ncsx

BMW NCS Expert in your browser. A TypeScript port of the BMW factory coding tool (NCSEXPER 4.0.1), built on the same engine stack as the sibling projects ediabasx (EDIABAS) and inpax (INPA).

Read the chassis's DATEN catalog, browse every ECU coding option in plain English, edit individual FSW/PSW values, then write the result back to the car over a K+DCAN cable or a remote gateway — all without leaving the browser. No installer, no Wine, no admin rights.

Live at ncsx.bimmerz.app (Chromium-only — uses File System Access + Web Serial).

What you need

• A BMW Standard Tools install (genuine, BMW-shipped data). The app picks the root folder containing NCSEXPER/, EDIABAS/, and EC-APPS/ and reads from it read-only — nothing is uploaded.
• A K+DCAN cable plugged into a USB port (Web Serial), a Tactrix OpenPort 2.0 (SAE J2534), or an ediabasx gateway running over WebSocket if the cable is on a different machine.
• Chrome, Edge, Opera, or Brave on desktop. Firefox and Safari lack the required Web Platform APIs.

What works today

• Chassis catalog browser — every chassis declared in BR_REF.DAT, with all of its ECU coding variants discoverable through SGFAM / SGAUSWAHL.
• Vehicle identity — read VIN + FA (post-E60) or ZCS (E36/E38/E39/E46/E53) from the appropriate per-chassis identity SG. SGFAM's FA/ZCS flags pick the right SG automatically — no hardcoded tables.
• FA-driven ECU filter — once identity is loaded, the SG list filters to what the car actually has, matching NCSEXPER's AUFTRAGSAUSDRUCK evaluation.
• Per-CABD function tree — every FSW / PSW / property / unoccupied slot rendered with NCSDummy keyword translations, current PSW highlighted from the live netto.
• Read coding — CODIERDATEN_LESEN through the per-CABD A_*.ipo dispatcher, same path NCS Expert uses (auth gates, multi-step state machines, CI lookups all honoured).
• Edit + write coding — stage PSW changes, see the byte-level diff, SG_CODIEREN through the IPO. End-to-end verified on E46 KMB + AKMB + GM5.
• Generic job runner — JOB_ERMITTELN enumerates every job the IPO declares (matching NCSEXPER's "Change Job" dialog); user can dispatch any of them through a dropdown.
• Apply defaults — destructive write of the CABD's ANLIEFERZUSTAND via SG_CODIEREN, gated to CABDs that ship a complete factory netto.
• Export / import — FSW_PSW.TRC (full snapshot), FSW_PSW.MAN (staged edits), NETTODAT.TRC (raw bytes). All formats match what NCS Expert writes to WORK/.
• Shareable patches — .ncsxpatch.yaml files wrap the same FSW/PSW edits in a YAML envelope with title / description / author / keywords / chassis, can cover multiple modules in one file, and support optional coding-index pinning + require_current pre-write assertions. Save as patch / Append to patch / Apply patch sit next to the MAN buttons. Format reference: docs/patches.md.

See docs/STATUS.md for the live status board.

Architecture

Three layers, each with its own repo:

ncsx       (this repo)   — NCS Expert: coding flow, FA, chassis catalog
inpax                    — INPA: IPO bytecode interpreter, screen/menu UI
ediabasx                 — EDIABAS: BEST/2 SGBD interpreter, wire transports

ncsx parses BMW's DATEN files, builds typed function-lists, dispatches BMW's own A_<cabd>.IPO coding scripts through the inpax interpreter, and lets the IPO's CABI/CDH calls drive ediabasx's wire layer. Going through the IPO is load-bearing — it carries per-CABD auth gates, multi-step write protocols, and checksum recalculation that direct apiJob calls would skip.

Packages

Pure libraries, all under @emdzej/ncsx-*. Most are independently useful for anyone parsing BMW's data formats — no dependency on the web app.

