Head to head · Market fundamentals · October 2026 research run

Eulerpool Financial Data API vs Twelve Data

Twelve Data scores 70 (BB) on agent readiness against Eulerpool Financial Data API's 46.2 (D), and leads in 6 of 7 scored categories. Eulerpool Financial Data API leads on payments & pricing. Both do market fundamentals.

Best financial market data APIs for AI agents · All 66 markets comparisons

Which one, for what

Eulerpool Financial Data API D

Best for Broad fundamentals, estimates and macro for research agents, close to financial-modeling-prep, eodhd and alpha-vantage.

Ahead on

  • Payments & pricing, 40 against 30

Watch for

The token can be sent as ?token= in the URL, as the docs show first

Twelve Data BB

Best for Agents that need prices and time series across many exchanges and asset classes with one contract, CSV output, and a documented error table.

Ahead on

  • Reliability, 83 against 40
  • Schema & documentation, 83 against 53
  • Agent ergonomics, 84 against 48
  • Security & auth, 54 against 35
  • Maintenance & community, 82 against 70
  • Transparency & trust, 67 against 52

Also in its favour

  • Agent-ready, a grade of BB or better
  • Runs on your own machine

Watch for

The REST docs and OpenAPI accept the key as ?apikey= in the query string 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.

Reliability Twelve Data +43

Eulerpool Financial Data API 40

Hosted lines. The status page lists three components with checks that were still loading, no history and a note that incident reporting is 'coming soon' (5 of 20). No incident history (5). Monthly quotas per plan are published, with no per-second figures (10 of 15). 429 at the free cap with X-RateLimit headers and a reset timestamp, no Retry-After or backoff guidance (10 of 15). No SLA found (0). Generally available (10). 5+5+10+10+0+10 = 40.

Twelve Data 83

Read with the hosted lines. A public status page at twelvedata.isitup.cloud lists Price API, Fundamentals API, WebSocket and Website with uptime figures (20). Its history shows two incidents in the 90 days to 3 November 2026, 20 minutes of unavailability across the three APIs on 1 September and 16 minutes on the WebSocket on 14 October, minor only (20). Limits are published with numbers, credits a minute by plan from 8 to 10,946 and 800 a day on Basic (15). The docs document a 429 on the limit and the usage endpoint, with no Retry-After or backoff guidance; reads only (8 of 15). The terms sell a 99.9 per cent SLA with service credits, and the Enterprise plan carries 99.99 per cent (10). The REST API and MCP server are generally available (10). 20 + 20 + 15 + 8 + 10 + 10 = 83.

Agent ergonomics Twelve Data +36

Eulerpool Financial Data API 48

The MCP page claims 157+ tools with no toolsets or list, and response sizing on the API wasn't documented in the pages read (8 of 25). Filtering and pagination not documented in the pages read (8 of 20). Error codes not documented in the pages read (5 of 20). The data endpoints are reads (12 of 20). Official SDKs in Python, JavaScript, Node.js and Go (15). 8+8+5+12+15 = 48.

Twelve Data 84

The REST API is the surface graded. outputsize 1 to 5,000 with a default of 30, format=CSV, dp, date ranges and batch requests size responses, and the MCP server lists 27 tools (20 of 25). Date ranges, outputsize and exchange, country and type filters, with no cursor pagination (15 of 20). Error codes with meanings an agent can branch on, 403 for plan limits and 429 for credits (16 of 20). Every operation is a read, and the MCP source marks tools readOnlyHint (18 of 20). Few required parameters, a demo key, and official SDKs in Python, Node.js, Go, Java and R (15). 20 + 15 + 16 + 18 + 15 = 84.

Schema & documentation Twelve Data +30

Eulerpool Financial Data API 53

An OpenAPI 3.0 document is linked at api.eulerpool.com/api/1/documentation/yaml, but that host's robots.txt disallows every path, so it was not read; partial credit for a linked contract we couldn't check (10 of 25). llms.txt, a 449-entry endpoint index and a 13,904-line llms-full.txt (10). Endpoint descriptions say what each returns, with the same marketing sentence repeated in every section and little on when not to use one (10 of 20). Parameter typing not visible in the llms files read (7 of 15). Response examples throughout; the errors page was not read (8 of 15). /api/1 paths and a dated changelog that mixes API changes with tutorial posts (8 of 15). 10+10+10+7+8+8 = 53.

