Bits to atoms.
Atoms to bits.

If you still have a script called parse_bag_final_v7.py, we need to talk.

Bagel by Extelligence lets you ask questions about robotics, drone, and IoT data in plain English. Every calculation over your message data is DuckDB SQL, not model guesswork, and Bagel shows you the query so you can audit it.

Is my IMU sensor overheating?

Bagel also has an intelligent edge data reduction pipeline: describe an event and Bagel runs the detection on the robot, keeping the windows that matter and dropping the rest. An MCP server puts all of it in your LLM's hands: Claude Code, Gemini, Cursor, or a fully local model.

Bagel was the first MCP server to ship a real analysis toolkit for robotics data, and it keeps the LLM where it belongs: in front of your logs, never in your robot's control loop.

📦 Install

Bagel is on PyPI as bagel-mcp. No Docker and no ROS install needed for recorded data.

Claude Code, one line (needs uv):

claude mcp add bagel -- uvx --from "bagel-mcp[ros]" bagel-mcp --transport stdio

pip, into any Python 3.10 to 3.12 environment:

pip install "bagel-mcp[ros]"

Then point your MCP client at the bagel-mcp command it installed (setup for Claude Desktop, Cursor and Codex is in the Quickstart). Open your agent and ask:

Summarize the bag "~/logs/run_42.mcap".

The ros extra reads ROS 1 and ROS 2 bags. Flight logs, CAN / MDF4, live MQTT and the rest are extras too. Live ROS robots (rosbridge) and fleet/edge pipelines run in Docker.

🥯 Key Features

• Ask in plain language: No deep domain expertise needed.
• Transparent calculations: Deterministic SQL queries. No black-box LLM math.
• Natural-language pipelines: "Keep 10s around every hard brake, drop the rest": one sentence becomes an auditable pipeline: previewed before a byte is written, then run once, across a fleet, or standing at the edge.
• Broad LLM support: Claude Code, Gemini, Cursor, Codex, and more.
• Installs your way: pip / uvx for recorded data, Docker images for live robots and the edge.
• Extensible capabilities: Bagel can learn new tricks.
• Wide format coverage: Missing your data format? Open a ticket.

🥯 Try it in 60 seconds

No MCP client, no LLM, no config: run the same deterministic checks against a bundled sample log and get a robot-health report card straight to your terminal.

docker run -it --rm ghcr.io/extelligence-ai/bagel/px4:latest demo

sample.ulg - 41.5s, 2018 messages, 77 topics

Power      ⚠️  min 21.07V, largest drop 2.37V at ~t=+4.8s, end 23.45V (battery_status_0)
IMU        ✅  accel_z stddev 1.6x the log baseline at ~t=+36.8s (sensor_combined_0)
GPS        —  skipped: no GPS topic
Data gaps  ✅  no gap > 1.05x median interval (checked battery_status_0, sensor_combined_0)
...

The ROS2 images (ros2-kilted, ros2-jazzy, ros2-iron, ros2-humble) run demo the same way, against a lighter bundled sample (px4 is the one that ships with a flight log rich enough to show every check). Point it at your own log with demo /path/to/log (mount it with -v first), or keep reading for the full MCP setup below.

⚡️ Quickstart

Two ways to run Bagel. Pick by data:

🐍 Install with uvx or pip (no Docker)

Your MCP client launches the server itself over stdio, so there is nothing to start or keep running. Pick uvx (nothing to manage: it fetches and caches Bagel on first use) or pip (a normal install you control).

With uvx. Install uv (curl -LsSf https://astral.sh/uv/install.sh | sh on macOS and Linux), then:

Claude Code:

claude mcp add bagel -- uvx --from "bagel-mcp[ros]" bagel-mcp --transport stdio

Any client that takes a JSON MCP config (Claude Desktop, Cursor, Codex, ...):

{
  "mcpServers": {
    "bagel": {
      "command": "uvx",
      "args": ["--from", "bagel-mcp[ros]", "bagel-mcp", "--transport", "stdio"]
    }
  }
}

With pip. Python 3.10 to 3.12; a virtual environment keeps it tidy:

python3 -m venv ~/.bagel-venv
~/.bagel-venv/bin/pip install "bagel-mcp[ros]"
claude mcp add bagel -- ~/.bagel-venv/bin/bagel-mcp --transport stdio

For a JSON config, use the full path as the command: "command": "/Users/you/.bagel-venv/bin/bagel-mcp", "args": ["--transport", "stdio"].

