A fact check you can inspect.

Read the contract before the code

These are static example files, not live API endpoints. No claim is sent to a server for assessment, no key is required, and no evidence search is performed. The Atlas archive and its source passage are fictional. The visible interface switches between predefined records to illustrate response semantics.

The proposed model keeps the exact claim, the evidence passage, and the assessment separate. A supported status means the named passage supports the claim within the example’s scope. It is not a universal guarantee of truth. The homepage shows a shortened display record; the downloadable files below use the complete contract.

The fictional source passage

Atlas demonstration release note · paragraph 1

The Atlas demonstration archive opened in 2021. It accepts JSON exports.

This is the entire evidence used in all three examples. It supplies a year and an export format. It does not supply a collection count. No real project, publisher, or study is being assessed.

The complete example record

The supported example contains a stable local claim identifier, an explicit scope, a completion state, and an assessment linked to its evidence. Its source URL leads to the fictional passage on this page.

{
  "schema_version": "1.0",
  "example": true,
  "claim_id": "demo-001",
  "claim_text": "The Atlas demonstration archive opened in 2021.",
  "scope": "Fictional Atlas evidence pack only; not a real-world verification.",
  "processing_status": "complete",
  "assessment": {
    "status": "supported",
    "reason": "The example passage explicitly gives 2021 as the opening year.",
    "evidence": [
      {
        "source_id": "example-release-note",
        "source_title": "Atlas demonstration release note (fictional)",
        "source_url": "https://factapi.com/docs/#sample-evidence",
        "locator": "Paragraph 1",
        "passage": "The Atlas demonstration archive opened in 2021. It accepts JSON exports.",
        "relationship": "supports"
      }
    ]
  }
}

Field reference

Download the local examples

Every file below is included with this website. Open the record directly or save it for your own implementation discussion. The JSON Schema describes this small example contract; it intentionally does not pretend to cover production errors, authentication, billing, or a real service’s operations.

Adapt the pattern, evaluate the behavior

For a production design, add a documented error contract, source-version history, assessment timestamps, authorization, and a privacy-appropriate retention policy. Define whether identifiers are local or externally resolvable. Test unknown labels, missing passages, partial documents, and unavailable sources before letting a consumer interpret the result.

Validate the structure and the semantics separately. A record can satisfy a JSON Schema while containing an assessment that does not follow from its evidence. Keep human-reviewed examples for the support relationship, and test the entire handoff from extraction through the final display.

Continue with structured fact data for provenance, claim extraction for preserving meaning, and LLM evaluation for checking an actual assessment workflow.