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Best data provider APIs for AI agents
All 9 ranked data provider APIs on the Anchor benchmark, with a pick for each need and where each one falls short. Scores come from public evidence, re-checked as vendors change.
- 9 ranked
- 1 agent-ready
- 2 accept x402
- 9 hosted endpoints
- Updated 9 October 2026
Top three
Picks by need
Worked out from the scores, prices and facts, so they change when the research does.
Highest score overall
BB, 71.7/100 on the benchmark.
Also Massive (formerly Polygon.io), B, 69.8/100.
Schema & documentation
Massive (formerly Polygon.io) B
89/100 on schema & documentation, against 72 for the overall leader.
Maintenance & community
90/100 on maintenance & community, against 82 for the overall leader.
Transparency & trust
76/100 on transparency & trust, against 73 for the overall leader.
Paying per call with no account (x402)
accepts x402, $0.01 a call.
Also Massive (formerly Polygon.io), accepts x402, $0.01 a call.
The shortlist
| # | Tool | Grade | Best for | Price | Where |
|---|---|---|---|---|---|
| 1 | CoinGecko x402 API CoinGecko |
BB 71.7 | An agent that needs a spot or on-chain token price now and has a wallet but no account. | $0.01 / call | hosted |
| 2 | Massive (formerly Polygon.io) Massive |
B 69.8 | Agents that need US equities, options or futures data with real history, and the only listing here selling US stock data over x402. | $0.01 / call | hosted |
| 3 | Wikimedia REST API Wikimedia Foundation |
B 66.5 | Grounding an agent in general knowledge with citations and history. | Free | hosted |
| 4 | Open-Meteo Open-Meteo |
B 63.4 | Prototypes, personal agents and non-commercial apps that need forecasts or historical weather with no signup. | Freemium | hosted |
| 5 | Companies House API Companies House |
D 49.3 | UK company lookups, KYC, officer and PSC checks where the statutory source matters. | Free | hosted |
| 6 | CoinDesk Data API CoinDesk Data (formerly CCData / CryptoCompare) |
D 46.6 | Institutional crypto work that needs derivatives, order books, regulated reference rates or deep history, with a human buying the plan. | Paid | hosted |
| 7 | FRED API Federal Reserve Bank of St. Louis |
E 42.7 | Looking up US and international macroeconomic series, their metadata and their revision history in a live session. | Free | hosted |
| 8 | Alpha Vantage Alpha Vantage Inc. |
E 41.3 | A personal research or analysis agent that wants many asset classes, fundamentals, indicators and news sentiment from one key at a flat price. | $49.99 / mo | hosted and local |
| 9 | SEC EDGAR APIs U.S. Securities and Exchange Commission |
E 40.8 | Reading a US-listed company's filing history and its reported financial figures from the primary source, with free reuse. | Free | hosted |
How to choose
- Coverage and history depthCheck how far back the data goes and which markets, companies or regions it covers, because gaps in history break any backtest or trend an agent builds.
- Real-time or delayed dataConfirm whether prices and figures are real-time, delayed or end-of-day, since an agent acting on a stale figure may report values that no longer hold.
- Revisions and restatementsCheck whether figures get revised after publication and whether old versions stay available, so an agent can tell what was known at the time it made a decision.
- Licence for agent useRead the licence for redistribution and storage, since data licensed for viewing may not let an agent cache, resell or pass figures on.
Each one in detail
CoinGecko x402 API
BB 71.7/100CoinGecko exposes pay-per-call endpoints under an /x402/ path prefix of its Pro API, settled in USDC on Base with no API key.
Verdict Five x402 endpoints at $0.01 USDC a request on Base or Solana, no key or account. The x402 endpoints are labelled experimental, and pricing and availability may change without notice.
Choose it for An agent that needs a spot or on-chain token price now and has a wallet but no account.
Strengths
- Five x402 endpoints at $0.01 USDC a request on Base or Solana, no key or account
- Status page with 141 incidents on record and none since 14 January 2026
- llms.txt, Markdown docs and an OpenAPI file for the keyed Pro API
Weaknesses
- The x402 endpoints are labelled experimental, and pricing and availability may change without notice
- No historical data over x402, so charts and backtests still need a Pro key
- No published rate limits for x402 callers and nothing on whether failed paid calls are charged
Price $0.01 / callAuth Nonex402 yeshosted
Massive (formerly Polygon.io)
B 69.8/100US market data API for stocks, options, indices, forex, crypto and futures, from the consolidated tapes.
Verdict 23 US stock routes over x402 at agent.massive.com, $0.01 each on Base, and only successful requests are charged. About 18 unplanned incidents since 3 July, including 2.5 hours of intermittent 502s on stock aggregates on 2 September.
Choose it for Agents that need US equities, options or futures data with real history, and the only listing here selling US stock data over x402.
