OpenRemap

An offline-first engine for analyzing, comparing, and reproducing ECU binary changes.

Embed it as a library, automate it in a pipeline, or run it from the terminal — your ECU data never leaves your machine.

🌐 openremap.com — full documentation, guides, and changelog.

Runs entirely offline. No accounts, no telemetry, no data leaves your machine — ever.

What it is

OpenRemap is an offline-first ECU binary analysis engine, exposed as a Python library and a CLI. The same pipeline that powers the command-line tool is fully available as importable services — no subprocess, no parsing stdout.

from openremap.core.services.identifier import identify_ecu
from openremap.core.services.confidence import score_identity
from openremap.core.services.patcher    import ECUPatcher

data     = open("ecu.bin", "rb").read()
identity = identify_ecu(data, filename="ecu.bin")
result   = score_identity(identity)

print(f"{identity['ecu_family']}  {result.tier}")  # EDC17  High

All services accept bytes and dict — no file paths, no hidden state, trivial to test and wrap in an API endpoint or a desktop app.

CPU-bound algorithms (entropy analysis, context-anchor search) run on a compiled Rust backend via PyO3. Pre-built wheels ship the native extension for Linux, macOS, and Windows — pip install openremap and it just works. A pure-Python fallback covers platforms without pre-built wheels.

→ Full integration guide

The problem

ECU work revolves around three tasks that today require expensive commercial software (€2,500–€8,000+) or manual hex-editor work with no audit trail:

1. Identify a binary — manufacturer, ECU family, software revision, confidence score
2. Diff two binaries — what changed between a stock file and a tuned file, captured as a portable recipe
3. Apply a recipe to another binary — validate, patch, and verify — all-or-nothing

Whether you are building a tuning application, automating a workflow, or just need a reliable offline tool — OpenRemap gives you a clean Python API and a full CLI for all three.

What OpenRemap does

What it does NOT do

• Map editing — OpenRemap works at the byte level, not the map level. Use WinOLS or ECM Titanium to find and edit maps. Use OpenRemap to capture, share, and reapply those edits.
• Checksum correction — you must run the output through WinOLS, ECM Titanium, or equivalent before flashing. Always.
• ECU reading/writing — it operates on .bin files you already have.

Supported ECUs

30 extractors across 4 manufacturers, covering ECUs from 1982 to present:

→ Full reference: Bosch · Siemens · Delphi · Marelli

Confidence scoring

Every identification includes a confidence verdict — HIGH, MEDIUM, LOW, SUSPICIOUS, or UNKNOWN — built from multiple signals:

• Detection strength — how rigorous the extractor's matching cascade is
• Software version format — manufacturer-aware canonical format checking (Bosch 1037-prefixed, Delphi 8-digit GM-style, etc.)
• Identity fields present — hardware number, calibration ID, ECU variant
• Filename analysis — tuning keywords (stage2, dpf_off, egr_off) and generic names (1.bin) flag suspicious files
• Family-aware scoring — ECU families that architecturally lack certain fields are never penalised for their absence

→ Full scoring breakdown

The recipe format

The .remap recipe is a self-contained JSON file. Every changed byte is listed with its offset, original value, modified value, and a context anchor — 32 bytes of surrounding data that let the patcher find the right location even if the binary has shifted slightly between software revisions.

Recipes are human-readable, Git-diffable, and shareable. No proprietary format, no binary blobs. A recipe is a portable, reproducible record of a tune — you can review it, version it, and apply it to any matching ECU.

→ Recipe format specification

Install

Works on Windows, macOS, and Linux. One command:

pip install openremap

Or with uv (recommended):

uv tool install openremap

Pre-built wheels include the compiled Rust backend — no Rust toolchain required. On platforms without a pre-built wheel, the pure-Python backend takes over automatically.

Detailed guides:

• 🪟 Windows — Step-by-step guide · written for people who rarely use a terminal
• 🍎 macOS / 🐧 Linux — One-command install
• 🛠️ Contributing / development — Clone and run from source

Get started

openremap

The full terminal UI launches — identify files, scan folders, cook recipes, and apply tunes, all from one interface.

The complete CLI is also there when you need it:

openremap workflow    # Prints a plain-English step-by-step guide
openremap commands    # Quick reference of all available commands

→ Full CLI reference

Documentation

• 🌐 openremap.com — website with full guides and changelog
• Integration guide — using OpenRemap as a Python library
• How it all works
• CLI commands overview
• Confidence scoring — tiers, signals, and breakdown
• Recipe format (.remap)
• Supported families: Bosch · Siemens · Delphi · Marelli
• Contributing — adding extractors, code style, PRs

Contributing

Contributions are welcome — especially new ECU family extractors. See CONTRIBUTING.md.

License

MIT — see LICENSE.

⚠️ Checksum verification is mandatory. Before flashing any tuned binary to a vehicle, you must run it through a dedicated checksum correction tool (ECM Titanium, WinOLS, or equivalent). openremap tune confirms the recipe was applied correctly — it does not correct or validate ECU checksums. Flashing a binary with an incorrect checksum will brick your ECU.

⚠️ Research and educational use only. Any output produced by this software must be reviewed by a qualified professional before being flashed to a vehicle. The authors accept no liability for damage, loss, or legal consequences arising from its use. Read the full DISCLAIMER.