[rudycelekli]

The graph engine's MCP server (graphicle-graph serve, stdio and HTTP) answers initialize with whatever protocolVersion the client sent, even one it does not know.

What happens

→ {"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"1999-01-01"}}
← {"jsonrpc":"2.0","id":1,"result":{"protocolVersion":"1999-01-01", ...}}

The client is told the server speaks a version it has never heard of.

Why it matters

The MCP lifecycle says a server that does not support the requested version must answer with one it does support. The client then decides whether it can continue. Graphify's server negotiates this way through the MCP Python SDK, so on this point the port differs from its reference. The graphicle program's own server already checks the requested version against a list (api.rs, initialize).

Change

initialize answers with the requested version when it is one of 2024-11-05, 2025-03-26, 2025-06-18 or 2025-11-25 (the same list as the program's server). Otherwise it answers 2025-06-18, the version the engine already answered when the client gave none. A client asking for any of those four versions sees no change.

Test

hardening_tests::mcp_initialize_answers_a_protocol_version_it_speaks: each known version is answered as requested. An unknown version, a non-string and a missing one are answered with 2025-06-18.

Verification

In crates/graphicle-graph, with Rust 1.95.0:

• cargo fmt --package graphicle --package graphicle-graph --check: clean
• cargo clippy --locked --all-targets --features postgres,bedrock -- -D warnings: clean on Rust 1.95.0 (macOS). The transcription feature was left out locally because whisper-rs-sys needs cmake here; CI builds it.
• cargo test --locked --all-targets --features postgres,bedrock: 963 passed, 0 failed.

I left CHANGELOG.md to you.

🤖 Generated with Claude Code

[VikramLex]

Thank you, @rudycelekli. Merged for 0.1.2. Answering a version the server knows, instead of echoing the client's, matches the MCP lifecycle, and the test covers the known, unknown and malformed cases. The CHANGELOG credits you.