Strengths
- 23 US stock routes over x402 at agent.massive.com, $0.01 each on Base, and only successful requests are charged
- OpenAPI document with enums and error responses, plus an llms.txt indexing about 150 endpoints
- Official clients in Python, JavaScript, Go and the JVM, and a hosted MCP server whose three tools are marked read-only
Weaknesses
- About 18 unplanned incidents since 3 July, including 2.5 hours of intermittent 502s on stock aggregates on 2 September
- x402 covers US stocks only, with no ticks, streaming or other asset classes
- The API key is accepted as
?apiKey=in the query string
Price $0.01 / callAuth API keyx402 yeshosted
Wikimedia REST API
B 66.5/100Keyless REST API for Wikipedia and the other Wikimedia projects, with page content, search and full revision history.
Verdict Keyless reads in about 300 language editions with revision history since 2001. api.wikimedia.org is being retired in stages through 2026.
Choose it for Grounding an agent in general knowledge with citations and history.
Strengths
- Keyless reads in about 300 language editions with revision history since 2001
- Open source server (GPL-2.0-or-later) and CC BY-SA 4.0 content
- Public status history at wikimediastatus.net with start and end times
Weaknesses
- api.wikimedia.org is being retired in stages through 2026
- Anonymous clients without a descriptive User-Agent get 10 requests a minute, and the limits live in config rather than in docs we could read
- No llms.txt and no official SDK for the REST API
Price FreeAuth Nonex402 nohosted
Open-Meteo
B 63.4/100Open-source weather API over 30+ national and global weather models, with forecasts, historical reanalysis back to 1940 and no key for non-commercial use.
Verdict No key or account for non-commercial use, at 600 calls a minute and 10,000 a day. Commercial prices appear only at Stripe checkout.
Choose it for Prototypes, personal agents and non-commercial apps that need forecasts or historical weather with no signup.
Strengths
- No key or account for non-commercial use, at 600 calls a minute and 10,000 a day
- OpenAPI 3.1 files for nine APIs with an enum for every weather variable
- Five releases between 11 July and 10 September 2026, AGPL-3.0 code and CC BY 4.0 data
Weaknesses
- Commercial prices appear only at Stripe checkout
- The commercial key is sent as
&apikey=in the URL - Status page is uptime monitors with no incident write-ups we could read
Price FreemiumAuth Nonex402 nohosted
Companies House API
D 49.3/100Free REST API for the UK register of companies, with officers, filing history, charges and persons with significant control.
Verdict The statutory register itself, 5,516,377 companies in June 2026. A person has to create the account and key.
Choose it for UK company lookups, KYC, officer and PSC checks where the statutory source matters.
Strengths
- The statutory register itself, 5,516,377 companies in June 2026
- Free, with a Swagger 2.0 spec and a streaming API for changes
- Keys sent in a header, restrictable by IP address and domain, and easy to rotate
Weaknesses
- A person has to create the account and key
- 600 requests per five minutes per key, and the whole window returns 429 once you go over
- No status page, SLA, llms.txt or official SDK
Price FreeAuth API keyx402 nohosted
CoinDesk Data API
D 46.6/100Institutional market-data REST and WebSocket API covering spot, futures, options, reference-rate indices (CADLI, CCIX), asset metadata, on-chain data and news across 300+ exchanges, with an official hosted MCP server since May 2026.
Verdict Official OpenAPI 3.0.3 document at data-api.coindesk.com/info/v1/openapi, with enums, examples and error responses from 400 to 503. No free or trial access since 2026-05-21, and no x402, so a person has to buy a plan before an agent gets data.
Choose it for Institutional crypto work that needs derivatives, order books, regulated reference rates or deep history, with a human buying the plan.
Strengths
- Official OpenAPI 3.0.3 document at data-api.coindesk.com/info/v1/openapi, with enums, examples and error responses from 400 to 503
- Spot, futures, options, CADLI and CCIX indices, on-chain and news from one key, with history to 2010
- Hosted MCP server with 39 tools across spot and index, futures, options, news and on-chain, behind OAuth with PKCE
Weaknesses
- No free or trial access since 2026-05-21, and no x402, so a person has to buy a plan before an agent gets data
- Docs portal, llms.txt, pricing page and status page all render only in a browser
- No public changelog since the monthly product updates stopped in July 2025
Price PaidAuth API keyx402 nohosted
Full assessment · Against #1, CoinGecko x402 API
Disclosure Anchor Terminal's founder built this API at CryptoCompare, which became CCData and was acquired by CoinDesk in 2024. He no longer works there. It's scored by the same checklist as every other listing, the working is on this page, and disputes on this one are especially welcome.
FRED API
E 42.7/100REST API from the Federal Reserve Bank of St. Louis for FRED, its database of more than 800,000 economic time series. Version 1 returns series, releases, categories and observations, and version 2 returns every series on a release in bulk.
