# Bitfinex API vs KuCoin

> Bitfinex scores 58.4 (C) to KuCoin's 53.9 (D) for exchange market data. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/bitfinex-vs-kucoin
- Markdown: https://www.anchorterminal.com/compare/bitfinex-vs-kucoin.md (~4,750 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: 2026-11-04

Bitfinex API scores 58.4 (C) on agent readiness against KuCoin's 53.9 (D), and leads in 3 of 7 scored categories. KuCoin leads on schema & documentation, maintenance & community and transparency & trust. Both do exchange market data.

- Bitfinex API: grade C, 58.4/100, rank #675 of 1349. Markdown https://www.anchorterminal.com/tools/bitfinex.md · JSON https://www.anchorterminal.com/api/v1/tools/bitfinex.json
- KuCoin: grade D, 53.9/100, rank #824 of 1349. Markdown https://www.anchorterminal.com/tools/kucoin.md · JSON https://www.anchorterminal.com/api/v1/tools/kucoin.json
- Best crypto exchange APIs and MCP servers for AI agents: https://www.anchorterminal.com/best/crypto-exchanges/index.md
- All 210 exchanges comparisons: https://www.anchorterminal.com/compare/crypto-exchanges/index.md

## Which one, for what

### Bitfinex API (C)

Good for: An agent trading spot, margin or derivatives, or lending on the funding market, with scoped keys, official clients and paper trading.

Ahead on:
- Reliability, 85 against 45
- Security & auth, 62 against 55
- Payments & pricing, 40 against 35

Watch for: No official MCP server, OpenAPI file or AsyncAPI file; the registry's Bitfinex servers are third parties proxying public market data

### KuCoin (D)

Good for: An agent trading spot, margin and futures in a person's KuCoin account outside the restricted list, with no sandbox and no MCP server, so through the SDK or raw REST.

Ahead on:
- Schema & documentation, 60 against 48
- Maintenance & community, 73 against 41
- Transparency & trust, 54 against 49

Watch for: No official MCP server; the registry's `kucoin` entry is a third party's keyless market-data package


## Why the edge

### Reliability: Bitfinex API +40

- Bitfinex API (85): Read with the hosted lines on the v2 API at api.bitfinex.com. bitfinex.statuspage.io is a Statuspage site with history back to May 2021 (20). Its feed has no entry between 25 March 2026 and 3 November 2026, so the last 90 days are clean on the record; the feed logs platform-wide outages only (a 14-hour maintenance in March 2026, a 3-hour outage in August 2025), so smaller incidents may go unrecorded. Judgement call (30). Rate limits with numbers, 10 to 90 a minute per IP and the WebSocket connection limits (15). `ERR_RATE_LIMIT` and the 60-second block are documented, with no Retry-After; orders take a `cid` but no idempotency key or retry guidance was found (10 of 15). No SLA found (0). Generally available (10). 20 + 30 + 15 + 10 + 0 + 10 = 85.
- KuCoin (45): Graded with the hosted lines on the API at api.kucoin.com. No status page found (status.kucoin.com does not resolve, the docs link none), so 0 for the page and 5 for no readable history. Rate limits are published per VIP level with per-endpoint weights and IP limits for public endpoints (15). Every response carries gw-ratelimit-limit, gw-ratelimit-remaining and gw-ratelimit-reset, 429000 is documented with a wait rule, and orders take a clientOid the docs recommend as a UUID (15). No SLA (0). The UTA V2 API is the production surface (10). 45.

### Maintenance & community: KuCoin +32

- Bitfinex API (41): Read as a closed service with open clients. The last dated change we could read is bitfinex-api-node 9.1.0 on 18 July 2026, 108 days before the check; the docs changelog stops in October 2024 (10). Not three dated releases in the last 90 days (0). The bitfinexcom organisation pushes often (bfx-report on 3 November 2026) and the clients have issue trackers, but support articles answered 403 and no reply times were read (10 of 25). Official clients current in four languages, Node 9.1.0 of July 2026 and Python 4.0.0 of October 2025; not in the MCP registry (15). The Node client has a dependency history of security fixes (its last GitHub release notes name two) and no CI was read (6 of 10). 10 + 0 + 10 + 15 + 6 = 41.
- KuCoin (73): Read as a closed hosted service. The changelog's newest past entry is 2 November 2026 and the universal SDK was pushed 15 September (30). Nine dated changelog entries since 5 August 2026 (20). A Telegram API group (t.me/KuCoin_API) and api@kucoin.com for limit requests, no public issue tracker for the API; the SDK repository's issues were not checked (10 of 25). Official SDKs current in five languages, no MCP registry presence (13 of 15). No package health signal checked (0 of 10). 73.

