Compatibility matrix

Recorded on 14 September 2026 on Windows 11. Every cell is a result that was observed, with the date; nothing is marked from documentation alone, and failures are recorded as found. The full record is compatibility.md.

What each column checks

Column	What it records
Discovery	The client reads its configuration and starts the server
Tool listing	All five tools appear in the client
Content form	A STATIC or DYNAMIC-PARAMETRIC fix instruction comes back correct
Constraint form	A DYNAMIC-DELEGATED fix instruction comes back correct
Per-call approval	Whether each tool call needs your confirmation by default
Response size	Whether the largest response, 11,988 bytes, reaches the agent whole

The matrix

Client	Discovery	Tool listing	Content form	Constraint form	Per-call approval	Response size
VS Code 1.137.0, Copilot agent	Pass. The agent’s first connection is refused once with -32022 and connects on retry	Pass, 5 of 5	Pass, SEC-002	Pass, STR-003	Asks before a tool’s first call; allowing it for the session covers later calls	Whole, but not inline: over the agent’s limit, saved to a file the agent read back
Cursor 3.20.17, Agent	Pass, after switching the server on	Pass, 5 of 5	Pass, SEC-002 and BLD-001	Pass, STR-003	No prompt on any of 3 calls, on the fresh-install default	Pass, 28 of 28 items
Windsurf, now Devin 3.10.23, agent	Fails from the shared configs, which use ${workspaceFolder}; passes from Devin’s own .devin/mcp_config.local.json	Pass, 5 of 5	Pass, SEC-002 and BLD-001	Pass, STR-003	Asks on every call	Pass, all 28 items

What differs between clients

Once each client could start the server, every tool was listed and both contract forms came back intact. What differs is everything around the protocol:

• Launch configuration. VS Code and Cursor resolve ${workspaceFolder}. Devin does not, and it imports the other clients’ files anyway, so a configuration that works in two IDEs breaks the third. prodpilot connect devin --project PATH writes Devin its own file. See Windsurf (now Devin).
• Approval. VS Code asks before a tool’s first call. Devin asks before every call. Cursor, on its fresh-install default, asks before none, so nothing in the client stops the agent calling prodpilot_deploy by itself; the tool’s own description tells the agent to confirm with you first. See Cursor.
• Response size. The largest result arrived whole and inline in Cursor and Devin. In VS Code it went over the Copilot agent’s inline limit and reached the model through a saved file, at the cost of an extra step and an extra approval. Every other ProdPilot response is 3 KB or less.
• Protocol version. Copilot’s agent in VS Code opens on the 2026-07-28 protocol and then sends the older handshake on the same connection, which the MCP SDK refuses by design. The client’s own retry connects. See Troubleshooting.

What these results do not cover

• These runs checked that each agent receives the contracts intact. The agents were told not to apply the delegated contract, so how often a live agent’s change passes verification is not measured.
• The matrix was recorded from a development checkout. prodpilot connect, added afterwards, has not yet been observed inside Cursor and Devin.
• A deploy started by an IDE agent has not yet been observed on a real service.
• Other MCP clients were not tested and are not claimed.