Format support comes as extras, so that a PX4 user never downloads the automotive parsers. List the ones you need, comma-separated: uvx --from "bagel-mcp[ros,px4,automotive]" bagel-mcp --transport stdio, or pip install "bagel-mcp[ros,px4,automotive]". If you ask about a format whose extra is missing, Bagel's error names the exact command to add it.

MCAP, CSV / JSON / Parquet, ROS text logs, PlotJuggler / Lichtblick / LeRobot exports and S3 upload need no extra.

To upgrade, repeat the extras you installed with, so their dependencies update too. uvx picks up new releases on its own (force it with uvx --refresh --from "bagel-mcp[ros,px4]" bagel-mcp --help); with pip, run pip install -U "bagel-mcp[ros,px4]", using your own list of extras.

Then prompt, pointing at your own file:

Summarize the metadata of the MCAP bag "~/logs/run_42.mcap".

[!NOTE] No ROS installation is needed for bag files: the ros extra reads and writes them with the pure-Python rosbags library (sqlite3 and MCAP storage, zstd / bz2 / lz4 compression, message types from the bag itself or from the bundled interface definitions of every distro from Humble on). Live ROS topics (rosbridge) and the fleet/edge runtime stay with Docker.

🐳 Run with Docker (live robots, fleet and edge, distro-specific ROS)

[!TIP] Already have Claude Code? Just paste the link to this repo and tell Claude what environment you want:

Set up https://github.com/Extelligence-ai/bagel for ROS2 Kilted.

Claude will clone the repo, start Docker, and wire up the MCP connection for you.

📋 Prerequisites

Install Docker Desktop and Claude Code (or another MCP-enabled LLM).

[!NOTE] arm64 hosts (Apple Silicon, Raspberry Pi, Jetson, Graviton): ros2-kilted — the default service, and the one server.json pins — ships as a multi-arch image, so Docker pulls a native arm64 build. No extra setup.

The other services are published for amd64 only. Docker Desktop emulates them automatically, so they run on Apple Silicon (slower, but they work). On arm64 Linux with plain Docker Engine there is no emulation by default and they fail immediately with exec format error — install QEMU/binfmt first:

Terminal

Copy

docker run --privileged --rm tonistiigi/binfmt --install amd64

1. Clone and start Bagel

git clone https://github.com/Extelligence-ai/bagel.git && cd bagel
docker compose run --service-ports ros2-kilted

[!TIP] Port 8000 already in use? Set MCP_SERVER_PORT to something else, for example MCP_SERVER_PORT=8100 docker compose run --service-ports ros2-kilted, and use that port in step 2.

Pick the service that matches your environment:

The -jev image (beta) adds PyTorch for running a decision model on the robot (backend: local in the anomaly gate). Build any other service the same way with --build-arg JEV_MODE=true. CPU-only robots don't need it: the hosted Jev backend works in every image.

[!TIP] To give Bagel access to your local files, edit compose.yaml before starting Docker: uncomment and update the volumes section under your chosen service.

Wait for this output:

INFO:     Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)

2. Connect Claude Code

In a new terminal:

claude mcp add --transport sse bagel http://localhost:8000/sse

[!NOTE] The MCP endpoint is bound to localhost only (not exposed to the LAN) for security. To share it with other machines, drop the 127.0.0.1 prefix in compose.yaml and put an authenticated proxy in front: see SECURITY.md.

3. Prompt

claude

Summarize the metadata of the ROS2 bag "./data/sample/ros2/mcap".

That’s it: you’re chatting with your data.

🔒 Prefer fully offline?

Swap step 2 for a local model: your data and your LLM stay on the machine:

brew install ollama && ollama serve &                                  # or ollama.com
ollama pull qwen3:8b
uvx ollmcp --mcp-server-url http://localhost:8000/sse --model qwen3:8b

Model picks, expectations, and troubleshooting: Local LLMs guide.

🔌 Agent plugins (Claude Code and Codex)

Bagel ships an agent plugin: four skills that teach the agent when and how to drive the server (log triage, pipeline authoring, live sinks, visualization export) plus the MCP connection, wired automatically. The same plugin/ directory serves both Claude Code and OpenAI Codex.