### Schema & documentation: KuCoin +12

- Bitfinex API (48): No OpenAPI or AsyncAPI file was found on docs.bitfinex.com, in llms.txt or in the client repositories (0). llms.txt and a .md twin of every docs page (10). Each reference page states the endpoint's purpose and fields, and the introduction says when to use api-pub against api, but nothing says when not to use an endpoint (14 of 20). Responses are positional arrays described in field tables, inputs are typed in prose with some enumerations (wallet names, order types) and required fields marked; the withdrawal CODE field is work in progress (7 of 15). Signed-request recipes in five languages, but authenticated errors are documented as 400 with an empty object and there is no error reference (9 of 15). Version v2 in the path and a dated changelog, whose last entry is October 2024 and whose v1 deprecation has no date (8 of 15). 0 + 10 + 14 + 7 + 9 + 8 = 48.
- KuCoin (60): No OpenAPI or other machine-readable contract was found; the docs link a Postman workspace and the universal SDK is generated from an internal spec (8 of 25). No llms.txt; the skills hub ships Markdown SKILL.md files with endpoint tables for seven product areas, read-only (6 of 10). One docs page per endpoint with a description, permission and weight, but no when-to-use guidance (12 of 20). Typed parameter tables with enums for type and side and required flags (11 of 15). Request and response examples per endpoint and a unified six-digit error code scheme introduced with V2 (10 of 15). Dated changelog with V1 to V2 versioning (13 of 15). 60.

### Security & auth: Bitfinex API +7

- Bitfinex API (62): Revocable keys with per-scope read and write flags, a permissions endpoint, 2FA and email confirmation at creation, strictly increasing nonces, and IP binding to 20 addresses per the support article's search text (the article answered 403); no key expiry (24 of 30). `withdraw` and `ui_withdraw` are separate scopes and read-only keys are possible, but the support text says keys from email-and-password accounts start with every permission enabled and no confirmation step is documented for API withdrawals (14 of 20). The API returns exchange data, not third-party text (10). Login history and an account changelog (audit) endpoint are documented (10 of 15). No security.txt, no readable disclosure policy and no certification page readable (4 of 20). 24 + 14 + 10 + 10 + 4 = 62.
- KuCoin (55): API key with a user-set passphrase, HMAC-SHA256 signing, nine permission groups, IP allow-lists required for Withdrawal and FlexTransfers, trading keys without an IP disabled after 30 days of inactivity, revocation on the management page; no OAuth and no expiry on General keys (24 of 30). A General-only key is a true read-only mode and withdrawals are a separate permission; no confirmation step for writes beyond the key scope (12 of 20). Tools return the exchange's own data (10). The API key info endpoint shows permissions and IP lists; no per-call audit log was found (5 of 15). No security.txt, no disclosure policy or bounty on a page we could read, a whistleblower notice on the legal page (4 of 20). 55.

### Payments & pricing: Bitfinex API +5

- Bitfinex API (40): No machine payment protocol (0). The fees page is public without login (20), though it shows zero maker and taker with no tiers or date. The API is free, public endpoints need no account, and paper trading needs no money (20). A person must sign up in a browser with identity checks and mint the key (0). 0 + 20 + 20 + 0 = 40.
- KuCoin (35): No machine payment protocol (0). The spot base fee is stated in support articles without login, the futures base rate and the full tier table sit in images or behind script (15 of 20). Market data needs no key, no card is asked for at sign-up (20). A person registers, verifies identity and mints the key in a browser (0). 35.

### Transparency & trust: KuCoin +5

- Bitfinex API (49): The editorial half. A closed service whose Exchange Terms and API Terms of Service loaded only navigation, so the licence terms are unknown; the clients are MIT and Apache-2.0 (8 of 30). The privacy statement loaded only navigation, so retention and data handling are unchecked (0 of 30). The docs say v1 will be deprecated "at some point in the future" with no date, and the Python client's 4.0.0 removed endpoints with a release note (5 of 20). Subprocessors and data locations are in the unread privacy statement (0). 8 + 0 + 5 + 0 = 13.
- KuCoin (54): The editorial half. A closed hosted service with terms that are clear on use, liability and law but name no company (12 of 30). The privacy policy gives retention periods by purpose and provider (2 years after closure, 14 months for Firebase, 3 years for Jumio, 5 years for Sumsub) and names 41 services, with no data centre locations (22 of 30). Endpoints are removed and fields deprecated in dated changelog entries with no notice period or policy (8 of 20). Third parties named by service, locations not stated beyond transfers around the globe (10 of 20). 52.

