Backlog MCP Server

A Model Context Protocol (MCP) server for interacting with the Backlog API. This server provides tools for managing projects, issues, wiki pages, and more in Backlog through AI agents like Claude Desktop / Cline / Cursor etc.

Features

Project tools (create, read, update, delete)
Issue tracking and comments (create, update, delete, list)
Version/Milestone management (create, read, update, delete)
Wiki page support
Git repository and pull request tools
Notification tools
GraphQL-style field selection for optimized responses
Token limiting for large responses

Getting Started

Requirements

Docker
A Backlog account with API access
API key from your Backlog account

Option 1: Install via Docker

The easiest way to use this MCP server is through MCP configurations:

Open MCP settings
Navigate to the MCP configuration section
Add the following configuration:

{
  "mcpServers": {
    "backlog": {
      "command": "docker",
      "args": [
        "run",
        "--pull",
        "always",
        "-i",
        "--rm",
        "-e",
        "BACKLOG_DOMAIN",
        "-e",
        "BACKLOG_API_KEY",
        "ghcr.io/nulab/backlog-mcp-server"
      ],
      "env": {
        "BACKLOG_DOMAIN": "your-domain.backlog.com",
        "BACKLOG_API_KEY": "your-api-key"
      }
    }
  }
}

Replace your-domain.backlog.com with your Backlog domain and your-api-key with your Backlog API key.

✅ If you cannot use --pull always, you can manually update the image using:

docker pull ghcr.io/nulab/backlog-mcp-server:latest

Option 2: Install via npx

You can also run the server directly using npx without cloning the repository. This is a convenient way to run the server without a full installation.

Open MCP settings
Navigate to the MCP configuration section
Add the following configuration:

{
  "mcpServers": {
    "backlog": {
      "command": "npx",
      "args": ["backlog-mcp-server"],
      "env": {
        "BACKLOG_DOMAIN": "your-domain.backlog.com",
        "BACKLOG_API_KEY": "your-api-key"
      }
    }
  }
}

Replace your-domain.backlog.com with your Backlog domain and your-api-key with your Backlog API key.

Option 3: Manual Setup (Node.js)

Clone and install:

git clone https://github.com/nulab/backlog-mcp-server.git
cd backlog-mcp-server
pnpm install
pnpm run build

Create .env from template and set required variables:

cp .env.example .env

Set the following values in .env:

BACKLOG_DOMAIN=your-domain.backlog.com
BACKLOG_API_KEY=your-api-key

Run locally:

pnpm run dev

Set your json to use as MCP

{
  "mcpServers": {
    "backlog": {
      "command": "node",
      "args": ["your-repository-location/build/index.js"],
      "env": {
        "BACKLOG_DOMAIN": "your-domain.backlog.com",
        "BACKLOG_API_KEY": "your-api-key"
      }
    }
  }
}

HTTP transport (Streamable HTTP)

By default the server uses stdio. To run the MCP Streamable HTTP transport instead (JSON-RPC over HTTP, same tools as stdio), start with --transport http or set MCP_TRANSPORT=http.

pnpm run build
MCP_TRANSPORT=http MCP_HTTP_PORT=3333 node build/index.js

Endpoint: POST (and GET for server-initiated streams) on http://<host>:<port><path> (default path /mcp).
Protocol: MCP 2026-07-28. The protocol is stateless: there is no initialize handshake and no mcp-session-id header. Clients send their metadata in _meta on every request and discover capabilities via server/discover. Streamable HTTP also requires the Mcp-Method header (and Mcp-Name on tools/call).
Backward compatibility: Clients on 2025-11-25 and earlier are still served over the same endpoint, statelessly. Because no session is kept, the 2025 session operations (GET / DELETE with an mcp-session-id) answer 405.
Security: Default bind is 127.0.0.1. On a bare loopback bind, Host and Origin are both validated against the localhost set (DNS rebinding protection). Behind a reverse proxy, set --http-allowed-hosts to the public hostname; that turns off the localhost Origin default, since a browser client's Origin is its own site and never this server's hostname. Add --http-allowed-origins to restrict which client origins may reach the server. Do not expose the HTTP port to untrusted networks without authentication and TLS; it allows full use of your Backlog API key via MCP tools.