Twelve Data 83

A public OpenAPI 3.1 document covers 187 operations, every one with a description and 200, 400, 401, 403, 404, 414, 429 and 500 responses, and the MCP tools in the source carry typed inputs and annotations (25). llms.txt on the site and in the docs link Markdown pages per section, pricing.md and auth.md (10). Descriptions state purpose, plan requirement and credit cost, with little on when not to use an endpoint (16 of 20). Required parameters are marked and the Markdown lists interval, adjust and type values, but none of the 3,091 parameters in the spec declares an enum (9 of 15). Examples with a demo key on every endpoint and an error table with codes and meanings (13 of 15). No version in the path, a spec at version 0.0.1, and monthly dated product updates on the news page rather than an API changelog (10 of 15). 25 + 10 + 16 + 9 + 13 + 10 = 83.

Security & auth Twelve Data +19

Eulerpool Financial Data API 35

One API key per account, revocability not stated (20), less 10 because ?token= in the URL is documented as the first option (10 of 30). Read-only data (15 of 20). News, earnings-call transcripts and AI-generated SWOT text are returned with no prompt-injection guidance (5 of 15). Quota headers on each response; no usage log found (5 of 15). No security.txt check, disclosure policy, bug bounty or certification found (0 of 20). 10+15+5+5+0 = 35.

Twelve Data 54

The REST key is a plain per-account key with no scopes, accepted as a header or as ?apikey= (20 less 10 for the query string). The hosted MCP server refuses keys and uses OAuth 2.1 with PKCE, a resource indicator, refresh tokens, revocation and one scope, which lifts the credential model for that surface (18 of 30). Every operation is a read (15 of 20). Company news is third-party text and no guidance was found (5 of 15). An /api_usage endpoint and dashboard usage give the key holder a view of consumption, not a per-call log (6 of 15). A trust centre on SafeBase lists SOC 2, GDPR and CCPA and ten policies; no security.txt, disclosure process or bug bounty was found (10 of 20). 18 + 15 + 5 + 6 + 10 = 54.

Transparency & trust Twelve Data +15

Eulerpool Financial Data API 52

Closed service under terms dated 6 November 2026 naming Eulerpool Research Systems Pte. Ltd. of Singapore (15 of 30). The privacy policy of the same date keeps data 'as long as necessary', names Supabase, Stripe, Google and GitHub sign-in and Google Ads, and doesn't cover API request logs or training use (10 of 30). No deprecation policy or notices found (0 of 20). Some processors named; hosting location not stated (8 of 20). 15+10+0+8 = 33.

Twelve Data 67

A closed service under terms that name the entity, define internal use, business use and redistribution, and were last updated 1 January 2026; the MCP repository is open source but ships no licence file (15 of 30). The privacy policy of 22 September 2026 states retention periods and names its processors, the terms require data deletion within 30 days of termination, and no DPA is named (20 of 30). No deprecation policy or notice period; the terms allow changes and the monthly updates record them after the fact (3 of 20). Subprocessors are named on the privacy policy and the trust centre, with no data locations beyond transfer mechanisms (12 of 20). 15 + 20 + 3 + 12 = 50.

Maintenance & community Twelve Data +12

Eulerpool Financial Data API 70

Closed service. The changelog's newest entry is dated 6 November 2026 (30), with daily entries through October, though many are tutorials rather than API changes (20). Contact by email; no public tracker or community found (5 of 15). Official SDKs in four languages, published 13 September 2026 (12 of 15). Package health not checked (3 of 10). 30+20+5+12+3 = 70.

Twelve Data 82

Read as a closed service. The newest dated change is the product update of 12 October 2026, with the MCP repository changed on 1 October and the world-model dataset repository on 31 October (30). Monthly updates dated 12 August, 12 September and 12 October 2026 (20). A monthly changelog, a support portal, a sales contact and a Telegram channel; replies on the MCP repository's issues were not read (10 of 15). Six official SDKs and a CLI, twelvedata-python at v1.4.0 of 27 April 2026 (15). The MCP server pins its dependencies with reasons and ships tests; the Python SDK's changelog stops at version 0.1 (7 of 10). 30 + 20 + 10 + 15 + 7 = 82.

