Runtime MCP Server

Runtime MCP server is a hosted integration for AI assistants that speak the Model Context Protocol. Grackle GenAIScript runtime implementation.

What you get

That's the collective noun. Also what you get when you stop babysitting one agent in a terminal and start running many — each on its own wire, with its own key, leaving its own name in the log.

What the assistant can call

Once Runtime is connected, these are the calls the assistant has available:

• Claude — mounted read-only (redirected via CLAUDE_CONFIG_DIR)
• GH_TOKEN — enables the GitHub CLI and Codespace adapter inside the container
• Adapter — Command
• Findings — Categorized discoveries shared across agents within a workspace — architecture decisions, bugs, API patterns, dependency issues. Tagged and
• Personas — Named agent configurations that bundle a system prompt, runtime, model, tool allowlists, and MCP permissions. Assign a "Software Architect" to
• Environments — Each agent runs inside an isolated environment. Connect one or many:
• Themes — 9 built-in themes — Grackle, Glassmorphism, Matrix, Neubrutalism, Monokai, Ubuntu, Sandstone, Verdigris, and Primer (several with light/dark

Configuration and credentials

You will need one environment variable: ANTHROPIC_API_KEY. The server will not start without them, which is usually why the tools fail to appear on a first run. Keep credentials in your client's env block or a secrets manager rather than in a file you might commit.

• Docker (recommended — the Grackle app and its dependencies are bundled in the image) - Node.js >= 22, < 24 (for npm install — Node 24+ is not yet supported) > You still need to provide your own model credentials (via environment variables or mounted config files). Some features like the Docker adapter require access to the host Docker socket.

Setting it up

Being a remote server, there is no local install. You register the endpoint with your client, authorise it once, and the tools appear.

Choosing this one

Among the developer tooling options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Runtime's toolset — Claude, GH_TOKEN, Adapter and 4 more — is a fair guide to whether it matches your workflow. It is maintained by nickpape; worth a glance at recent repository activity before you build anything load-bearing on it.

SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.

Before you rely on it

• Your data travels to the provider's service, so the usual questions apply about what you send and what they retain.
• Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
• MCP clients confirm each tool call by default. Leave that on until you have watched what the runtime mcp server does with a few real requests.