Pay-Per-Call APIs for AI Agents — Priced Before You Pay, Failed Calls Never Charged (USDC on Base)
Pay per call, from $0.001. No accounts, no keys, no subscriptions. The price is quoted in the 402 challenge before you pay, and failed calls are never charged. Enrichment, blockchain data, ZK proofs, SEO, media and more — settled in USDC on Base via the x402 payment protocol.
How it works
The x402 protocol turns HTTP 402 Payment Required into an onchain payment flow.
Agent reads metadata
GET the endpoint. Receive an OpenAPI spec + x402 payment details (payTo, amount, asset, network).
Sees 402 response
Server returns HTTP 402 with a signed payment requirement in USDC on Base or Solana.
Signs & pays onchain
Agent wallet broadcasts a USDC microtransaction on Base. No human needed, no account to create.
Gets the result
Server verifies the payment header and returns the API response. Done.
All APIs
Each tool is a standalone paid endpoint. Browse the catalog — click any card for details.
Fetch a URL and convert its main content to clean, LLM-ready Markdown. Strips nav/ads/sidebars.
Get the live USD price of any token by symbol (e.g. BTC, ETH, SOL, PEPE).
Get a complete wallet portfolio: native ETH balance, ERC-20 balances, NFT holdings, recent transfers.
Scan recent blocks for large ETH transfers involving an address. Filter by direction and threshold.
Aggregate native balance and token/NFT counts for an address across eth, arb, base, polygon, opt.
Diff two OpenAPI specs and generate a structured breaking-change changelog. Deterministic, no LLM.
Diff git commits and generate a structured breaking-change changelog. Provide repo URL + base commit.
Render a Mermaid diagram to an image (PNG or SVG). Returns base64-encoded image.
Convert an HTML string to clean, LLM-ready Markdown. Handles headings, links, tables, code blocks.
Generate a QR code or barcode as an image (SVG or PNG). QR, Code128, EAN, UPC, ISBN, and more.
Generate an Open Graph social-card image (1200x630 PNG) from a title and description.
Search live job postings by keywords and locations. Returns structured results: title, company, location, salary, and more.
Verify a Semaphore ZK proof locally using Groth16 (embedded official vkey). No external dependency — pure on-device verification.
Verify a World ID 4.0 proof via the Worldcoin Developer Portal API. Generates RP signature, proxies to Worldcoin, returns nullifier + validity.
Batch verify up to 10 Semaphore proofs in a single request. Returns per-proof results with timing stats.
Verify a Sign-In-With-Ethereum (EIP-4361) signature as a paid oracle: returns wallet address + chainId, mints nothing.
Verify a NIP-98 Nostr HTTP auth event with replay protection (each event id verifies once). Returns the signer pubkey.
Verify an ed25519 Solana wallet signature over a nonce-bearing message. One verification per nonce; returns signer pubkey.
Convert an Ethereum address to its EIP-55 checksummed form — required on SIWE message line 2 before signing.
Chat with a language model. OpenAI-compatible /v1/chat/completions. 50+ models — free (auto, eco, premium) are $0, paid models at cost.
Convert a PDF document to clean, LLM-ready Markdown. Direct URL or base64 file bytes. Reports, papers and contracts become RAG-ready text.
Convert a DOCX (Word) document to Markdown. Contracts, resumes, reports and letters — headings, lists and tables preserved.
Convert a PPTX (PowerPoint) presentation to Markdown. Each slide becomes a heading — pitch decks turn into LLM-readable text.
Convert XLSX or CSV to a Markdown table AND a JSON array of row objects in one call. All sheets included, flattened in order.
Convert an EPUB e-book to Markdown. Chapters become headings; metadata included — feed whole books into LLM context.
Convert any document to Markdown with automatic format detection — pdf, docx, pptx, xlsx, csv, epub, html, text. One endpoint for all of them.
Verify a stablecoin: issuer identity, GENIUS Act qualification status, and latest reserve attestation. Resolves the token from chain+address, a known symbol, or a tx hash. Free preview validates the input and returns the issuer only.
Buy a digital gift card code (Foot Locker, Target, AMC, 1000+ brands). Search the catalog free, pay the face value + fee in USDC — code delivered instantly, settled on Base via x402.
Create a permanent short link on freeq.one (custom or random slug, optional TTL expiry). Returns the short URL plus a one-time manage_secret that gates free stats and deletion of the link.
Click stats for a freeq.one short link: total clicks and last-30-day daily counts. Free for the link owner (pass the manage_secret); paid calls serve agent link-verification flows.
Ephemeral webhook receiver: creates a single-use HTTPS URL that catches any POST (Stripe, GitHub, internal) for up to an hour. Sender ingest is free; reads are $0.01, +1h extends are $0.05. In-memory, auto-deletes on expiry.
Live Google organic results for any keyword. Returns top 10 titles, URLs, snippets, and rank. Priced below typical SEO-data APIs.
Google search volume, CPC, and competition for up to 100 keywords. Priced below typical SEO-data APIs.
Generate keyword ideas from a seed keyword with volume data. Priced below typical SEO-data APIs.
