APIs › Document & File Utilities › File Type Detection

File Type Detection

Identifies the true file type from magic bytes and structure rather than the filename, returning the matched signature.

POST /v1/files/type-detect $0.003 per call

Specification

Endpoint

POST /v1/files/type-detect

Price

$0.003 per call · tier micro_data

Payment

x402 on X Layer (chain 196) · settled in USDG or USDT0 · schemes exact, aggr_deferred

Data source

Local sandboxed processing of the uploaded file

Timeout

120 seconds

Max request

20 MB

Version

1.0.0

Calling it

The first call returns a 402 with the payment challenge. Retry with a signed authorisation in the X-PAYMENT header — see the payment guide for the exact shape.

curl -i -X POST "https://api.dana-edu.pp.ua/v1/files/type-detect" \
  -H "content-type: application/json" \
  -d '{ ... }'

Response

Real output, captured by running this endpoint at build time — not written by hand. Volatile fields such as timestamps are elided. Captured 2026-07-30.

{
  "filename": "<varies per call>",
  "size_bytes": 1764,
  "declared_content_type": "application/pdf",
  "detected": {
    "detected": true,
    "mime_type": "application/pdf",
    "extension": "pdf",
    "label": "PDF document",
    "is_executable": false,
    "is_archive": false,
    "matched_signature": "255044462d",
    "signature_offset": 0
  },
  "declared_matches_detected": true,
  "method": "magic-byte signature matching on the file's content. The filename and the declared Content-Type are reported but never used to decide."
}

Every response is wrapped in the same envelope: data plus warnings, sources, confidence, informational_only and a measured processing_ms. See the envelope reference.

Related endpoints