Head to head · Exchange market data · October 2026 research run

Bitfinex API vs Kraken API

Kraken API scores 71 (BB) on agent readiness against Bitfinex API's 58.4 (C), and leads in 5 of 7 scored categories. Bitfinex API leads on reliability. Both do exchange market data.

Best crypto exchange APIs and MCP servers for AI agents · All 210 exchanges comparisons

Which one, for what

Bitfinex API C

Best 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 67

Watch for

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

Kraken API BB

Best for An agent that trades spot, xStocks, forex or futures on a person's Kraken account from a local machine, with paper trading to test first and an approval gate on live orders.

Ahead on

  • Schema & documentation, 80 against 48
  • Agent ergonomics, 79 against 61
  • Security & auth, 80 against 62
  • Maintenance & community, 81 against 41
  • Transparency & trust, 65 against 49

Also in its favour

  • Agent-ready, a grade of BB or better
  • Runs on your own machine
  • Free to start without a card

Watch for

No self-service spot sandbox; the spot UAT environment is on request through an account manager, and paper trading lives in the CLI

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Maintenance & community Kraken API +40

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.

Kraken API 81

Read as a closed service with an open-source client. Changelog entry of 27 October 2026 and kraken-cli v0.5.1 on 29 October (30). Fourteen changelog entries since 19 August 2026 and CLI tags on 6 and 7 August and 28 and 29 October (20). A public changelog, api@kraken.com, a status page and a CLI repository merging pull requests at the end of October; issue replies not read (11 of 15). An official Rust SDK pushed in October 2026 and a Go module from January; the MCP server is not in the official registry (12 of 15). The CLI has release and secure SDLC workflows, deny.toml and a pinned toolchain; the SDK's CI not read (8 of 10). 30 + 20 + 11 + 12 + 8 = 81.

Schema & documentation Kraken API +32

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.

Kraken API 80

No OpenAPI file was found for the REST API in the docs read; the CLI's agents/tool-catalog.json gives JSON Schema inputs for all 188 commands and the 152 MCP tools (15 of 25). The docs serve Markdown twins such as quickstart.md and the CLI ships llms.txt, AGENTS.md and CONTEXT.md (10). Endpoint pages and guides on order lifecycle, errors and rate limits say what each call does, with less on when not to use one (15 of 20). Enums for order types, time in force and flags, and enums and required fields in the tool catalogue (12 of 15). Python, Node.js and cURL examples, an errors guide and the CLI's error-catalog.json with retry guidance (13 of 15). A changelog of 120 dated entries with deprecations dated (15). 15 + 10 + 15 + 12 + 13 + 15 = 80.

Reliability Bitfinex API +18

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.

Kraken API 67

Read with the hosted lines on the spot API. status.kraken.com is a Statuspage site with REST, WebSocket and FIX components (20). The incidents feed read covers 4 September to 3 November 2026. On 30 October spot and derivatives clients could not connect or submit orders across web, mobile, REST, WebSocket and FIX for 59 minutes 39 seconds, rated minor by Kraken; on 28 October some FIX clients were rejected on reconnection for 1 hour 59 minutes while other interfaces worked; the futures engine was degraded for 3 minutes on 13 October. A whole-exchange order outage 21 seconds short of an hour is read as one major (10 of 30). Numeric limits per key by tier and per pair for the matching engine (15). EAPI:Rate limit exceeded and EService:Throttled with a retry timestamp, a client order id and a validate flag on orders, but no Retry-After header (12 of 15). No SLA (0). Generally available (10). 20 + 10 + 15 + 12 + 0 + 10 = 67.

Agent ergonomics Kraken API +18

Bitfinex API 61

Graded on the REST API. Limits on trades, candles and book depth, and pub:list config endpoints keep responses small, but positional arrays make every field a lookup (14 of 25). start, end, limit and sort on history endpoints and per-symbol variants (16 of 20). ERR_RATE_LIMIT is actionable; authenticated 400s return {} and withdrawal status strings may change, so an agent cannot branch on causes (8 of 20). A client id on orders, order multi-op and cancel-multiple, but no idempotency key and no retry contract (8 of 20). Few required parameters and official clients in Node, Python, Go and Ruby (15). 14 + 16 + 8 + 8 + 15 = 61.