Environment variables (CLI flags override when both are set):

Variable	Description
`MCP_TRANSPORT`	`stdio` (default) or `http`
`MCP_HTTP_HOST`	Bind address (default `127.0.0.1`)
`MCP_HTTP_PORT`	Port (default `3333`)
`MCP_HTTP_PATH`	URL path (default `/mcp`)
`MCP_HTTP_JSON_RESPONSE`	`true` to prefer JSON responses over SSE (applies to `2026-07-28` clients only)
`MCP_HTTP_ALLOWED_HOSTS`	Comma-separated allowed `Host` hostnames (port-agnostic). Required when binding to `0.0.0.0`; also the escape hatch for a loopback bind behind a proxy (DNS rebinding protection)
`MCP_HTTP_ALLOWED_ORIGINS`	Comma-separated allowed `Origin` hostnames for browser-based clients. Defaults to the localhost set on a bare loopback bind, and to no `Origin` check otherwise

OAuth 2.0 Authentication (Remote MCP)

When exposing the MCP server over a network, you can enable OAuth 2.0 authentication so that each user authenticates with their own Backlog account instead of sharing a single API key.

The server implements the MCP Third-Party Authorization Flow by acting as both an OAuth authorization server (for MCP clients) and an OAuth client (for Backlog).

Prerequisites

Register an OAuth application in your Backlog space:
- Go to your Backlog space → Personal Settings → Register Application
- Set the Redirect URI to <MCP_SERVER_BASE_URL>/callback (e.g., https://mcp.example.com/callback)
- Note the Client ID and Client Secret
Set the following environment variables (in addition to BACKLOG_DOMAIN):

Variable	Description
`BACKLOG_OAUTH_CLIENT_ID`	OAuth Client ID from your Backlog application
`BACKLOG_OAUTH_CLIENT_SECRET`	OAuth Client Secret from your Backlog application
`MCP_SERVER_BASE_URL`	Public URL of your MCP server (e.g., `https://mcp.example.com`)

Note: BACKLOG_API_KEY is not required when OAuth is enabled — each user authenticates with their own Backlog account.

Example

BACKLOG_DOMAIN=your-space.backlog.com \
BACKLOG_OAUTH_CLIENT_ID=your-client-id \
BACKLOG_OAUTH_CLIENT_SECRET=your-client-secret \
MCP_SERVER_BASE_URL=https://mcp.example.com \
node build/index.js --transport http --http-host 0.0.0.0 --http-port 3333 \
  --http-allowed-hosts mcp.example.com

--http-allowed-hosts is required in practice when binding to 0.0.0.0: without it there is no DNS rebinding protection, and the server logs a warning at startup.

The server automatically exposes the following OAuth endpoints when OAuth is enabled:

Endpoint	Description
`GET /.well-known/oauth-authorization-server`	OAuth Authorization Server Metadata (RFC 8414)
`GET /.well-known/oauth-protected-resource/mcp`	OAuth Protected Resource Metadata (RFC 9728)
`POST /register`	Dynamic Client Registration (RFC 7591)
`GET /authorize`	Authorization endpoint (redirects to Backlog OAuth)
`GET /callback`	Backlog OAuth callback
`POST /token`	Token endpoint (authorization code & refresh token)

MCP clients that support the MCP authorization specification will use these endpoints automatically.

Limitations:

OAuth mode currently supports a single Backlog organization. It is not compatible with the multi-organization configuration.

Client registrations and tokens are stored in memory and will be lost on server restart.

Tool Configuration

You can selectively enable or disable specific toolsets using the --enable-toolsets command-line flag or the ENABLE_TOOLSETS environment variable. This allows better control over which tools are available to the AI agent and helps reduce context size.

