MassRobotics AMR Interop · Vecna APT / ATG / AFL / CPJ

A Vecna fleet on the interop wire, no robots required

A spec-faithful emulator of the MassRobotics AMR Interoperability Standard — the open interop layer Vecna Robotics co-developed and certifies its fleet against. Both roles ship: emulated robots that deliver an identityReport and stream statusReports from a live movement model, and a fleet-side receiver that validates every message against the official schema and keeps a per-robot registry. All over a hand-rolled, stdlib RFC 6455 WebSocket — zero runtime network dependencies.

Judged by the standard's own referee

Self-validation is circular, so this emulator is run against the reference receiver from the official MassRobotics-AMR/AMR_Interop_Standard repository — the Node/Ajv implementation, built unmodified in Docker at the same commit the vendored schema is pinned to.

External conformance

Official Node/Ajv reference receiver

All four Vecna vehicle models connect at once; the harness witnesses the receiver's own verdicts on its /ui WebSocket, where it broadcasts {message, isValid, errors} for everything it validates. Every identityReport and statusReport we send — idle, navigating with path and destinations, erroring, charging — is judged valid, and a deliberately-invalid probe is judged invalid, proving the witness channel detects bad traffic rather than rubber-stamping.

Harness + repro assets

The oracle

Vendored byte-for-byte, zero repairs

AMR_Interop_Standard.json at commit f9357a4 (2021-10-08), retrieved 2026-08-16 — vendored with no normalizations; upstream and vendored hashes are identical:

sha256 816c8f78e1d280d10983a1bcea69a3c8e6572e5bb6f777a0863e6a5b2c3fc288

Every outgoing message is validated against it and raises on violation; every incoming message is validated and recorded — problems are kept per robot, never silently dropped.

Five minutes to a reporting fleet

$ uv run massrobotics-emulator receiver --port 3000 --verbose
$ uv run massrobotics-emulator robot --receiver ws://127.0.0.1:3000 --model APT --count 2 --patrol
# --model APT|ATG|AFL|CPJ picks a Vecna vehicle preset;
# --count N runs a fleet on one connection each;
# --patrol drives a loop instead of idling;
# --interval sets the statusReport period (seconds).

import asyncio
from massrobotics_emulator import InteropReceiver, MassRoboticsAMR, vecna_config

async def main():
    receiver = InteropReceiver()
    await receiver.start()
    robot = MassRoboticsAMR(vecna_config("APT"))
    await robot.start(receiver.uri)
    (record,) = await receiver.wait_for_robots(1)
    robot.navigate_to(25.0, 10.0)
    print(await receiver.next_status(
        record.uuid, lambda s: s["operationalState"] == "navigating"))
    await robot.stop()
    await receiver.stop()

asyncio.run(main())

The wire, replayed

This session was recorded from the emulator, exactly as sent: one APT delivers its identityReport, is told navigate_to(25, 10), and streams statusReports — position, quaternion heading, velocity, battery, predicted path and destinations — until it arrives. Every message shown was judged schema-valid by the receiver when recorded.

speed

Full messages, verbatim (note the schema's own field-naming split — current location says planarDatum, predicted locations say planarDatumUUID):

What the schema actually says

Vendoring the official artifact surfaced upstream quirks — documented in the package's schemas/registry.json and honored on the wire, never silently repaired.

Quirk	Detail
The examples fail the schema	Both example messages in the standard's own `examples/` directory use uppercase UUIDs, but every `uuid` pattern in the schema requires lowercase hex (`^[0-9a-f]{8}-…`). This emulator always emits lowercase UUIDs.
`cargoMaxWeight` is a string	Typed `string` despite its description saying "Max weight of cargo in kg". Emitted as a string here, schema-faithfully.
Two names for the map reference	The current location object calls it `planarDatum`; predicted locations (`path`, `destinations`) call it `planarDatumUUID`. Both spellings are intentional per the schema and used as-is.
Location is stricter than the prose	`statusReport.location` requires `angle` (a quaternion) and `planarDatum` — stricter than the PDF suggests. The reference receiver enforces the schema, so the emulator always sends both.
`uniqueItems` on predictions	`path` and `destinations` declare `uniqueItems`, so consecutive identical predicted locations would be invalid; the movement model guarantees distinct entries.

What ships in the package

Surface	Coverage
Robot role	`MassRoboticsAMR`: WebSocket client delivering one `identityReport` and streaming `statusReports` while a movement model drives position, heading, velocity, battery, and predicted path/destinations
Fleet role	`InteropReceiver`: WebSocket server validating every incoming message and keeping a live per-robot registry — identity, status history, connection state, recorded validation problems
Vehicle presets	Vecna's certified fleet via `vecna_config()`: APT pallet truck, ATG tugger, AFL counterbalanced forklift, CPJ cobot pallet jack; any identity via `AMRConfig`
Validation	Outbound messages that violate the vendored schema raise; inbound violations are recorded per robot, never dropped
Transport	Hand-rolled stdlib RFC 6455 client + server (`ws.py`), strict about masking, fragmentation, control frames, and close codes
Tests	Schema-quirk regressions, RFC 6455 conformance with adversarial raw-byte peers, and full sender↔receiver loops on simulated time

Want this for your fleet manager?

MiR REST, VDA 5050, Omron ARCL, MassRobotics Interop — same pattern each time: official spec as the oracle, provenance with hashes, adversarial tests, live validation against independent implementations. If your integration needs an emulator for another manufacturer, that pattern is repeatable.

Talk to advin.io See the VDA 5050 app