Data and API policy

Evidence, not an authoritative record

VAT Ledger distinguishes source facts from its own interpretation. Filed routes are intentions, airborne observations are snapshots, and detected movements are rule-based inferences. Event attribution and movement detection can be incomplete or wrong and must not be represented as official VATSIM records.

Data sources and retention

The archive is built from the public VATSIM network and event feeds plus open airport reference data from OurAirports. It may include CID, name, callsign, controller position, frequency, flight plan, aircraft type, position and timestamps. Operational data is retained for up to 24 months. VAT Ledger has no guaranteed historical coverage before its collector first observed a record.

Acceptable API use

• Respect response labels, rate-limit headers and uncertainty disclosures.
• Cache responses where appropriate and identify VAT Ledger as the source.
• Do not circumvent quotas by rotating keys or accounts.
• Do not use the API to harass, track, profile or target individual VATSIM members.
• Do not resell or bulk republish the archive as an authoritative flight record.
• Protect API keys and revoke them promptly if exposed.

Quota units and access

Default accounts may hold three active keys. Each key allows 30 quota units per minute, with a shared account allowance of 60 units per minute and 5,000 units per UTC day. Most requests cost one unit; airport detail requests cost two. Successful responses include minute-limit headers, and quota errors include a reset time and Retry-After. Access may be suspended for abuse, security risk or a material breach of this policy.

See the API reference for endpoint costs and authentication details.

Corrections and contact

To report inaccurate attribution, request a data review or discuss a higher API allowance, contact simon@bjerrebakholdt.dk.