MAVPose reads ArduPilot and PX4 flight logs into clean, time-aligned pandas data with real units, and its optional assistant turns a plain-English request into a plot. The assistant works with any AI provider, including local models. The model never sees the raw log: it gets the log's message types and a precise column schema with units, and replies with a small JSON plot spec that MAVPose checks and draws itself, so no generated code runs. Specs are saved, so any plot can be redrawn later without a model.

$ mavpose flight.tlog --model openai:<model> --prompt "Plot altitude over time"
🤖 Model: openai:<model>

📂 Parsing log schema: flight.tlog
✅ Found 38 message types.

🔍 Finding relevant message types for: 'Plot altitude over time'
   → ['GLOBAL_POSITION_INT', 'VFR_HUD']

🗃️  Extracting telemetry to Parquet...
┌──────────────────────────────────────────────────────────┐
│  🗃️  Extracted Parquet schema                               │
├──────────────────────────────────────────────────────────┤
│  [GLOBAL_POSITION_INT]  1842 rows                          │
│      time_s: float64 s  [0.0 … 312.4]                     │
│      alt: float64 m  [487.32 … 512.1]                     │
│  [VFR_HUD]  1842 rows                                      │
│      time_s: float64 s  [0.0 … 312.4]                     │
│      alt: float64 m  [476.1 … 501.3]                      │
└──────────────────────────────────────────────────────────┘
   Saved → /path/to/telemetry.parquet

✍️  Asking openai:<model> to design the plot...
✅ Plot saved to: /path/to/plot.png
   Spec saved to: /path/to/plot.json  (redraw with --spec)

Architecture

┌──────────────────────────────────────────────────────────┐
│  PHASE 1 — Extraction  (parent process, no LLM)             │
├──────────────────────────────────────────────────────────┤
│                                                             │
│  LogExtractor.schema_only()                                 │
│    └─ pymavlink fast scan → {msg_type: {fields, count}}     │
│                                                             │
│  find_relevant_data_types(prompt)                           │
│    └─ the model picks from the log's message types        │
│                                                             │
│  LogExtractor.extract_all()  ←  full row materialisation    │
│    └─ per-msg-type DataFrames, time_s column, cast numerics │
│                                                             │
│  LogExtractor.export_parquet(msg_types, path)               │
│    └─ clean telemetry.parquet + schema summary dict         │
│                                                             │
├──────────────────────────────────────────────────────────┤
│  PHASE 2 — LLM Plot Generation                              │
├──────────────────────────────────────────────────────────┤
│                                                             │
│  LLM receives:                                              │
│    └─ schema: {msg_type: {columns: {col: dtype, unit, range}}} │
│                                                             │
│  Default: LLM replies with a JSON plot spec                 │
│    {"panels": [{"series": [{"msg_type", "field"}]}]}       │
│    └─ MAVPose validates it against the log and draws it    │
│    └─ invalid spec? the error goes back to the LLM, N×     │
│    → plot.png + plot.json (redraw with --spec)             │
│                                                             │
│  --code: LLM writes a pandas + matplotlib script instead    │
│    └─ run in a restricted subprocess, fixed up to N×       │
│    → plot.png + plot.py                                    │
└──────────────────────────────────────────────────────────┘

Why this matters: In the old design, the LLM had to write pymavlink code to parse a binary .tlog — a notoriously tricky API with blocking/non-blocking subtleties, timestamp inconsistencies, and message-type guesswork. By the time the LLM touched the data, it was flying blind. Now it receives a typed, time-aligned Parquet file with exact column names, dtypes, and value ranges. Writing pd.read_parquet() + matplotlib code against a known schema is trivially reliable.

