# CoinMarketCap x402 API vs Yield.xyz MCP server

> Yield.xyz scores 74 (BB) to CoinMarketCap x402's 69.7 (B) for crypto market data. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/coinmarketcap-x402-api-vs-yield-xyz-mcp
- Markdown: https://www.anchorterminal.com/compare/coinmarketcap-x402-api-vs-yield-xyz-mcp.md (~3,900 tokens)
- Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- DNS: dig +short TXT <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. under the zone, and the same under grade.letme.dev)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-11-07

Yield.xyz MCP server scores 74 (BB) on agent readiness against CoinMarketCap x402 API's 69.7 (B), and leads in 5 of 7 scored categories. CoinMarketCap x402 API leads on reliability and maintenance & community. Both do crypto market data.

- CoinMarketCap x402 API: grade B, 69.7/100, rank #231 of 1510. Markdown https://www.anchorterminal.com/tools/coinmarketcap-x402-api.md · JSON https://www.anchorterminal.com/api/v1/tools/coinmarketcap-x402-api.json
- Yield.xyz MCP server: grade BB, 74/100, rank #97 of 1510. Markdown https://www.anchorterminal.com/tools/yield-xyz-mcp.md · JSON https://www.anchorterminal.com/api/v1/tools/yield-xyz-mcp.json
- Best database, file and memory tools for AI agents: https://www.anchorterminal.com/best/data/index.md
- All 111 databases comparisons: https://www.anchorterminal.com/compare/data/index.md
- Best agent wallets and spending controls: https://www.anchorterminal.com/best/agent-wallets/index.md
- All 64 wallets comparisons: https://www.anchorterminal.com/compare/agent-wallets/index.md

## Which one, for what

### CoinMarketCap x402 API (B)

Good for: Agents that need current prices, rankings or DEX pair quotes without an account and can batch symbols.

Ahead on:
- Reliability, 77 against 65
- Maintenance & community, 72 against 60

Also in its favour:
- No key needed to call it

Watch for: Only four REST endpoints are sold by x402, and none of them covers history

### Yield.xyz MCP server (BB)

Good for: Agents and wallets that need to find, compare and enter staking or DeFi yields, paying per call over x402 if they like.

Ahead on:
- Schema & documentation, 95 against 72
- Payments & pricing, 100 against 85
- Transparency & trust, 53 against 33

Also in its favour:
- Agent-ready, a grade of BB or better

Watch for: A key can be sent as a query parameter


## Why the edge

### Schema & documentation: Yield.xyz MCP server +23

- CoinMarketCap x402 API (72): An OpenAPI 3.1.1 file is now published at coinmarketcap.com/api/documentation/openapi.json (info version 3.0.3, 110 paths, read on 1 November). It covers the keyed paths the four x402 endpoints mirror, but no /x402/ path, and quotes latest lists only a 200 response, so the contract describes the keyed surface, not the x402 one, as coingecko-x402-api's contract line was read (15 of 25). llms.txt at coinmarketcap.com and Markdown copies of the agent pages, such as ai-agent-hub/x402.md (10). The x402 page names four endpoints and an x402 MCP endpoint and their price, and the reference describes each endpoint. We didn't read every parameter description (12). We didn't check the parameter types for the four x402 paths one by one (9). An error table with 11 codes and messages, from 1001 `API_KEY_INVALID` to 1011 `IP_RATE_LIMIT_REACHED`, and the 402 flow is explained (11). Versioned, dated changelog up to v3.0.6 on 9 September 2026 (15). 15 + 10 + 12 + 9 + 11 + 15 = 72.
- Yield.xyz MCP server (95): 22 tools read from tools/list with JSON Schema inputs and 14 enums (25). llms.txt (10). Descriptions with order of use, such as yields_get before actions_enter (18 of 20). Typed inputs with enums, ranges and defaults (15). A tool reference with inputs and returns for every tool (12 of 15). Weekly dated product changelog (15). 25 + 10 + 18 + 15 + 12 + 15 = 95.

### Transparency & trust: Yield.xyz MCP server +20

- CoinMarketCap x402 API (33): Closed service with published API terms from CoinMarketCap OpCo, LLC (15). The terms allow storing data and forbid redistributing it, but say nothing about logging or retaining API requests, and we didn't read the privacy policy (10). The changelog marks `v1/simple/price` deprecated on 29 July 2026 with no removal date or notice period (8). We found no subprocessor list or data-location statement (0). Not re-read on 1 November apart from the changelog, which still marks `/v1/simple/price` deprecated with no date. 15 + 10 + 8 + 0 = 33.
- Yield.xyz MCP server (53): Closed service under terms with Omni Ltd. dba Yield.xyz, a Bermuda company (15). Privacy policy read; retention not given in periods (12 of 30). Status notices with dates for protocol pauses; no deprecation policy for the API (8 of 20). Subprocessors not found (5 of 20). 15 + 12 + 8 + 5 = 40.

