Authentication - Parallax API

The Parallax MCP server implements the MCP Authorization specification (OAuth 2.1). In a client that supports OAuth, connect the server URL and sign in through your browser. The client manages the access token for subsequent requests. When a client first connects to https://mcp.chicago.global/api/mcp:

Discovery

The client reads the server’s OAuth metadata from the well-known endpoints:

https://mcp.chicago.global/.well-known/oauth-protected-resource
https://mcp.chicago.global/.well-known/oauth-authorization-server

Dynamic client registration

The client registers itself automatically (no pre-provisioned client ID needed) and receives its OAuth credentials.

Browser sign-in

A browser window opens for you to sign in to your Parallax account and approve access. Authentication is handled by Parallax Intelligence, Inc., which provides the Parallax platform, API, and MCP server and is the data controller for Parallax users.

Token issued

The client receives an access token and uses it as a bearer token on every MCP request.

This flow is built in to Claude, Cursor, and VS Code. If your client only supports local stdio servers, use mcp-remote — it performs the same OAuth flow and caches the tokens locally.

Programmatic access (bearer token)

For scripts, tests, or servers that can’t do an interactive browser flow, send a bearer token directly in the Authorization header of your JSON-RPC request:

curl -s -X POST https://mcp.chicago.global/api/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "Authorization: Bearer $PARALLAX_TOKEN" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/call",
    "params": { "name": "get_company_info", "arguments": { "symbol": "AAPL.O" } }
  }'

Use an MCP client or SDK for session initialization and transport handling. Depending on the response content type, the server can return JSON or Server-Sent Events (data: lines). Read the result.content of the JSON-RPC response whose id matches your request.

Treat bearer tokens like passwords. Don’t commit them to source control or expose them in client-side code. Contact parallax@chicago.global to request programmatic credentials.

CORS

The server sends permissive CORS headers and handles OPTIONS preflight, so browser- and edge-based MCP clients can connect. The OAuth and .well-known routes are intentionally reachable without a session so machine clients can complete discovery and registration.

Troubleshooting

401 Unauthorized on tool calls

Your token expired or wasn’t sent. Re-authorize the connector, or (for programmatic use) obtain a valid replacement token for your Authorization header. The server supports the authorization-code grant; clients should reauthorize when a replacement is needed rather than request a refresh-token grant.

A tool call is refused for billing

Tool calls are billed in credits from your organization’s balance. Check the balance in the Console under Settings → API Console. The tool reference lists the credit cost of each tool.

Last modified on November 6, 2026

​OAuth sign-in (recommended)

​Programmatic access (bearer token)

​CORS

​Troubleshooting

OAuth sign-in (recommended)

Programmatic access (bearer token)

CORS

Troubleshooting