Features

• Plain-English plots — describe any flight data; MAVPose figures out which MAVLink fields to use
• ArduPilot and PX4 — one API for MAVLink .tlog, ArduPilot DataFlash .bin/.log and PX4 ULog .ulg logs
• Headless extraction layer — LogExtractor parses every supported format into per-message-type DataFrames before the LLM is ever invoked:
  • one clock — every message type shares a single time_s axis (tlog receive time, DataFlash TimeUS, or ULog timestamp from logging start); native time fields are kept as columns
  • real units — scaled fields are converted using unit metadata from the log or the autopilot's own message definitions (alt mm → m, lat degE7 → deg, voltage_battery mV → V, …) and every column's unit is reported; pass convert_units=False for raw values
  • unknown values removed — "not provided" markers (MAVLink current_battery = -1, eph = UINT16_MAX; PX4 battery_status.current_a = -1, …) become NaN instead of fake readings, using the invalid markers from the official MAVLink and PX4 definitions; counts appear in extractor.unknown_counts and the LLM schema. Pass filter_unknown=False to keep them
  • corruption-tolerant — bad packets are skipped and counted (extractor.stats) instead of silently ending the parse
• Clean Parquet handoff — only the relevant message types are exported; the LLM sees exact column names, dtypes, min/max ranges — no binary guesswork
• Any AI provider — OpenAI, Anthropic, Gemini, OpenRouter, Groq, DeepSeek, Mistral, Together, local Ollama / LM Studio, or any OpenAI-compatible server
• Smart message selection — the model picks the message types it needs from the log's own list
• No generated code by default — the model describes the plot as a JSON spec; MAVPose validates it against the log and draws it, with units on every axis. Invalid specs go back to the model with the exact error
• Reproducible plots — every spec is saved as plot.json; mavpose flight.bin --spec plot.json redraws it on any log, no model or API key needed
• Code mode when you need it — --code has the model write a pandas + matplotlib script instead, for plots a spec can't describe
• Restricted execution (code mode) — generated code runs in a clean subprocess (no API keys in its environment) under a PEP 578 audit hook that blocks process spawning, network access and file writes outside the output folder, with CPU/memory limits and a timeout. This is defence in depth, not a hard security boundary: for untrusted logs or prompts, also run MAVPose in a container
• Interactive REPL mode — omit --prompt to enter a live loop; Parquet is re-extracted per query with the relevant types
• CI-tested — lint (ruff) and pytest run on every push

Tech Stack

Prerequisites

• Python 3.10+
• For the chat assistant only: an API key for any supported AI provider, or a local model server (Ollama, LM Studio)

Installation

MAVPose has two layers. Install only what you need:

The core never imports the chat layer, so pip install mavpose has no LLM, vector-store or plotting dependencies.

To work on MAVPose itself:

git clone https://github.com/AyushMaria/MAVPose.git
cd MAVPose
python -m venv venv
source venv/bin/activate      # Windows: venv\Scripts\activate
pip install -e ".[dev]"       # core + chat + test tools
cp template.env .env          # chat assistant only

Open .env and fill in your key. If you installed from PyPI, there's no template.env: just create a file named .env in the folder you'll run mavpose from (MAVPose looks there and in parent folders), or set the variables in your shell.

OPENAI_API_KEY=your-key-here          # or ANTHROPIC_API_KEY, GEMINI_API_KEY, OPENROUTER_API_KEY, ...
MAVPOSE_MODEL=openai:<model>          # provider:model; see "Choosing an AI provider"

⚠️ Never commit .env — it is already listed in .gitignore.

Usage

The mavpose command is the chat assistant and needs pip install "mavpose[chat]"; without it, the command explains what to install.

Single prompt

mavpose flight.tlog --prompt "Plot altitude over time"

Interactive REPL

Omit --prompt to enter a live loop:

mavpose flight.tlog

📊 Plot request > Plot battery voltage and current
📊 Plot request > Show GPS latitude and longitude
📊 Plot request > quit

All CLI flags

usage: mavpose [-h] [--prompt PROMPT] [--model PROVIDER:MODEL] [--code] [--spec FILE]
               [--out-dir DIR] [--format {png,svg,pdf}] [--dpi N] [--retries N] [--verbose] log_file

positional arguments:
  log_file              Path to a flight log: MAVLink .tlog, ArduPilot .bin/.log, or PX4 .ulg

options:
  -p, --prompt TEXT     Plot request. Omit for interactive mode.
  -m, --model P:M       Model as provider:model, e.g. openai:<model>, ollama:llama3.1:8b
                        (default: MAVPOSE_MODEL, or the provider whose key is set)
  --code                Have the model write a Python script instead of a plot spec
  --spec FILE           Redraw a saved plot spec (plot.json) on this log; no model needed
  -o, --out-dir DIR     Folder for all outputs (created if needed; default: the log's folder)
  -f, --format FMT      png (default), svg or pdf
  --dpi N               Resolution (default: 150, or 400 with --code); ignored for svg
  -r, --retries N       Attempts per request when the spec or script fails (default: 3)
  -v, --verbose         Enable debug logging

The output plot is saved as plot.png (or .svg / .pdf with --format), its spec as plot.json, and intermediate telemetry as telemetry.parquet, all in the same directory as your log file, or in --out-dir. Each run replaces the previous files. mavpose only reports success when a new plot was saved; with --prompt it exits with status 1 otherwise.

