11 APIs for the decisions an agent cannot afford to guess.

One payment rail. No account, no API key, no subscription. Every answer carries evidence you can check, and a failed call is never charged.

Two families. Guards answer whether an action is safe while it is still reversible — an unsigned Base transaction, a token approval, a payment destination, a PostgreSQL statement, a shell command. Resolvers turn ambiguous input into a checked answer — a document into schema-valid JSON, a local time into an exact instant, an untrusted page into clean text, an address or a receipt into decoded facts.

• Evidence, not confidence scores. Findings carry a stable code, a severity, and the decoded payload that produced them. A caller can act on "the tag block at offset 1841 decodes to ignore all previous instructions"; nobody can act on 0.87.
• "Unknown" is a real answer. It outranks a warning and is never quietly downgraded to allow. A preflight that cannot say "I do not know" converts absence of evidence into assurance of safety.
• Deterministic outside extraction. Nine of 11 routes run no model on any path, so the same input and declared data versions give a byte-identical answer, permanently.
• Nothing is retained. Caller content is processed in memory and never persisted. Analytics record non-content fields only.

The 11 APIs

Pick a row by what you are about to do. Every route is pay-per-call over x402 V2 with USDC on Base mainnet, needs no account and no API key, and settles only once it has produced a usable answer. This origin serves the two extraction routes; the other 9 run on their own subdomains and each stays authoritative for its own schemas, benchmarks, and payment manifest.

Prices shown as "list" are for orientation only; the authoritative amount always comes from that service's live 402 challenge. For a machine-readable index of every capability, read /apis.json or /SKILL.md.

Extraction, the two routes served from this origin

Everything below documents the two extraction routes only, because they are the ones hosted here. The other 9 APIs are documented at their own origins — follow the brief links in the table above rather than reading this section for them.

Send text, HTML, or a PNG/JPEG/WebP image plus your JSON Schema. Receive JSON that validates with Ajv draft 2020-12, or a typed error and you are not charged.

• Text/HTML evidence: Benchmarked 100% schema-valid with ~0.99 field F1 and zero hallucinations across a 10-doc-type text/HTML corpus (11 items, incl. an adversarial prompt-injection tier), p50 latency ~1.5s and p95 ~57.7s. Evidence: /.well-known/benchmarks.json.
• Image evidence: Five real paid image calls passed schema validation and all 148 independently transcribed field anchors across a synthetic invoice/receipt launch corpus, with p50 latency ~2.6s and p95 ~4.1s. Small-corpus limitations are published at /.well-known/image-benchmarks.json.

PDFs and multi-image requests are not supported. Convert each page to PNG, JPEG, or WebP and call the image endpoint once per image.

Production API: V2

POST /v2/extract is the canonical SchemaSure API for production agents, integrations, and marketplace discovery. It is always paid from the first call and uses x402 V2 with USDC on Base mainnet (eip155:8453).

curl -i -X POST https://schemasure.com/v2/extract \
  -H 'content-type: application/json' \
  -d '{"input":"Invoice #A-1042 — Acme Corp. Total due: $1,299.00 USD on 2026-08-01.","schema":{"type":"object","additionalProperties":false,"required":["invoiceNumber","total","currency","dueDate"],"properties":{"invoiceNumber":{"type":"string"},"total":{"type":"number"},"currency":{"type":"string","enum":["USD","EUR","GBP"]},"dueDate":{"type":"string","format":"date"}}}}'

Do not hardcode payment terms—validate the live challenge. The server verifies before work and settles only after producing schema-valid output.

Document image extraction: V2 only

POST /v2/extract-image reads invoices, receipts, forms, labels, screenshots, and photographed documents into your JSON Schema. Send base64 PNG, JPEG, or WebP bytes. This service is always paid via x402 V2 from the first call—there is no free or V1 image endpoint.

