Change-detection alerts, billed on a real self-custody rail.

01Quickstart — watching your first page

Every call is https://<host>/… — same origin on the public storefront, no CORS, no SDK. A key is minted open (no account), then everything after it is yours alone.

# 1 · mint an API key — shown once, hashed at rest
curl -X POST https://<host>/keys \
  -H 'content-type: application/json' \
  -d '{"name":"my-agent","start_credits":0}'
# → { "customer_id":3, "api_key":"4f2e…(48 hex)", "credits":0 }

# 2 · watch a URL, webhook on change
curl -X POST https://<host>/watch \
  -H "authorization: Bearer $KEY" -H 'content-type: application/json' \
  -d '{"url":"https://example.com","webhook_url":"https://myapp.app/hooks/watchbot"}'
# → { "watched":true, "id":12, "url":"https://example.com", "webhook_url":"…" }

# 3 · buy credits → real invoice (USDC/USDT/ETH)
curl -X POST https://<host>/purchase \
  -H "authorization: Bearer $KEY" -H 'content-type: application/json' \
  -d '{"credits":900}'
# → { "order_id":19, "asset":"USDC", "min_usdc":"9.000000", "recipient":"0xFCEf…b50e", "accept_on":[…], "expires_at":"…" }

# 4 · the moment payment confirms, Watchbot credits you and calls your webhook
curl https://<host>/orders -H "authorization: Bearer $KEY"
# → paid orders flip to "paid" automatically

02Authentication

Register via POST /keys (open — no account, no KYC on the earning side). The bearer key is returned once, then only its SHA-256 hash is stored — it cannot be re-read or reset. Send it as Authorization: Bearer <key>.

03Endpoints

{
  "ok": true,
  "uptime_s": 598,
  "targets": 1, "customers": 3,
  "poll_interval_ms": 60000,   // target poll cadence
  "price_per_check": 1         // credits per check
}

{
  "product": "Watchbot", "rail": "live",
  "settlements": 1,
  "revenue_usd": 6.78,          // settled value, $1 → 100 credits
  "credits_issued": 678,
  "first_paid_at": "2026-09-11 17:38:19",
  "open_orders": 0,
  "changes_detected": 230,
  "note": "revenue = landed value credited (USDC/USDT at 6-dec, ETH at live CoinGecko rate)",
  "at": "2026-09-11T20:05:11.184Z"
}

{
  "customer_id": 3,
  "name": "my-agent",
  "api_key": "4f2e…48 hex chars…",
  "credits": 0,
  "note": "store this key — bearer auth, hashed at rest, shown once"
}

// 200
{ "deleted": true }
// 404 — not your target, or no such target

[
  { "id": 44, "target_id": 12, "url": "https://example.com",
    "from_hash": "0f2a…", "to_hash": "9c1e…", "type": "content changed",
    "at": "2026-09-11 12:34:56" }
]

{
  "customer": "my-agent",
  "balance_credits": 834,
  "plan": null,
  "usage": [
    { "kind": "topup",    "credits": 900,  "at": "…" },
    { "kind": "check",    "credits": -1,   "at": "…" }
  ]
}

{
  "order_id": 19,
  "status": "pending",
  "asset": "USDC", "min_usdc": "9.000000", "credits": 900,
  "recipient": "0x0732C669c7C971DaD117a58e22F93D70c111233C",
  "accept_on": [
    { "chain": "Base", "tokens": ["USDC","USDT"], "explorer": "https://basescan.org/tx/" },
    { "chain": "Ethereum", "tokens": ["USDC","USDT"], "explorer": "https://etherscan.io/tx/" }
  ],
  "also_accept": [
    { "asset": "ETH", "chain": "Ethereum", "note": "native ETH, any amount — credited at the live CoinGecko rate" }
  ],
  "expires_at": "2026-09-12T17:38:19.000Z",
  "how": "send USDC or USDT (any amount ≥ the minimum) on any listed chain, or native ETH on Ethereum, to the recipient. Watchbot credits you automatically — credits = dollars you sent × 100 …"
}

Lead Radar — business leads from several sources, 10¢ per lead with email

Say who and where ("dentists in Austin TX"). Lead Radar searches Google Maps, OpenStreetMap and Wikidata (plus Foursquare, TomTom and Geoapify where enabled), merges them into one record per business, and returns the businesses with name, address, phone, website, rating, review count and — where the business publishes one — an email found on its own site. Leads with an email cost 10 credits (10¢); leads without one are free. The easiest way in is the Lead Radar panel in your dashboard.

Radars — ranked, 5¢ a match

Two sibling radars run on the same rail and the same honest rule: nothing is delivered unpaid, and a ranked match costs 5 credits (5¢) from your prepaid balance. Grant Radar ranks non-dilutive grant feeds hourly. Tender Radar ranks World Bank procurement + US Federal Register notices deadline-first and records the exact terms each match hit (matched_terms), so a capability profile self-corrects instead of being a blind keyword box. Both are idempotent — every opportunity delivers to a profile exactly once, and a fresh profile catches up on the recent pool on its first scan.