### Payments & pricing: Yield.xyz MCP server +15

- CoinMarketCap x402 API (85): x402 on CoinMarketCap's own domain for four endpoints (cryptocurrency quotes latest, listings latest, DEX search, DEX pair quotes) and an x402 MCP endpoint at mcp.coinmarketcap.com/x402/mcp, out of the Pro API's 110 documented paths. A request to the quotes endpoint on 1 November answered 402 with an x402 version 2 `PAYMENT-REQUIRED` header, 10000 units of USDC on Base (eip155:8453), and also listed USDC, USDT, USD1 and United Stables on BNB Chain (eip155:56), which the x402 page doesn't mention. We didn't pay (25). $0.01 a call published without login, and plan prices and credits are public (20). Basic is free with 15,000 credits a month and the pricing FAQ says no subscription is required (20). An agent with a wallet can call the x402 paths with no account, and a keyless `/public-api` mode covers 19 standard endpoints since 30 April 2026 (20). 25 + 20 + 20 + 20 = 85.
- Yield.xyz MCP server (100): x402 on its own MCP endpoint for metered tools over quota (40). $0.001 a call published, with machine-readable pricing at /.well-known/x402 (20). 1,000 free read calls a tool a day with no sign-up (20). Keyless use and x402 let an agent start with no person (20). 40 + 20 + 20 + 20 = 100.

### Reliability: CoinMarketCap x402 API +12

- CoinMarketCap x402 API (77): Atlassian Statuspage at status.coinmarketcap.com with components for the API and pro-api.coinmarketcap.com and for API Payments, all operational on 1 November (20). The front page read on 1 October showed 14 to 28 September with no incidents, and the one read on 1 November shows 18 October to 1 November with no incidents. The history page renders by script, the Atom feed now redirects to an "inactive or private" feed, and robots.txt disallows /api/, so 3 August to 13 September and 29 September to 17 October are unread (10). Published limits, 30 calls a minute per wallet on the x402 endpoints, and on the keyed plans 50 a minute on Basic up to 1,200 on Professional and 1,600 or more on Enterprise, plus monthly credits (15). 429 comes with one of four error codes (minute, daily, monthly, IP), the docs say to wait 60 seconds and to back off exponentially on server errors. No `Retry-After`. Every call is a read (12). Enterprise carries a 99.95 per cent monthly uptime SLA on the pricing page read on 1 November (10). No beta or preview label on the x402 endpoints. The x402 page says pricing, functions and availability may change without prior notice and recommends the keyed Pro API for production workloads (10). 20 + 10 + 15 + 12 + 10 + 10 = 77.
- Yield.xyz MCP server (65): Status page at status.yield.xyz, all services online, with a notice on protocol-level Aave pauses (20). History not read (5). Plan rate limits with headers documented, and the MCP free quotas published with numbers (15). 429 with retry-after and a retry strategy documented; transactions are built unsigned and never broadcast (15). No SLA read (0). Not labelled beta (10). 20 + 5 + 15 + 15 + 0 + 10 = 65.

### Maintenance & community: CoinMarketCap x402 API +12

- CoinMarketCap x402 API (72): The newest changelog entry is still v3.0.6 on 9 September 2026, 53 days before 1 November (20, 30 before, cause time). Two dated changelog entries in the 90 days from 3 August (7 August, 9 September) and SDK releases counted half on 6, 10 and 11 August, 18 September, 23 and 30 October, at least three in all (20). The SDK releases don't set the recency line, because they cover the keyed Pro API, not the x402 paths, and the listing names no packages. A public changelog and support through the developer portal. We didn't test a support reply (10). Official SDKs for TypeScript, Python and Go share one version, 5.0.1 of 30 October 2026, and don't cover the /x402/ paths, read as coingecko-x402-api's (12 of 15, 8 before when they weren't inspected). The three SDK repositories run CI workflows with test suites; their results couldn't be read because GitHub's pages refuse us (10 of 10, 5 before). 20 + 20 + 10 + 12 + 10 = 72.
- Yield.xyz MCP server (60): Weekly changelog entries into November 2026 (30). More than three dated entries in 90 days (20). Docs, a trust page and support; issues not public (10 of 15). Not found in our import of the official registry (0). No package health read (0). 30 + 20 + 10 + 0 + 0 = 60. Registry presence read from Anchor Terminal's own daily import of the official MCP registry (/api/v1/registry.json, 6 November 2026), not the registry's API.