Package	Purpose
@emdzej/ncsx-chassis	Load a complete chassis bundle from DATEN (DST + SGET + SGVT + SGFAM + ZST + AT + SWT + CABD loader).
@emdzej/ncsx-cabd	CABD coding-rule decoder/encoder — converts between byte-level netto and logical FSW/PSW values.
@emdzej/ncsx-coder	End-to-end coding orchestrator — chassis + FA + edits → CodingPlan[] ready to ship.
@emdzej/ncsx-daten	DATEN binary frame parser — signature, frame types, format strings, OPERATION / EINHEIT decoders.
@emdzej/ncsx-text-tables	.AT text-table parser family (ZST, AT, SGFAM, AT.M00, AT.ZUS, VARIABLE.ASC).
@emdzej/ncsx-function-list	Build a typed FunctionList from a parsed CABD (NCSDummy keyword translations baked in).
@emdzej/ncsx-ecu-select	AUFTRAGSAUSDRUCK predicate evaluator — filters SGs to what the FA-derived ASW says is installed.
@emdzej/ncsx-fa-asw	FA → ASW (Ausstattungsschluessel-Wert) — walks AT/SWTASW to expand FA tokens.
@emdzej/ncsx-identity	Read VIN / FA / ZCS from a connected ECU; picks the right identity SG per chassis.
@emdzej/ncsx-inpax-cabi-provider	CABI/CDH bridge — implements the 80+ CDH* functions NCSEXPER's A_*.ipo dispatchers call.
@emdzej/ncsx-options	NCSDummy-style coding-option overlay (per-FSW friendly names + valid PSW set).
@emdzej/ncsx-patches	.ncsxpatch.yaml shareable-coding-patches format — parse / serialize / validate against a FunctionList.
@emdzej/ncsx-pfl	.pfl profile INI parser.
@emdzej/ncsx-predicate	Byte-coded AUFTRAGSAUSDRUCK predicate compiler/runner.
@emdzej/ncsx-property-formulas	Inverse formulas for property-style FSWs (mileage / date / VIN).
@emdzej/ncsx-trace	TraceOverlay — track staged edits across the chassis.
@emdzej/ncsx-translations	NCSDummy community keyword → English dictionary loader.
@emdzej/ncsx-wire	Shared EdiabasLike type contracts.

Apps

App	What it is
@emdzej/ncsx-web	The browser SPA at ncsx.bimmerz.app. Pure client-side: Svelte 5 + Vite + Tailwind.

Logging

Powered by @emdzej/bimmerz-logger. The web app's Settings dialog has a Logging section with a default-level dropdown plus per-category overrides covering all three subsystems this app embeds:

• NCSX.* — chassis loader, CABI provider, web app surface (from @emdzej/ncsx-chassis).
• INPAX.* — IPO interpreter (from @emdzej/inpax-interpreter).
• EDIABASX.* — BEST/2 interpreter (from @emdzej/ediabasx-ediabas).

Levels are hierarchical — a rule for EDIABASX covers every EDIABASX.* subcategory unless something more specific matches. Changes take effect immediately (logger handles are proxies, no component reload needed).

Develop

pnpm install                          # at the repo root
pnpm web                              # dev server on http://localhost:5175

pnpm build                            # build everything via turbo
pnpm typecheck                        # tsc --noEmit + svelte-check
pnpm lint                             # eslint
pnpm test                             # vitest across all packages

Per-package work uses the standard pnpm filter pattern:

pnpm --filter @emdzej/ncsx-cabd test
pnpm --filter @emdzej/ncsx-web dev

Most packages ship a built dist/ consumed by the web app; rebuild a package (pnpm --filter <name> build) if changes don't show up in the dev server.

Reverse-engineering notes

The reverse-engineering documentation lives under docs/ — it covers NCSEXPER's architecture, the DATEN file formats, the coding flow byte-by-byte, and the CABI/CDH binding plan. Start with docs/STATUS.md for the current snapshot and docs/NCSEXPER-REVERSE-ENG.md for the architecture overview.

These are written for someone who wants to understand why the code does what it does — they're not required reading to use the web app or the libraries.

Related projects

• ediabasx — EDIABAS / BEST/2 interpreter and wire transports (Web Serial, gateway).
• inpax — INPA / IPO bytecode interpreter with screen and menu UI providers.
• tisx — TIS graphics decoder.
• wdsx — Wiring Diagram System.
• NCS Dummy — the long-standing community Windows tool whose keyword translations and FSW-naming heuristics this project builds on.

Right to Repair

The Right to Repair movement advocates for consumers' ability to fix the products they own — from electronics to vehicles — without being locked out by manufacturers through proprietary tools, paywalled documentation, or artificial restrictions.

I build these tools because I believe repair is a fundamental right, not a privilege.

Too often, service manuals, diagnostic software, and technical documentation are kept behind closed doors — unavailable to individuals even when they're willing to pay. This wasn't always the case. Products once shipped with schematics and repair guides as standard. The increasing complexity of modern technology doesn't change the fact that capable people exist who can — and should be allowed to — use that information.

These projects exist to preserve access to technical knowledge and ensure that owners aren't left at the mercy of vendors who may discontinue support, charge prohibitive fees, or simply refuse service.

Support

If you find this project useful, consider buying me a coffee ☕ or sponsoring on GitHub or if it's your thing: via PayPal

License

PolyForm Noncommercial 1.0.0 — free for noncommercial use (personal projects, research, education, hobby diagnostics on your own car). Commercial use requires a separate licence — open an issue if you need one.

This repository contains no BMW proprietary data. All DATEN files, SGBDs, and IPOs the tool consumes must come from a legally-acquired BMW Standard Tools install on the user's own machine.

Disclaimer

This project is for educational and research purposes only. It is not affiliated with BMW AG.