Connect downstream MCP tools.

Two different connections

Your host connects to LeanCTX as an MCP server. LeanCTX can also connect to configured downstream MCP servers. Those are separate connections with separate credentials and permissions.

A downstream MCP server may expose read or write operations. LeanCTX’s presence does not make all of them read-only.

Discover before calling

{"name":"ctx_tools","arguments":{"action":"list"}}

{"name":"ctx_tools","arguments":{"action":"find","query":"Find an issue by its number"}}

The discovery response identifies a downstream server::tool handle and the relevant schema. Call that actual handle with arguments valid for that tool.

Configure the transport

The gateway.servers configuration supports the declared command/argument or URL transport fields. Secret-bearing environment and header fields need careful handling.

Use the configuration reference for captured field names. An enabled entry does not prove that the server connected successfully.

Keep authorization explicit

Review the downstream tool’s side effects, especially creation, deletion, sending and publishing. Discovery is not permission to execute an action.

Use ctx_call for built-in LeanCTX operations; ctx_tools is the downstream MCP gateway. Tool discovery is separate from governed model and tool execution: discovered tools still require the applicable identity, policy, approval and budget checks.

Sources & versions3 references · Reviewed 17 Sept 2026

• ctx_tools.rsrust/src/tools/ctx_tools.rsGitHub
• mod.rsrust/src/core/config/schema/mod.rsReviewed checkout
• 05-advanced.mddocs/reference/05-advanced.mdGitHub

Core checkout

0ce2207ee4

Installed runtime

3.10.2

SDK release

1.1.0

Separate baselines for source, CLI/configuration and SDK contracts. Review does not certify every platform or integration.

Versions & compatibility