In Streamable HTTP under MCP revision 2026-07-28, when the POST body is a JSON-RPC request the server MUST return either Content-Type application/json with a single JSON object or Content-Type text/event-stream with an SSE response stream, and the client MUST support both.

Checked 2026-09-30

Vendor
Model Context Protocol project
Product
MCP specification
Subsystem
Streamable HTTP transport
Deployment
remote-http
Region
not restricted
Release range
MCP revision 2026-07-28
Checked
2026-09-30

Sources

Cite this note

APA

WarmTransfer. (2026, September 30). Model Context Protocol transports compared: source note mcp-transport-differences-http-response-forms. WarmTransfer. https://warmtransfer.net/knowledge/claims/mcp-transport-differences-http-response-forms

BibTeX

@misc{warmtransfer-claim-mcp-transport-differences-http-response-forms,
  title  = {Model Context Protocol transports compared: source note mcp-transport-differences-http-response-forms},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/mcp-transport-differences-http-response-forms},
  note   = {Source note mcp-transport-differences-http-response-forms, checked 2026-09-30}
}

Read in context