Errors

Errors are always JSON with a stable machine-readable code:

{
  "error": {
    "code": "render_timeout",
    "message": "Page did not finish rendering within the time limit…",
    "docs": "https://rasterkit.com/docs/errors#render_timeout"
  }
}

Catalog

Code	HTTP	Retry?	Meaning
`invalid_request`	400	No — fix the request	Validation failed; details[] lists each problem.
`unauthorized`	401	No — fix the key	Missing or unknown API key (X-Api-Key header or Bearer token).
`signature_invalid`	401	No	Signed URL signature mismatch.
`signature_expired`	401	No — re-sign	Signed URL past its expires timestamp.
`quota_exceeded`	402	After upgrade	Free plan hard stop at 100 renders/month.
`key_suspended`	403	No — contact support	Key revoked or account suspended.
`template_not_found`	404	No	No such template on your account.
`job_not_found`	404	No	Unknown job id (or not yours).
`payload_too_large`	413	No — shrink the body	Body over 10 MB.
`template_invalid`	422	No — fix the template	Handlebars compilation failed.
`navigation_failed`	422	Maybe	Target URL unreachable (DNS, connection, TLS).
`rate_limited`	429	Yes — with backoff	Plan requests/second exceeded. See Retry-After.
`spend_cap_reached`	429	After raising cap	Soft overage protection on paid plans (4× included by default).
`url_blocked`	451	No	URL resolves to a private/reserved address (SSRF protection).
`internal_error`	500	Yes — once	Our fault. Logged with your request id.
`render_timeout`	504	Yes — tune waits	Page did not settle within timeout_ms.

Retry guidance

rate_limited — wait for Retry-After (1 s) and retry; better, add client-side throttling to your plan's req/s.
render_timeout — retry once; if persistent, lower wait_until to domcontentloaded or raise timeout_ms.
internal_error — retry once with backoff, then contact support with the request time and endpoint.
Validation errors (invalid_request) include a details array listing each failing field — fix and resend, don't retry blindly.