WebLens
Premium web intelligence API for AI agents, with x402 micropayments. No account needed — pay per request in USDC on Base or Solana.
🌐 Live API: https://api.weblens.dev 📖 Interactive docs: https://api.weblens.dev/docs 🤖 Agent guide: https://api.weblens.dev/llms.txt 🔎 Marketplace: listed on x402scan
Try it free, right now
No wallet, no signup — these are rate limited to 10 requests/hour per IP:
curl https://api.weblens.dev/r/https://example.com # any page as markdown
curl https://api.weblens.dev/s/cloudflare+workers # web search
Preview before you pay (free)
An agent shouldn't have to buy a call to learn what it returns. POST /preview is free and
answers that up front — the live price, a one-line summary, and a real sample of the exact
response shape:
curl -X POST https://api.weblens.dev/preview \
-H "Content-Type: application/json" \
-d '{"endpoint": "/answer"}'
{
"endpoint": "/answer",
"price": "$0.05",
"currency": "USD",
"summary": "A direct answer with inline [n] citations to real sources.",
"sample": { "query": "...", "answer": "...", "citations": [], "confidence": 0.92 },
"sampleType": "recorded",
"livePreviewAvailable": false,
"livePreviewHint": "This endpoint calls a paid upstream provider, so free live previews are not offered — the recorded sample shows the exact response shape."
}
Live vs recorded. A real, truncated live preview runs only for endpoints whose marginal cost
is a plain fetch — currently /fetch/basic, /contents and /map — and only when you pass a
url. Everything else is backed by a metered upstream (SerpAPI, Anthropic); running those free
would burn upstream credits, so they return the recorded sample, which still shows every field
name and type. An endpoint that isn't sold returns 404.
# live: the first 500 chars of the real result, for free
curl -X POST https://api.weblens.dev/preview \
-H "Content-Type: application/json" \
-d '{"endpoint": "/fetch/basic", "url": "https://example.com"}'
Rate limited to 10 requests/hour per IP like the rest of the free tier.
ERC-8004: receipts and feedback
ERC-8004 (Trustless Agents) keeps compact signals on-chain and the detailed documents off-chain. WebLens hosts the off-chain half — the part a service operator can run without deploying a contract. To be precise about what that is and isn't: WebLens is not registered on-chain, holds no agent id, and writes nothing to any registry.
Two more things worth stating plainly:
- A receipt is unsigned. Its evidence is the settlement
transactionit names, which anyone can check on-chain; nothing else here is trustless. - The buyer authors the feedback document and posts
giveFeedback()themselves. WebLens only hosts the document verbatim and returns its hash; it never authors, edits, or submits feedback.
Endpoints
All paid endpoints are POST with a JSON body. Prices are per request in USDC.
Core
Search
Social
Extraction & research
/research/deep is the only long-running endpoint: it plans sub-questions, runs a web search per
sub-question, fetches and dedupes the sources, then synthesizes a cited answer — all in one
synchronous call. A standard run (3 sub-questions, 8 sources, $0.20) takes roughly 30–60
seconds; deep (5 sub-questions, 12 sources, $0.35) takes longer. Set a generous HTTP timeout
(120s+) and don't retry on a client timeout, or you'll pay twice.
Intelligence
Free and unauthenticated: /, /health, /docs, /openapi.json, /llms.txt, /discovery, /.well-known/x402, /mcp, /r/{url}, /free/fetch, /preview, /.well-known/agent-registration.json, /receipts/{requestId}, /feedback, /feedback/{id}.
Dynamically-priced endpoints (/fetch/pro, /extract) apply a complexity multiplier — up to 3× for bot-protected domains. Cached responses on the fetch family are 70% cheaper. The exact price is always in the 402 challenge.