/plugin marketplace add Extelligence-ai/bagel
/plugin install bagel@bagel

Codex and ChatGPT users: install bagel from the OpenAI Plugins Directory (one click), or clone the repo and add it as a plugin marketplace (the repo carries .agents/plugins/marketplace.json). Directory installs bundle the skills only (the directory accepts only public HTTPS MCP servers, and Bagel's runs on your machine), so also connect the server once with codex mcp add bagel --url http://localhost:8000/mcp, or in ~/.codex/config.toml:

[mcp_servers.bagel]
url = "http://localhost:8000/mcp"

Repo-marketplace and Claude Code installs wire this connection automatically. Maintainers build the directory ZIP with uv run python scripts/package_codex_directory.py.

Then start the container for your data format (see Quickstart): the plugin connects to http://localhost:8000/mcp by default. Any other MCP client can discover the same workflows server-side via the list_agent_capabilities tool.

Keep what matters, drop the rest

A robot records more data than you can afford to move. Bagel turns a question into a detector, runs it where the data is recorded, and ships only the windows around real events.

Here it is in one conversation:

Don't know the event in advance? The anomaly gate (beta) learns what normal looks like on the robot, asks Jev to name whatever isn't, and keeps only those slices, each with a JSON label, for any bucket: S3, GCS, Azure, MinIO or R2.

The session above: a 20-minute (1,200 s) recording and the prompt "keep 10 seconds before and after every deceleration harder than −10 m/s²". The preview detects 7 events, merges them into 4 windows, and keeps 92 s of the 1,200 (7.6%); the run writes a 2.1 GB bag down to 161 MB. These figures are illustrative demo output, not a measured benchmark: the ratio is event-window duration over total duration, so it depends entirely on your workload.

✅ Supported Data Formats

🆚 Bagel vs. the Tools You Already Use

You already have ros2 *, PlotJuggler, and grep. Bagel doesn't replace them: it answers the questions they make you work for, then hands off to them:

One sentence of plain language, one answer, instead of a pipeline of commands and a script you'll delete tomorrow.

💬 What Can I Prompt?

You can ask Bagel almost anything. For example:

What’s the correlation between current and voltage in the /spot/status/battery_states topic?

I think the robot hit a pothole. Can you check for sudden deceleration on the z-axis to confirm?

Every time the drone decelerates harder than -10 m/s², keep 10 seconds before and after. Drop everything else.

Did anything change on this robot since last week?

Time to put Bagel to the test: can it catch a drone doing barrel rolls? Spoiler: 🎉 It totally can.

💡 How Bagel Works

When you ask a question, Bagel analyzes your data source’s metadata and topics to build a high-level understanding.

Based on your prompt, if further inspection is needed, Bagel identifies the most relevant topics and interprets their meaning and structure. Bagel then writes the relevant topic messages to an Apache Arrow file and uses DuckDB to generate and execute queries against it.

This process is repeated as needed, running new queries until Bagel finds the best answer to your question.

LLMs excel at language but struggle with math. Bagel overcomes this by generating deterministic DuckDB SQL queries. These queries are displayed for you to audit, and you can guide Bagel to correct any errors.

🐶 Teach Bagel a New Trick

Bagel learns new capabilities through POML files: a structured set of instructions that describe a “trick,” such as computing latency statistics.

✍️ Create a .poml file

For example, let’s define ./bagel_mcp/agent/examples/woof.poml.

<poml>
    <task>
        Count the topics in the data source.
        If the count is odd, say "woof", else say "meow".
    </task>

    <output-format>
        Return the sound, the topic count, and a few cute emojis. Nothing else.
    </output-format>
</poml>

🗣️ Use the capability

Prompt Bagel:

Run the POML capability "./bagel_mcp/agent/examples/woof.poml" on the ROS2 bag "./data/sample/ros2/mcap".

Result:

meow 🐱 4 topics 🐱💤🎯

Teach it your own tricks (no rebuild)

Bagel discovers your own capabilities from ~/.bagel/capabilities/:

• In conversation: do a workflow once, then say "save that as a capability called battery-triage" — Claude calls save_agent_capability and it's reusable in any future session.
• As a file: drop a markdown file with your steps (or a POML file, if you want parameterized templates — see bagel_mcp/agent/compose/pipeline.poml for the house style) into ~/.bagel/capabilities/.

