---
name: Atomic Chat Tool
slug: atomic-chat-tool
category: AI Engineering
description: Atomic Chat Tool adds a stdio-based MCP server that exposes models running in the local Atomic Chat desktop app as tools for the container agent. Use it to let Claude offload work to local models served by Atomic Chat on its OpenAI-compatible API.
github: "https://github.com/nanocoai/nanoclaw/tree/main/.claude/skills/add-atomic-chat-tool"
language: TypeScript
stars: 30510
forks: 12854
install: "npx degit https://github.com/nanocoai/nanoclaw/tree/main/.claude/skills/add-atomic-chat-tool ~/.claude/skills/add-atomic-chat-tool"
installs_to: ~/.claude/skills/add-atomic-chat-tool
source_path: .claude/skills/add-atomic-chat-tool/SKILL.md
collection_size: 25
category_size: 2451
collection_url: "https://dirskills.com/collections/nanocoai/nanoclaw"
added: 2026-08-14T07:11:26.246Z
last_synced: 2026-08-14T07:11:26.246Z
canonical_url: "https://dirskills.com/skills/atomic-chat-tool"
---

# Atomic Chat Tool

Atomic Chat Tool adds a stdio-based MCP server that exposes models running in the local Atomic Chat desktop app as tools for the container agent. Use it to let Claude offload work to local models served by Atomic Chat on its OpenAI-compatible API.

**Install:**

```bash
npx degit https://github.com/nanocoai/nanoclaw/tree/main/.claude/skills/add-atomic-chat-tool ~/.claude/skills/add-atomic-chat-tool
```

## README

# Add Atomic Chat Integration

This skill adds a stdio-based MCP server that exposes models running in the local [Atomic Chat](https://github.com/AtomicBot-ai/Atomic-Chat) desktop app as tools for the container agent. Claude remains the orchestrator but can offload work to local models served by Atomic Chat on `http://127.0.0.1:1337/v1` (OpenAI-compatible).

Tools exposed:
- `atomic_chat_list_models` — list models currently available in Atomic Chat (`GET /v1/models`)
- `atomic_chat_generate` — send a prompt to a specified model and return the response (`POST /v1/chat/completions`)

Model management (download, delete) is done through the **Atomic Chat desktop UI** — the app is a fork of Jan and manages its own model library.

The skill ships the MCP server source (and its test) in this folder and copies them into the agent-runner tree at install time, then registers the server in `index.ts` and forwards host env vars in `container-runner.ts`. Registering the server is enough to expose its tools — the agent's allow-pattern (`mcp__atomic_chat__*`) is derived from the registered server name.

## Phase 1: Pre-flight

### Check if already applied

Check if `container/agent-runner/src/atomic-chat-mcp-stdio.ts` exists. If it does, skip to Phase 3 (Configure).

### Check prerequisites

Verify Atomic Chat is installed and its local API server is running. On the host:

```bash
curl -s http://127.0.0.1:1337/v1/models | head
```

If the request fails:

1. Install Atomic Chat from the [latest release](https://github.com/AtomicBot-ai/Atomic-Chat/releases) (macOS only for now — `atomic-chat.dmg`).
2. Open the app.
3. Open **Settings → Local API Server** and make sure it's enabled on port `1337`.
4. Go to the **Hub** (or **Models**) tab and download at least one model (e.g. Llama 3.2 3B, Qwen 2.5 Coder 7B).
5. Load the model once by sending any message in Atomic Chat's UI to warm it up.

## Phase 2: Apply Code Changes

### Copy the skill's source and tests into both trees

This skill reaches into both the container (Bun) tree and the host (Node) tree, so its
files go into both, alongside the integration points they cover.

```bash
S=.claude/skills/add-atomic-chat-tool
# Container (Bun) tree — the MCP server and the registration wiring test
cp $S/atomic-chat-mcp-stdio.ts        container/agent-runner/src/atomic-chat-mcp-stdio.ts
cp $S/atomic-chat-registration.test.ts container/agent-runner/src/atomic-chat-registration.test.ts
# Host (Node) tree — the env-forwarding helper and the wiring test
cp $S/atomic-chat-env.ts              src/atomic-chat-env.ts
cp $S/atomic-chat-wiring.test.ts      src/atomic-chat-wiring.test.ts
```

### Register the MCP server in the agent-runner

Edit `container/agent-runner/src/index.ts`. Find the `mcpServers` object that currently looks like this:

```ts
  const mcpServers: Record<string, { command: string; args: string[]; env: Record<string, string> }> = {
    nanoclaw: {
      command: 'bun',
      args: ['run', mcpServerPath],
      env: {},
    },
  };
```

Add an `atomic_chat` entry alongside `nanoclaw`:

```ts
  const mcpServers: Record<string, { command: string; args: string[]; env: Record<string, string> }> = {
    nanoclaw: {
      command: 'bun',
      args: ['run', mcpServerPath],
      env: {},
    },
    atomic_chat: {
      command: 'bun',
      args: ['run', path.join(__dirname, 'atomic-chat-mcp-stdio.ts')],
      env: {
        ...(process.env.ATOMIC_CHAT_HOST ? { ATOMIC_CHAT_HOST: process.env.ATOMIC_CHAT_HOST } : {}),
        ...(process.env.ATOMIC_CHAT_API_KEY ? { ATOMIC_CHAT_API_KEY: process.env.ATOMIC_CHAT_API_KEY } : {}),
      },
    },
  };
```

`atomic-chat-registration.test.ts` asserts this entry is present and points at the server module — the tool only appears to the agent if it is registered here.

### Forward host env vars into the container

The env-forwarding logic lives in the copied `src/atomic-chat-env.ts` (`atomicChatEnvArgs()`), so the reach-in into `buildContainerArgs` is a single call.

