Elfa MCP
Model Context Protocol server for the Elfa API — crypto social intelligence from X and Telegram, plus Auto, a condition engine that watches the market and fires an action when your conditions are met.
Works with any MCP client: Claude Code, Claude Desktop, Cursor, VS Code, Codex, and anything else that speaks MCP.
Install
Get an API key at dev.elfa.ai. No install step — npx fetches the server on demand.
One click
Claude Desktop
Download elfa-mcp-<version>.mcpb from the latest release and open it. Claude Desktop installs it, prompts for your API key, and keeps it updated. Nothing else to configure.
Claude Code
claude mcp add elfa --env ELFA_API_KEY=your-key -- npx -y @elfa-ai/mcp
Cursor, VS Code, Claude Desktop, and other clients
{
"mcpServers": {
"elfa": {
"command": "npx",
"args": ["-y", "@elfa-ai/mcp"],
"env": {
"ELFA_API_KEY": "your-key"
}
}
}
}
VS Code uses "servers" instead of "mcpServers". Everything else is the same.
Ask "what's trending in crypto right now?" to confirm it works.
Configuration
| Variable | Required | Purpose |
|---|---|---|
ELFA_API_KEY | yes | Authenticates every request |
ELFA_HMAC_SECRET | no | Signs Auto requests. Needed only to connect an exchange, or to run a query whose action places an order |
ELFA_TIMEOUT | no | Request timeout in ms, default 120000 |
ELFA_RETRIES | no | Retries on failure, default 0 |
ELFA_MCP_MAX_RESPONSE_CHARS | no | Response size ceiling, default 60000 |
ELFA_EXTRA_HEADERS | no | JSON object of extra headers to send upstream, for proxies and non-production environments |
The timeout is high and retries are off on purpose. The interpretation endpoints are LLM-backed and can take over a minute, and they cost credits per attempt, so a silent retry would bill you again for a call you never saw. Raise ELFA_RETRIES only if you are calling the cheap measurement endpoints.
Some MCP clients apply their own timeout, often around 60 seconds. narratives and market_chat can exceed that; the request still completes and is still charged, even if the client gives up first.
Without ELFA_HMAC_SECRET everything still works except exchange linking and order-placing queries — those return a message telling you what to set.
Tools
12 tools, mapped to every documented /v2 operation.
| Tool | Mode | Cost | What it does |
|---|---|---|---|
api_status | read | Free | Check API key tier, credit usage and remaining requests. Also confirms the API is reachable. |
mentions | read | 1 per call | Social mentions from X and Telegram. mode=top ranks a ticker's mentions by engagement, mode=search filters by keyword or account, mode=news returns the token news feed. |
trending | read | 1 per call | What is gaining social attention. scope=tokens for tickers, scope=contracts_twitter or scope=contracts_telegram for contract addresses. |
narratives | read | 5 per call | Written narrative analysis with source links. scope=market extracts market-wide narratives, scope=keywords summarises events for specific keywords. |
account_stats | read | 1 per call | Smart follower and engagement stats for an X account. |
market_chat | read | Varies by speed | Ask for written market analysis. Supports conversational chat, macro overview, quick summary, token intro, token analysis and account analysis. |
auto_build | read | 1 plus LLM usage | Turn a plain-language monitoring request into an EQL query. Returns a draft to validate and activate, it does not activate anything itself. |
auto_validate | read | Free | Check EQL syntax and get a cost estimate before activating. Accepts an inline query or a draft id. |
auto_query | read | Free | Read side of Auto: list queries, poll one query, and read its executions and LLM sessions. |
auto_query_write | write | 5 plus LLM usage to create, free to cancel or delete | Activate, cancel or delete an Auto query. Activated queries run unattended and fire their action when conditions are met. |
auto_draft | write | Free, except convert which costs the same as creating a query | Manage inactive Auto drafts. Drafts do not evaluate until converted into an active query. |
auto_exchanges | write | Free | List, connect and disconnect the exchange accounts Auto uses for order actions, and check whether a symbol is tradeable. |
Not exposed as tools:
chat-stream-v2— A tool call returns one result, so streaming adds nothing. market_chat covers the same analysis.auto-stream-queries-v2— Long lived streams have no tool equivalent. Poll with auto_query.auto-stream-query-v2— Long lived streams have no tool equivalent. Poll with auto_query.
Streaming endpoints stay available through the SDKs for applications that can consume SSE.
Where this differs from the raw API
The tools deliberately do not inherit every API default, because an agent pays for verbosity in context.
| API | Here | Why | |
|---|---|---|---|
pageSize | 10 to 50 depending on endpoint, max 100 | 10 | Page through rather than pull everything |
speed on chat | expert | fast | Cheaper by default, ask for expert when depth matters |
| Mention fields | full record | high signal fields | Pass verbosity: "detailed" for the rest |
| Large responses | returned whole | trimmed to fit, with a note | Keeps one call from filling the context window |
Every value is still settable per call, and pageSize accepts up to 100.
Auto
Auto queries run unattended. Once armed, a query keeps evaluating and fires its action without asking again.
The flow is three steps:
auto_build— describe what to watch in plain language, get EQL backauto_validate— check the syntax and get the credit costauto_query_write— activate it
Actions can notify you, call a webhook, message a Telegram bot, run an LLM analysis, or place an order on a connected exchange. Order actions need ELFA_HMAC_SECRET and a connected exchange.
Connecting an exchange
| Venue | Connect from here | Credentials |
|---|---|---|
binance | yes | apiKey, secret |
pacifica | yes | privateKey, walletAddress |
hyperliquid | no, wallet is set up in the Elfa app | none |
gmx | no, wallet is set up in the Elfa app | none |
Credentials are verified on connect, so a wrong value fails there rather than when an order fires. They are ordinary tool arguments, so they pass through the model and land in the client's transcript.
There is no push channel over MCP. Poll auto_query with method=get, and wait for the returned pollAfterSeconds between calls.
Remote server
The same server runs over Streamable HTTP for hosted deployments:
ELFA_MCP_TRANSPORT=http ELFA_MCP_PORT=3000 npx -y @elfa-ai/mcp
It is stateless — no sessions, one server instance per request, safe behind a load balancer. Credentials come from x-elfa-api-key and x-elfa-hmac-secret request headers, falling back to the environment. Set ELFA_MCP_ALLOWED_ORIGINS to a comma separated allowlist when exposing it publicly.
Safety
api_status is the fastest way to tell an auth problem from a credit problem.
Mentions, news and narratives return third-party social text that anyone can write. The server marks it as untrusted in every response, and the server instructions tell the model to treat it as data. Keep that in mind before letting an agent chain from that content into auto_query_write or auto_exchanges.
Development
npm install
npm run build
npm run verify
npm run verify runs typecheck, tests, the spec drift check, and the docs check.
manifest.json maps every documented API operation to the tool that covers it. npm run check:drift fails if the API grows an operation the server does not handle. The tool table above is generated from the same file with npm run docs:tools.
Links
License
MIT