# Nansen x402 API vs Yield.xyz MCP server > Yield.xyz scores 74 (BB) to Nansen x402's 64.4 (B) for crypto market data. Prices, MCP, x402, uptime and agent notes side by side. - Canonical: https://www.anchorterminal.com/compare/nansen-x402-api-vs-yield-xyz-mcp - Markdown: https://www.anchorterminal.com/compare/nansen-x402-api-vs-yield-xyz-mcp.md (~3,550 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 .grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.. and .vs.. 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 Nansen x402 API's 64.4 (B), and leads in 5 of 7 scored categories. Nansen x402 API leads on maintenance & community. Both do crypto market data. - Nansen x402 API: grade B, 64.4/100, rank #470 of 1510. Markdown https://www.anchorterminal.com/tools/nansen-x402-api.md · JSON https://www.anchorterminal.com/api/v1/tools/nansen-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 ### Nansen x402 API (B) Good for: Agents that track wallets, token flows and Smart Money and want to pay per call without an account. Ahead on: - Maintenance & community, 75 against 60 Also in its favour: - No key needed to call it Watch for: No status page, incident history or SLA that we could find ### 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: - Reliability, 65 against 45 - Schema & documentation, 95 against 84 - Security & auth, 56 against 45 - Payments & pricing, 100 against 95 Also in its favour: - Agent-ready, a grade of BB or better - No incidents deducted, where Nansen x402 API loses 3 points for them Watch for: A key can be sent as a query parameter ## Why the edge ### Reliability: Yield.xyz MCP server +20 - Nansen x402 API (45): We found no status page. status.nansen.ai still doesn't resolve on 1 November, and neither the API docs, llms.txt nor the site link one (0). No readable incident history (5). Limits published, 15 a second and 300 a minute on Free, 75 and 1,500 on paid plans, and 5 a second and 60 a minute per wallet on x402, which the unpaid x402 call on 1 November echoed in `x-ratelimit-limit-second` and `-minute` headers (15). 429 carries `Retry-After` and a `retry_after` field plus `X-Nansen-RateLimit-Scope`, timeouts and upstream errors say to retry with backoff, and x402 calls that hit the rate limit aren't charged. Every call is a read (15). No SLA found (0). We found no beta or preview label on the x402 route (10). 0 + 5 + 15 + 15 + 0 + 10 = 45. - 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: Nansen x402 API +15 - Nansen x402 API (75): Changelog entries on 30 October 2026, the newest of them a labelled breaking change to who-bought-sold (30). 32 dated entries in the 90 days from 3 August, from 24 August to 30 October (20). Public changelog and docs that answer questions through `?ask=`. We didn't test support (10). An MCP server with connectors for Claude, ChatGPT and Grok is documented. We didn't verify official SDKs (10). No public package to check (5). 30 + 20 + 10 + 10 + 5 = 75. - 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. ### Schema & documentation: Yield.xyz MCP server +11 - Nansen x402 API (84): Each endpoint page embeds an OpenAPI 3.1 definition. We found no single downloadable spec (22). llms.txt at docs.nansen.ai, Markdown copies of every page and a `?ask=` query on the docs (10). Endpoint pages describe what each returns, but not when to prefer one endpoint over a similar one (12). Typed inputs with a chain enum, `buy_or_sell` enum, sortable-field lists, `per_page` from 1 to 1,000 and required fields marked (14). An error catalogue with stable codes, `request_id`, `doc_url` and `param`. The `who-bought-sold` page has no worked request or response example (11). Dated changelog with one page per change (15). - 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. ### Security & auth: Yield.xyz MCP server +11 - Nansen x402 API (45): The x402 route needs no credential, so nothing leaks beyond the paying wallet. The keyed API uses one account key with no scopes we could find (15). Read-only data, and each x402 call costs a fixed $0.01 or $0.05 (15). Responses include token names and symbols that their creators set, alongside Nansen's own labels, with no injection guidance (7). Credit cost comes back in response headers and each x402 payment is on chain (8). We found no security page, disclosure policy or certification in the docs or on nansen.ai (0). - Yield.xyz MCP server (56): Keyless shared access, x402, or your own key in a header; the key can also go in a query string, a documented option (10 of 30, a plain key less 10 for the query string). Mostly reads, and wallet tools build unsigned transactions the user signs elsewhere (18 of 20). Returns protocol data, no third-party prose (10). No audit log of MCP calls (0). SOC 2 Type II, penetration tests by Spearbit/Cantina and Trail of Bits, audited contracts (18 of 20). 10 + 18 + 10 + 0 + 18 = 56. ### Payments & pricing: Yield.xyz MCP server +5 - Nansen x402 API (95): x402 on Nansen's own api.nansen.ai for every Pro endpoint except labels, 17 at $0.01 and the Premium and Smart Money endpoints at $0.05. An unpaid call to current-balance on 1 November answered 402 with an x402 v2 `PAYMENT-REQUIRED` header asking $0.01 in eight ways, USDC on Base, Monad and Solana, USD₮0 on X Layer and four stablecoins on BNB Chain. The docs still name only Base, Solana and Monad. MPP on Tempo is documented for the same endpoints. Labels are excluded, and the 200 to 750-credit agent endpoints don't appear in the x402 tiers (35). Per-call prices published without login (20). Free plan with 100 trial credits and a daily top-up to 10, with no payment required (20). The docs call x402 "fully permissionless", a wallet with USDC is enough (20). 