## Score by category

| Category | Weight | Bitfinex API | KuCoin | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 85 | 45 | Bitfinex API +40 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 48 | 60 | KuCoin +12 |
| Agent ergonomics | 13% (16.2 this run) | 61 | 62 | KuCoin +1 |
| Security & auth | 14% (17.5 this run) | 62 | 55 | Bitfinex API +7 |
| Payments & pricing | 10% (12.5 this run) | 40 | 35 | Bitfinex API +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 41 | 73 | KuCoin +32 |
| Transparency & trust | 7% (8.8 this run) | 49 | 54 | KuCoin +5 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **58.4 · C** | **53.9 · D** | |

## Facts side by side

| Fact | Bitfinex API | KuCoin |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | iFinex Inc. | KuCoin |
| Hosted endpoint | no (local only) | no (local only) |
| Transports |  |  |
| Auth | API key | API key |
| Pricing | Pay per use | Pay per use |
| x402 | no | no |
| Licence | Proprietary hosted API under Bitfinex's API Terms of Service, which our reader couldn't load. The official client libraries (Node, Python, Go, Ruby) are MIT or Apache-2.0 | none |
| Read-only variant documented | no | yes |
| llms.txt | yes | no |
| Last release | 2026-07-18 | 2026-11-02 |
| Terms last updated | couldn't be read | no date given |
| Privacy policy last updated | couldn't be read | no date given |
| Customer content may train models | couldn't be read | not found in the text |
| Terms restrict automated access | couldn't be read | yes |
| Terms restrict benchmarking | couldn't be read | not found in the text |
| Terms or service can change without notice | couldn't be read | yes |
| Arbitration or class-action waiver | couldn't be read | yes |
| Popularity | 480 stars | 55 stars |

## Verdicts

**Bitfinex API.** Bitfinex gives an agent scoped keys with a separate withdraw permission, paper-trading sub-accounts on the production API, llms.txt and official clients in four languages. There is no official MCP server, responses are positional arrays with empty error bodies, rate limits run 10 to 90 a minute per IP, and the terms, API terms and privacy statement could not be read.

**KuCoin.** KuCoin publishes pooled rate limits with remaining and reset headers, scoped keys where withdrawals and transfers need an IP allow-list, an official SDK in five languages and read-only agent skills. It runs no MCP server, has no sandbox, status page or OpenAPI file, and its terms name no legal entity.

## Before you call either

### Bitfinex API

1. Mint a key with read on the scopes the task needs and write only on `orders`; never grant `withdraw` to a trading key, and bind the key to known IPs
2. Use one key per client process, since each key keeps its own strictly increasing nonce and a reused nonce is rejected
3. Rehearse on a paper-trading sub-account with the TEST symbols before touching real balances; the sub-account cannot be converted later
4. Plan requests against the per-endpoint limit of 10 to 90 a minute per IP; `ERR_RATE_LIMIT` blocks the IP for 60 seconds with no Retry-After
5. Map each response by position from the docs' field tables and set a `cid` on orders, because responses are arrays and a 400 carries no reason

### KuCoin

1. Mint a key with General only for research; add Spot or Futures only with an IP allow-list, since unbound trading keys are disabled after 30 days of inactivity
2. Send a UUID clientOid on every order and keep it for the retry, and read the order back by clientOid before placing again
3. Budget requests by weight against gw-ratelimit-remaining and sleep for gw-ratelimit-reset milliseconds on 429000; sub-accounts share the pool
4. There is no sandbox, so rehearse with the smallest order size on a dedicated sub-account
5. Use the UTA V2 endpoints and hosts; the Classic API loses endpoints without notice, as the margin credit endpoints did on 21 October 2026

## Questions

### Which is better for AI agents, Bitfinex API or KuCoin?

Bitfinex API scores 58.4 (C) on agent readiness against KuCoin's 53.9 (D), and leads in 3 of 7 scored categories. KuCoin leads on schema & documentation, maintenance & community and transparency & trust.

### Do Bitfinex API and KuCoin need an API key?

Both need an API key.

### Can an agent call Bitfinex API and KuCoin without installing anything?

No hosted endpoint is listed for Bitfinex API. No hosted endpoint is listed for KuCoin.


