Head to head · Market prices · October 2026 research run

Finnhub vs Tiingo

Tiingo scores 46.2 (D) on agent readiness against Finnhub's 45.1 (E), and leads in 2 of 7 scored categories. Finnhub leads on schema & documentation and maintenance & community. Both do market prices.

Best financial market data APIs for AI agents · All 55 markets comparisons

Which one, for what

Finnhub E

Best for Agents that need one key across quotes, fundamentals, estimates, filings and transcripts with official libraries, and a free key for prototypes.

Ahead on

  • Schema & documentation, 58 against 39
  • Maintenance & community, 60 against 50

Also in its favour

  • Free to start without a card

Watch for

The Swagger document declares the key only as a token query parameter, and the examples carry it in the URL

Tiingo D

Best for Agents that need clean US end-of-day composites with dividend and split adjustments, fund fees and news on a cheap plan, and anyone who values a long changelog.

Ahead on

  • Reliability, 60 against 48
  • Transparency & trust, 57 against 27

Watch for

The connecting guide documents the token as ?token= in the URL alongside the header

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.

Transparency & trust Tiingo +30

Finnhub 27

A closed service whose terms exist at a page that robots.txt disallows, so they were not read; the pricing page says every self-serve plan is personal use, and no legal entity or governing law was found (8 of 30). No privacy policy was found, /privacy redirecting to the home page (0 of 30). No deprecation policy or dated notices found (0 of 20). Stripe and Braintree scripts load on the site, but no processor list or data location is disclosed (0 of 20). 8 + 0 + 0 + 0 = 8.

Tiingo 57

A closed service whose terms sit on app.tiingo.com, which answered 403 to every request, so they were not read; the pricing and documentation pages define internal, commercial and redistribution licences (8 of 30). The privacy policy is on the same host and was not read (0 of 30). The developer programme commits to a year of continued support after a breaking change, with changes posted in the changelog and emailed to registered developers, and the changelog's 9 October 2026 entry describes a changed default for prevClose (16 of 20). Equinix hosting is named on the about page, with no processor list or data location (4 of 20). 8 + 0 + 16 + 4 = 28.

Schema & documentation Finnhub +19

Finnhub 58

A public Swagger 2.0 document covers 116 paths with a description on every operation, declaring the key as a query parameter and a 200 response only; the MCP tools were not read (20 of 25). /llms.txt returns the site's HTML shell and no Markdown docs exist (0 of 10). Each operation states its purpose, a premium marker and, on quote, advice against polling, with little on when not to use it (14 of 20). Required flags and types are set on 248 parameters, but allowed values such as news categories sit in description text and no enum is declared (8 of 15). Every operation has example URLs and sample code in five languages, while the only documented error is the 429 (9 of 15). The path carries v1 and no changelog or dated change notes were found (7 of 15). 20 + 0 + 14 + 8 + 9 + 7 = 58.

Tiingo 39

No OpenAPI document or MCP server was found (0 of 25). llms.txt and llms-full.txt are served, with product routing and licence notes (10). Each documentation page states the endpoint's purpose and timing, such as prices after 5.30 pm ET with corrections to 8 pm, with little on when not to use it (12 of 20). Parameters and response fields are tabled with names and meanings, but types, defaults and allowed values are partly in prose (8 of 15). Examples in Python, Node and PHP on every page; no error responses documented (7 of 15). A changelog dated by entry since 2017 and a one-year support commitment after breaking changes, with no version in the path (12 of 15). 0 + 10 + 12 + 8 + 7 + 12 = 39.

Reliability Tiingo +12

Finnhub 48

Read with the hosted lines. No status page was found on the site, in the docs document or on the MCP page (0), so no incident history could be read (5). Limits are published with numbers, 60 calls a minute on the free key, 150 to 900 a minute by plan, and 30 calls a second on top of every plan (15). The docs say the limit answers 429 and the MCP page says to wait a minute, with no Retry-After or backoff guidance (8 of 15). The home page says 99.99 per cent uptime with an SLA available for enterprise clients (10). The API is generally available (10). 0 + 5 + 15 + 8 + 10 + 10 = 48.

Tiingo 60

Read with the hosted lines. A public status page on Instatus at status.tiingo.com lists 13 components with a notice history (20). The history in the 90 days to 3 November 2026 shows a 9 hour 59 minute outage of the Blue Ocean ATS endpoints on 21 October, a WebSocket issue on 21 September and two maintenance windows, with nothing recorded before 21 September; a long outage of one niche feed rather than the core price API (15). Limits are published with numbers, 50 and 10,000 requests an hour, 1,000 and 100,000 a day and 1 GB and 40 GB a month (15). No 429, Retry-After or backoff guidance was found (0). No SLA found (0). The end-of-day, news, crypto and forex APIs are generally available, while Equity Realtime and BOATS are in beta (10). 20 + 15 + 15 + 0 + 0 + 10 = 60.

