Transient documents, durable evidence

Visual document diff for failed attachment assertions

When an attachment hash or fingerprint fails, SpecTestEngine can render the actual response temporarily and open a protected review link. Upload the expected file yourself, inspect page-level changes, tune sensitivity, and decide whether the difference is a regression or a reviewed baseline update.

What you can do

  • Compare PDF and image responses page by page with Expected, Actual, and Changes views.
  • Create immutable diff generations when sensitivity changes, while preserving the earlier diagnostic result.
  • Copy an organization- and project-scoped viewer link so an AI agent or teammate can direct the authorized user to the same evidence.
  • Preview the new attachment hash and fingerprint before creating a baseline-update draft; the specification is never silently overwritten.
  • Mark evidence as a confirmed regression or requiring investigation and retain that decision with the diff metadata.

Starts with

  • A failed document attachment assertion from a REST, SOAP, GraphQL, or mixed Flow run.
  • The actual response attachment captured only for immediate in-memory rendering.
  • A reference PDF or image uploaded by the authorized user, plus optional comparison sensitivity.

Produces

  • Encrypted rendered page artifacts, changed-page counts, pixel-change ratio, and immutable generation history with a diagnostic TTL.
  • A protected viewer URL, status, expiry time, and summary usable from UI, SDK, or MCP.
  • A reviewed baseline hash and fingerprint proposal for a new specification revision. Raw response and uploaded reference documents are not stored.

Use it when

  • Investigate invoices, reports, statements, tickets, labels, charts, or generated PDFs whose attachment assertion changed.
  • Separate harmless visual movement from a real regression by regenerating with an explicitly reviewed threshold.
  • Let an AI agent report a failed document assertion and hand the user a direct protected evidence link.
  • Refresh expired evidence by rerunning the source specification or flow step, then compare it with the reference again.
  • visual document diff
  • attachment assertion
  • PDF diff
  • image diff
  • document regression
  • baseline update
  • encrypted derivative
  • diagnostic TTL

Visual document diff

response.body · REST_SPEC_RUN · run docs-run-42
Expires 8/3/2026, 6:00:00 PMREADY
Page 1
diff document page 1
Comparison controls
Reference document
Choose the document used to create the assertion hash.
Sensitivity24
1Changed pages
1.74%Changed pixels
2Generation
Generation 2