MCP Server

The Onset MCP server lets AI assistants and coding agents work with your changelog directly: listing releases, drafting and publishing new ones, and managing subscribers, without leaving the chat or your editor. It implements the Model Context Protocol over Streamable HTTP, and authenticates with OAuth 2.1, so you sign in with your normal Onset account. No API key required.

Server URL: https://mcp.onset.io/mcp

Connect your client

Any client that supports remote MCP servers over Streamable HTTP with OAuth can connect. Point it at https://mcp.onset.io/mcp — there’s no API key to paste.

Claude
Claude Code
Cursor
VS Code
Codex

Open connector settings

In Claude, go to Settings → Connectors and click Add custom connector.

Add the Onset server

Paste https://mcp.onset.io/mcp and continue.

You’ll be redirected to Onset to sign in (or you’ll continue with your existing session).

Choose a workspace

Pick the workspace you want to connect, then click Authorize. Access is limited to that one workspace.

Add the server from your terminal:

claude mcp add --transport http onset https://mcp.onset.io/mcp

Then run /mcp inside Claude Code, pick onset, and complete the sign-in and workspace selection in your browser. Tokens are stored and refreshed for you; use Clear authentication in the /mcp menu to revoke access.Add --scope project to share the server with your team through a checked-in .mcp.json, or --scope user to make it available in every project.

Add Onset to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project only):

{
  "mcpServers": {
    "onset": {
      "url": "https://mcp.onset.io/mcp"
    }
  }
}

Open Settings → Features → Model Context Protocol. Cursor discovers the Onset authorization server automatically, registers itself, and opens your browser so you can sign in and pick a workspace.

Add Onset to .vscode/mcp.json in your project:

{
  "servers": {
    "onset": {
      "type": "http",
      "url": "https://mcp.onset.io/mcp"
    }
  }
}

Or run MCP: Add Server from the Command Palette and choose HTTP, which writes the same entry. To make Onset available everywhere instead of one project, use MCP: Open User Configuration.On first use, VS Code opens a browser window for the OAuth flow. Start the server with MCP: List Servers → onset → Start if it hasn’t connected yet.

Add the server from your terminal:

codex mcp add onset --url https://mcp.onset.io/mcp
codex mcp login onset

Or edit ~/.codex/config.toml directly:

[mcp_servers.onset]
url = "https://mcp.onset.io/mcp"

codex mcp login onset opens your browser for the OAuth flow. Run /mcp in the Codex TUI to confirm the server is connected. The CLI and the IDE extension share this config, so you only set it up once.

Once connected, ask things like “What did we ship last month?” or “Draft a release for version 2.1 from these notes.”

Workspace access

Each connection is scoped to a single workspace, chosen at the moment you authorize. The workspace is bound into the access token, and every request is re-checked against your current membership, so if you’re removed from a workspace, the connection stops working immediately. To connect a different workspace, authorize again and select it. Each workspace is granted separately. Anyone who can access a workspace through the Onset API can use these tools for that workspace.

Available tools

Releases

Tool	Description
`list_releases`	List releases, optionally filtered by status, project, or labels
`get_release`	Get a single release by id or number
`create_release`	Create a new release as a draft
`update_release`	Update the content of an existing release
`publish_release`	Publish a release now, schedule it, or reschedule it

Projects, labels & contributors

Tool	Description
`list_projects`	List projects in the workspace
`list_labels`	List labels in the workspace
`list_contributors`	List workspace members available as contributors

Subscribers

Tool	Description
`list_subscribers`	List changelog subscribers
`list_subscriber_lists`	List subscriber lists
`create_subscriber`	Add a subscriber, optionally to specific lists

Read tools can run without confirmation. Tools that create or change data will ask you to confirm before running.

Creating, updating or publishing a release, and adding a subscriber, fire the same webhooks as the REST API and dashboard. If your workspace has webhook endpoints configured, those requests are sent to your external URLs.

Drafts and publishing

create_release always creates a draft. Nothing appears on your changelog until it’s published, so you can let an assistant write a release and review it before anyone sees it. Publishing is a separate, explicit step (publish_release), and most clients ask you to confirm before running it. You can publish immediately (RELEASED) or schedule it for a future date (SCHEDULED, available on plans that include scheduled releases). The same tool works on a release that’s already scheduled, so you can ask to publish it early or move it to a different date. Once a release is live, use update_release to change its content. This mirrors the REST API, where releases are also created as drafts and published through a separate endpoint.

Notifications are never sent over MCP. Publishing through an AI assistant does not send subscriber emails or Slack and Discord messages. To notify people, publish from the Onset dashboard, where you choose the channels.

Prompts and resources

Alongside tools, the server exposes:

draft_release_notes is a prompt that turns a list of changes into structured release notes. Provide your highlights plus an optional version and tone.
onset://releases/{id} exposes your releases as readable Markdown, so clients that support resources can pull a release into context directly.

Support for prompts and resources varies by AI client. All clients support tools.

Plan limits

MCP requests count toward the same plan limits as the REST API. For example, adding a subscriber fails once you reach your plan’s subscriber limit.

Troubleshooting

The client can't connect to the server

Confirm the URL is exactly https://mcp.onset.io/mcp. Web clients like Claude connect from their own servers, so the endpoint must be reachable from the public internet.

Tools return a workspace error

Your connection may point at a workspace you’re no longer a member of. Remove the server and add it again, selecting a current workspace.

Wrong workspace connected

Reconnect and pick the workspace you want on the authorization screen. Each connection covers exactly one workspace.

Tools don't show up after connecting

Restart the server or reload the client. In VS Code, run MCP: Reset Cached Tools. In Cursor, check Output → MCP Logs for connection errors.

Getting started

Releases

Audience

Page

Developers

Integrations

Connect your client

Workspace access

Available tools

Releases

Projects, labels & contributors

Subscribers

Drafts and publishing

Prompts and resources

Plan limits

Troubleshooting

​Connect your client

​Workspace access

​Available tools

​Releases

​Projects, labels & contributors

​Subscribers

​Drafts and publishing

​Prompts and resources

​Plan limits

​Troubleshooting

Connect your client

Workspace access

Available tools

Releases

Projects, labels & contributors

Subscribers

Drafts and publishing

Prompts and resources

Plan limits

Troubleshooting