Maintenance & community Finnhub +10

Finnhub 60

Read as a closed service. The newest dated change is 2 November 2026, when finnhub-go, finnhub-ruby and finnhub-php gained a price target history endpoint; the MCP page is dated 6 August 2026 (30). Only that one dated change falls in the last 90 days, the previous library commits being 22 June 2026 (5 of 20). Support by email, with no public changelog or community channel found (5 of 15). Six official client libraries, finnhub-python at 2.4.29 of 24 June 2026 (15). The libraries are generated from the API document; no CI run was visible and the Python README names an older version than PyPI (5 of 10). 30 + 5 + 5 + 15 + 5 = 60.

Tiingo 50

Read as a closed service. The changelog's newest entry is 9 October 2026 (30). Entries dated 9 October and 8 September 2026 fall in the last 90 days, with 21 July just outside, and the status page adds a maintenance window on 28 September (12 of 20). A dated changelog, a support address and a blog, with the developer programme promising priority email support (8 of 15). No official SDK (0 of 15). No package to assess (0 of 10). 30 + 12 + 8 + 0 + 0 = 50.

Score by category

CategoryWeight this runFinnhubTiingoEdge
Reliability16%204860Tiingo +12
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25839Finnhub +19
Agent ergonomics13%16.25656even
Security & auth14%17.53232even
Payments & pricing10%12.53030even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86050Finnhub +10
Transparency & trust7%8.82757Tiingo +30
Negative events≤1500
TotalE 45.1/100D 46.2/100

Facts side by side

FactFinnhubTiingo
KindHTTP APIHTTP API
VendorFinnhubTiingo Inc.
Hosted endpointhttps://finnhub.io/api/v1https://api.tiingo.com
TransportsHTTP, Streamable HTTP, websocketHTTP, websocket
AuthOAuth or keyAPI key
PricingFreemiumFreemium
x402nono
Tools exposed70none
Read-only variant documentednono
llms.txtnoyes
Last release2026-11-022026-10-09
Terms last updatedcouldn't be readcouldn't be read
Privacy policy last updatedno document linked2026-02-18
Customer content may train modelscouldn't be readcouldn't be read
Terms restrict automated accesscouldn't be readcouldn't be read
Terms restrict benchmarkingcouldn't be readcouldn't be read
Terms or service can change without noticecouldn't be readcouldn't be read
Arbitration or class-action waivercouldn't be readcouldn't be read
Popularity1.1k starsnone

Verdicts

Finnhub

A public Swagger document covers 116 endpoints, six official client libraries exist, and a free key gives 60 calls a minute with no card. The key is documented in the query string, no status page, changelog, error reference or privacy policy was found, and robots.txt kept the terms from our reader.

Tiingo

A dated changelog since 2017, a one-year support commitment after breaking changes, an Instatus status page and a free token at 1,000 requests a day. The token is documented in the URL, no OpenAPI document, error reference, SDK or MCP server exists, and the terms and privacy policy sit on a host that refused our reader.

Before you call either

Finnhub

  1. Send the key as the X-Finnhub-Token header, not as token= in the URL, and keep under 30 calls a second on top of the plan's per-minute limit
  2. Check the premium marker before calling; a free key reaches 29 operations and the rest answer with an error
  3. Poll /quote sparingly; the docs say constant polling is not recommended and point to the websocket for real-time updates
  4. Expect 401 {"error":"Please use an API key."} without a key and 429 over the limit; wait a minute before retrying, as the MCP page advises
  5. Self-serve plans are personal use; anything commercial needs the enterprise contact route

Tiingo

  1. Send the token as Authorization: Token <token>, not as ?token= in the URL
  2. Ask for format=csv on large price pulls; the docs say CSV is 4 to 5 times faster than JSON, and bandwidth counts against the monthly cap
  3. Count requests an hour and a day, not per second; 50 an hour on Starter, 10,000 on Power, reset on the hour and at midnight ET
  4. Expect 403 {"detail":"Please supply a token"} without a token; other error shapes are undocumented, so log the body
  5. Use dashes in share classes (BRK-A), and fetch supported_tickers.zip rather than guessing symbols

Questions

Which is better for AI agents, Finnhub or Tiingo?

Tiingo scores 46.2 (D) on agent readiness against Finnhub's 45.1 (E), and leads in 2 of 7 scored categories. Finnhub leads on schema & documentation and maintenance & community.

Do Finnhub and Tiingo need an API key?

Finnhub takes an API key or an OAuth sign-in. Tiingo needs an API key.

Can an agent call Finnhub and Tiingo without installing anything?

Yes. Finnhub has a hosted endpoint at https://finnhub.io/api/v1 and Tiingo at https://api.tiingo.com.

Other comparisons with Finnhub or Tiingo

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