FAQ
Short, direct answers to the most frequent questions about acf-mcp: determinism, signing, supported platforms, extensions, and stated boundaries.
Determinism and architecture
Does acf-mcp call an LLM internally?
No. No LLM call, ever. The engine is a deterministic pattern matcher over a signed knowledge base. Same canonical input ⇒ same output, byte-for-byte. That property is what makes the trace defensible to an auditor.
Why no internal LLM?
Because the server’s value is precisely the auditability of its output. An LLM produces non-reproducible outputs. The ACF® doctrine needs a verifiable chain of causality between an agent’s input and the qualification produced. That is incompatible with an LLM.
Is the doctrine the same across versions?
No. The doctrine is versioned, hashed and Ed25519-signed. Every release publishes a doctrine_version, a doctrine_hash and a signature. The current version is exposed by the MCP resource acf://meta.
Signing and cryptography
Why Ed25519 and not RSA?
Three reasons: (1) compactness, 32 bytes public key, 64 bytes signature; (2) constant-time verification, which removes a class of side-channel attacks; (3) no suspect parameters (no contested NIST curve).
Will the keys rotate?
Yes. Rotations are announced at least one minor version ahead, with an overlap window during which both keys verify. The full history lives at signatures / public key.
Usage and clients
Can I use acf-mcp without Claude Desktop?
Yes. Any client implementing MCP works: Cursor, Windsurf, Continue, Zed, or a custom client. See the quickstart page for configuration blocks.
Does it run on Windows / Linux / macOS?
Yes, anywhere Node.js ≥ 18 runs. No native binary, no platform-specific dependency.
Is there a hosted version of acf-mcp?
No. acf-mcp is a local server, started by your MCP client on your machine via npx; there is no hosted endpoint. See the Authentication page.
Can I keep my own copy of the doctrine?
Yes for the archive: the signed bundle ships in the package (dist/archive/doctrine-v1.0.json). Copy it wherever you want; the signature stays valid as long as the file is not modified.
Boundaries and extensibility
Is this legal advice?
No. acf-mcp produces a preliminary qualification. The final decision belongs to the DDAO (Delegated Decision Agent Officer) or the competent counsel.
Can I extend with my own tools?
The server is open-source. Fork or pull request, no external plugin mechanism, to preserve determinism and signing. See contributing.
What if I need a custom doctrine?
Out of the server’s scope. The ACF® doctrine is versioned and signed by a maintainer; a derivative signed by another key is no longer ACF®. If your case warrants a doctrine change, open an issue.