Find organic competitors for any domain. Priced below typical SEO-data APIs.
Get all keywords a domain ranks for with position and volume. Priced below typical SEO-data APIs.
Backlink overview for any domain — referring domains, backlink count, authority. Priced below typical SEO-data APIs.
Detect search intent (informational, transactional, commercial) for a keyword. Priced below typical SEO-data APIs.
Text-to-image generation (fast tier, 2-6s). Returns a permanent hosted image URL. Game assets, avatars, illustrations, concept art.
Premium text-to-image generation (10-30s) — better prompt adherence and typography. Returns a permanent hosted image URL.
Photo to 3D model (fast tier, 10-30s). Single 2D image URL to a textured low-poly GLB mesh + preview thumbnail. Game-ready — Three.js, Unity, Godot.
Photo to 3D model (high-detail tier, 1-3 min). High-poly textured GLB with PBR-like shading + preview thumbnail. Game-ready — Three.js, Unity, Godot.
Provision a Referral-as-a-Service (RaaS) project — one-time $0.05. Returns project_id and apiKey (hashed server-side; shown once — store now). Then call https://api.freeq.one/v1/raas with x-api-key: mint referral codes, track stats, and credit referrers when referred x402 settlements verify on Base.
Behavioral on-chain risk score (0-100) for a wallet or token contract: activity, age, counterparty concentration, asset diversity and large-transfer share, plus a smart-money score for wallets. Not sanctions or honeypot screening.
Resolve one person's work email from a full name and company domain. Returns the best address with its verification status plus every work email found. Unfinished lookups return status "pending"; a settled no-match returns 404 and is not charged.
Enrich one person by professional-profile URL, or by full name plus company domain or company name. Returns the work email (verification status plus all variants found) and the full public profile: headline, current role, experience history, education, skills, location. Unfinished lookups return status "pending"; a settled no-match returns 404 and is not charged.
Company firmographics by domain (preferred) or exact name: description, industry, company type, exact and range headcount, headcount growth by timespan, founding year, headquarters, specialties and LinkedIn URL. A settled no-match returns 404 and is not charged.
Firmographics, headcount-growth classification, homepage tech detection, and an explainable 0-100 lead score. Score reflects findability, size and growth — not buying intent or funding; funding, revenue, layoffs and hiring-posting counts unavailable upstream. A settled no-match returns 404 and is not charged.
Extract structured JSON from a document: sections, tables, key-values and caller-named fields. PDF, DOCX, PPTX, XLSX, CSV, EPUB, HTML, text. Deterministic parsing — no OCR, no LLM inference.
Single-page SEO audit: 0-100 score, graded checks and prioritized fixes from the page's own HTML. Deterministic — no JS rendering, no rankings, no backlinks, no crawl.
Full-browser screenshot of any public page as base64 PNG or JPEG: viewport or full-page, custom size, rendered in headless Chromium.
Domain reputation bundle: 0-100 trust score and band from registration age, DNS, email auth, TLS, redirects and blocklists. Deterministic — no malware verdicts, no history.
Free (no payment required): supported swap currencies with networks, fixed/floating availability and address format: the full SimpleSwap catalog for building a swap.
Free (no payment required): fixed or floating quote for one swap: amount you receive, locked rate id and expiry for fixed quotes. Quote only — no order is created.
Create a non-custodial swap order and get the deposit address: send exactly the expected amount there and the payout goes to your address. No funds move in this call.
Free status check (no payment required): track a swap order by id: status, amounts, deposit and payout transactions. Read-only — never moves funds. Upstream cost is $0, so the check is free.
Certificate Transparency bundle: cert history, first-seen, issuer timeline and CT-log subdomain hints for a domain, plus a continuity score. From crt.sh — no live TLS check, no full enumeration.
Package supply-chain risk bundle: 0-100 safety score and risk band for an npm or PyPI package, with OSV vulnerabilities and fixed versions plus maintenance and adoption evidence. Known-vuln data only — no code scan.
Wayback Machine homepage history for a domain: 0-100 longevity score and band, first/last captures, captures by year, and recent snapshots with archive links. Homepage only — no subpages or content diffs.
Run Rust code with network access outside the major clouds in an isolated, secure environment and return stdout, stderr and exit code.
SEC financial snapshot for a listed company by ticker or CIK: latest 10-K revenue, net income, total assets, diluted EPS and shares, prior-year revenue growth, and recent filings with document links. Filed XBRL facts only — no prices, estimates, or advice.
SEC insider trades for a listed company by ticker or CIK: recent Form 4 buys, sells, grants and exercises with shares, price and holdings, plus net flow and cluster buys. Filed facts only — no advice.
Exploit risk for one CVE from free public sources: NVD CVSS score and vector, CWE and affected products, FIRST EPSS 30-day exploit probability and percentile, and CISA KEV known-exploited flag with ransomware use. No exploit code or PoC.
FDA drug safety bundle for one drug: FAERS adverse-event report total, top reported reactions and serious share, enforcement recalls with class and reason, and label boxed warning, indications and contraindications. Reported facts only — no medical advice.