Verdict A free, read-only API to more than 800,000 economic series with revision history, documented endpoint by endpoint with typed parameters and examples. The terms forbid storing or caching FRED content and using the API to develop or train AI systems, version 1 carries the key in the URL, and no status page or OpenAPI file was found.
Choose it for Looking up US and international macroeconomic series, their metadata and their revision history in a live session.
Strengths
- Free, with no paid tier. One key per application from a free FRED account
- 31 version 1 requests cover series, observations, search, releases, categories, sources and tags, each documented with typed parameters, defaults and XML and JSON examples
- Real-time periods and vintage dates return a series as it stood on a past date, from the ALFRED archive
Weaknesses
- The FRED Services Terms of Use forbid using the API to develop or train any AI or machine-learning system, and forbid storing, caching or archiving FRED content
- Version 1 takes the key only as the
api_keyquery parameter, so it travels in the URL - No OpenAPI file, llms.txt, official SDK or API changelog was found
Price FreeAuth API keyx402 nohosted
Alpha Vantage
E 41.3/100Alpha Vantage is a market data API for stocks, options, indices, forex, crypto, commodities, fundamentals, news sentiment, economic series and technical indicators. Agents call one REST endpoint with a function name, or the official MCP server at mcp.alphavantage.co.
Verdict One GET endpoint covers about 130 documented functions, with a free key at 25 requests a day and an official MCP server whose tools are all marked read-only. The REST key travels only in the query string, errors come back as HTTP 200 with a text message, and no status page, SLA or OpenAPI document was found.
Choose it for A personal research or analysis agent that wants many asset classes, fundamentals, indicators and news sentiment from one key at a flat price.
Strengths
- About 130 documented functions behind one GET endpoint, each with demo URLs and sample code in Python, NodeJS, PHP and C#
- Free key at 25 requests a day with no card, and five public monthly plans from $49.99 (75 requests a minute) to $249.99 (1,200)
- Official MIT MCP server, hosted at
mcp.alphavantage.co/mcpwith OAuth (PKCE, dynamic client registration, onealphavantage:readscope) and read-only hints on every tool
Weaknesses
- The REST key is documented only as
apikey=in the query string, with no scopes and no self-service rotation found - Errors and limit notices return HTTP 200 with an
Error MessageorInformationtext field. No error reference, 429 or Retry-After guidance was found - No status page, SLA, OpenAPI document, llms.txt, API version or API changelog was found
Price $49.99 / moAuth OAuth or keyx402 nohosted and local
SEC EDGAR APIs
E 40.8/100Free JSON APIs from the U.S. Securities and Exchange Commission on data.sec.gov for EDGAR. They return each filer's submission history and the XBRL financial data extracted from company reports, with no key or account.
Verdict The official source for US company filings and reported financial figures, free, keyless and, per the SEC, updated in real time as filings are disseminated. Documentation is one page with no OpenAPI file, error reference or changelog, responses cannot be filtered or sized, and there is no status page, SLA or support for scripted access.
Choose it for Reading a US-listed company's filing history and its reported financial figures from the primary source, with free reuse.
Strengths
- No key, account or card. A request needs only a User-Agent header that declares who is calling
- The SEC is the primary source. Filings reach the submissions API with a typical delay under a second and the XBRL APIs under a minute, per the docs
- Content on sec.gov is public information that may be copied or redistributed without the SEC's permission, per its dissemination statement
Weaknesses
- No OpenAPI file, llms.txt, response schema, error reference or official SDK was found. The documentation is one page of prose with example URLs
- No query parameters. A filing history cannot be filtered by form or date, and the submissions response for Apple was 164 KB uncompressed on 9 October 2026
- No status page or SLA was found for data.sec.gov, and the SEC says it gives no technical support for scripted access
Price FreeAuth Nonex402 nohosted
Head to head
- CoinGecko x402 API vs Massive (formerly Polygon.io) BB 71.7 vs B 69.8
Questions
What are the highest-rated data provider APIs for AI agents?
CoinGecko x402 API has the highest benchmark score of the 9 ranked data provider APIs, 71.7 (BB). Massive (formerly Polygon.io) is second with 69.8 (B).
How many data provider APIs are agent-ready?
1 of the 9 ranked here grade BB or better, the bar for agent-ready on the Anchor benchmark.
Which data provider APIs accept x402 payments?
CoinGecko x402 API and Massive (formerly Polygon.io). An agent can pay these per call in USDC with no account.
How is this list ranked?
By the Anchor benchmark score out of 100, a weighted mean of the scored categories minus deductions for negative events, from public evidence re-checked as vendors change. Listings cannot pay for a place. The latest assessment behind this page is from 9 October 2026.
How this list is made
The order is the Anchor benchmark score, the same number as on each listing and in the top list. Each listing is graded from public evidence against the benchmark checklist, and the picks above are worked out from those grades, prices and facts. No listing pays for its place, and paid audits or listing help never change a score.
Full ranked table · 31 head-to-head comparisons · Best tools in every category