Import it in `src/container-runner.ts` (alongside the other local imports):

```ts
import { atomicChatEnvArgs } from './atomic-chat-env.js';
```

Then, in `buildContainerArgs`, find the `TZ` env line and add the call right after it:

```ts
  args.push('-e', `TZ=${TIMEZONE}`);
  args.push(...atomicChatEnvArgs());
```

`atomic-chat-wiring.test.ts` asserts this `args.push(...atomicChatEnvArgs())` call exists inside `buildContainerArgs`.

### Surface `[ATOMIC]` log lines at info level

> **Shared block.** This rewrites the `container.stderr` logger, which other local-model tools (e.g. `add-ollama-tool` for `[OLLAMA]`) also edit to surface their own prefix. Touch only the `[ATOMIC]` branch and leave the rest of the block intact, so the edits coexist and removal restores it cleanly.

In the same file, find the stderr logger:

```ts
  container.stderr?.on('data', (data) => {
    for (const line of data.toString().trim().split('\n')) {
      if (line) log.debug(line, { container: agentGroup.folder });
    }
  });
```

Replace it with:

```ts
  container.stderr?.on('data', (data) => {
    for (const line of data.toString().trim().split('\n')) {
      if (!line) continue;
      if (line.includes('[ATOMIC]')) {
        log.info(line, { container: agentGroup.folder });
      } else {
        log.debug(line, { container: agentGroup.folder });
      }
    }
  });
```

### Add env-var stubs to `.env.example`

Append to `.env.example`:

```bash
# Atomic Chat MCP tool (.claude/skills/add-atomic-chat-tool)
# Override the host where Atomic Chat exposes its OpenAI-compatible API.
# Default: http://host.docker.internal:1337 (with fallback to localhost)
# ATOMIC_CHAT_HOST=http://host.docker.internal:1337

# Optional API key. Leave unset for a local Atomic Chat install — it does not require auth.
# ATOMIC_CHAT_API_KEY=
```

### Validate code changes

```bash
pnpm run build
pnpm exec tsc -p container/agent-runner/tsconfig.json --noEmit
# Host tree: buildContainerArgs wiring
pnpm exec vitest run src/atomic-chat-wiring.test.ts
# Container tree: index.ts registration
(cd container/agent-runner && bun test src/atomic-chat-registration.test.ts)
./container/build.sh
```

All must be clean before proceeding. The wiring and registration tests confirm the two
integration points — the `buildContainerArgs` call and the `index.ts` registration — are
actually in place; a failure means one drifted. (The MCP server's own request/response
behavior against Atomic Chat is the author's build-time concern, not part of these tests —
verify it manually in Phase 4.)

## Phase 3: Configure

### Set Atomic Chat host (optional)

By default, the MCP server connects to `http://host.docker.internal:1337` (Docker Desktop) with a fallback to `localhost`. To use a custom host, add to `.env`:

```bash
ATOMIC_CHAT_HOST=http://your-atomic-chat-host:1337
```

### Set API key (optional)

Atomic Chat does **not require authentication** when running locally — leave this unset. Only set it if you've put Atomic Chat behind a reverse proxy that enforces auth:

```bash
ATOMIC_CHAT_API_KEY=sk-...
```

### Restart the service

Run from your NanoClaw project root:

```bash
source setup/lib/install-slug.sh
launchctl kickstart -k gui/$(id -u)/$(launchd_label)  # macOS
# Linux: systemctl --user restart $(systemd_unit)
```

## Phase 4: Verify

### Test inference

Tell the user:

> Send a message like: "use atomic chat to tell me the capital of France"
>
> The agent should use `atomic_chat_list_models` to find available models, then `atomic_chat_generate` to get a response.

### Check logs if needed

```bash
tail -f logs/nanoclaw.log | grep -i atomic
```

Look for:
- `[ATOMIC] Listing models...` — list request started
- `[ATOMIC] Found N models` — models discovered
- `[ATOMIC] >>> Generating with <model>` — generation started
- `[ATOMIC] <<< Done: <model> | Xs | N tokens | M chars` — generation completed

## Troubleshooting

### Agent says "Atomic Chat is not installed" or tries to run a CLI

The agent is looking for a CLI that doesn't exist instead of using the MCP tools. This means:
1. The MCP server wasn't copied — check `container/agent-runner/src/atomic-chat-mcp-stdio.ts` exists
2. The MCP server wasn't registered — check `container/agent-runner/src/index.ts` has the `atomic_chat` entry in `mcpServers` (the allow-pattern is derived from this, so registration is the only thing to check)
3. The container wasn't rebuilt — run `./container/build.sh`

### "Failed to connect to Atomic Chat"

1. Verify the host API is reachable: `curl http://127.0.0.1:1337/v1/models`
2. Confirm the Local API Server is enabled in Atomic Chat's settings
3. Check Docker can reach the host: `docker run --rm curlimages/curl curl -s http://host.docker.internal:1337/v1/models`
4. If using a custom host, check `ATOMIC_CHAT_HOST` in `.env`

### `model not found` / 404 on generate

The model ID passed to `atomic_chat_generate` must exactly match one of the IDs returned by `atomic_chat_list_models`. Ask the agent to list models first, then pick one from that list.

### Slow first response

Atomic Chat lazy-loads models into memory on first use. The initial call may take longer while the model warms up. Subsequent calls against the same model are fast.

### Agent doesn't use Atomic Chat tools

The agent may not know about the tools. Try being explicit: "use the atomic_chat_generate tool with llama3.2-3b-instruct to answer: ..."

### Context window or output size issues

Atomic Chat respects each model's native context length. If you hit limits, pass `max_tokens` explicitly when calling `atomic_chat_generate`, or switch to a model with a larger context window in the Atomic Chat UI.