## For agents

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

## Other comparisons with Bitfinex API or KuCoin

- [Bitfinex API vs Bitget](https://www.anchorterminal.com/compare/bitfinex-vs-bitget.md)
- [Bitfinex API vs Bithumb Open API](https://www.anchorterminal.com/compare/bitfinex-vs-bithumb.md)
- [Bitfinex API vs Bitstamp API](https://www.anchorterminal.com/compare/bitfinex-vs-bitstamp.md)
- [Bitfinex API vs Bybit](https://www.anchorterminal.com/compare/bitfinex-vs-bybit.md)
- [Bitfinex API vs Coinbase Advanced Trade API](https://www.anchorterminal.com/compare/bitfinex-vs-coinbase-advanced-trade.md)
- [Bitfinex API vs Coinbase MCP server (Coinbase for Agents)](https://www.anchorterminal.com/compare/bitfinex-vs-coinbase-mcp.md)
- [Bitfinex API vs Crypto.com Exchange API](https://www.anchorterminal.com/compare/bitfinex-vs-crypto-com-exchange.md)
- [Bitfinex API vs Deribit](https://www.anchorterminal.com/compare/bitfinex-vs-deribit.md)
- [Bitfinex API vs dYdX](https://www.anchorterminal.com/compare/bitfinex-vs-dydx.md)
- [Bitfinex API vs Gate](https://www.anchorterminal.com/compare/bitfinex-vs-gate-io.md)
- [Bitfinex API vs Gemini Exchange API](https://www.anchorterminal.com/compare/bitfinex-vs-gemini-exchange.md)
- [Bitfinex API vs HTX trading API](https://www.anchorterminal.com/compare/bitfinex-vs-htx.md)
- [Bitfinex API vs Hyperliquid](https://www.anchorterminal.com/compare/bitfinex-vs-hyperliquid.md)
- [Bitfinex API vs Kraken API](https://www.anchorterminal.com/compare/bitfinex-vs-kraken.md)
- [Bitfinex API vs MEXC API](https://www.anchorterminal.com/compare/bitfinex-vs-mexc.md)
- [Bitfinex API vs OKX API](https://www.anchorterminal.com/compare/bitfinex-vs-okx.md)
- [Bitfinex API vs Uniswap Trading API](https://www.anchorterminal.com/compare/bitfinex-vs-uniswap.md)
- [Bitfinex API vs Upbit Open API](https://www.anchorterminal.com/compare/bitfinex-vs-upbit.md)
- [Bitget vs KuCoin](https://www.anchorterminal.com/compare/bitget-vs-kucoin.md)
- [Bithumb Open API vs KuCoin](https://www.anchorterminal.com/compare/bithumb-vs-kucoin.md)
- [Bitstamp API vs KuCoin](https://www.anchorterminal.com/compare/bitstamp-vs-kucoin.md)
- [Bybit vs KuCoin](https://www.anchorterminal.com/compare/bybit-vs-kucoin.md)
- [Crypto.com Exchange API vs KuCoin](https://www.anchorterminal.com/compare/crypto-com-exchange-vs-kucoin.md)
- [Gate vs KuCoin](https://www.anchorterminal.com/compare/gate-io-vs-kucoin.md)
- [Gemini Exchange API vs KuCoin](https://www.anchorterminal.com/compare/gemini-exchange-vs-kucoin.md)
- [HTX trading API vs KuCoin](https://www.anchorterminal.com/compare/htx-vs-kucoin.md)
- [KuCoin vs MEXC API](https://www.anchorterminal.com/compare/kucoin-vs-mexc.md)
- [KuCoin vs OKX API](https://www.anchorterminal.com/compare/kucoin-vs-okx.md)
- [KuCoin vs Uniswap Trading API](https://www.anchorterminal.com/compare/kucoin-vs-uniswap.md)
- [KuCoin vs Upbit Open API](https://www.anchorterminal.com/compare/kucoin-vs-upbit.md)
- [Binance API vs Bitfinex API](https://www.anchorterminal.com/compare/binance-vs-bitfinex.md)
- [Binance API vs KuCoin](https://www.anchorterminal.com/compare/binance-vs-kucoin.md)
- [Coinbase Advanced Trade API vs KuCoin](https://www.anchorterminal.com/compare/coinbase-advanced-trade-vs-kucoin.md)
- [Coinbase MCP server (Coinbase for Agents) vs KuCoin](https://www.anchorterminal.com/compare/coinbase-mcp-vs-kucoin.md)
- [Kraken API vs KuCoin](https://www.anchorterminal.com/compare/kraken-vs-kucoin.md)
- [Deribit vs KuCoin](https://www.anchorterminal.com/compare/deribit-vs-kucoin.md)
- [dYdX vs KuCoin](https://www.anchorterminal.com/compare/dydx-vs-kucoin.md)
- [Hyperliquid vs KuCoin](https://www.anchorterminal.com/compare/hyperliquid-vs-kucoin.md)

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Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp