Errors

Every failure is a problem detail (RFC 9457) with a stable code.

Content-Type: application/problem+json

{
  "type": "https://api.reflowpdf.com/docs/errors#template_not_found",
  "title": "Template not found",
  "status": 404,
  "detail": "No template `invoice-modern`. GET /v1/templates lists them.",
  "code": "template_not_found",
  "request_id": "req_x7Kq2mVb9TcA3pLw"
}

Branch on code: it never changes; title and detail are for people. Every response, failed or not, carries Request-Id: give it to support.

code	Status	What happened	What to do
`invalid_request`	400	A field is missing, unknown or of the wrong type. `detail` names it.	Fix the request; repeating it unchanged gives the same answer.
`invalid_json`	400	The body is not valid JSON.	Send JSON with `Content-Type: application/json`.
`template_not_fillable`	400	A template of yours designed on the page was sent `data`.	Print it without `data`, or make it a template in the editor's Code view.
`invalid_html`	400	The engine could not read the HTML.	Send a whole HTML document.
`template_error`	400	The template does not read: an expression, a tag or a filter it cannot parse. `detail` names each, with its line.	Fix the template — see the template language. Nothing is printed half-read.
`unauthorized`	401	No `Authorization` header.	Send `Authorization: Bearer rpdf_…`.
`invalid_api_key`	401	The key is not valid, or was revoked.	Make a new key in your account.
`license_required`	401	A print condition's profile was asked for without an API key or an engine license's token.	Send one (`Authorization: Bearer …`); `@reflowpdf/engine` sends its license's token itself.
`license_inactive`	402	The engine license is not paid for, or its subscription has ended.	Renew it at app.reflowpdf.com → account menu → Engine licenses. The engine prints as the trial meanwhile.
`plan_required`	403	A claim of the Pro and Max plans (`pdf_a`, `pdf_x`, `pdf_ua: 2`) on another plan.	Choose Pro or Max (account menu → Billing), or leave the option out.
`insufficient_scope`	403	The key may not make this request: it lacks the scope the route asks for — `print`, `templates`, `account`, or `assistant` for the MCP server. `detail` names it.	Give the key the scope (account menu → API keys → Access), or use another key.
`ip_not_allowed`	403	The key is kept to its allowed addresses, and the request came from another. `detail` says from where.	Add the address to the key (account menu → API keys → Access), or send from an allowed one.
`not_found`	404	No such path.	See the reference.
`template_not_found`	404	No such template in the gallery or in your library.	`GET /v1/templates` lists them.
`job_not_found`	404	No such job in this account, or it is over 24 hours old.
`file_not_found`	404	No such file, or it expired (files are kept 24 hours).	Print again.
`license_not_found`	404	No engine license has this key.	Check the key (`rpdfl_…`) you were given with the license.
`font_not_found`	404	No such family in ReflowPDF's font catalogue (`GET /v1/fonts/{family}`).	Give the family yourself: `@font-face`, or `engine.registerFont()` in the engine package.
`method_not_allowed`	405	The path does not take this method.	`Allow` names the one it takes.
`idempotency_in_progress`	409	A request with this `Idempotency-Key` is still being done.	Wait, then repeat to read its response.
`job_not_finished`	409	A job's webhook was asked again before the job finished.	Ask again once it is done.
`no_webhook`	409	A job's webhook was asked again, and the job has no `webhook_url`.	Read the job instead: `GET /v1/jobs/{id}`.
`delivery_in_progress`	409	A job's webhook was asked again while an attempt to deliver it is under way.	Wait (`Retry-After`), then read the job: its `webhook` says how the delivery went.
`file_expired`	410	The answer of an `Idempotency-Key` is no longer kept: the file of a PDF or of images is kept one hour, a link 24 hours; or it was deleted, or could not be kept (the first answer delivered it).	Repeat with a new `Idempotency-Key`.
`payload_too_large`	413	The body is over 15 MB.	Put large images on https URLs instead of `data:` URIs.
`document_too_large`	413	The document is over the size a print lays out.	Split it into parts.
`result_too_large`	413	The result is over the 1 GB a file stored for a link may be.	Ask for the file in the response (`Accept: application/pdf`, no `Idempotency-Key`).
`unsupported_media_type`	415	The body is not JSON.	Send `Content-Type: application/json`.
`document_unreachable`	422	The page of `url` could not be fetched: not a public http(s) address on ports 80/443, it answered an error or redirected more than 5 times, it is not HTML, or it is over 15 MB or 20 s. `detail` says which.	Fetch it yourself and send it as `html`, with `options.base_url` for its relative addresses.
`engine_unavailable`	422	The `engine` named prints here no more (a previous version prints until three newer ones have shipped, 30 days at most). `detail` names the versions that do.	Pin a version `GET /v1/engines` lists, or leave `engine` out for the current one.
`invalid_pdf`	422	A PDF to merge, split or compress is not a PDF, or one that cannot be read. `detail` names the part.	Send the PDF itself; a damaged file may open after it is saved again by its maker.
`pdf_encrypted`	422	A PDF to merge, split or compress is encrypted, and its `password` was not given or is wrong.	Give the part its `password`.
`unfulfillable`	422	Not possible for this document: a claim it cannot keep (`detail` says why — a colour that cannot be converted to the press's inks, transparency PDF/X-1a cannot flatten…), an unknown print condition, a page it does not have, or images over the budget of a request (250 megapixels, 256 MB).	Change the document or the option `detail` names; nothing was counted.
`render_failed`	422	The document could not be laid out.	Check the document; tell support its `request_id` if it persists.
`idempotency_key_reused`	422	The `Idempotency-Key` was used with another request in the last 24 hours.	Use a new key for a new request.
`rate_limited`	429	Too many requests of this account at once, or in the last minutes.	Wait `Retry-After` seconds; the SDKs do. `RateLimit-*` on every answer say where you stand.
`storage_quota`	429	The files your account stores for links fill its space: Free 256 MB, Pro and Max 2 GB (each file is stored 24 hours).	Delete some (`DELETE /v1/files/{id}`), wait for them to expire, or ask for the file in the response instead of a link.
`interrupted`	500	A job (its `error.code`): it was interrupted on our side and could not be run again.	Create the job again.
`internal_error`	500	Something failed on our side; nothing was printed.	Repeat (with the same `Idempotency-Key`); give support the `request_id` if it persists.
`render_failed`	502	The engine failed to print.	Repeat; give support the `request_id` if it persists.
`engine_busy`	503	The engine is busy.	Wait `Retry-After` seconds.
`storage_full`	503	Files cannot be stored for links right now.	Ask for the file in the response, or try again in a few minutes.
`render_timeout`	503	The print took over its time limit: 90 seconds for a request, 3 minutes for a job.	Print a long document as a job; make it lighter, or split it.