Tools

Six tools, name-first: finnhub_search_symbols resolves a company name to a US ticker, then the other five work from that symbol — a live quote, full company context, earnings, news, and analyst consensus.

finnhub_search_symbols

Resolve a company name, partial name, or ticker fragment to Finnhub stock symbols. Run this first when you have a name, not a ticker — the rest of the surface needs a symbol.

• Full-text match across symbols and descriptions; likely-US Common Stock matches surfaced first
• query accepts 1–20 characters; use a shorter company name or ticker fragment when needed
• Each result carries isLikelyUS, a symbol-format heuristic: plain tickers and .A/.B class shares are likely US, while exchange suffixes such as .SS, .T, and .L are not. Quote and profile responses remain authoritative
• limit (1–50, default 10); reports the total match count and discloses truncation when more matched than returned

finnhub_get_quote

Real-time price quote for one US symbol. The market-hours flag is the point — the response never presents a stale price as live.

• Current price, absolute and percent change, session open/high/low, previous close, and an ISO 8601 quote time
• Pairs /quote with /stock/market-status (parallel fan-out) to derive priceIsLive — true only when the US market is open; when closed, current is the prior close, surfaced as such
• Exposes Finnhub's nullable session (pre-market, regular, or post-market) and returned holiday event name without inferring either value
• Market-status failing degrades to marketOpen: null, session: null, and holiday: null rather than tanking the quote
• Unknown US ticker → symbol_not_found; international or paid-only symbol → not_us_or_paid

finnhub_get_company

Full company context for one US symbol in a single call — profile is hollow without the valuation numbers, so this is deliberately one tool over three.

• Profile: name, exchange, industry, country, currency, market cap, shares outstanding, IPO date, website, logo
• Headline fundamentals: P/E (TTM), EPS (TTM), 52-week range, beta, dividend yield, net/gross margin, revenue growth YoY, ROE — every field nullable, surfaced honestly for thinly-covered names rather than zero-filled
• Sector peers from /stock/peers (includes the queried symbol)
• Combines three endpoints under a parallel fan-out; metrics or peers failing degrade to a partial list, profile drives the not-found / forbidden errors

finnhub_get_earnings

Earnings data for one symbol or across the market, selected by mode.

• history (requires symbol): past quarters — actual vs. estimate EPS, absolute surprise, and surprise % (the market-moving signal), newest first
• calendar (uses from / to, defaults to today through +14 days; optional symbol filter): upcoming releases across the market or for one symbol — date, EPS/revenue estimates, expected report time
• limit (1–100, default 50); reports total rows and discloses truncation

finnhub_get_news

Financial news for one company or the broad market, selected by mode.

• company (requires symbol): recent articles over a date range (defaults to the last 7 days) — headline, source, ISO 8601 datetime, summary, URL
• market (uses category): broad headlines by general, forex, crypto, or merger (see the finnhub://news-categories resource)
• limit (1–100, default 15 — news lists run long); articles newest first, with total and truncation disclosure

finnhub_get_recommendations

Analyst recommendation consensus for one US symbol — the view to pair with the live quote and fundamentals.

• Per-month strong-buy / buy / hold / sell / strong-sell counts, newest first (typically 12–24 months of history)
• limit (1–24, default 12 — one year); reports total months and discloses truncation
• Empty result (no analyst coverage) → no_coverage, distinct from an invalid symbol

Resource

The resource is a convenience mirror — its data is fully covered by the category enum on finnhub_get_news, so tool-only clients lose nothing. Live data (quotes, news, earnings) is intentionally not exposed as a resource: it's time-sensitive, and the value is in the freshness, so it's reachable only through the tools.

