Setup · MCP · JSON-RPC 2.0

Set up in one line

Point-in-time market data, built to avoid look-ahead and survivorship bias, as typed MCP tools your agent calls directly. Start with no key: an anonymous session is a trial capped at 25 tool calls a day, and verifying an email — which you can do from inside the chat — opens the free tier at 100 calls a day. 

$ claude mcp add --transport http synapse-discovery "https://synapsediscovery.io/mcp/jsonrpc?src=install"

30 typed tools over JSON-RPC 2.0 and Streamable HTTP. Nothing to install from us. Full catalog: /mcp/tools.

01 / Clients

Pick your client

Claude Code

One command in your terminal. Keep the quotes: the address carries a ?, which some shells would otherwise expand.

Terminal
claude mcp add --transport http synapse-discovery "https://synapsediscovery.io/mcp/jsonrpc?src=install"

Cursor

Add the server to your MCP configuration file (mcp.json).

mcp.json
{
  "mcpServers": {
    "synapse-discovery": {
      "url": "https://synapsediscovery.io/mcp/jsonrpc?src=install"
    }
  }
}

VS Code

Add the server to .vscode/mcp.json in your workspace, or to your user MCP configuration.

.vscode/mcp.json
{
  "servers": {
    "synapse-discovery": {
      "type": "http",
      "url": "https://synapsediscovery.io/mcp/jsonrpc?src=install"
    }
  }
}

claude.ai custom connector

This is a remote MCP server, so there is nothing to run locally: add a custom connector in Claude's connector settings and paste the address below. Clients that look a server up can read our discovery manifest at /.well-known/mcp.json.

Connector URL
https://synapsediscovery.io/mcp/jsonrpc?src=install

Menus move between releases, so we do not print a click path here — the address above is all the connector needs.

With your API key

Send your key in the X-API-Key header and the connection uses your plan's limits instead of the anonymous trial. With a key you may also skip the handshake and POST a single tools/call. A client that accepts only a URL connects on the keyless trial.

Claude Code
claude mcp add --transport http synapse-discovery "https://synapsediscovery.io/mcp/jsonrpc?src=install" \
  --header "X-API-Key: sd_live_..."
mcp.json (Cursor)
{
  "mcpServers": {
    "synapse-discovery": {
      "url": "https://synapsediscovery.io/mcp/jsonrpc?src=install",
      "headers": { "X-API-Key": "sd_live_..." }
    }
  }
}
.vscode/mcp.json (VS Code — prompts for the key, so it is not saved in the file)
{
  "inputs": [
    { "type": "promptString", "id": "synapse-key",
      "description": "Synapse Discovery API key", "password": true }
  ],
  "servers": {
    "synapse-discovery": {
      "type": "http",
      "url": "https://synapsediscovery.io/mcp/jsonrpc?src=install",
      "headers": { "X-API-Key": "${input:synapse-key}" }
    }
  }
}
REST, no MCP client
# ARKK's newest N-PORT report public on 2021-02-12 (the 2020-10-30 report)
curl -H "X-API-Key: sd_live_..." \
  "https://synapsediscovery.io/api/v1/funds/ARKK/holdings?as_of=2021-02-12"

There is no package to install: the REST API and the MCP server are the product, and the machine-readable spec is at /openapi.yaml.

02 / Try it

Three questions to start with

Paste one into your agent once the server is connected.

“What was ARKK's newest public N-PORT report on 2021-02-12?”

Position-level holdings from the newest N-PORT report we hold that had been filed by then, with its report date and SEC accession — not today's portfolio, and not a top-10 list.

“What was Apple's newest reported period on 2019-01-29, and on 2019-01-30?”

SEC statements as first filed, cut at the day each filing reached EDGAR: the December 2018 quarter appears on 2019-01-30, the day its 10-Q was filed.

“What did the Treasury yield curve look like on 2020-03-16?”

That day's Treasury yields across maturities, with the 2-year/10-year spread.

03 / Keys

From keyless trial to a key

  1. Connect with no key

    An anonymous session is created for you and capped at 25 tool calls a day — enough to evaluate without an account. Every result carries a _quota block, and get_quota reports what is left.

  2. Verify an email without leaving the chat

    Ask the agent to call request_email_verification with your address, then read the emailed code back to it for confirm_email_verification. Both are tools, so the whole path runs over tools/call, and an API key comes back in the reply. You can do the same step in a browser at /mcp/verify.

  3. You are on the free tier

    100 calls a day, 10 a minute. Manage keys at /portal/api-keys; paid plans raise the daily cap and how far back price and NAV history reaches, and Quant adds bulk downloads — see pricing.

Next

The endpoint reference, the OpenAPI spec, and the known-issues list.

API documentation OpenAPI spec Known limitations