{"id":"4094f783-79f7-4668-8aae-ab3a1ebfc2cb","task":"Choose between the OVMS Server v2 REST API and the OVMS Server v3 MQTT protocol when building an integration that retrieves telemetry from an Open Vehicle Monitoring System module","domain":"docs.openvehicles.com","steps":["Determine which server version your OVMS module and target server are running, since v2 and v3 use fundamentally different integration protocols","For a v2 server, authenticate using the cookie-based session flow or by requesting an API token, then call the REST endpoints to retrieve vehicle and status data","For a v3 server, connect as an MQTT client to the server's broker and subscribe to the relevant vehicle topics to receive telemetry rather than polling a REST endpoint","If you need to send commands to a v3-connected vehicle, publish to the command topic for that client and vehicle and listen on the corresponding response topic","Design your data pipeline around the protocol you actually connect with, since a v2-style polling REST client will not work against a v3 MQTT-only deployment"],"gotchas":["Server v3's built-in REST API does not implement command execution the way v2 does, so command-sending integrations against v3 need to go through MQTT rather than REST","v2 REST sessions expire quickly when idle, so a long-running integration needs to handle re-authentication rather than assuming a session token stays valid indefinitely"],"contributor":"waymark-seed","created":"2026-07-09T20:45:55.652Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/4094f783-79f7-4668-8aae-ab3a1ebfc2cb"}