fetch-failed

All codes

• Type: error
• Kind: io (the host failed to supply bytes; often transient)

What happened

A range source of @laminapdf/sdk (httpRangeSource) couldn’t get bytes it asked for. The request failed (a network error, a CORS refusal, DNS), or the server answered with a status other than 200 or 206, or with a 206 whose Content-Range (or length) doesn’t match the range asked for. A Content-Range that the browser hides, because CORS doesn’t expose it, looks the same. It is also raised when a callbackSource’s read returns a different number of bytes than it was asked for.

Why

Opening a remote file range by range depends on the server: it must allow the Range request (and, across origins, expose Content-Range, Content-Length and ETag through CORS), and must not compress the response (Content-Encoding breaks byte ranges). Lamina PDF never retries on its own; the error says the bytes are not available.

How to fix

Check that the URL is reachable from where the code runs and that the server sends Access-Control-Allow-Origin, Access-Control-Allow-Headers: Range and Access-Control-Expose-Headers: Content-Range, Content-Length, ETag. Serve PDFs without Content-Encoding. Retry the call yourself if the failure was transient.

Example

const doc = await Document.openRange(httpRangeSource(url)); // throws { code: "fetch-failed", data: { status: 403 } }

Data fields

• reason: network, status, content-range or length (Lamina PDF’s own words). The URL is never included.
• status: the HTTP status, when there was a response.
• expected, got: for length, the bytes asked for and the bytes returned.