# Fresh402

> Fresh402 2.2.0 is a pay-per-use web intelligence API for agents and developers, available through REST and MCP.

Use Fresh402 to check whether a web source has changed before reusing it, extract content for retrieval, or compare a persistent watch with its previous snapshot or fixed baseline. It processes public HTTPS HTML, JSON and text without executing JavaScript, rendering a browser or using LLM inference. Target security checks and rate, size and capacity limits apply.

## Free operations

- POST /v1/register (MCP: fresh402_register): create a persistent baseline or retrieve an existing watch. Re-registering the same watch does not fetch the target again.
- GET /v1/history and GET /v1/diff: read retained legacy snapshot metadata and deterministic text differences; these never fetch a target and do not expose paid Smart Diff results.
- Service metadata, OpenAPI, x402 discovery and MCP tool discovery are free.

## Paid operations

- Check: POST /v1/check (MCP: fresh402_check), $0.005 USDC per call. Check a URL or watch for changes, with noise filtering, conditional HTTP and an optional compact deterministic diff.
- Web Extract: POST /v2/extract (MCP: fresh402_extract), $0.01 USDC per call. Extract text, metadata, headings, links and JSON-LD, with optional CSS scoping.
- Smart Diff: POST /v2/smart-diff (MCP: fresh402_smart_diff), $0.015 USDC per call. Compare a watch against its previous Smart Diff snapshot or baseline using structural changes and deterministic significance rules.

Payment uses x402 v2 exact USDC on Base mainnet (eip155:8453). REST calls without payment return HTTP 402 with PAYMENT-REQUIRED requirements. MCP tools return an isError payment challenge with requirements in structuredContent; HTTP 200 alone does not mean a paid call succeeded. Read the challenge for the current amount, asset, network and recipient before signing. REST payment goes in PAYMENT-SIGNATURE; MCP payment goes in params._meta["x402/payment"]. Confirmed settlement returns a receipt in PAYMENT-RESPONSE or result._meta["x402/payment-response"].

Persist a client-generated recovery token before paying, following the OpenAPI recovery parameter. Retry identical input with the original payment and recovery token to recover a retained paid result without another settlement. If settlement is pending, do not sign a replacement payment.

## Documentation and discovery

- [Public API reference (OpenAPI 3.1)](https://fresh402.kirilllabs.workers.dev/openapi.json): request schemas, examples, payment headers, recovery parameters and response formats; authoritative API documentation.
- [MCP endpoint](https://fresh402.kirilllabs.workers.dev/mcp): Streamable HTTP; use POST initialize and tools/list for tool discovery. GET is not supported.
- [x402 discovery](https://fresh402.kirilllabs.workers.dev/.well-known/x402): paid REST resource URLs.
- [Service metadata](https://fresh402.kirilllabs.workers.dev/): deployed version, endpoints and pricing.
- [Project README](https://github.com/kirillradchenko96/fresh402): public project documentation.