Everything you need to call Verisyn.

Lightweight by design. Verisyn has one paid tool and three free ones.

Quick Start

Send a document and one or more evidence files to verify_claims. Files travel as base64 inside a JSON body, both over REST and over MCP.

POST https://verisyn.run/api/asp/verify_claims

{
  "document": {
    "file_name": "board-deck.pptx",
    "file_base64": "..."
  },
  "evidence": [
    { "file_name": "q3.xlsx", "file_base64": "..." }
  ],
  "options": {}
}

Authentication

No API keys, no accounts. Free tools are open. The paid tool is gated by an x402 payment challenge instead of a credential, see Pricing for the full payment details.

verify_claims

evidence is always an array, even when only one file backs the document today. Only the first evidence file is checked against in the current release.

document.file_name	string	Original filename of the document (.docx, .pdf, .pptx, .md).
document.file_base64	string	Base64-encoded document bytes.
evidence[].file_name	string	Original filename of the evidence file (.xlsx, .csv).
evidence[].file_base64	string	Base64-encoded evidence bytes.
options	object	Reserved for future verification options.

Responses

A successful verify_claims call always returns 200 with a Trust Report, including when the trust score is low. A low score is the product working correctly, not a failed request.

{
  "status": "OK",
  "report": {
    "reportId": "report_...",
    "trustScore": 82,
    "claimsChecked": 6,
    "verified": 4,
    "warnings": 1,
    "critical": 1,
    "unmatched": 0,
    "results": [ ... ]
  }
}

Errors

VALIDATION_ERROR	400	The request body did not match the expected schema.
INVALID_DOCUMENT	400	The document could not be read (unsupported format or corrupted file).
INVALID_SOURCE	400	An evidence file could not be parsed (unsupported format, empty, or malformed).
REPORT_NOT_FOUND	404	No report exists for the given report_id.
CLAIM_NOT_FOUND	404	No claim exists on that report for the given claim_id.
TIMEOUT	504	The request exceeded its bounded processing time.

MCP

One Streamable HTTP endpoint. The same payment gate applies whether a tool is called through MCP or through the REST API directly.

POST https://verisyn.run/api/mcp
{ "jsonrpc": "2.0", "id": 1, "method": "tools/list" }

SDK

There is no dedicated client SDK yet. Call the REST API directly with any HTTP client, or connect an MCP client to the endpoint above.

Examples

See the Examples page for realistic input, evidence, and result walkthroughs.