MCP API

Module: im.ttalk/clj-agent-mcp

Source: modules/clj-agent-mcp/src

Client

Namespace: im.ttalk.agent.mcp.client

(require '[im.ttalk.agent.mcp.client :as client]
         '[im.ttalk.agent.mcp.transport :as transport])

(def c (client/client {:transport (transport/http-transport {:url "https://example.com/mcp"})}))
(client/connect! c)
(client/list-tools c)
(client/call-tool c "search" {"query" "clojure"})

Function	Contract
client	Create a client; no network call yet
connect!	Negotiate protocol capabilities; idempotent
list-tools	Return the server's raw tool descriptors
call-tool	Call a tool and return its MCP result
read-resource	Read an MCP resource
get-prompt	Read an MCP prompt template
instructions	Server usage guidance suitable for a system prompt
request!	Send a named protocol request

Transports are in im.ttalk.agent.mcp.transport: Streamable HTTP and stdio. A plain (fn [message] response) is also a valid transport for tests.

Server

Namespace: im.ttalk.agent.mcp.server

(def s (mcp/server {:name "my-server"
                    :version "1.0"
                    :tools [weather-tool]
                    :instructions "Use tools only when needed."}))

handle-message is a pure one-message-in/one-response-out function and is the preferred entry point for HTTP hosts. stdio-server! runs the stdio transport and blocks until stdin closes. The server reports only capabilities it can actually serve.

Protocol constants and envelopes are isolated in im.ttalk.agent.mcp.protocol. It supports the modern per-request protocol era and the legacy initialize handshake era.

Tool bridging

Namespace: im.ttalk.agent.mcp.tools

Function	Purpose
connect-servers	Connect to servers and list converted tools
->inline-tool	Convert one MCP tool descriptor to an inline tool map
with-tools	Merge converted MCP tools into an agent configuration
result-text	Render an MCP result for the LLM history
app-tools	Identify tools advertising MCP Apps UI resources

MCP tools become ordinary inline tools from the agent loop's perspective, while retaining annotations needed for approval and UI integration.