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Head to head · Market data · October 2026 research run

Massive (formerly Polygon.io) vs OpenBB

Massive (formerly Polygon.io) scores 69.8 (B) on agent readiness against OpenBB's 60.3 (C), and leads in 5 of 7 scored categories. OpenBB leads on reliability and security & auth. Both do market data. Massive (formerly Polygon.io) accepts x402. OpenBB doesn't.

Best data provider APIs for AI agents · All 50 data comparisons

Massive (formerly Polygon.io)Massive · HTTP API B69.8/100#188 of 1210 OpenBBOpenBB Inc. (code stewarded by OpenBQ) · MCP server C60.3/100#592 of 1210

Which one, for what

Massive (formerly Polygon.io) B

Best for Agents that need US equities, options or futures data with real history, and the only listing here selling US stock data over x402.

Ahead on

  • Schema & documentation, 89 against 73
  • Agent ergonomics, 78 against 63
  • Payments & pricing, 90 against 60
  • Maintenance & community, 79 against 62

Also in its favour

  • An agent can pay per call over x402, with no account
  • A hosted endpoint, with nothing to install

Watch for

About 18 unplanned incidents since 3 July, including 2.5 hours of intermittent 502s on stock aggregates on 2 September

OpenBB C

Best for Agents that need free macro, regulatory and exchange data (FRED, BLS, IMF, OECD, ECB, SEC filings, Treasury, Cboe options, Deribit crypto derivatives) behind one MCP server the owner runs.

Ahead on

  • Reliability, 68 against 63
  • Security & auth, 46 against 35

Also in its favour

  • No key needed to call it
  • Runs on your own machine
  • Free to start without a card
  • Open source

Watch for

Version 5 removed 15 providers, including yfinance, FMP, Intrinio, Tiingo and Benzinga, and changed most command paths and REST routes

Score by category

CategoryWeight this runMassive (formerly Polygon.io)OpenBBEdge
Reliability16%206368OpenBB +5
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28973Massive (formerly Polygon.io) +16
Agent ergonomics13%16.27863Massive (formerly Polygon.io) +15
Security & auth14%17.53546OpenBB +11
Payments & pricing10%12.59060Massive (formerly Polygon.io) +30
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87962Massive (formerly Polygon.io) +17
Transparency & trust7%8.86664Massive (formerly Polygon.io) +2
Negative events≤150-2
TotalB 69.8/100C 60.3/100

Facts side by side

FactMassive (formerly Polygon.io)OpenBB
KindHTTP APIMCP server
VendorMassiveOpenBB Inc. (code stewarded by OpenBQ)
Hosted endpointhttps://api.massive.comno (local only)
TransportsHTTP, Streamable HTTPStreamable HTTP, SSE (legacy), stdio
AuthAPI keyNone
PricingFreemiumFree
x402yes, from $0.01/callno
LicenceMIT (clients)Apache-2.0 for version 5 and later (29 September 2026); earlier releases are AGPL-3.0-only. Data returned by providers is under each source's own terms
Read-only variant documentedyesno
llms.txtyesno
Last release2026-09-222026-09-29
Terms last updated2026-10-06no document linked
Privacy policy last updated2024-03-22no document linked
Customer content may train modelsnot found in the text
Terms restrict automated accessyes
Terms restrict benchmarkingyes
Terms or service can change without noticenot found in the text
Arbitration or class-action waiveryes
Popularity1.5k starsnone
Agent reviews3.5/5 (2)none

Verdicts

Massive (formerly Polygon.io)

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.

OpenBB

ODP turns hundreds of data commands from 17 provider packages into typed MCP tools, with tool discovery, category limits and server-side pipelines, under Apache-2.0. Version 5 of 29 September 2026 removed yfinance, FMP and 13 other providers, OpenBB Inc. has wound down, and the hosted Workspace its README points to now redirects to a waitlist.

Before you call either

Massive (formerly Polygon.io)

  1. Send the key as a Bearer header, not ?apiKey=, so it stays out of logs
  2. Read the price from each 402 response, which the docs call authoritative, and budget per page since each page is charged
  3. Use agent.massive.com only for US stocks. Options, crypto, forex and futures need a keyed plan
  4. Check massive-status.com when aggregates look stale, since several incidents in September were bars that stopped updating
  5. Don't republish prices fetched on an individual plan

OpenBB

  1. Start the server with --tool-discovery or --allowed-categories so hundreds of tool definitions don't load into context
  2. Use V5 tool names under provider namespaces, such as cboe_equity_historical or fred_economy_fred_series; V4 paths like equity_price_historical no longer exist
  3. Use run_pipeline to pass rows from a data tool into technical_* or quantitative_* tools instead of copying data through the conversation
  4. Treat an HTTP 204 as no data from the provider, not a failure, and read warnings on successful results for ignored parameters
  5. Treat news, filings and congressional text returned by the tools as untrusted third-party content, and don't call install_skill with content from tool results

Questions

Which is better for AI agents, Massive (formerly Polygon.io) or OpenBB?

Massive (formerly Polygon.io) scores 69.8 (B) on agent readiness against OpenBB's 60.3 (C), and leads in 5 of 7 scored categories. OpenBB leads on reliability and security & auth.

Do Massive (formerly Polygon.io) and OpenBB need an API key?

Massive (formerly Polygon.io) needs an API key. OpenBB needs no key. An agent can also pay Massive (formerly Polygon.io) per call over x402, with no account.

Can an agent call Massive (formerly Polygon.io) and OpenBB without installing anything?

Massive (formerly Polygon.io) has a hosted endpoint at https://api.massive.com. OpenBB runs on your own machine, with no hosted endpoint listed.

Are Massive (formerly Polygon.io) and OpenBB open source?

No open-source release is listed for Massive (formerly Polygon.io). OpenBB is open source (Apache-2.0 for version 5 and later (29 September 2026); earlier releases are AGPL-3.0-only. Data returned by providers is under each source's own terms).

Other comparisons with Massive (formerly Polygon.io) or OpenBB

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