---

Tools

Seven tools covering the two-phase EIA workflow — find the right dataset route, pull the data, and query spilled results via SQL:

Tool	Description
eia_browse_routes	Lists child routes under a given path in the EIA dataset taxonomy. Start at root to see top-level categories, then drill into subcategories and leaf routes.
eia_describe_route	Returns full metadata for a leaf route: available facets with valid values, data column names, frequency options, units, and date range. Call before eia_query_route to understand filter options.
eia_search_routes	Fuzzy text search across route names, descriptions, and category labels. Resolves natural-language queries like "gasoline retail prices" or "solar capacity by state" to matching route paths.
eia_query_route	Fetches data from a leaf route with optional facet filters, date range, frequency, and column selection. Spills large result sets to a DataCanvas table for SQL analysis.
eia_dataframe_describe	Lists active DataCanvas dataframes created by prior eia_query_route calls. Shows table name, column names and types, row count, and canvas ID.
eia_dataframe_query	Runs a read-only SQL SELECT against a DataCanvas dataframe by canvas ID or table name.
eia_dataframe_drop	Drops a DataCanvas dataframe, freeing its memory. Only exposed when EIA_DATAFRAME_DROP_ENABLED=true.

eia_browse_routes

Walk the EIA dataset taxonomy from root to leaf.

• Root call returns 14 top-level categories: electricity, petroleum, natural-gas, coal, international, total-energy, steo, aeo, ieo, seds, crude-oil-imports, nuclear-outages, densified-biomass, co2-emissions
• Intermediate paths return subcategories; leaf routes are flagged so callers know when to switch to eia_describe_route
• STEO (Short-Term Energy Outlook) is a flat leaf with 1,469 named series — no sub-routes

---

eia_describe_route

Full schema for a leaf route. Required before constructing facet filters.

• Returns facets with valid values (fetched via per-facet API calls and cached in-process)
• Returns data column names, units, frequency options, and date range
• eia_search_routes and eia_browse_routes resolve the route path; this tool provides the filter vocabulary

---

eia_search_routes

Fuzzy search across the in-memory route index.

• Indexes route names, descriptions, and category labels — plus STEO's 1,469 series names
• Resolves natural language ("natural gas spot prices", "ethanol net imports") to queryable route paths
• Route tree is cached in-process at first call; subsequent searches hit the Fuse.js index with no upstream cost

---

eia_query_route

Pull data from a leaf route.

• Facet filters keyed by facet ID (e.g. { "stateid": "TX", "sectorid": ["RES", "COM"] })
• Date range and frequency selection; valid values discoverable via eia_describe_route
• Pagination via offset/length (max 5,000 rows per page); total row count in response
• All numeric values arrive as strings from the EIA API — units appear as inline {col}-units fields per row
• DataCanvas spillover when result set exceeds length: returns canvas_id for SQL queries over the full dataset

Features

Built on @cyanheads/mcp-ts-core:

• Declarative tool definitions — single file per tool, 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

EIA-specific:

• Full coverage of EIA API v2 — all 14 top-level dataset categories
• In-process route tree cache with Fuse.js fuzzy index — built once at startup, no repeated upstream calls
• Per-route facet cache via Promise.all fan-out — valid filter values available without re-fetching
• STEO series names (1,469 entries) indexed for natural-language discovery
• DataCanvas (DuckDB) opt-in for tabular spillover — graceful degradation when unavailable

Getting started

Get a free API key at api.eia.gov, then add the following to your MCP client configuration file.

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

Or with npx (no Bun required):

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

Or with Docker:

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

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

MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 EIA_API_KEY=your-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 EIA API key from api.eia.gov. The DEMO_KEY hits rate limits quickly; a real key is required for sustained use.

Installation

1. Clone the repository:

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

2. Navigate into the directory:

cd eia-energy-mcp-server

3. Install dependencies:

bun install

4. Configure environment:

cp .env.example .env
# edit .env and set required vars (at minimum, EIA_API_KEY)

Configuration

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

Variable	Description	Default
EIA_API_KEY	Required. Free API key from api.eia.gov — appended as api_key on every request.	—
EIA_BASE_URL	EIA API base URL.	https://api.eia.gov/v2
EIA_DATASET_TTL_SECONDS	Per-table TTL for DataCanvas dataframes in seconds.	86400 (24 h)
EIA_DATAFRAME_DROP_ENABLED	Set to true to expose eia_dataframe_drop. Off by default to avoid accidental canvas cleanup.	false
CANVAS_PROVIDER_TYPE	Set to duckdb to enable DataCanvas spillover for large result sets (Node only).	—
MCP_TRANSPORT_TYPE	Transport: stdio or http.	stdio
MCP_HTTP_PORT	HTTP server port.	3010
MCP_HTTP_ENDPOINT_PATH	HTTP endpoint path.	/mcp
MCP_PUBLIC_URL	Public origin override for TLS-terminating reverse-proxy deployments.	—
MCP_AUTH_MODE	Auth mode: none, jwt, or oauth.	none
MCP_LOG_LEVEL	Log level (RFC 5424).	info
LOGS_DIR	Directory for log files (Node.js only).	<project-root>/logs
STORAGE_PROVIDER_TYPE	Storage backend: in-memory, filesystem, supabase, cloudflare-kv/r2/d1.	in-memory
OTEL_ENABLED	Enable OpenTelemetry instrumentation.	false

Running the server

Local development

• Build and run:

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

• Run checks and tests:

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

Project structure

Directory	Purpose
src/index.ts	createApp() entry point — registers tools and inits services.
src/config	Server-specific environment variable parsing and validation with Zod.
src/mcp-server/tools	Tool definitions (*.tool.ts) — browse, describe, search, query, and three DataCanvas dataframe tools.
src/services/eia	EIA API v2 service — route tree cache, Fuse.js index, facet fan-out, HTTP client.
src/services/canvas-bridge	DataCanvas bridge — registers EIA query results as DuckDB dataframes, routes SQL queries.
tests/	Unit and integration tests mirroring src/.
docs/	Design documents (design.md, idea.md).

Development guide

See CLAUDE.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
• Always call eia_describe_route before eia_query_route — facet values require a separate API fan-out and are not embedded in route metadata
• Wrap EIA responses: validate raw → normalize to domain type → return output schema; data values are strings — never coerce silently

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.