MCP call tool

Tag 15: the server relays an MCP exchange the container asked of the client’s servers, its params verbatim; the client answers with exactly one channel response, a result or an error, which the server relays to the container.

The server opens this channel when the container’s proxy sends the corresponding MCP ask on /requests. The params are relayed verbatim; the client’s one answer is relayed back.

• The request. The tag byte 15 followed by the params as JSON. Request states its form.
• The response. Exactly one channel response, a result or an MCP error, and the channel response finish. Response states the sequence.
• The conduit. The server relays the one channel response to the proxy’s /mcp/call-tool/{channel} as one message and closes that connection. The server does not read the params or the answer, and does not send the ask twice.