ccr-mcp

MCP server that lets Claude Code (Anthropic CLI) delegate work to subagents routed through claude-code-router (ccr) — typically backed by DeepSeek or another non-Anthropic model.

The point: keep the orchestration in your paid Claude Code (Opus) session, but push the heavy I/O (file reads, code generation, tool loops) into a child Claude Code that talks to a cheaper model. The child's tool I/O never enters your parent context — only a short summary returns. That's what makes the routing economically meaningful.

Architecture

your Claude Code (Opus, paid sub)
        │
        │  tool: spawn_agent / chat
        ▼
ccr-mcp (this repo, Python stdio)
        │
        │  spawn:  ccr code -p "<task>" --output-format json --dangerously-skip-permissions
        │  http:   POST 127.0.0.1:3456/v1/messages
        ▼
ccr router (musistudio/claude-code-router)
        │
        ▼
DeepSeek V4 / Gemini / Ollama / etc.

Tools exposed to Claude Code

Tool	Purpose
spawn_agent(task, cwd?, timeout?)	Launch a Claude Code subagent in the background. Returns agent_id.
agent_status(agent_id)	Non-blocking status check.
agent_result(agent_id, wait=True, max_wait?)	Block until done (or up to max_wait), return final summary + token/cost meta.
agent_logs(agent_id, tail=60)	Last N stdout/stderr lines for debugging.
agent_kill(agent_id)	SIGTERM the subagent.
list_agents()	All known agents with status + elapsed time.
quick_chat(prompt, model?, system?, max_tokens?)	Single short HTTP call (no subagent, no tools, no memory). For quick factual queries.
list_providers()	Show providers, models, and routing from ccr config.
health()	Check ccr router reachability.

Requirements

• Python 3.10+
• uv (or pip)
• Node 18+ and npm install -g @musistudio/claude-code-router
• Claude Code CLI (@anthropic-ai/claude-code)
• A DeepSeek API key (or any provider supported by ccr)

Install

git clone https://github.com/marianomelo/ccr-mcp.git
cd ccr-mcp
uv sync

Register with Claude Code (user scope, available in any project):

claude mcp add ccr -s user -- uv --directory "$PWD" run ccr-mcp

Verify:

claude mcp list   # should show: ccr ... ✓ Connected

Configure ccr (one-time)

Create ~/.claude-code-router/config.json. A working starter for DeepSeek V4 is in scripts/config.example.json — drop in your API key.

Note: DeepSeek V4 thinking-mode breaks in multi-turn agentic loops with the stock ccr setup. Use the companion fix: marianomelo/ccr-deepseek-thinking-fix. The example config already references it.

Run ccr as a systemd user service so it survives terminal close:

cp scripts/ccr.service ~/.config/systemd/user/ccr.service
# edit Environment=PATH and ExecStart paths to match your `which ccr` and `which node`
systemctl --user daemon-reload
systemctl --user enable --now ccr.service
loginctl enable-linger "$USER"   # so the service runs without a login session

Optional: usage segment in Claude HUD

If you use Claude HUD, the scripts/claude-hud-with-ccr.sh wrapper appends a one-line ccr usage segment under HUD's statusline:

[Opus 4.7] admin · Context ░░░░░░ 0%
ccr 12.4K↑ 3.1K↓ · 7 req · ds-v4-pro

Setup:

cp scripts/claude-hud-with-ccr.sh ~/.claude/plugins/claude-hud-with-ccr.sh
chmod +x ~/.claude/plugins/claude-hud-with-ccr.sh
# edit ~/.claude/settings.json statusLine.command to point at the wrapper

The segment is produced by scripts/ccr_segment.py, which parses ccr's JSON-Lines log and sums today's tokens.

Token economics — read this

spawn_agent is what gives you actual savings: tool I/O lives in the subagent. quick_chat returns the full text into your parent context, so it only saves on tasks where DeepSeek's response is short.

Rule of thumb:

• Big input → small output (read 10 files, summarize) → use a subagent.
• Big input → big output (generate a long file) → use a subagent that writes the file directly. Do not Read it back into Opus unless you need to.
• Short factual question → quick_chat is fine.

Caveats

• --dangerously-skip-permissions is passed to the subagent (it's headless, no human to approve tool prompts). Only spawn it in directories you control.
• Sessions live only in MCP process memory; they don't survive claude mcp restarts.
• spawn_agent startup is ~3-5s (full Claude Code bootstrap inside the subprocess).
• DeepSeek V4 thinking-mode works only with the companion transformer fix.
• Tool-use reliability with non-Anthropic models is lower than with Claude. Some agent tasks will fail and need retry.

Cost reference (observed in stress tests)

Task	Model	Time	Cost
Read CSV + stats + write report	deepseek-v4-pro	31s	$0.12
Debug Python bug + fix + verify	deepseek-v4-pro	36s	$0.20
Generate module + tests + run + verify	deepseek-v4-pro	33s	$0.06

Related

• musistudio/claude-code-router — the router
• marianomelo/ccr-deepseek-thinking-fix — fix for DeepSeek V4 thinking-mode multi-turn bug
• jarrodwatts/claude-hud — statusline plugin

License

MIT