All projects on Base matching “free”

Pick free or freemium software for a small business by business type. $1 USDC on Base per call. Returns one tool per need from freesmallbiztools.com's checked listings (vendor quote and check date), with alternatives and caveats. Types: service, trades, retail, online_store, creator, consultant, agency, nonprofit. Don't use this for paid enterprise software comparisons.

Free public-domain books on "South African War, 1899-1902": the catalogue's works tagged with that Library of Congress subject (104 in Project Gutenberg alone, plus Internet Archive scans), ranked by relevance and popularity, with direct download links. Add words to narrow. Re-verified daily. $0.01 per page of 20.

Find the cheapest WORKING x402 service for a task. Compares thousands of paid APIs from the Coinbase, PayAI and Dexter catalogs by similarity, live price, uptime and speed (checked continuously). Send the header "X-Free-Tier: 1" for 20 free requests per day. /v1/check is always free.

Paid book chapter (x402): Automate the Boring Stuff with Python: What Is Programming. Unit of a larger practical-skills library; free catalog at /library/discovery.json. Book slug: automatetheboringstuffwithpythonnew. Response format: Markdown (.md) for agent parsing. USDC on Base via Coinbase CDP facilitator. Free teasers and discovery.json require no payment.

Distributed lock / idempotency primitive for multi-agent swarms. claim(key) returns a token if free (with TTL); release(token) frees it; check(key) reports whether held. Stops multiple agents from double-processing the same work item.

Cash flow statements for a company by ticker or CIK, standardized from SEC filings: operating, investing and financing cash flows, capital expenditure, free cash flow and their main line items. Period annual, quarterly or ttm; filter by report_period or filing_date. Use when an agent needs operating cash flow, capex or free cash flow as reported. Non-Professional use; Professional use needs a plan

WhiteMagic hosted recall — agent memory for cross-session continuity: read-only hybrid search (BM25 + vector + associative) over a curated public corpus. Call when an agent needs durable context from prior sessions or the public knowledge store. Keyless discovery (initialize/tools/list) is free; free evaluation keys and a daily no-key trial are available. One paid tool call per payment.

Ranked Polymarket market-flow screener with factual concentration and liquidity-compatibility fields for the observed window. BEFORE YOU PAY: free substitute https://dash.polym.uk/markets.json. THIS ADDS: Little today, and we would rather you knew: the free snapshot has every field this route returns, for the whole decomposed set instead of the 40 rows this caps at, and it also carries the dominan

Store a secret (API key, webhook payload, signed URL) encrypted with WebCrypto AES-256-GCM and share a claim URL that yields the secret exactly once. A Durable Object serializes reads so single-use delivery is race-free, and every burn returns an Ed25519-signed attestation. Creating a vault requires x402 payment; the recipient's claim read (GET /v/:vault_id) is free.

Investor research and stock analysis for AI trading agents. This route buys up to five cited overview views for 0.02 USDC, with historical cutoffs. Discover all 16 research tools, their exact prices, free coverage and wallet MCP in the free catalog. Catalog: https://beliefstate.ai/v1/research. Full schemas: https://beliefstate.ai/openapi.json.

BotsRated (beta): full measurement history for one seller host: every receipt with timestamp, status, latency, hashes, signatures and tx links. Free sample: /v1/sample/report. First 10 calls per client per UTC day are free. Terms: https://botsrated.com/terms

One dated record row from the Receipts Index: what one AI engine answered for one check on one UTC date, as the businesses it named and the sources it showed. Returns the CSV header and one row; some fields are blank on some rows. Row ids are listed free at /v1/index and a free sample is at /v1/sample. A row id that does not exist returns 404 with no charge.

US Treasury par yield curve from 1 month to 30 years (percent) for the latest day or any date since 1990, with 10y-2y and 10y-3m spreads, inversion flag and up to 60 days of history. Use for risk-free rates, discounting, macro analysis or answering where 10-year yields are.

Only the calendar events added or resolved changed since your cursor (delta of / — Keyset delta of /v1/calendar: pass since=<next_cursor from your last call> and get only the calendar events added or resolved added or changed after it, plus changed_count and a new next_cursor. Omit since once to bootstrap. Cursors are stable across restarts. Poll the free sibling /v1/calendar/changes for counts…

Text-to-speech (OpenAI-compatible /v1/audio/speech). 4,358 voices across 9 providers (KokoroTTS, AWS Polly, Azure, MiniMax, more — free catalog at GET /v1/audio/voices). Returns mp3. Up to 3000 chars. $0.000006 USDC per character (Telnyx list rate, zero margin): pay per character via the upto scheme (min $0.002 network settlement floor, so ≤333-char calls settle at $0.002), or flat $0.018 exact.

