Kylon Developer Docs

Kylon proxy endpoints return provider-compatible errors where practical. Shared proxy errors use a small JSON shape.

Missing or invalid API key

{
  "error": "unauthorized",
  "message": "Missing API key"
}

or:

{
  "error": "unauthorized",
  "message": "Invalid API key"
}

Fix: pass a valid Kylon key using x-api-key or Authorization: Bearer.

{
  "error": "unauthorized",
  "message": "No access to the required skill. Please check the agent skill settings."
}

Fix: enable the required provider capability for the agent, or call an endpoint the agent is allowed to use.

Some endpoints validate required fields directly:

{
  "error": "Missing required fields: toolkit, method, url"
}

Fix: check the endpoint documentation and include the required fields.

{
  "error": "payment_required",
  "code": "payment_required",
  "message": "Workspace credits are unavailable or exhausted",
  "details": {}
}

Fix: add credits, reduce usage, or retry after a script-level limit resets.

Buffered provider proxy routes generally return:

{
  "error": "proxy_error",
  "message": "Provider error message"
}

Model-compatible routes may return provider-shaped errors instead, such as OpenAI-style or Anthropic-style error objects.

Status	Recommended action
`400`	Fix the request shape or missing fields
`401`	Check API key and provider access
`402`	Check credits or script-level credit policy
`429`	Back off and retry with jitter
`499`	Client disconnected; retry if still needed
`5xx`	Retry with exponential backoff if the operation is idempotent