Available Toolsets

The following toolsets are available (enabled by default when "all" is used):

Toolset	Description
`space`	Tools for managing Backlog space settings and general information
`project`	Tools for managing projects, categories, custom fields, and issue types
`issue`	Tools for managing issues and their comments, version milestones
`wiki`	Tools for managing wiki pages
`git`	Tools for managing Git repositories and pull requests
`notifications`	Tools for managing user notifications
`document`	Tools for viewing documents and document trees

Specifying Toolsets

You can control toolset activation in the following ways:

Using via CLI:

--enable-toolsets space,project,issue

Or via environment variable:

ENABLE_TOOLSETS="space,project,issue"

If all is specified, all available toolsets will be enabled. This is also the default behavior.

Using selective toolsets can be helpful if the toolset list is too large for your AI agent or if certain tools are causing performance issues. In such cases, disabling unused toolsets may improve stability.

🧩 Tip: project toolset is highly recommended, as many other tools rely on project data as an entry point.

Dynamic Toolset Discovery (Experimental)

If you're using the MCP server with AI agents, you can enable dynamic discovery of toolsets at runtime:

Enabling via CLI:

--dynamic-toolsets

Or via environment variable::

-e DYNAMIC_TOOLSETS=1 \

With dynamic toolsets enabled, the LLM will be able to list and activate toolsets on demand via tool interface.

Scope over HTTP: MCP 2026-07-28 has no protocol sessions, so an activated toolset is remembered per server process, not per client. On the HTTP transport every connected client shares one toolset state, and it resets when the process restarts. Tool visibility is shared; authorization is not — every call is still authenticated with the caller's own credentials.

Available Tools

Toolset: `space`

Tools for managing Backlog space settings and general information.

get_space: Returns information about the Backlog space.
get_users: Returns list of users in the Backlog space.
get_myself: Returns information about the authenticated user.

Toolset: `project`

Tools for managing projects, categories, custom fields, and issue types.

get_project_list: Returns list of projects.
add_project: Creates a new project.
get_project: Returns information about a specific project.
get_project_users: Returns list of users in a specific project.
update_project: Updates an existing project.
delete_project: Deletes a project.

Toolset: `issue`

Tools for managing issues, their comments, and related items like priorities, categories, custom fields, issue types, resolutions, and watching lists.

get_issue: Returns information about a specific issue.
get_issues: Returns list of issues.
count_issues: Returns count of issues.
add_issue: Creates a new issue in the specified project.
update_issue: Updates an existing issue.
delete_issue: Deletes an issue.
get_issue_comments: Returns list of comments for an issue.
add_issue_comment: Adds a comment to an issue.
update_issue_comment: Updates a comment on an issue.
get_related_issues: Returns list of issues related to a specific issue.
add_related_issue: Relates an issue to another issue.
remove_related_issue: Removes the relation between an issue and a related issue.
get_priorities: Returns list of priorities.
get_categories: Returns list of categories for a project.
get_custom_fields: Returns list of custom fields for a project.
get_issue_types: Returns list of issue types for a project.
get_resolutions: Returns list of issue resolutions.
get_watching_list_items: Returns list of watching items for a user.
get_watching_list_count: Returns count of watching items for a user.
add_watching: Adds a new watch to an issue.
update_watching: Updates an existing watch note.
delete_watching: Deletes a watch from an issue.
mark_watching_as_read: Marks a watch as read.
get_version_milestone_list: Returns list of version milestones for a project.
add_version_milestone: Creates a new version milestone for a project.
update_version_milestone: Updates an existing version milestone.
delete_version_milestone: Deletes a version milestone.

Toolset: `wiki`

Tools for managing wiki pages.

get_wiki_pages: Returns list of Wiki pages.
get_wikis_count: Returns count of wiki pages in a project.
get_wiki: Returns information about a specific wiki page.
add_wiki: Creates a new wiki page.