Features

Built on @cyanheads/mcp-ts-core:

• Declarative tool and resource definitions — single file per primitive, framework handles registration and validation
• Unified error handling — handlers throw, framework catches, classifies, and formats
• Pluggable auth: none, jwt, oauth
• Swappable storage backends: in-memory, filesystem, Supabase, Cloudflare KV/R2/D1
• Structured logging with optional OpenTelemetry tracing
• STDIO and Streamable HTTP transports

Finnhub-specific:

• Single rate-aware Finnhub client — token injected server-side (never a tool input), with timeout and retry calibrated to the 60 req/min free tier
• Live market-status pairing on quotes so a closed-market price is reported as the prior close, never as live
• Status classification at the service boundary: 403 → a clear not_us_or_paid domain error, 401 → loud configuration failure at first call (not "no data"), 429/5xx → retried
• finnhub_get_company fans out profile + metrics + peers in parallel and degrades to partial results when a leg fails

Agent-friendly output:

• Honest sparsity — every fundamental is nullable and absent values stay null; Finnhub's thinly-covered names are surfaced as-is, never zero-filled or fabricated
• Two distinct "not available" signals — symbol_not_found (unknown US ticker, detected from the all-zero quote / empty profile sentinel) vs. not_us_or_paid (international or paid-only, HTTP 403) — so an agent can tell them apart and recover
• Typed error contracts with recovery hints on every failure, plus the isLikelyUS search heuristic so an agent can prioritize likely free-tier symbols
• Capped lists report their total count and disclose truncation, so an agent knows when more data exists

Getting started

This server requires a free Finnhub API key (Dashboard → API key). The free tier covers US equities in real time at 60 req/min.

Each user must obtain their own API key. Use is subject to Finnhub's Terms of Service — the free tier is for personal use only, and redistributing or sharing access to Finnhub data with third parties requires written approval from Finnhub.

Add the following to your MCP client configuration file.

{
  "mcpServers": {
    "finnhub-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/finnhub-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info",
        "FINNHUB_API_KEY": "your-api-key"
      }
    }
  }
}

Or with npx (no Bun required):

{
  "mcpServers": {
    "finnhub-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/finnhub-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info",
        "FINNHUB_API_KEY": "your-api-key"
      }
    }
  }
}

Or with Docker:

{
  "mcpServers": {
    "finnhub-mcp-server": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "MCP_TRANSPORT_TYPE=stdio",
        "-e", "FINNHUB_API_KEY=your-api-key",
        "ghcr.io/cyanheads/finnhub-mcp-server:latest"
      ]
    }
  }
}

For Streamable HTTP, set the transport and start the server:

MCP_TRANSPORT_TYPE=http MCP_SESSION_MODE=stateless MCP_HTTP_PORT=3010 FINNHUB_API_KEY=... bun run start:http
# Server listens at http://localhost:3010/mcp

Prerequisites

• Bun v1.3.0 or higher (or Node.js v24+).
• A free Finnhub API key. The free tier is US equities only, real-time, 60 req/min — international symbols (any exchange-suffixed ticker like .TO or .DE) and candle/forex endpoints are paid-tier and return a clear error.

Installation

1. Clone the repository:

git clone https://github.com/cyanheads/finnhub-mcp-server.git

2. Navigate into the directory:

cd finnhub-mcp-server

3. Install dependencies:

bun install

4. Configure environment:

cp .env.example .env
# edit .env and set FINNHUB_API_KEY

Configuration

All configuration is validated at startup via Zod schemas in src/config/server-config.ts. Key environment variables:

See .env.example for the full list of optional overrides.

Running the server

Local development

• Build and run:

  sh

  Copy

  # One-time build
  bun run rebuild
  
  # Run the built server
  bun run start:stdio
  # or
  bun run start:http
  

• Run checks and tests:

  sh

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  bun run devcheck   # Lint, format, typecheck, security
  bun run test       # Vitest test suite
  bun run lint:mcp   # Validate MCP definitions against spec
  

Docker

docker build -t finnhub-mcp-server .
docker run --rm -e MCP_TRANSPORT_TYPE=http -e FINNHUB_API_KEY=your-key -p 3010:3010 finnhub-mcp-server

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/finnhub-mcp-server. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

Development guide

See CLAUDE.md / AGENTS.md for development guidelines and architectural rules. The short version:

• Handlers throw, framework catches — no try/catch in tool logic
• Use ctx.log for request-scoped logging, ctx.state for tenant-scoped storage
• Register new tools and resources via the barrels in src/mcp-server/*/definitions/index.ts
• Wrap the Finnhub API: validate raw → normalize to domain type → return output schema; never fabricate missing fields

Contributing

Issues and pull requests are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.