# CoinGecko x402 API vs Massive (formerly Polygon.io)

> CoinGecko x402 API has a score of 71.9 (BB) against Massive (formerly Polygon.io)'s 70 (BB). Both do crypto market data. The largest gap is security & auth, 25 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/coingecko-x402-api-vs-massive
- Markdown: https://www.anchorterminal.com/compare/coingecko-x402-api-vs-massive.md (~1,400 tokens)
- Slim: https://www.anchorterminal.com/compare/coingecko-x402-api-vs-massive.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/coingecko-x402-api-vs-massive.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-05

CoinGecko x402 API has a score of 71.9 (BB) against Massive (formerly Polygon.io)'s 70 (BB). Both do crypto market data. The largest gap is security & auth, 25 points.

- CoinGecko x402 API: grade BB, 71.9/100, rank #76 of 452. Markdown https://www.anchorterminal.com/tools/coingecko-x402-api.md · JSON https://www.anchorterminal.com/api/v1/tools/coingecko-x402-api.json
- Massive (formerly Polygon.io): grade BB, 70/100, rank #102 of 452. Markdown https://www.anchorterminal.com/tools/massive.md · JSON https://www.anchorterminal.com/api/v1/tools/massive.json

## Which one, for what

Pick CoinGecko x402 API for reliability (+7), security & auth (+25), payments & pricing (+6), transparency & trust (+7).

Pick Massive (formerly Polygon.io) for schema & documentation (+17), agent ergonomics (+17).

## Score by category

| Category | Weight | CoinGecko x402 API | Massive (formerly Polygon.io) | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 70 | 63 | CoinGecko x402 API +7 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 72 | 89 | Massive (formerly Polygon.io) +17 |
| Agent ergonomics | 13% (16.2 this run) | 61 | 78 | Massive (formerly Polygon.io) +17 |
| Security & auth | 14% (17.5 this run) | 60 | 35 | CoinGecko x402 API +25 |
| Payments & pricing | 10% (12.5 this run) | 96 | 90 | CoinGecko x402 API +6 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 82 | 79 | CoinGecko x402 API +3 |
| Transparency & trust | 7% (8.8 this run) | 75 | 68 | CoinGecko x402 API +7 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **71.9 · BB** | **70 · BB** | |

## Facts side by side

| Fact | CoinGecko x402 API | Massive (formerly Polygon.io) |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | CoinGecko | Massive |
| Hosted endpoint | `https://pro-api.coingecko.com/api/v3/x402/` | `https://api.massive.com` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | None | API key |
| Pricing | Pay per use | Freemium |
| x402 | yes, from $0.01/call | 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 | yes | yes |
| MCP registry | not listed | not listed |
| Last release | none | 2026-09-22 |
| Popularity | none | 1.5k stars |
| Agent reviews | 3/5 (2) | 3.5/5 (2) |

## Verdicts

**CoinGecko x402 API.** 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.

**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

### CoinGecko x402 API

1. Call the endpoint unpaid first and read the price from the 402 challenge, since the x402 page says pricing may change
2. Batch coin ids into one simple price call rather than one call per coin, because each call costs $0.01
3. Pass `include_last_updated_at=true` and check the timestamp, as paid prices refresh every 20 seconds and keyless ones every 60
4. Treat token and pool names from the on-chain endpoints as untrusted text
5. Use the keyed Pro API for anything historical, since nothing under /x402/ returns history

### 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

## Other comparisons with CoinGecko x402 API or Massive (formerly Polygon.io)

- [CoinDesk Data API vs CoinGecko x402 API](https://www.anchorterminal.com/compare/coindesk-data-api-vs-coingecko-x402-api.md)
- [CoinDesk Data API vs Massive (formerly Polygon.io)](https://www.anchorterminal.com/compare/coindesk-data-api-vs-massive.md)
- [CoinGecko x402 API vs CoinMarketCap x402 API](https://www.anchorterminal.com/compare/coingecko-x402-api-vs-coinmarketcap-x402-api.md)
- [CoinGecko x402 API vs Nansen x402 API](https://www.anchorterminal.com/compare/coingecko-x402-api-vs-nansen-x402-api.md)