MCP Server — ChatCLI as a server (and ACP)

Beyond being an MCP client (consuming external tools — see MCP Integration), ChatCLI can also be a server: other agents/clients — Claude Code, Claude Desktop, IDEs, editors, even another ChatCLI — can drive ChatCLI over the protocol.

These are two external subcommands, both speaking JSON-RPC over stdio (stdin/stdout carry the protocol; all logging goes to the file logger):

chatcli mcp-server (alias mcp-serve) — an MCP (Model Context Protocol) server. Negotiates revision 2025-03-26 or 2024-11-05.
chatcli acp — an ACP (Agent Client Protocol) server, for editors (Zed) and agent-to-agent use.

`chatcli mcp-server`

Exposes ChatCLI’s entire capability surface — not a curated subset:

Harness tools

Tool	What it does
`ask_chatcli`	Chat with the full ChatCLI experience pipeline — the user’s long-term memory and profile, `/context` attachments for the session, pinned and trigger-activated skills, knowledge retrieval and token-aware history compaction: the same enrichment an interactive turn gets. Keeps server-side history per `session`; accepts per-call `provider` / `model` overrides; `plain: true` skips the pipeline for a cheap raw turn.
`agent_task`	The full agent (ReAct) loop on a task — the agent autonomously uses every built-in tool, memory, knowledge and any MCP server ChatCLI is itself connected to. The `session` id scopes which `/context` attachments and knowledge bases the run sees. Accepts `provider` / `model` and `quality` toggles.
`coder_task`	The coder loop (read/edit code, run commands in the workspace). Same routing, quality and session-scoping options.
`manage_session`	Persist and restore the conversations behind `ask_chatcli`’s `session` parameter — save/load/list/delete/clear/active, plus full-text `search` across the saved-session store and `fork` to copy a saved session. Shares the `/session` store with the interactive REPL. Live sessions also autosave by default as rolling `mcp-<session>` mirrors after every turn (`CHATCLI_MCP_SESSION_AUTOSAVE`; unset follows `CHATCLI_SESSION_AUTOSAVE`), and `clear` saves one last time before discarding.
`list_providers`	The routing surface: configured providers, active provider/model, and each provider’s cataloged models.

The quality parameter maps to the CHATCLI_QUALITY_* namespace, so a caller can turn on plan, refine, verify, reflexion, convergence and lessons for a single run:

{ "name": "agent_task", "arguments": {
    "task": "audit the auth flow",
    "provider": "DEVIN", "model": "gpt-5.6-sol",
    "quality": { "CHATCLI_QUALITY_ENABLED": "true" }
} }

Every plugin tool

All registered built-in and external plugins are advertised individually (37 on a default build): files (read, search, tree, coder), web (websearch, webfetch, http, api-explorer), memory (memory, recall), knowledge (knowledge, context, compress, docs-flatten), visuals (diagram, graphview, image), plus moa, lsp, scheduler, session, osv, wikipedia, registry-tags, todo, tools, channels, send, proc, skill, speak…

Each tool carries its usage embedded in the description and a readOnlyHint annotation derived from ChatCLI’s per-plugin capability metadata.
Arguments follow the same contract the agent uses: a JSON envelope ({"cmd":"read","args":{...}}) or a flat string.
Interactive tools that require a live terminal (ask, voice, park) are never exposed — over stdio they would hang forever.

Exposure policy — `CHATCLI_MCP_TOOLS`

Value	Behavior
`all` (default)	Every tool, including write/exec — starting the server is the opt-in.
`safe`	Only tools whose capability metadata reports read-only.
`read,search,recall`	Explicit allowlist (comma-separated, with or without `@`).

Skills as MCP prompts

Every installed skill is served through prompts/list / prompts/get — the client can pull ChatCLI’s whole skill catalog as ready-to-use prompts.