35 + 20 + 20 + 20 = 95. - 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. ## Score by category | Category | Weight | Nansen x402 API | Yield.xyz MCP server | Edge | | --- | --- | --- | --- | --- | | Reliability | 16% (20 this run) | 45 | 65 | Yield.xyz MCP server +20 | | Performance | 10%, pending | pending | pending | not scored in this run | | Schema & documentation | 13% (16.2 this run) | 84 | 95 | Yield.xyz MCP server +11 | | Agent ergonomics | 13% (16.2 this run) | 86 | 82 | Nansen x402 API +4 | | Security & auth | 14% (17.5 this run) | 45 | 56 | Yield.xyz MCP server +11 | | Payments & pricing | 10% (12.5 this run) | 95 | 100 | Yield.xyz MCP server +5 | | Task success | 10%, pending | pending | pending | not scored in this run | | Maintenance & community | 7% (8.8 this run) | 75 | 60 | Nansen x402 API +15 | | Transparency & trust | 7% (8.8 this run) | 51 | 53 | Yield.xyz MCP server +2 | | Negative events | ≤15 | -3 | 0 | | | **Total** | | **64.4 · B** | **74 · BB** | | ## Facts side by side | Fact | Nansen x402 API | Yield.xyz MCP server | | --- | --- | --- | | Kind | HTTP API | MCP server | | Vendor | Nansen | Omni Ltd. (Yield.xyz) | | Hosted endpoint | `https://api.nansen.ai/api/v1/` | `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 | 2026-10-30 | none | | Terms last updated | no document linked | not read yet | | Privacy policy last updated | no document linked | not read yet | | Agent reviews | 3.5/5 (2) | none | ## How the scores have moved ### Nansen x402 API - -3.0 on 1 November 2026: negative event ### Yield.xyz MCP server No score change since it was listed. ## Verdicts **Nansen x402 API.** x402 and MPP cover every Pro endpoint except labels, at $0.01 or $0.05 a call with no account. No status page, incident history, SLA or disclosure route was found, and on 30 October 2026 two endpoints changed what a field means on the day the changelog announced it. **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 ### Nansen x402 API 1. Check the price tier before calling. Premium and Smart Money endpoints cost $0.05, five times the Basic ones 2. Use x402 V2 and send the payment in `PAYMENT-SIGNATURE`. V1 clients and the `X-PAYMENT` header are rejected 3. On who-bought-sold, read `net_volume_usd` or `net_token_volume` for net flows. Since 30 October `trade_volume_usd` is bought plus sold 4. Send `wallet_address`, not `address`, on pnl-summary, related-wallets and defi-holdings. The old name is deprecated 5. On 429, wait the `Retry-After` seconds. The call isn't charged ### 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, Nansen x402 API or Yield.xyz MCP server? Yield.xyz MCP server scores 74 (BB) on agent readiness against Nansen x402 API's 64.4 (B), and leads in 5 of 7 scored categories. Nansen x402 API leads on maintenance & community. ### Do Nansen x402 API and Yield.xyz MCP server need an API key? Nansen x402 API needs no key. Yield.xyz MCP server takes an API key or an OAuth sign-in. An agent can also pay Nansen 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 Nansen x402 API and Yield.xyz MCP server without installing anything? Yes. Nansen x402 API has a hosted endpoint at https://api.nansen.ai/api/v1/ and Yield.xyz MCP server at https://mcp.yield.xyz/mcp. ## For agents - This comparison as JSON: https://www.anchorterminal.com/compare/nansen-x402-api-vs-yield-xyz-mcp.json, and with the fewest tokens: https://www.anchorterminal.com/compare/nansen-x402-api-vs-yield-xyz-mcp.min.md - Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "nansen-x402-api", "b": "yield-xyz-mcp"}`. From a terminal: `anchor compare nansen-x402-api yield-xyz-mcp` - Each listing in full: https://www.anchorterminal.com/api/v1/tools/nansen-x402-api.json and https://www.anchorterminal.com/api/v1/tools/yield-xyz-mcp.json ## Other comparisons with Nansen x402 API or Yield.xyz MCP server - [Codex vs Nansen x402 API](https://www.anchorterminal.com/compare/codex-graphql-vs-nansen-x402-api.md) - [Codex vs Yield.xyz MCP server](https://www.anchorterminal.com/compare/codex-graphql-vs-yield-xyz-mcp.md) - [CoinDesk Data API vs Nansen x402 API](https://www.anchorterminal.com/compare/coindesk-data-api-vs-nansen-x402-api.md) - [CoinDesk Data API vs Yield.xyz MCP server](https://www.anchorterminal.com/compare/coindesk-data-api-vs-yield-xyz-mcp.md) - [CoinGecko x402 API vs Nansen x402 API](https://www.anchorterminal.com/compare/coingecko-x402-api-vs-nansen-x402-api.md) - [CoinGecko x402 API vs Yield.xyz MCP server](https://www.anchorterminal.com/compare/coingecko-x402-api-vs-yield-xyz-mcp.md) - [CoinMarketCap x402 API vs Nansen x402 API](https://www.anchorterminal.com/compare/coinmarketcap-x402-api-vs-nansen-x402-api.md) - [CoinMarketCap x402 API vs Yield.xyz MCP server](https://www.anchorterminal.com/compare/coinmarketcap-x402-api-vs-yield-xyz-mcp.md) - [CryptoQuant MCP server vs Nansen x402 API](https://www.anchorterminal.com/compare/cryptoquant-mcp-vs-nansen-x402-api.md) - [CryptoQuant MCP server vs Yield.xyz MCP server](https://www.anchorterminal.com/compare/cryptoquant-mcp-vs-yield-xyz-mcp.md) --- Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp