Since.dev MCP server

Since.dev MCP

What changed in the packages, APIs and services your code depends on, and the fixes it needs.

Product · Documentation · MCP reference

Since.dev tracks every package in 18 registries, every AI model's retirement on each platform that serves it, API changes and runtime end-of-life dates, each with its source. This repository connects your agent to it: a hosted remote MCP server, plus a plugin for Claude Code, Cursor and Codex that tells the agent when to use it. There is no server code to install or run.

Install

Every install signs in through your browser (OAuth). You approve the client for one Since.dev workspace, and no key is stored in a file. A free account works.

Claude (claude.ai and the Claude apps)

Open Since.dev in the connector directory, click Connect and sign in.

Claude Code

Install the plugin, which adds the server and four skills:

/plugin marketplace add since-dev/mcp
/plugin install since-dev@since-dev

Or add only the server, then run /mcp to sign in:

claude mcp add --transport http since https://api.since.dev/mcp

Cursor

Click Add to Cursor above, or install the Cursor plugin (Since-dev/cursor) to get the server, the skills and a rule that checks dependency, model and runtime changes.

VS Code

Click Install in VS Code above, or run:

code --add-mcp '{"name":"since","type":"http","url":"https://api.since.dev/mcp"}'

Codex

Install the plugin:

codex plugin marketplace add since-dev/mcp

Or add only the server and sign in:

codex mcp add since --url https://api.since.dev/mcp
codex mcp login since

Gemini CLI

gemini extensions install https://github.com/since-dev/mcp

Then sign in through the browser from Gemini CLI with /mcp auth since. Or add only the server:

gemini mcp add --transport http since https://api.since.dev/mcp

Any other MCP client

Add a remote server with this URL over Streamable HTTP and sign in when the client asks:

https://api.since.dev/mcp

For a client that reads an mcpServers file, see examples/mcp.json. For VS Code's .vscode/mcp.json, see examples/vscode-mcp.json.

Use an API key instead

Some clients can't sign in through a browser. For those, create a key and send it as a Bearer token:

1. Sign in at https://app.since.dev and pick the workspace the agent should use.
2. Open API keys (https://app.since.dev/api-keys) and choose Create API key. The key starts with sc_live_ and is shown once.
3. Add the header Authorization: Bearer <your API key> in your client's secret settings. Never commit a key.

A key reaches only its own workspace, over the API and MCP, and any member with a seat can revoke it under API keys.

What's inside

• The server: 3 tools, from the same record as the Since.dev API. whats_changed and check_code only read, so your client runs them without asking. fix_code opens fix pull requests, so your client asks before every call.
• Skills (Claude Code, Cursor, Codex and other clients that read Agent Skills): since-before-upgrading, since-model-retirements, since-what-changed, since-ci-and-runtimes. They tell the agent when to check: before upgrades, when code names a model, before writing against something it learned in training, and when editing CI or runtimes.
• For Cursor: the plugin at Since-dev/cursor adds a rule that brings the same checks to manifest, lockfile, Dockerfile and workflow edits.

Tools

tools/list returns each tool's full input schema.

Tools

whats_changed and check_code only read, and both work on every plan; checking a connected repository (check_code with repo) is on the Business and Platform plans. fix_code writes: with code it returns a patch, on the Team plan and up, and with repo it opens fix pull requests for a person to review, on the Business and Platform plans. Each call costs credits; a bad input or a call the plan does not include is refused with a plain sentence and costs nothing.

Tool	What it does	Key inputs
whats_changed	What changed in a package, a provider, a model, a runtime or a connected repository, since your training cutoff, a date or a version, with severity, dates, replacements and cited evidence. Also lists a provider's current models to use in new code (current=true), gives one change in full with its migration steps (id), answers whether something is still supported, and lists upcoming retirements (as iCalendar too).	One of package (any spelling or purl), provider, model, repo, surface or id (one change, as a check_code finding names it); optional since (a date, a version or cutoff:<model>), current (with provider), within (for example 90d), kind, severity, reaches (with repo), cursor, limit
check_code	Checks code against what changed, before you rely on it: a snippet you just wrote, a model id, a package version, a manifest or a whole repository. Returns what is affected, where (file and line), how severe, how many days are left, the replacement and the source. Anything Since cannot settle is needs_review, never a guess. It only reads.	One of model, package (with a version), surface, code (with language), manifest or lockfile (path and content), repo, or repoUrl (a public GitHub repository); optional state, severity, detail (summary or full), limit, cursor
fix_code	Fixes what check_code found: the patch for a snippet, in seconds, or a connected repository's fix pull requests, one per provider, each checked before it opens. Nothing merges: every pull request waits for a person to review it. Fixes count against the month's fix pull requests, not credits.	One of repo or code (with language or path); optional state, severity, detail, limit

Examples

Each step shows the name and arguments the agent sends in a tools/call request.

1. Before writing code against a model, check the id:

   { "name": "check_code", "arguments": { "model": "<model id>" } }
   

   The result lists the model's status (supported, deprecated, retired or unknown) and a finding for each change that applies, with its severity, daysLeft, replacement and cited source.

2. Before upgrading a package, read what changed from the version you have:

   { "name": "whats_changed", "arguments": { "package": "npm:react", "since": "18.2.0" } }
   

   Each change carries its canonical surface, kind, severity, dates, replacement and evidence. package.releasesBehind says how far behind the version is, and coverage says which sources were read and how fresh they are. Page with nextCursor.

3. See what retires in the next 90 days for a provider:

   { "name": "whats_changed", "arguments": { "provider": "anthropic", "within": "90d" } }
   

4. Fix what a connected repository's check found (your client asks first):

   { "name": "fix_code", "arguments": { "repo": "<repository id>" } }
   

Treat unknown and needs_review as not settled, never as fine.

Requirements

• A Since.dev account. Create one with email, GitHub or Google. Each account includes one Free workspace.
• Credits. Each call costs credits from the workspace's monthly allowance, and every response says how many are left. See pricing.

Support

• Documentation: https://since.dev/docs, including the MCP reference
• Questions about this connection: open an issue
• Email: support@since.dev

License

The files in this repository are MIT licensed. See LICENSE.