v2json / messages
V2X message reference
V2X message types
The ETSI C-ITS message set: what each message is, its messageID in the ITS PDU
header, and the standard that defines it. Decode any of them to JSON with the free API.
| Type | ID | Sender (ITS-S) | Message | Standard |
|---|---|---|---|---|
| CAM | 2 | VehicleRSU | Cooperative Awareness — a station's position, speed and heading, sent continuously | EN 302 637-2 ↗·TS 103 900 ↗ |
| DENM | 1 | VehicleRSUPersonalCentral | Decentralized Environmental Notification — an event or hazard warning | EN 302 637-3 ↗·TS 103 831 ↗ |
| CPM | 14 | VehicleRSU | Collective Perception — the objects a station's sensors detect | TS 103 324 ↗ |
| VAM | 16 | VRU (Tx) | VRU Awareness — a vulnerable road user announcing itself | TS 103 300-3 ↗ |
| MAPEM | 5 | RSU * | MAP — intersection topology, lanes and connections | TS 103 301 ↗ |
| SPATEM | 4 | RSU * | Signal Phase and Timing — live traffic-light state | TS 103 301 ↗ |
| SREM | 9 | Vehicle | Signal Request — priority or preemption request to a junction | TS 103 301 ↗ |
| SSEM | 10 | RSU | Signal Status — the junction's response to requests | TS 103 301 ↗ |
| IVIM | 6 | RSU | In-Vehicle Information — road signs and zones delivered to the vehicle | TS 103 301 ↗ |
| RTCMEM | 13 | RSU | RTCM Corrections — GNSS RTK correction data a roadside unit broadcasts | TS 103 301 ↗ |
Detailed pages roll out per type. CPM is live; the rest are in progress.
* TS 103 301 defines MAPEM and SPATEM as infrastructure services (§4.2) but does not bind them to a station type with a normative shall; RSU is the intended sender.
How do I decode any of these?
Paste a hex stream into the workbench, or POST it to /api/v1/decode.
The type is auto-detected from the messageID, so you rarely need to name it. The
integration guide has copy-paste examples for decode, encode and round-trip.