Unrecognizable bytes are rejected before any request. The result package is downloaded as a stream with a cumulative size cap, and error statuses are classified before the size check. Parsing runs in a worker thread so cancellation and call deadlines stay effective. parse_layout shares the first protocol stage without behavior change.
The service wraps every failure, including its own 400s, as a 500 with a parsing-failed detail. Only a fixed set of known bad-input markers is narrowed to a rejected request, and only when the caller passes markers; the shared default classification is unchanged.
Content comes from the middle json and its paired markdown; the content list is deliberately ignored because it escapes markdown characters. The external-data exception boundary covers both reading and structure parsing so no native exception escapes the OCR client. The layout parser is unchanged.
The service dispatches on the upload filename extension. A PDF sent as image.jpg made /ocr/text return a success response with hallucinated text. Only PDFs are relabelled; everything else keeps the legacy image label.
Verifier mutation test: flipping _translate_429 to parse the summary
left all 824 tests green. The padding was one long string value, so the
cut landed inside it - and head-and-tail retention kept the trailing
error object, leaving the summary parseable. Many keys put the cut
between structural tokens, where the summary stops being valid JSON.
Mutation now fails as it should. Also splits OCR 429 out on its own.
Issue #10 Task 4: the OCR side said only 'HTTP 404'. The issue reported
the chat path, but the batch that lost its 400 was reading tables - the
same blind spot, one transport over. Reuses the shared summarizer.
iomgaa