 	Labels []int64 `json:"labels"`
-	Closed bool    `json:"closed"`
+	// list of project ids
+	Projects []int64 `json:"projects"`
+	Closed   bool    `json:"closed"`
 }
 
 // EditIssueOption options for editing an issue
@@ -112,7 +115,9 @@ type EditIssueOption struct {
 	Assignee  *string  `json:"assignee"`
 	Assignees []string `json:"assignees"`
 	Milestone *int64   `json:"milestone"`
-	State     *string  `json:"state"`
+	// list of project ids to set (replaces existing projects)
+	Projects *[]int64 `json:"projects"`
+	State    *string  `json:"state"`
 	// swagger:strfmt date-time
 	Deadline       *time.Time `json:"due_date"`
 	RemoveDeadline *bool      `json:"unset_due_date"`

modules/structs/project.go

@@ -0,0 +1,33 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package structs
+
+import (
+	"time"
+)
+
+// Project represents a project
+// swagger:model
+type Project struct {
+	// ID is the unique identifier for the project
+	ID int64 `json:"id"`
+	// Title is the title of the project
+	Title string `json:"title"`
+	// Description provides details about the project
+	Description string `json:"description"`
+	// OwnerID is the owner of the project (for org-level projects)
+	OwnerID int64 `json:"owner_id,omitempty"`
+	// RepoID is the repository this project belongs to (for repo-level projects)
+	RepoID int64 `json:"repo_id,omitempty"`
+	// CreatorID is the user who created the project
+	CreatorID int64 `json:"creator_id"`
+	// IsClosed indicates if the project is closed
+	IsClosed bool `json:"is_closed"`
+	// swagger:strfmt date-time
+	Created time.Time `json:"created_at"`
+	// swagger:strfmt date-time
+	Updated time.Time `json:"updated_at"`
+	// swagger:strfmt date-time
+	Closed *time.Time `json:"closed_at,omitempty"`
+}