Use with AI agents (MCP)
Remote HTTP — nothing to install:
{ "mcpServers": { "weblens": { "url": "https://api.weblens.dev/mcp" } } }
API usage
# Fetch a page as markdown
curl -X POST https://api.weblens.dev/fetch/basic \
-H "Content-Type: application/json" \
-d '{"url": "https://example.com"}'
# Search, with page content included
curl -X POST https://api.weblens.dev/search \
-H "Content-Type: application/json" \
-d '{"query": "latest AI news", "limit": 5, "includeContent": true}'
# Structured extraction
curl -X POST https://api.weblens.dev/extract \
-H "Content-Type: application/json" \
-d '{"url": "https://example.com/product",
"schema": {"title": {"type": "string"}, "price": {"type": "number"}},
"instructions": "Extract the product title and price"}'
# Crawl a site (pay for the page budget you request)
curl -X POST https://api.weblens.dev/crawl \
-H "Content-Type: application/json" \
-d '{"url": "https://example.com", "limit": 10, "maxDepth": 2}'
# Deep research with inline citations (slow — 30-60s, so raise the client timeout)
curl --max-time 120 -X POST https://api.weblens.dev/research/deep \
-H "Content-Type: application/json" \
-d '{"query": "How are AI agents using micropayments in 2026?", "depth": "standard"}'
Each returns 402 Payment Required with the price until you attach payment — see below.
How payments work
WebLens implements x402 v2:
POSTany paid endpoint with no payment.- Get
402 Payment Requiredwith aPAYMENT-REQUIREDheader carrying the price, network, asset, and pay-to address. - Sign a USDC transfer authorization with your wallet.
- Retry the same request with a
Payment-Signatureheader. - The payment is verified on-chain and you get your data.
On Base, payments settle through Coinbase's CDP facilitator, with PayAI taking over any payment CDP fails on; on Solana, through PayAI. Any x402 v2 client works — @x402/axios, @x402/fetch, or the bundled MCP server, which handles the whole flow for you.
Prepaid API keys are the alternative for developers who pay by card, where card sales are switched on: POST /billing/checkout {"pack": "10"} returns a Stripe Checkout link for a $10, $50 or $100 pack, and the page after payment shows an API key once. Send it as Authorization: Bearer <key> on any paid endpoint; each call is debited at its list price, and failed calls are refunded. GET /account shows the balance.
Development
pnpm install
pnpm run dev # local dev server on :8787
pnpm run build # tsc --noEmit (type check)
pnpm run lint # eslint
pnpm run test # vitest (unit + property + workerd integration)
pnpm run deploy # wrangler deploy (production)
Secrets are set with wrangler, never committed:
wrangler secret put SERP_API_KEY # search + all verticals + transcripts
wrangler secret put ANTHROPIC_API_KEY # AI extraction, research, answers, intel
wrangler secret put CDP_API_KEY_ID # optional: CDP facilitator fallback
wrangler secret put CDP_API_KEY_SECRET
Testing against testnet
wrangler dev --env testnet # Base Sepolia, fake USDC
API_URL=http://localhost:8787 PRIVATE_KEY=0x... npx tsx scripts/test-payment-testnet.ts
Get free testnet USDC from the Circle faucet on Base Sepolia.
Discovery
pnpm run verify-bazaar # check the x402 discovery extension on every route
/openapi.json doubles as the discovery document for x402scan — it carries info.x-guidance, per-operation x-payment-info, and security: [] on free operations. WebLens is listed on x402scan and indexed in the PayAI facilitator catalog.
Note on the Coinbase CDP Bazaar: it only indexes services whose payments the CDP facilitator itself settles. WebLens uses PayAI as its primary facilitator (CDP has an open Base-mainnet settlement bug, x402#1065), so it does not appear there.
Tech stack
- Cloudflare Workers — edge runtime, Durable Objects, KV, Browser Rendering
- Hono — web framework
- x402 — HTTP-native micropayments
- Zod — request validation
- Vitest + fast-check — unit, property, and real-workerd integration tests
Links
License
MIT