Fresh402Open account ↗

Task guide · API 3.0.2 · MCP and REST

A website change detection API
with state between agent sessions.

A short script can fetch a page and compute a hash. Fresh402 is useful when separate agent runs need the same hosted baseline, content rules and bounded evidence without maintaining their own observation database. You decide when each operation runs: this is not an automatic monitoring scheduler.

Try an eligible walletless Check Compare with local tools

Monitor public technical documentation on demand

  1. Register a public HTTPS HTML, JSON or text URL using free fresh402_register or POST /v1/register. Save the real returned watch_id and hash outside the model conversation. Canonical URL and saved content rules identify a watch; repeated registration reuses state without fetching or refreshing.
  2. In a later session, restore that ID and call fresh402_check with {"watch_id":"YOUR_REAL_WATCH_ID"}. Do not supply a URL or override the saved rules. Default max_age_seconds:0 revalidates; a positive age permits cached evidence at the same authorized price.
  3. Read changed, hash, fetched_at and cache/observation fields. A first URL observation can return changed:null, not proof of a change. For structured detail, separately authorize Smart Diff against supported previous, baseline or retained-hash evidence.

Check costs $0.005 USDC / 2 current Web credits; Smart Diff costs $0.015 / 4. Each call has a separate authorization. No combined endpoint, background polling or guaranteed semantic interpretation is implied. Reference selection, retention and recovery.

Compare remotely fetched OpenAPI specifications

Register unfiltered public JSON OpenAPI 3.0/3.1, keep its watch ID, then use fresh402_openapi_contract_diff to inspect supported directional changes against previous or baseline evidence. Supported findings include operation/path, required-field, type/enum/null and effective authentication changes; ambiguous cases require review. The first supported comparison seeds history. $0.020 USDC / 5 current Web credits per call.

Fresh402 does not accept arbitrary local files, fetch external references, parse YAML or execute described API operations. For two files already on your computer, larger contracts or broader compatibility analysis, an established local differ such as oasdiff may be simpler and cheaper. Hosted state is valuable only if your workflow actually needs it.

Extract structured information from a public webpage

fresh402_extract accepts a public URL without registration. It returns bounded readable text, metadata, headings, links and supported structured data. HTML selectors and ignore rules scope noisy regions; exact JSON Pointer inputs select JSON values. Optional feed_mode:entries supports bounded RSS2/Atom projection. No linked-page crawl or general JavaScript rendering. $0.010 USDC / 3 current Web credits.

For recurring observations, a Check can decide whether separately paid extraction is useful. Check plus Extract costs $0.015 / 5 credits, not the price of one bundled operation. A local parser such as Trafilatura or an ordinary HTTP request may suit a one-off page better. Exact inputs and constraints.

Observe public Base wallet and smart-contract state

The finalized Base mainnet pilot exposes Contract Watch ($0.010), Wallet Watch ($0.020) and Token Facts ($0.010 USDC). It provides bounded single-provider evidence, not a full transaction index, safety score, financial advice or complete contract audit. Shared RPC limits can deny work. Existing Web prepaid rights do not automatically cover these tools; eligible finalized all-service credits and explicit terms apply. Coverage and limitations.

Start free; inspect payment requirements deliberately

Connect an ordinary Streamable HTTP MCP client to https://api.fresh402.com/mcp. For an eligible walletless Check, first require instant_evaluation.enabled:true at API discovery, then call fresh402_check with {"url":"https://example.com/","evaluation":true}. No wallet, API key, custom header or proprietary SDK is needed. One attempt per verified network prefix per approved period shares finite capacity; exact replay returns the retained original result, not a new fetch. A 429 never authorizes payment.

The expanded machine trial is different: it requires an unfunded EOA ownership signature and a private trial credential. Paid operations require explicit compatible x402, enabled native MPP or prepaid authorization. A normal unsigned paid request returns payment requirements; inspect the network, native USDC asset, exact price, recipient and original resource before any separately approved signing. HTTP 402 is not a payment or result. Recover an uncertain original with its original evidence and private recovery material; never authorize a replacement as a retry. Payment and recovery details.

Use a local solution when it already fits

If you already retain ETags, baselines, normalization rules and diff evidence, Fresh402 may add little value. Prefer local tools for one-off supplied files or unsupported formats. Fresh402 has no arbitrary authenticated crawling, general browser rendering, automatic scheduling or universal correctness guarantee. Security and limits · All current prices and package scopes · Standard-client quickstart.