Toolset: `git`

Tools for managing Git repositories and pull requests.

get_git_repositories: Returns list of Git repositories for a project.
get_git_repository: Returns information about a specific Git repository.
get_pull_requests: Returns list of pull requests for a repository.
get_pull_requests_count: Returns count of pull requests for a repository.
get_pull_request: Returns information about a specific pull request.
add_pull_request: Creates a new pull request.
update_pull_request: Updates an existing pull request.
get_pull_request_comments: Returns list of comments for a pull request.
add_pull_request_comment: Adds a comment to a pull request.
update_pull_request_comment: Updates a comment on a pull request.

Toolset: `notifications`

Tools for managing user notifications.

get_notifications: Returns list of notifications.
get_notifications_count: Returns count of notifications.
reset_unread_notification_count: Resets unread notification count.
mark_notification_as_read: Marks a notification as read.

Toolset: `document`

Tools for managing documents and document trees in Backlog projects.

get_document_tree: Returns the hierarchical tree of documents for a project, including folders and ne
get_documents: Returns a flat list of documents in a project or folder.
get_document: Returns detailed information about a specific document, including metadata, content, an

Usage Examples

Once the MCP server is configured in AI agents, you can use the tools directly in your conversations. Here are some examples:

Listing Projects

Could you list all my Backlog projects?

Creating a New Issue

Create a new bug issue in the PROJECT-KEY project with high priority titled "Fix login page error"

Getting Project Details

Show me the details of the PROJECT-KEY project

Working with Git Repositories

List all Git repositories in the PROJECT-KEY project

Managing Pull Requests

Show me all open pull requests in the repository "repo-name" of PROJECT-KEY project

Create a new pull request from branch "feature/new-feature" to "main" in the repository "repo-name" of PROJECT-KEY project

Watching Items

Show me all items I'm watching

i18n / Overriding Descriptions

You can override the descriptions of tools by creating a .backlog-mcp-serverrc.json file in your home directory.

The file should contain a JSON object with the tool names as keys and the new descriptions as values.
For example:

{
  "TOOL_ADD_ISSUE_COMMENT_DESCRIPTION": "An alternative description",
  "TOOL_CREATE_PROJECT_DESCRIPTION": "Create a new project in Backlog"
}

When the server starts, it determines the final description for each tool based on the following priority:

Environment variables (e.g., BACKLOG_MCP_TOOL_ADD_ISSUE_COMMENT_DESCRIPTION)
Entries in .backlog-mcp-serverrc.json - Supported configuration file formats: .json, .yaml, .yml
Built-in fallback values (English)

Sample config:

{
  "mcpServers": {
    "backlog": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "BACKLOG_DOMAIN",
        "-e",
        "BACKLOG_API_KEY",
        "-v",
        "/yourcurrentdir/.backlog-mcp-serverrc.json:/root/.backlog-mcp-serverrc.json:ro",
        "ghcr.io/nulab/backlog-mcp-server"
      ],
      "env": {
        "BACKLOG_DOMAIN": "your-domain.backlog.com",
        "BACKLOG_API_KEY": "your-api-key"
      }
    }
  }
}

Exporting Current Translations

You can export the current default translations (including any overrides) by running the binary with the --export-translations flag.

This will print all tool descriptions to stdout, including any customizations you have made.

Example:

docker run -i --rm ghcr.io/nulab/backlog-mcp-server node build/index.js --export-translations

or

npx github:nulab/backlog-mcp-server --export-translations

Using Environment Variables

Alternatively, you can override tool descriptions via environment variables.

The environment variable names are based on the tool keys, prefixed with BACKLOGMCP and written in uppercase.

Example: To override the TOOL_ADD_ISSUE_COMMENT_DESCRIPTION:

{
  "mcpServers": {
    "backlog": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e", "BACKLOG_DOMAIN",
        "-e", "BACKLOG_API_KEY",
        "-e", "BACKLOG_MCP_TOOL_ADD_ISSUE_COMMENT_DESCRIPTION"
        "ghcr.io/nulab/backlog-mcp-server"
      ],
      "env": {
        "BACKLOG_DOMAIN": "your-domain.backlog.com",
        "BACKLOG_API_KEY": "your-api-key",
        "BACKLOG_MCP_TOOL_ADD_ISSUE_COMMENT_DESCRIPTION": "An alternative description"
      }
    }
  }
}

The server loads the config file synchronously at startup.

