AI Agents & MCP

MCP vs REST vs WebSocket: Which Quote.Trade Interface Should You Use?

Use MCP when an agent needs discoverable tools and approvals, REST for direct request-and-response API calls, and WebSocket for live market and account updates. Most production integrations use more than one.

15 minutesBeginnerDevelopers, architects, and platform teams

What you will accomplish

  • Choose the right interface for the job
  • Understand the job of each interface
  • Use MCP, REST, and WebSocket together when the application needs more than one
  • Confirm orders and account changes from Quote.Trade data

Before you begin

  • A clear use case: research, execution, or continuous events
  • Quote.Trade API and MCP documentation
MCPAgent tool discovery and approved actions
RESTDirect requests and signed operations
WebSocketContinuous market and private events
Client/workspace constraintAn MCP server can expose a tool that the selected client plan or workspace policy does not allow
Step-by-step

Use MCP for agent tools and approvals

MCP gives an AI client a structured list of tools and inputs. Use it for status checks, market questions, order previews, and explicitly approved actions. It is optional; applications can also integrate directly through REST and WebSocket.

Use REST for direct API calls

Use REST for public snapshots, account reads, signed order requests, and other direct API calls. Keep credentials on the server and check the current order before retrying a timed-out write request.

Use WebSocket for live updates

Use the public liquidity stream for live quotes and the private listen-key stream for order, account, position, and risk updates. After a disconnect, reconnect and reload the current REST state before sending another order.

Give each interface one clear job

A practical agent can use MCP for user-facing tool calls, REST for server-side API requests, and WebSocket for live confirmation and risk updates. Keep one internal symbol and order format across all three.

text
MCP: discover tools → explain → preview → request approval
REST: sign → submit → query current orders and account
WebSocket: receive fills → positions → risk updates

Decide what happens when an interface fails

Handle each failure differently: reconnect a dropped WebSocket, back off after REST rate limits, and reinitialize a failed MCP session. After a timeout or 5xx on an order, stop and check the order and position before retrying.

Troubleshooting

Common problems and fixes

The bot polls ticker hundreds of times per minute

Use WebSocket for live prices and REST only for an occasional fresh snapshot.

The agent says an order filled but no event exists

Query authenticated order/account state and private events. Do not treat the conversational response as proof of execution.

Different interfaces use inconsistent symbols

Load the current Quote.Trade market list and map every interface to the exact symbol returned there.

Primary sources

Ready for the next step?

Open Quote.Trade API documentation

Open Quote.Trade API documentation