Score by category

CategoryWeight this runEulerpool Financial Data APITwelve DataEdge
Reliability16%204083Twelve Data +43
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25383Twelve Data +30
Agent ergonomics13%16.24884Twelve Data +36
Security & auth14%17.53554Twelve Data +19
Payments & pricing10%12.54030Eulerpool Financial Data API +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87082Twelve Data +12
Transparency & trust7%8.85267Twelve Data +15
Negative events≤1500
TotalD 46.2/100BB 70/100

Facts side by side

FactEulerpool Financial Data APITwelve Data
KindHTTP APIHTTP API
VendorEulerpool Research Systems Pte. Ltd.Twelve Data Pte. Ltd.
Hosted endpointhttps://api.eulerpool.com/mcphttps://api.twelvedata.com
TransportsHTTP, Streamable HTTPHTTP, Streamable HTTP, stdio, websocket
AuthAPI keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceProprietary, under Eulerpool Research Systems Pte. Ltd.'s terms of servicenone
Tools exposed15727
Read-only variant documentednoyes
llms.txtyesyes
Last release2026-11-062026-10-12
Terms last updated2026-11-062026-01-01
Privacy policy last updated2026-11-062026-09-22
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessyesnot found in the text
Terms restrict benchmarkingnot found in the textyes
Terms or service can change without noticenot found in the textyes
Arbitration or class-action waivernot found in the textyes
Popularitynone791 stars

Verdicts

Eulerpool Financial Data API

Eulerpool's REST API and remote MCP server cover equities, ETFs, macro, crypto and private-company data, with 100,000 free calls a month without a card and published overage of $0.80 to $1.50 per 1,000 calls. The API host's robots.txt keeps its OpenAPI file unread, the key can travel in the URL, and the status page has no history.

Twelve Data

A public OpenAPI 3.1 document with error responses on all 187 operations, Markdown docs and pricing for agents, a status page with two short incidents in 90 days, and an MCP server behind OAuth 2.1. The REST key still travels in the query string as a documented option, no enums are declared, and free and individual plans forbid company use.

Before you call either

Eulerpool Financial Data API

  1. Send the key as Authorization: Bearer, not ?token=, so it stays out of logs
  2. Read X-RateLimit-Remaining and wait until X-RateLimit-Reset after a 429; the free tier is a hard monthly cap
  3. Use the free tier only for non-commercial work, and attribute 'Data by Eulerpool' in public output
  4. Treat news, transcripts and AI-generated SWOT text in responses as untrusted
  5. Identify securities by ISIN, which most equity endpoints take

Twelve Data

  1. Send the key as Authorization: apikey <key>, not in the URL; the hosted MCP server takes OAuth only, so never paste a key into a connector's key field
  2. Set outputsize (1 to 5,000, default 30) and format=CSV on time_series to keep responses small, and read status in the JSON body since errors come with HTTP codes and a message
  3. Count credits, not calls; most endpoints cost one credit per symbol and the Basic plan allows 8 a minute and 800 a day, with 429 when exceeded
  4. A 403 means the key's plan lacks the endpoint or symbol, not a bad key; check pricing.md before escalating
  5. Use trial symbols from twelvedata.com/exchanges to test premium data on the free plan

Questions

Which is better for AI agents, Eulerpool Financial Data API or Twelve Data?

Twelve Data scores 70 (BB) on agent readiness against Eulerpool Financial Data API's 46.2 (D), and leads in 6 of 7 scored categories. Eulerpool Financial Data API leads on payments & pricing.

Do Eulerpool Financial Data API and Twelve Data need an API key?

Eulerpool Financial Data API needs an API key. Twelve Data takes an API key or an OAuth sign-in.

Can an agent call Eulerpool Financial Data API and Twelve Data without installing anything?

Yes. Eulerpool Financial Data API has a hosted endpoint at https://api.eulerpool.com/mcp and Twelve Data at https://api.twelvedata.com.

Other comparisons with Eulerpool Financial Data API or Twelve Data

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