{
  "matches": [
    { "title": "…Rural Water Supply…", "source": "worldbank",
      "fit": 3, "matched_terms": "water, construction, consultancy",
      "deadline": "2026-10-02T00:00:00Z",        // ISO; missing deadline sorts last
      "sector": "…", "country": "Congo, Democratic Republic of",
      "meta": "{\"method\":\"Request for Quotations\",\"ref\":\"…\"}",
      "link": "https://projects.worldbank.org/…",
      "delivered_at": "…" }
  ]
}

Pulls the NVD CVE feed every 6 hours and alerts only when a CVE's description or CPE touching your technologies clears your severity threshold. Each ranked alert debits 5 credits.

curl -X POST https://store.watchtbot.site/vuln-profiles \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name":"web stack","technologies":"nodejs express postgresql","severity_threshold":"high"}'

Scans arXiv daily against your keywords. Each ranked paper debits 2 credits — titles, abstracts, authors via GET /paper-matches.

curl -X POST https://store.watchtbot.site/research-profiles \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name":"my research watch","keywords":"transformer calibration rlhf"}'

Watches npm/PyPI/RubyGems/crates.io releases plus OSV advisories for the packages you name, every 6 hours. Updates debit 3 credits; one debit per newly vulnerable package.

curl -X POST https://store.watchtbot.site/dep-profiles \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name":"my deps","package_registry":"npm","dependencies":["lodash","express"]}'

Watch a CoinGecko coin for price thresholds, checked every 15 minutes. 2 credits per check, 5 per fired alert (one fire per condition per hour).

curl -X POST https://store.watchtbot.site/crypto-alerts \
  -H "Authorization: Bearer YOUR_KEY" -H "Content-Type: application/json" \
  -d '{"coin_id":"bitcoin","above":100000,"below":60000}'

Watch any of 166 currency pairs off the er-api feed, checked hourly. 2 credits per check, 5 per fired alert (max one per 45 min).

curl -X POST https://store.watchtbot.site/fx-alerts \
  -H "Authorization: Bearer YOUR_KEY" -H "Content-Type: application/json" \
  -d '{"base":"USD","quote":"INR","below":92}'

Watch NWS active alerts for US states, scanned every 15 min. 3 credits per sweep that surfaces a new matched event, 5 per alert sent.

curl -X POST https://store.watchtbot.site/weather-profiles \
  -H "Authorization: Bearer YOUR_KEY" -H "Content-Type: application/json" \
  -d '{"states":"NC,VA","severity_threshold":"severe"}'

04Webhook delivery

When a watched page's fingerprint changes, Watchbot POSTs to your webhook_url with a JSON body. Payload:

// Header: content-type: application/json · user-agent: Watchbot/0.2
{
  "event": "target.changed",
  "target_id": 12,
  "url": "https://example.com",
  "from_hash": "0f2a1b…",   // previous fingerprint
  "to_hash":   "9c1e77…",   // new fingerprint — different ⇒ content changed
  "at": "2026-09-11 12:34:56"
}

05Rails · credits · invoices

The automaton earns on a self-custody wallet — no platform escrow between payer and earner.

06Errors

Errors are always JSON: {"error":"…"}.

06bfetch402 — pay-per-call web intel (x402-style, no account)

The MCP tools above need an API key; fetch402 does not. It is a standalone x402-style rail where your agent pays per call in USDC on Base and the server verifies the transfer on-chain before serving. Full reference at /x402; machine-readable spec:

https://store.watchtbot.site/x402/v1/spec        # tools + prices
https://store.watchtbot.site/x402/llms.txt       # agent-readable docs

Flow: unpaid call answers 402 with payment details → send exact USDC on Base → repeat with header X-PAYMENT-TX: <tx hash> → content served. One tx = one delivered call; failed calls never consume your tx.

07MCP Server — tools for AI agents

Every product runs as an Model Context Protocol server, so Claude, ChatGPT, or your own automaton can call the tools directly and pay per call from the same credit balance. Endpoint:

https://mcp.watchtbot.site/mcp

Connect from Claude Code

claude mcp add --transport http web4 https://mcp.watchtbot.site/mcp

Tools & pricing (1 credit = 1¢)

Auth

Every tool takes an api_key argument — the same key as the REST API. Register one free at the storefront, top up with USDC/USDT/ETH, and the tools debit that balance per call. Insufficient balance returns a 402 with a top-up hint.

Example session

# 1. check balance (free)
automaton_get_balance { "api_key": "…" }
# 2. queue a lead scrape — first run usually done in minutes
leadradar_create_profile { "api_key": "…", "query": "dentists in Austin TX", "depth": 1 }
# 3. collect results
leadradar_list_leads { "api_key": "…", "profile_id": 42, "emails_only": true }