LangBot Core Development

What it does

When your agent uses it

• Adding an HTTP API endpoint to the LangBot backend
• Choosing between user token, API key and public access for a route
• Setting up the Python and pnpm dev environment for LangBot
• Writing an Alembic migration for a LangBot schema change

Example prompts

• “Add a GET endpoint that lists a bot's recent messages, protected by an API key.”
• “Why does my LangBot route return 401 when I call it with the global key?”
• “Set up the LangBot backend and web UI dev servers on my machine.”
• “I changed an API response in LangBot. What else do I need to update?”

Requirements

• Python with `uv`
• pnpm for the web frontend

Workflow steps

2 steps, taken from the first numbered list in SKILL.md.

1. 1the global key from config.yaml api.global_api_key only for a
2. 2web-UI keys whose one-time lbk_ secret is stored only as a hash and is

What it can do on your machine

Read from SKILL.md and the folder at commit de886ed. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • uv
  • pnpm
  • pip

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • github.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names these keys or tokens, usually read from environment variables:

  • USER_TOKEN
  • API_KEY
  • USER_TOKEN_OR_API_KEY

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

LangBot Core Development loads about 1.4k tokens when it runs. Until then it costs about 142 tokens; SKILL.md has 403 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~142

When it runs · the whole SKILL.md, loaded when a task matches

~1.4k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NoteMentions a .env fileSKILL.md:28

  cp .env.example .env

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from langbot-app/LangBot at commit de886ed, republished under its Apache-2.0 licence (© langbot-app). 403 words, ~1,396 tokens.

name

langbot-dev

description

Develop, build, and debug the LangBot core backend and web frontend. Use when working inside the LangBot repository — backend (Python/Quart, src/langbot/pkg), the Vite/React web UI, HTTP API controllers/services, Alembic migrations, or the MCP server. Covers the dev environment (uv, pnpm), repo layout, the API auth model (user token / API key / global key), adding API endpoints, and the rule that API changes must update the MCP server and skills. Triggers on "langbot backend", "langbot dev", "langbot api", "add langbot endpoint", "langbot migration".

# Backend
pip install uv
uv sync --dev
uv run main.py            # API + UI on http://127.0.0.1:5300

# Frontend (separate terminal)
cd web
cp .env.example .env
pnpm install
pnpm dev                  # http://127.0.0.1:3000 (reads VITE_API_BASE_URL)

# Lint/format hooks (CI runs the same checks)
uv run pre-commit install

src/langbot/
├── __main__.py             # entrypoint, CLI flags (--standalone-runtime/-box/--debug)
├── pkg/
│   ├── api/
│   │   ├── http/           # Quart controllers + services
│   │   │   ├── controller/groups/   # route groups (@group.group_class)
│   │   │   └── service/             # business logic (called by controllers AND MCP)
│   │   └── mcp/            # MCP server (server.py = tools, mount.py = ASGI dispatch)
│   ├── core/               # app bootstrap, stages, task manager
│   ├── platform/ provider/ pipeline/ plugin/ box/ skill/ rag/ vector/
│   ├── command/ persistence/ storage/ config/ entity/ telemetry/
│   └── templates/config.yaml        # config template (top-level: api, system, plugin, box, space...)
├── web/                    # Vite SPA
└── docker/                 # compose deployment

# From project root (needs data/config.yaml)
uv run python -m langbot.pkg.persistence.alembic_runner autogenerate "description"

uv run pytest tests/unit_tests -q          # unit tests
uv run pytest tests/unit_tests/api -q      # API service tests
uv run python tests/manual/mcp_smoke.py    # MCP server e2e smoke

© langbot-app, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in skills/skills/langbot-dev of langbot-app/LangBot.

Open the folder on GitHubat commit de886ed