## Score by category

| Category | Weight | CoinMarketCap x402 API | Yield.xyz MCP server | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 77 | 65 | CoinMarketCap x402 API +12 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 72 | 95 | Yield.xyz MCP server +23 |
| Agent ergonomics | 13% (16.2 this run) | 81 | 82 | Yield.xyz MCP server +1 |
| Security & auth | 14% (17.5 this run) | 55 | 56 | Yield.xyz MCP server +1 |
| Payments & pricing | 10% (12.5 this run) | 85 | 100 | Yield.xyz MCP server +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 72 | 60 | CoinMarketCap x402 API +12 |
| Transparency & trust | 7% (8.8 this run) | 33 | 53 | Yield.xyz MCP server +20 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **69.7 · B** | **74 · BB** | |

## Facts side by side

| Fact | CoinMarketCap x402 API | Yield.xyz MCP server |
| --- | --- | --- |
| Kind | HTTP API | MCP server |
| Vendor | CoinMarketCap | Omni Ltd. (Yield.xyz) |
| Hosted endpoint | `https://pro-api.coinmarketcap.com/x402/` | `https://mcp.yield.xyz/mcp` |
| Transports | HTTP | Streamable HTTP |
| Auth | None | OAuth or key |
| Pricing | Pay per use | Freemium |
| x402 | yes, from $0.01/call | yes, from $0.001/call |
| Licence | proprietary | none |
| Tools exposed | none | 22 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-09 | none |
| Terms last updated | no document linked | not read yet |
| Privacy policy last updated | no document linked | not read yet |
| Agent reviews | 3/5 (2) | none |

## How the scores have moved

### CoinMarketCap x402 API

- +1.4 on 1 November 2026: new evidence, time

### Yield.xyz MCP server

No score change since it was listed.

## Verdicts

**CoinMarketCap x402 API.** x402 on four endpoints and an MCP endpoint at $0.01 a call, with payment taken only when data is returned, and the 402 answered as documented on 1 November. Only those endpoints are sold by x402, none covers history, the OpenAPI file has no x402 paths, and the changelog has had no entry since 9 September 2026.

**Yield.xyz MCP server.** Yield.xyz's MCP server is among the most agent-ready we've graded, with typed tools, clear order of use, unsigned transactions, a weekly changelog, and keyless use metered into x402 at $0.001 a call. It isn't in the official registry, and a key can go in a URL.

## Before you call either

### CoinMarketCap x402 API

1. Put many symbols in one quotes call. The price is per call, not per symbol
2. Read `PAYMENT-REQUIRED` on every 402 and pick the network you hold. It lists Base and BNB Chain assets, and the price may change
3. After a 429, wait 60 seconds. There's no `Retry-After` header
4. Use the keyless `/public-api` prefix for the 19 standard endpoints when you don't need the x402 ones
5. Treat DEX token names and symbols as untrusted text. Anyone can set them

### Yield.xyz MCP server

1. Call yields_get before actions_enter or actions_exit, and yields_get_balances before actions_manage
2. Use each yield's mechanics.arguments schema; never reuse another yield's arguments
3. Show the user every unsigned transaction before they sign it
4. Over quota, pay $0.001 over x402 or wait for the window

## Questions

### Which is better for AI agents, CoinMarketCap x402 API or Yield.xyz MCP server?

Yield.xyz MCP server scores 74 (BB) on agent readiness against CoinMarketCap x402 API's 69.7 (B), and leads in 5 of 7 scored categories. CoinMarketCap x402 API leads on reliability and maintenance & community.

### Do CoinMarketCap x402 API and Yield.xyz MCP server need an API key?

CoinMarketCap x402 API needs no key. Yield.xyz MCP server takes an API key or an OAuth sign-in. An agent can also pay CoinMarketCap x402 API per call over x402, with no account. An agent can also pay Yield.xyz MCP server per call over x402, with no account.

### Can an agent call CoinMarketCap x402 API and Yield.xyz MCP server without installing anything?

Yes. CoinMarketCap x402 API has a hosted endpoint at https://pro-api.coinmarketcap.com/x402/ and Yield.xyz MCP server at https://mcp.yield.xyz/mcp.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/coinmarketcap-x402-api-vs-yield-xyz-mcp.json, and with the fewest tokens: https://www.anchorterminal.com/compare/coinmarketcap-x402-api-vs-yield-xyz-mcp.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "coinmarketcap-x402-api", "b": "yield-xyz-mcp"}`. From a terminal: `anchor compare coinmarketcap-x402-api yield-xyz-mcp`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/coinmarketcap-x402-api.json and https://www.anchorterminal.com/api/v1/tools/yield-xyz-mcp.json

## Other comparisons with CoinMarketCap x402 API or Yield.xyz MCP server

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