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Ghost in the Droid

Claude Code (and Codex) as your LangChain LLM

Ghost’s LangChain integration lets an agent drive a real phone through 50+ LangChain tools. The LLM behind it is swappable — and you can point it at your local Claude Code subscription (Max/Pro) instead of a paid API. No API key, no per-token bill, and it’s the reliable path: a capable Claude model drives the tools where small local models hallucinate.

Why this is allowed: the integration spawns the official claude CLI as a subprocess — Anthropic’s own first-party client — which is permitted. What is not permitted (and actively enforced) is routing your subscription’s OAuth token through a third-party HTTP proxy. Subprocess ✅, token proxy ❌.

Setup

Section titled “Setup”

Requires Python 3.11+ and the Claude Code CLI already authenticated (claude logged in to your Max/Pro account).

Terminal window
python3.11 -m venv ~/.ghost-cc-venv
~/.ghost-cc-venv/bin/pip install \
  "git+https://github.com/thehumanworks/langchain-claude-code" \
  langgraph langchain-core

One patch is currently needed — the wrapper invokes tools via the private tool._run(**args), which newer langchain-core rejects (missing keyword-only argument: config). Use the public API instead, in langchain_claude_code/claude_chat_model.py → _wrap_langchain_tool:

# replace the _arun / _run branch with:
result = await tool.ainvoke(args)

Usage

Section titled “Usage”

The key difference from a normal ChatModel: Claude Code is the agent loop. It executes bound tools internally (exposing them to the CLI as an in-process MCP server), so you call .bind_tools(...).invoke(...) directly — do not wrap it in create_react_agent.

from langchain_claude_code import ChatClaudeCode
from integrations.langchain import ghost_langchain_tools


llm = ChatClaudeCode(
    model="sonnet",
    permission_mode="bypassPermissions",  # auto-approve the phone tool-calls
)
tools = ghost_langchain_tools("<device-serial>")   # 53 phone tools


result = llm.bind_tools(tools).invoke(
    "Open Reddit, go to r/LocalLLaMA, and give me the top 2 posts' "
    "title, upvotes and comments as a JSON array."
)
print(result.content)

Claude Code opens the app, navigates, OCRs the screen, and returns the answer — all on your subscription, no cloud API call.

Gotchas

Section titled “Gotchas”
  • permission_mode="bypassPermissions" is required, or Claude Code stops and asks you to approve each device tool call.
  • Ambient MCP servers shadow your bound tools. If the working directory has a .mcp.json (or you have global MCP servers) that expose similar tools, Claude Code may call those instead of the ones you passed to .bind_tools(...). Run it strict so only your bound tools are visible — set strict_mcp_config=True on the ClaudeAgentOptions the wrapper builds. Otherwise you’ll see the agent “work” but your tools never fire.
  • Forbid the shortcuts. With Bash/WebFetch/WebSearch available, a capable model may shell out to adb or fetch the data off the web instead of driving the device through your tools. Pass disallowed_tools=["Bash","WebFetch","WebSearch"] to force it onto the real integration.
  • Python 3.11+ only (the package won’t install on 3.10).
  • Each LLM turn spawns the claude CLI, so it’s a little slower than a hosted API — fine for demos and batch jobs.
  • Bind your LangChain tools; Claude Code runs its own loop, so skip create_react_agent.

Coming soon: Codex

Section titled “Coming soon: Codex”

The same pattern works for the OpenAI Codex CLI (your ChatGPT subscription). Notes for when the codex-backed wrapper lands:

  • Codex is logged in via ChatGPT — no API key.
  • Pick a ChatGPT-supported model (-m gpt-5.5); the default gpt-5.4 and the *-codex variants error with “not supported when using Codex with a ChatGPT account.”
  • Approvals: --dangerously-bypass-approvals-and-sandbox (or -a never).
  • Exit with /quit; skip the first-run update prompt and accept the trust dialog.