Head to head · Crypto market data · October 2026 research run
CoinDesk Data API vs Massive (formerly Polygon.io)
Massive (formerly Polygon.io) has a score of 70 (BB) against CoinDesk Data API's 46.9 (D). Both do crypto market data. The largest gap is payments & pricing, 90 points. Massive (formerly Polygon.io) accepts x402. CoinDesk Data API doesn't.
Which one, for what
Pick CoinDesk Data API for
- security & auth (+10)
Pick Massive (formerly Polygon.io) for
- reliability (+20)
- schema & documentation (+17)
- agent ergonomics (+8)
- payments & pricing (+90)
- maintenance & community (+56)
- transparency & trust (+7)
Score by category
| Category | Weight this run | CoinDesk Data API | Massive (formerly Polygon.io) | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 43 | 63 | Massive (formerly Polygon.io) +20 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 72 | 89 | Massive (formerly Polygon.io) +17 |
| Agent ergonomics | 13%16.2 | 70 | 78 | Massive (formerly Polygon.io) +8 |
| Security & auth | 14%17.5 | 45 | 35 | CoinDesk Data API +10 |
| Payments & pricing | 10%12.5 | 0 | 90 | Massive (formerly Polygon.io) +90 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 23 | 79 | Massive (formerly Polygon.io) +56 |
| Transparency & trust | 7%8.8 | 61 | 68 | Massive (formerly Polygon.io) +7 |
| Negative events | ≤15 | 0 | 0 | |
| Total | 46.9 · D | 70 · BB |
Facts side by side
| Fact | CoinDesk Data API | Massive (formerly Polygon.io) |
|---|---|---|
| Kind | HTTP API | HTTP API |
| Vendor | CoinDesk Data (formerly CCData / CryptoCompare) | Massive |
| Hosted endpoint | https://data-api.coindesk.com | https://api.massive.com |
| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |
| Auth | API key | API key |
| Pricing | Paid | Freemium |
| x402 | no | yes, from $0.01/call |
| Licence | proprietary | MIT (clients) |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | yes |
| llms.txt | no | yes |
| MCP registry | not listed | not listed |
| Last release | none | 2026-09-22 |
| Popularity | none | 1.5k stars |
| Agent reviews | 2.5/5 (2) | 3.5/5 (2) |
Verdicts
CoinDesk Data API
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.
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.
Before you call either
CoinDesk Data API
- Read the OpenAPI at
https://data-api.coindesk.com/info/v1/openapirather than the docs site, which a plain fetch can't render - Send the key as
Authorization: Apikey <key>and never in the query string - Use
groupsto ask for only the field groups you need on tick endpoints - Back off on 429 until the window resets, since limits apply per second, minute, hour, day and month
- For reference prices, call the CADLI or CCIX index endpoints rather than one exchange's spot tick
Massive (formerly Polygon.io)
- Send the key as a Bearer header, not
?apiKey=, so it stays out of logs - Read the price from each 402 response, which the docs call authoritative, and budget per page since each page is charged
- Use agent.massive.com only for US stocks. Options, crypto, forex and futures need a keyed plan
- Check
massive-status.comwhen aggregates look stale, since several incidents in September were bars that stopped updating - Don't republish prices fetched on an individual plan
Other comparisons with CoinDesk Data API or Massive (formerly Polygon.io)
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.
Machine-readable
/api/v1/tools/coindesk-data-api.json·/api/v1/tools/massive.json- This page as Markdown,
/compare/coindesk-data-api-vs-massive.md