Either way it shows up in list_agent_capabilities as user/<name> and runs with run_poml_capability — from Claude Code, Claude Desktop, or any MCP client. Teams: keep the directory in your own git repo and sync it to every robot; it's just files. On Linux, run mkdir -p ~/.bagel/capabilities once before starting the container so the mount is owned by you, not root.

📚 Guides

• Natural-language pipelines · the model: a cadence, gates, and tasks; preview → run → save → batch → standing at the edge
• Event-driven data reduction · detect events, keep windows around them (snippets or one reduced bag), batch across fleets, upload to the cloud
• Anomaly detection with Jev (beta) · learn normal on the robot, ask Jev to label what isn't, upload only those slices with a JSON label; preview_anomalies dry-runs the screen first
• Live ROS2 robots over rosbridge · a step-by-step tutorial
• ROS text logs · inspect ~/.ros/log errors and warnings without opening a bag
• MQTT · live IoT topics, Sparkplug B, edge recording
• PostgreSQL / TimescaleDB · every table is a topic
• InfluxDB 3 · every measurement is a topic
• Automotive MDF4 & CAN (beta) · channel groups and DBC messages are topics; units ride along
• Local LLMs · fully offline with Ollama: your data and your model never leave the machine

📦 Integrations

• Rerun · "show me that event in Rerun": any time window as a ready-to-open recording
• Lichtblick / Foxglove · event windows as MCAP + pre-framed layouts for either viewer
• PlotJuggler · open Bagel's MCAP outputs directly; one-sentence pre-framed sessions, flattened CSV/Parquet exports
• Cloudini · decode cloudini-compressed pointclouds, or compress a bag's PointCloud2 topics into CompressedPointCloud2
• Slack · pipelines post to your ops channel when they fire: "🚨 hard brake on {asset}"
• LeRobot (beta) · detected events become training episodes: a LeRobotDataset v3.0

🚧 Limitations

Rough edges we know about, so you don't find them the hard way:

• Two formats are beta. The automotive MDF4/CAN readers are verified against files we generate with the same libraries that read them (asammdf, python-can); real CANape/INCA/Vector-produced captures haven't crossed our test bench yet. LeRobot exports load-test clean with the real lerobot package, but no policy has been trained from a Bagel export yet.
• The Jev integration is beta, and stays beta while we learn from real deployments. That covers the anomaly and decide gates (recorded logs and live subscriptions), preview_anomalies, the on-robot local backend and the ros2-jazzy-jev image. Its Jev backend has been run against live Jev through Vercel AI Gateway on a real drive, a synthetic fault log and a live MQTT stream; a direct TypeSafe key is not yet exercised, and detection quality has not been measured on logs with known incidents. On a live subscription the flagged window is kept as Parquet (write_topics_to_file); MCAP/rosbag snippets need a recorded log and are refused there. The baseline is learned per run and restarts with the process, so in screen mode the first minutes of each run are never flagged. Labels, settings and defaults may change between releases.
• Reduction ratios are workload-dependent, and unbenchmarked. The ratio is event-window duration over total duration: quiet recordings reduce dramatically, eventful ones much less. The figures in this README are illustrative demo output, not a measured benchmark.
• No authentication on the MCP endpoint. By design it binds to localhost only; treat it like a database socket and see SECURITY.md before sharing it beyond your machine.
• Small local models struggle with multi-step pipelines. A 4-8B model handles tool selection and simple SQL; event-windowed reduction and multi-topic joins want a bigger model. See the Local LLMs guide.
• Live-database end-to-end tests run outside CI. The InfluxDB and Postgres suites' pure tests run in CI; their live end-to-end cases only execute against an instance you point them at. Everything else, including the ROS bag write paths, runs in CI.

🫶 Contributing

We’d love your help! The easiest way to support the project is by giving it a ⭐ on GitHub.

Other great ways to contribute:

• Request new features
• Report bugs
• Improve documentation
• Add new capabilities

Before contributing, please review the guidelines.

Join the conversation in our Discord server. We hang out there regularly.

📄 License

Bagel is open source under the Apache License 2.0.

Agent discovery and reproducible workflows

For maintainers: discovery audits and evaluation, listing maintenance, and reproducible user reports.