Cheapest real end-to-end test of your pay-per-call (HTTP 402) client: pay US$0.002, get back what was paid (payer, amount, network, timestamp) and the text you sent; the settlement receipt is in the PAYMENT-RESPONSE header. A free trial call returns paid_usd 0. Use it to check a wallet, a client library or a facilitator before buying something bigger.

Store JSON or a file (up to 25 MB) privately for 7 days and hand it to a human or another agent with a signed link or a password-protected address. Includes 100 reads. No account needed: pay $0.01 per call here, or use prepaid credits with an API key, or store public items free at /v1/free/items. Docs: https://fileshareforagents.online/llms.txt

Official euro foreign exchange reference rates from the European Central Bank, published each working day around 16:00 CET for about 30 currencies. Use it to convert amounts between EUR and USD, GBP, JPY, CHF and others at the official daily rate. Optional base currency (cross rates are computed from the EUR rates) and a comma-separated list of symbols. Note: free of charge at ecb.europa.eu; you p

File what you want to buy from an agent-facing API and cannot buy today. Optional kind is typically one of coin, country, vies_country, monitor_host, sms_service — free-form values possible. The $0.01 fee is there to keep intents honest, not to sell you anything: it is not a purchase of the capability and no promise that it gets built. Optionally add the price per call you would pay and your expec

Checks one email address and returns valid, risky or invalid with the reasons: address format, whether the domain can receive mail (live MX lookup), known throwaway domains (mailinator and others, invalid), shared inboxes like info@ or sales@ (risky), likely typos such as gmial.com with the fix in didYouMean, and free providers such as gmail.com (flag only). Does not ping the mailbox (no SMTP), so

Web research in one call: ask a question and get a short cited answer, summarize a topic or get a Wikipedia summary. Returns a 1-3 sentence answer, key points tied to source ids, and the sources used (typically 1-5: title, URL, publisher, date, supporting quote), confidence and a free permalink. Sources: Wikipedia first, plus web pages, Stack Overflow, GitHub, papers, docs. Example: "What is the M

Cross-chain swap quote over NEAR Intents (Aurora). Returns the deposit transaction to sign on the origin chain; the deposit address is the part of quoteId after "aurora:". After sending it, POST /proxy/v2/move-asset/deposit/submit with provider=aurora, the deposit address and the tx hash, then poll GET /proxy/v2/move-asset/deposit/status with provider=aurora and the deposit address. Both are free.

Paid ($0.05). ALWAYS runs a fresh 25-check scan of the origin (non-settling GET/HEAD + benign empty-POST probes), bypassing the 24h cache — use free GET /v1/report to read the cached result. Concurrent requests for the same origin join the in-flight scan rather than double-scanning. Returns grade, score, per-check status + evidence + fix instructions, and a shareable report URL. Unreachable/broken

Entry point to the x402 Carbon Retirement API on Base. Returns every endpoint you need plus a live snapshot of the top 3 carbon classes and marketplace listings by liquidity. Discover, quote and certificate are free. Retiring is paid: each retirement costs the credit price plus a fee, sent from your own wallet (prepare/retire) or relayed from a signed USDC authorization (prepare-auth + POST action

Phone number intelligence for agents: pass any number and get back whether it is a valid E.164 number, its country, the carrier that holds it, and the line type — mobile, landline, or VoIP. One paid call, no account, no API key. Decide whether a number is worth calling or texting, or flag a VoIP number before you trust it. Free-format numbers are normalized; a syntactically bad number is rejected

Settled funding rate history of every Binance USDT-M perpetual, crypto and TradFi, one row per settlement since 2026-05-31, each with its funding time, kept current hourly from Binance's settlement list (a delisted contract Binance still lists there keeps its placeholder rate): the series behind carry and basis work. The free metric-daily download carries one daily BTC funding aggregate.

Use it before you send to an address, or to screen sign-ups and leads for typos, disposable domains and role addresses. Checks syntax, MX records (with the A-record fallback), null MX, a list of about 120,000 disposable domains, role addresses (info@, support@…) and free providers, without sending anything. No SMTP probing, so it can't confirm the mailbox exists. Never charged for errors: we settl

Forward geocode a free-text address, place name, or city (e.g. "Tokyo, Japan") into geographic coordinates — latitude and longitude — plus its IANA timezone. Use this to convert a location description into coordinates for mapping, distance, or timezone-aware lookups, or as the first step before coordinate-based endpoints like weather forecasts.

Research outline 0.01 USDC (first pay · Base). Ladder: free GET /v0/sample-outline.json → POST /v0/outline → brief 0.02. Machine settle: GET /first-buy.json · lander /start · /.well-known/x402.

Free proxy API: get one fast, verified-alive proxy (HTTP, SOCKS) filtered by country, protocol and anonymity, for scraping