# MCP call tool

> Tag 7: the client sends the params of the MCP method; the server opens the proxy’s /tool/call-tool and relays exactly one channel response, the result or the MCP error, and the channel response finish.

Canonical: https://provider.diverge.network/2.3.0/endpoints/containers-tools-connect/client/mcp-call-tool/
Specification revision: 2.3.0

The client opens this channel for one tool of the MCP server of the container, called. The server opens
[`/tool/call-tool`](/2.3.0/proxy/tool/call-tool/) on the proxy with the params
and relays its one answer.

- **The request.** The tag byte `7` followed by the params as
  JSON. [Request](/2.3.0/endpoints/containers-tools-connect/client/mcp-call-tool/request/) states its form.
- **The response.** Exactly one channel response, the result or an
  MCP error, and the channel response finish.
  [Response](/2.3.0/endpoints/containers-tools-connect/client/mcp-call-tool/response/) states the sequence.
- **Every exchange is answered.** An MCP error the container's server
  returned, and the error the proxy sends for params that do not
  parse or a server it cannot reach, are relayed as the one channel
  response.