Kraken API 79

The MCP server loads services with -s, defaults to no live trading, and its 152 tool definitions average about 520 characters; the REST API takes count, limit and pair filters but has no field selection (18 of 25). Cursor pagination on ledgers and trades since 30 September and 6 October 2026, with ofs deprecated (17 of 20). Prefixed error strings such as EOrder:Rate limit exceeded and EAPI:Invalid nonce, and the CLI's error catalogue says which to retry (17 of 20). cl_ord_id and validate on orders, destructive_hint and elicitation on dangerous MCP tools, no idempotency key on REST (16 of 20). An official Rust SDK at 5 stars, a Go module and example clients, HMAC-SHA512 signing with a strict nonce (11 of 15). 18 + 17 + 17 + 16 + 11 = 79.

Security & auth Kraken API +18

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.

Kraken API 80

Keys with nine named permissions, optional expiry, IP restriction and nonce window, plus an OAuth sign-in from the CLI (authorisation code with PKCE, public client) that mints a no-withdrawal key expiring within 90 days or a read-only key (30). Read-only and no-withdrawal keys, position limits and pair allowlists in account settings, and MCP approval prompts for 33 dangerous tools (18 of 20). The API returns no untrusted content; the CLI docs warn that the feedback tool uploads a local file without approval (10). Keys and their permissions are listed in settings and ledgers record activity, but no per-call log for the operator was found (6 of 15). A valid security.txt, a bug bounty policy page, SECURITY.md and a secure SDLC workflow in the CLI; certifications not read (16 of 20). 30 + 18 + 10 + 6 + 16 = 80.

Transparency & trust Kraken API +16

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.

Kraken API 65

The editorial half. A closed service with clear terms naming regional Payward entities under California law; the CLI is MIT (15 of 30). The privacy notice was not read (5 of 30). The changelog dates deprecations and the terms carry a last-updated date (16 of 20). No subprocessor or data-location statement read (0 of 20). 15 + 5 + 16 + 0 = 36.

Score by category

CategoryWeight this runBitfinex APIKraken APIEdge
Reliability16%208567Bitfinex API +18
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.24880Kraken API +32
Agent ergonomics13%16.26179Kraken API +18
Security & auth14%17.56280Kraken API +18
Payments & pricing10%12.54040even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.84181Kraken API +40
Transparency & trust7%8.84965Kraken API +16
Negative events≤1500
TotalC 58.4/100BB 71/100

Facts side by side

FactBitfinex APIKraken API
KindHTTP APIHTTP API
VendoriFinex Inc.Payward, Inc.
Hosted endpointno (local only)no (local only)
Transportsstdio
AuthAPI keyOAuth or key
PricingPay per usePay per use
x402nono
LicenceProprietary 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-2.0Proprietary hosted service under Kraken's Global Terms of Service (30 October 2026). kraken-cli, which carries the kraken-mcp server, is MIT
Tools exposednone152
Read-only variant documentednoyes
llms.txtyesyes
Last release2026-07-182026-10-29
Terms last updatedcouldn't be read2026-10-30
Privacy policy last updatedcouldn't be read2026-10-21
Customer content may train modelscouldn't be readnot found in the text
Terms restrict automated accesscouldn't be readyes
Terms restrict benchmarkingcouldn't be readyes
Terms or service can change without noticecouldn't be readyes
Arbitration or class-action waivercouldn't be readyes
Popularity480 stars795 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.

Kraken API

Kraken pairs a documented REST, WebSocket and FIX API with the open-source kraken-cli, whose kraken-mcp server gates 33 dangerous tools behind approval and signs in by OAuth with a no-withdrawal key. Spot has no self-service sandbox, no OpenAPI file was found, and a 59-minute connectivity outage hit every interface on 30 October 2026.

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

Kraken API

  1. Start kraken-mcp with -s market,paper,feedback or the default services; add trade only with a least-privilege key, and never pass --allow-dangerous on an agent that reads untrusted input
  2. Ask the person to run kraken auth login in their own terminal; it needs a browser and saves a no-withdrawal key that expires in 90 days at most
  3. Send a fresh --cl-ord-id on each order and run it with --validate first; after a network error look the order up before sending it again
  4. Keep the nonce strictly increasing per key and stay under the tier's counter, since EAPI:Rate limit exceeded has no Retry-After header
  5. Test strategies in a paper workspace, which fills at live prices with no account, before a live workspace

Questions

Which is better for AI agents, Bitfinex API or Kraken API?

Kraken API scores 71 (BB) on agent readiness against Bitfinex API's 58.4 (C), and leads in 5 of 7 scored categories. Bitfinex API leads on reliability.

Do Bitfinex API and Kraken API need an API key?

Bitfinex API needs an API key. Kraken API takes an API key or an OAuth sign-in.

Can an agent call Bitfinex API and Kraken API without installing anything?

No hosted endpoint is listed for Bitfinex API. Kraken API runs on your own machine, with no hosted endpoint listed.

Other comparisons with Bitfinex API or Kraken API

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