Environment variables always take precedence over the config file.

Advanced Features

Tool Name Prefixing

Add prefix to tool names with:

--prefix backlog_

or via environment variable:

PREFIX="backlog_"

This is especially useful if you're using multiple MCP servers or tools in the same environment and want to avoid name collisions. For example, get_project can become backlog_get_project to distinguish it from similarly named tools provided by other services.

Response Optimization & Token Limits

Field Selection (GraphQL-style)

--optimize-response

Or environment variable:

OPTIMIZE_RESPONSE=1

Then, request only specific fields:

get_project(projectIdOrKey: "PROJECT-KEY", fields: "{ name key description }")

The AI will use field selection to optimize the response:

get_project(projectIdOrKey: "PROJECT-KEY", fields: "{ name key description }")

Benefits:

Reduce response size by requesting only needed fields
Focus on specific data points
Improve performance for large responses

Token Limiting

Large responses are automatically limited to prevent exceeding token limits:

Default limit: 50,000 tokens
Configurable via MAX_TOKENS environment variable
Responses exceeding the limit are truncated with a message

You can change this using:

MAX_TOKENS=10000

If a response exceeds the limit, it will be truncated with a warning.

Note: This is a best-effort mitigation, not a guaranteed enforcement.

Full Custom Configuration Example

This section demonstrates advanced configuration using multiple environment variables. These are experimental features and may not be supported across all MCP clients. This is not part of the MCP standard specification and should be used with caution.

{
  "mcpServers": {
    "backlog": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "BACKLOG_DOMAIN",
        "-e",
        "BACKLOG_API_KEY",
        "-e",
        "MAX_TOKENS",
        "-e",
        "OPTIMIZE_RESPONSE",
        "-e",
        "PREFIX",
        "-e",
        "ENABLE_TOOLSETS",
        "ghcr.io/nulab/backlog-mcp-server"
      ],
      "env": {
        "BACKLOG_DOMAIN": "your-domain.backlog.com",
        "BACKLOG_API_KEY": "your-api-key",
        "MAX_TOKENS": "10000",
        "OPTIMIZE_RESPONSE": "1",
        "PREFIX": "backlog_",
        "ENABLE_TOOLSETS": "space,project,issue",
        "ENABLE_DYNAMIC_TOOLSETS": "1"
      }
    }
  }
}

Development

Running Tests

pnpm test

Adding New Tools

Create a new file in src/tools/ following the pattern of existing tools
Create a corresponding test file
Add the new tool to src/tools/tools.ts
Build and test your changes

Command Line Options

The server supports several command line options:

--transport stdio|http: MCP transport (default: stdio). Use http for Streamable HTTP.
--http-host, --http-port, --http-path: HTTP bind address, port, and path (defaults: 127.0.0.1, 3333, /mcp).
--http-json-response: Prefer JSON responses over SSE. Applies to 2026-07-28 clients only; the backward-compatible 2025-11-25 path is served with the SDK's default response shaping.
--http-allowed-hosts: Comma-separated allowed Host hostnames (port-agnostic). Needed when binding to all interfaces, or on a loopback bind behind a reverse proxy.
--http-allowed-origins: Comma-separated allowed Origin hostnames for browser-based clients. Defaults to the localhost set on a bare loopback bind, and to no Origin check otherwise.
--export-translations: Export all translation keys and values
--optimize-response: Enable GraphQL-style field selection
--max-tokens=NUMBER: Set maximum token limit for responses
--prefix=STRING: Optional string prefix to prepend to all tool names (default: "")
--enable-toolsets <toolsets...>: Specify which toolsets to enable (comma-separated or multiple arguments). Defaults to "all". Example: --enable-toolsets space,project or --enable-toolsets issue --enable-toolsets git Available toolsets: space, project, issue, wiki, git, notifications.

