Transports

The heycreo MCP server supports three transport types. Choose the one that fits your client and deployment.

SSE (Server-Sent Events)

Endpoint: https://app.heycreo.io/api/sse

The SSE transport opens a persistent connection for server-to-client messages and uses HTTP POST for client-to-server messages. This is the most widely supported transport across MCP clients.

Use when:

• Your client supports SSE (most do: Claude Desktop, Cursor, etc.)
• You want real-time progress updates during long-running operations
• You're building a web-based integration

Streamable HTTP

Endpoint: https://app.heycreo.io/api/mcp

A simpler HTTP-based transport where each tool call is a single HTTP request/response cycle. The response can be streamed.

Use when:

• You prefer stateless request/response communication
• Your environment doesn't support long-lived connections
• You're building a server-side integration

STDIO

Transport: local process (no URL)

Standard input/output transport for local process communication: the MCP client spawns the server as a child process and exchanges messages over stdin/stdout. There is no HTTP endpoint involved.

In practice, clients that only speak STDIO connect to the remote SSE/HTTP endpoint through a local bridge: mcp-remote, which runs as a STDIO process and proxies to https://app.heycreo.io/api/mcp, injecting your auth headers. Claude Desktop and ChatGPT both support the remote endpoint natively via OAuth instead; see Client Examples.

Use when:

• Your client only supports local STDIO servers (bridge to the remote endpoint via mcp-remote)
• You're running the heycreo API locally during development
• You're building a CLI tool or local agent

Headers (all transports)

Both authentication and organization context are passed via HTTP headers, regardless of transport:

Authorization: Bearer <api_key_or_jwt>
X-heycreo-Org: <organization_slug>

Choosing a transport

Transport	Latency	Streaming	Best for
SSE	Low	Yes	AI clients (Claude, Cursor), web apps
Streamable HTTP	Medium	Yes	Backend integrations, serverless
STDIO	Lowest	No	Local development, CLI tools

For most use cases, SSE is the recommended default.