IMAGE_BASE64=$(base64 < invoice.png | tr -d '\n')
curl -i -X POST https://schemasure.com/v2/extract-image \
  -H 'content-type: application/json' \
  -d '{"image":{"data":"'"$IMAGE_BASE64"'","mimeType":"image/png"},"schema":{"type":"object","required":["invoiceNumber","total"],"properties":{"invoiceNumber":{"type":"string"},"total":{"type":"number"}}}}'

Successful response (data validates against the schema supplied in the request):

{
  "data": {
    "invoiceNumber": "INV-2048",
    "vendor": "Northstar Supplies",
    "total": 382.45
  },
  "meta": {
    "repairs": 0,
    "latencyMs": 910,
    "validated": true
  }
}

Maximum decoded image size: 8 MiB. The declared MIME type must match the file signature. Clear, upright, high-resolution images work best.

Try free on legacy V1

Evaluate extraction quality without connecting a wallet: the legacy POST /extract endpoint includes 3 limited free calls per client. When you are ready to automate or increase usage, move the agent to V2.

curl -X POST https://schemasure.com/extract \
  -H 'content-type: application/json' \
  -d '{"input":"Invoice #A-1042 — Acme Corp. Total due: $1,299.00 USD on 2026-08-01.","schema":{"type":"object","additionalProperties":false,"required":["invoiceNumber","total","currency","dueDate"],"properties":{"invoiceNumber":{"type":"string"},"total":{"type":"number"},"currency":{"type":"string","enum":["USD","EUR","GBP"]},"dueDate":{"type":"string","format":"date"}}}}'

Extraction pricing

• Text/HTML: $0.02/call, flat, failed calls free.
• Image: $0.06/image, flat, failed calls free. V2-only; no free image calls.
• Primary V2 API — USDC on Base mainnet. No signup, API keys, or account dashboard.
• Charge-only-on-success: verified up front, settled only after valid output is produced.
• Free evaluation calls are available only on the legacy V1 endpoint.

Why agents can trust extraction

Extraction error handling and retry policy

Every error is JSON: {"error":{"code":"...","message":"...","details":{...}}}. Do not blindly replay a paid request after losing its response; request idempotency is not yet available.

Text V2 request & response example

Canonical request body for /v2/extract:

{
  "input": "Invoice #A-1042 — Acme Corp. Total due: $1,299.00 USD on 2026-08-01.",
  "schema": {
    "type": "object",
    "additionalProperties": false,
    "required": [
      "invoiceNumber",
      "total",
      "currency",
      "dueDate"
    ],
    "properties": {
      "invoiceNumber": {
        "type": "string"
      },
      "total": {
        "type": "number"
      },
      "currency": {
        "type": "string",
        "enum": [
          "USD",
          "EUR",
          "GBP"
        ]
      },
      "dueDate": {
        "type": "string",
        "format": "date"
      }
    }
  }
}

Response (data validates against your schema; meta reports repairs and latency):

{
  "data": {
    "invoiceNumber": "A-1042",
    "total": 1299,
    "currency": "USD",
    "dueDate": "2026-08-01"
  },
  "meta": {
    "repairs": 0,
    "latencyMs": 640,
    "validated": true
  }
}

Best results come from describing your fields: a per-field description in your schema is the biggest accuracy lever. Max input 256 KB per call.

Extraction via MCP

Machine-readable discovery surfaces:

/llms.txt /SKILL.md /openapi.json /.well-known/x402 /.well-known/x402-image /.well-known/x402-v1 /.well-known/pricing.json /.well-known/benchmarks.json /.well-known/image-benchmarks.json /apis.json /.well-known/security.txt /.well-known/data-handling.json

MCP: run npx -y @noamjose/schemasure. The published thin client exposes extract_to_schema and extract_image_to_schema; set SCHEMASURE_PRIVATE_KEY for paid x402 V2 mode. The dedicated wallet signs locally and the key never reaches SchemaSure. Package and setup.

Data handling: production does not persist raw text, HTML, images, schemas, or extracted output. /metrics is an ephemeral per-process operational snapshot that resets on deploy; it is not an adoption counter.