To redraw a plot later, or on another flight's log, without any model:

mavpose other_flight.tlog --spec plot.json

Need a sample log file?
Download here

Output Files

Choosing an AI provider

The plot assistant works with any of these. Set the provider's key, then name the model as provider:model with --model or MAVPOSE_MODEL:

Existing setups with only OPENROUTER_API_KEY (and optionally OPENROUTER_MODEL) keep working as before. If exactly one provider key is set, a bare --model <model> is enough. Details: Plot assistant guide.

Project Structure

MAVPose/
├── mavpose/                       # pip install mavpose — core data layer
│   ├── flightlog.py               # mavpose.load() and FlightLog: the public API
│   ├── mcp_server.py              # mavpose-mcp: MCP tools for AI agents ([mcp] extra)
│   ├── log_extractor.py           # LogExtractor: one clock, real units, unknown markers
│   ├── ulog_reader.py             # PX4 ULog (.ulg) support via pyulog
│   ├── file_validator.py          # File validation (extension, size, symlink)
│   ├── data/
│   │   ├── mavlink_unknown_markers.json   # generated from the MAVLink spec
│   │   └── px4_fields.json                # units + markers from PX4 msg definitions
│   └── chat/                      # pip install "mavpose[chat]" — plot assistant
│       ├── plot_creator.py        # PlotCreator: LLM writes the plot script
│       ├── llm.py                 # Choosing the AI provider and model
│       ├── safe_executor.py       # Restricted subprocess executor (audit hook + limits)
│       └── cli.py                 # `mavpose` command
├── docs/                          # guide, format notes, API reference (MkDocs)
├── CHANGELOG.md
├── tools/
│   ├── gen_unknown_markers.py     # regenerates MAVLink markers from mavlink/mavlink
│   └── gen_px4_field_info.py      # regenerates PX4 units/markers from PX4-Autopilot/msg
├── tests/
│   ├── log_builders.py            # builds real .tlog / .bin files for tests
│   ├── test_real_logs.py          # end-to-end extraction tests
│   ├── test_core_boundary.py      # core must not depend on chat
│   └── …
├── .github/workflows/ci.yml       # ruff + pytest on 3.10–3.13, core-only job, strict docs build
├── template.env
└── LICENSE

Library API

import mavpose

log = mavpose.load("flight.tlog")          # .tlog, .bin, .log or .ulg
log
# <FlightLog 'flight.tlog': mavlink, 38 message types, 2443.8 s>

alt = log.series("GLOBAL_POSITION_INT", "relative_alt")   # Series indexed by time_s
alt.attrs["unit"]                                         # 'm'

log.unknown_counts        # {'GPS_RAW_INT': {'epv': 6338}}  "not provided" values now NaN
log.to_parquet("telemetry.parquet")

mavpose.load, FlightLog, LogExtractor, validate_mavlink_file and FileValidationError are the public API, covered by the stability policy. Full documentation:

• Concepts: time axis, units, unknown values, damaged logs
• Log formats: message names and quirks per format
• API reference and changelog

To preview the docs locally: pip install -e ".[docs]" && mkdocs serve.

MCP server for AI agents

pip install "mavpose[mcp]"
mavpose-mcp --root ~/flight-logs

Any MCP-capable assistant or agent framework can then call list_logs, summarize_flight, list_messages, describe_message, get_series, get_log_messages and export_parquet. The server is limited to the --root folders, read-only except export, and never runs code. Long series are downsampled for the agent's context, but min/max/mean always cover every sample. See docs/guide/mcp.md for client setup.

Plot assistant API — PlotCreator

from mavpose.chat import PlotCreator   # needs mavpose[chat]

creator = PlotCreator(max_retries=3, model="openai:<model>")   # or None: MAVPOSE_MODEL / detected key
creator.set_logfile_name("flight.tlog")

# Phase 1a: schema scan
creator.parse_mavlink_log()

# Phase 1b: the model picks message types; Parquet extraction
msg_types = creator.find_relevant_data_types("Plot altitude over time")
schema_summary = creator.extract_dataframes(msg_types)

# Phase 2: the model designs the plot as a JSON spec; MAVPose draws it
ok = creator.plot_from_spec("Plot altitude over time", schema_summary)
# → plot.png, plot.json and telemetry.parquet saved next to the log file
# Code mode: PlotCreator(mode="code"), then create_plot() and run_script(),
# which returns a RunResult (success, plot_path, code, error, attempts)

Running Tests

pip install -e ".[dev]"
python -m pytest

To lint:

ruff check .

In a core-only install (pip install -e .), the chat tests skip themselves.

Troubleshooting

Contributing

Contributions are welcome, from bug reports about logs MAVPose reads wrongly to code. See CONTRIBUTING.md to get set up, and the good first issue label for a place to start. Everyone taking part follows the code of conduct.

License

MIT — see LICENSE for details.