How do I get an API key for an external integration?
API keys are generated in Leon by an account administrator, who selects the scopes (permissions) the key needs and describes its usage purpose. Third-party applications acting on behalf of users should instead register as OAuth clients — contact Leon Support to start OAuth client registration.
Why does my API request return an authentication or permission error?
API errors of this type almost always mean the key is missing a required scope, is expired, or is sent incorrectly in the request. Verify the Authorization header, confirm the key is active, and compare the scopes assigned to the key against the fields your query touches.
Should I update an existing flight via the API or create a new one?
Update the existing flight whenever the operation is a change to an already-scheduled flight — creating a new flight produces a duplicate with a new identifier and breaks the link to checklists, sales data, and history. Create a new flight only for genuinely new legs.
Why did my flight fail to export to an integrated flight-planning system (for example, an EFB)?
Exports fail most often because required data is missing or invalid for the receiving system — for example, missing crew, unrecognized airport codes, or aircraft not mapped in the integration. Check the integration's error message on the flight, complete the missing data, and re-trigger the export.
Why weren't external marketplace requests imported into Leon?
Marketplace requests import only when the integration is active, and the aircraft involved are correctly mapped between the two systems. Verify the integration status and aircraft mapping for the affected tail, and check the integration error notifications configured on your account.
Does Leon provide a sandbox or test account for integration development?
Yes, test accounts with dummy data can be arranged for integrators developing against the Leon API, including OAuth flows. Contact Leon Support with a description of your integration to request one.
Does Leon keep a log of the webhooks it has sent?
No. Leon does not store a delivery history for webhooks. When data changes, the application publishes an internal event, and a separate subscription service performs the HTTP call to your registered endpoint. The only record of an individual delivery lives in that service's logs, which are kept for a limited period and are not visible in Leon. If you need to confirm whether a specific call was sent, contact Leon Support as soon as possible after the event.
What can sometimes be reconstructed is the cause of an event rather than its delivery. A change to Flight Support services on an existing flight writes a system message on the flight, which can be matched against the timestamp of a webhook you received. Assigning default services at the moment a flight is created publishes the same event but writes no message, so that case leaves no trace in Leon at all.
For this reason, we recommend treating webhooks as a notification to act on rather than as the source of truth, and reconciling periodically against the API.
Where can I find the Leon API documentation?
The Leon GraphQL API documentation, including the schema, authentication guidance, and integration guidelines, is available Leon Software API documentation. The schema itself can be introspected with a valid API key.