Example:

node build/index.js --optimize-response --max-tokens=100000 --prefix="backlog_" --enable-toolsets space,issue

HTTP example:

node build/index.js --transport http --http-port 3333 --http-path /mcp

Multi-Organization Support

This server can be configured to access multiple Backlog organizations from a single MCP server instance.

Configuration

Configure one env pair per organization and set a default organization:

BACKLOG_DEFAULT_ORG=COMPANY_A
BACKLOG_ORG_COMPANY_A_DOMAIN=company-a.backlog.com
BACKLOG_ORG_COMPANY_A_API_KEY=your-company-a-api-key
BACKLOG_ORG_COMPANY_B_DOMAIN=company-b.backlog.com
BACKLOG_ORG_COMPANY_B_API_KEY=your-company-b-api-key

This works whether the variables come from a local .env, your shell environment, or an MCP client config env block.

Example MCP config:

{
  "env": {
    "BACKLOG_DEFAULT_ORG": "COMPANY_A",
    "BACKLOG_ORG_COMPANY_A_DOMAIN": "company-a.backlog.com",
    "BACKLOG_ORG_COMPANY_A_API_KEY": "your-company-a-api-key",
    "BACKLOG_ORG_COMPANY_B_DOMAIN": "company-b.backlog.com",
    "BACKLOG_ORG_COMPANY_B_API_KEY": "your-company-b-api-key"
  }
}

If no multi-organization env vars are set, the server falls back to the existing single-organization configuration:

BACKLOG_DOMAIN=your-domain.backlog.com
BACKLOG_API_KEY=your-api-key

Tool Usage

When multi-organization env vars are configured, all normal tools accept an optional organization input field. When provided, the tool call is routed to that Backlog organization.

In single-organization mode the field is not published, since there would be only one organization to route to. Omitting it keeps roughly 8 KB of tool schema out of every tools/list response.

Examples:

{
  "organization": "COMPANY_B",
  "projectKey": "PROJECT"
}

If organization is omitted:

the organization named by BACKLOG_DEFAULT_ORG is used
if multi-organization env vars are present and BACKLOG_DEFAULT_ORG is missing, the server fails at startup

Organization Discovery

In multi-organization mode the server provides a list_organizations tool that returns the configured organization names, their domains, and which one is the default. It is not registered in single-organization mode.

Example response:

[
  {
    "name": "COMPANY_A",
    "domain": "company-a.backlog.com",
    "isDefault": true
  },
  {
    "name": "COMPANY_B",
    "domain": "company-b.backlog.com",
    "isDefault": false
  }
]

Notes

For multi-org mode, every organization must define both BACKLOG_ORG_<NAME>_DOMAIN and BACKLOG_ORG_<NAME>_API_KEY.
The <NAME> part is the organization name exposed through the organization tool input and list_organizations.

License

This project is licensed under the MIT License.

Please note: This tool is provided under the MIT License without any warranty or official support.
Use it at your own risk after reviewing the contents and determining its suitability for your needs.
If you encounter any issues, please report them via GitHub Issues.

Name		Name	Last commit message	Last commit date
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.claude/skills/implement-backlog-api-tool		.claude/skills/implement-backlog-api-tool
.github/workflows		.github/workflows
docs		docs
src		src
.env.example		.env.example
.gitignore		.gitignore
.npmrc		.npmrc
.prettierignore		.prettierignore
.prettierrc		.prettierrc
.tool-versions		.tool-versions
Dockerfile		Dockerfile
LICENSE		LICENSE
README.ja.md		README.ja.md
README.md		README.md
eslint.config.js		eslint.config.js
icon.png		icon.png
manifest.json		manifest.json
package.json		package.json
pnpm-lock.yaml		pnpm-lock.yaml
tsconfig.json		tsconfig.json
tsconfig.test.json		tsconfig.test.json
vitest.config.ts		vitest.config.ts

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