Local state as MCP resources — `chatcli://`

Everything the user built in ChatCLI is browsable read-only through resources/list / resources/read:

URI	Content
`chatcli://memory/index` · `longterm` · `profile` · `projects` · `stats`	The user’s long-term memory, profile and tracked projects
`chatcli://contexts` · `chatcli://contexts/{name}`	The `/context` store catalog and each context’s rendered content
`chatcli://knowledge/{kb}` · `chatcli://knowledge/{kb}/{source}?offset=N`	Knowledge-base TOC and paged document reads
`chatcli://skills` · `chatcli://skills/{name}`	Skill catalog with triggers (so a client can reproduce activation semantics) and each skill’s body
`chatcli://sessions` · `chatcli://sessions/{name}`	Saved-session names and their JSON content

Mutations go through the tools surface (memory, context, manage_session, …). CHATCLI_MCP_RESOURCES=off disables the resources surface entirely.

Cross-channel continuity — the conversation hub

The server joins the conversation hub in resume mode: it adopts the principal’s active conversation instead of rotating it, so a thread started in the interactive REPL or on a gateway channel (Telegram, Slack…) continues seamlessly from any MCP client — and the turns made over MCP show up back in the REPL. CHATCLI_MCP_HUB=off opts out; CHATCLI_MCP_HUB_PRINCIPAL isolates the MCP thread under its own principal.

Unattended safety — `CHATCLI_MCP_DANGER`

stdin carries the protocol, so the server runs unattended (every interactive confirmation auto-approves, like the gateway daemon). Dangerous commands in coder_task exec calls are always hard-blocked regardless of policy; for the remaining shell-command gate, CHATCLI_MCP_DANGER=block declines dangerous commands in-band (the model sees the refusal and replans) instead of auto-approving. Default is allow, matching the gateway.

No provider configured? Still useful

An MCP client brings its own model — ChatCLI’s direct tools don’t need a local LLM. Without any key/OAuth in ChatCLI, the LLM-backed tools (ask_chatcli, agent_task, coder_task) are simply hidden from tools/list, and every direct tool keeps working (persistent memory, knowledge bases, LSP, diagrams, scheduler… driven by the caller’s model). Configure a provider and restart to enable the harness tools.

Connecting from Claude Code

claude mcp add chatcli -- chatcli mcp-server

Or in a JSON config:

{
  "mcpServers": {
    "chatcli": {
      "command": "chatcli",
      "args": ["mcp-server"],
      "env": { "LLM_PROVIDER": "CLAUDEAI", "LLM_MODEL": "claude-sonnet-4-6" }
    }
  }
}

The agent and coder render to stdout; the backend captures that output during the run and returns it as the tool result. Direct tool calls are stdout-captured too, so a chatty plugin can never corrupt the protocol channel. Long-running calls don’t block the read loop — requests dispatch concurrently, which is what makes cancellation work.

`chatcli acp`

A full Agent Client Protocol server: sessions, modes, live streaming and cancellation.

Modes per session — advertised on session/new, switched with session/set_mode:
- chat — direct model conversation, no tools.
- agent (default) — the full autonomous loop with every ChatCLI tool.
- coder — the coding-focused loop.
Live streaming — agent/coder transcripts stream as agent_message_chunk updates while the loop works.
Cancellation — session/cancel interrupts an in-flight prompt (stopReason: "cancelled").

chatcli acp

Point any ACP consumer (Zed, or another agent’s ACP client) at that command.

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MCP Server — ChatCLI as a server (and ACP)

`chatcli mcp-server`

Harness tools

Every plugin tool

Exposure policy — `CHATCLI_MCP_TOOLS`

Skills as MCP prompts

Local state as MCP resources — `chatcli://`

Cross-channel continuity — the conversation hub

Unattended safety — `CHATCLI_MCP_DANGER`

No provider configured? Still useful

Connecting from Claude Code

`chatcli acp`

See also

​chatcli mcp-server

​Harness tools

​Every plugin tool

​Exposure policy — CHATCLI_MCP_TOOLS

​Skills as MCP prompts

​Local state as MCP resources — chatcli://

​Cross-channel continuity — the conversation hub

​Unattended safety — CHATCLI_MCP_DANGER

​No provider configured? Still useful

​Connecting from Claude Code

​chatcli acp

​See also

`chatcli mcp-server`

Harness tools

Every plugin tool

Exposure policy — `CHATCLI_MCP_TOOLS`

Skills as MCP prompts

Local state as MCP resources — `chatcli://`

Cross-channel continuity — the conversation hub

Unattended safety — `CHATCLI_MCP_DANGER`

No provider configured? Still useful

Connecting from Claude Code

`chatcli acp`

See also