{
  "title": "MCP legacy HTTP and SSE",
  "description": "Connect through the superseded HTTP plus SSE transport when migration compatibility is required. Compatibility evidence is tracked independently from other MCP capabilities.",
  "slug": "mcp-legacy-sse",
  "locale": "en",
  "seoTitle": "MCP legacy HTTP and SSE compatibility — Can My Agent Use",
  "socialTitle": "MCP legacy HTTP and SSE",
  "socialDescription": "Connect through the superseded HTTP plus SSE transport when migration compatibility is required. Unreviewed product cells remain unknown.",
  "llmSummary": "MCP legacy HTTP and SSE is an atomic MCP capability. Support for another MCP primitive does not imply this capability.",
  "audience": "Engineers comparing chat, desktop, and CLI agent harnesses.",
  "contentKind": "feature",
  "status": "published",
  "tags": [
    "interfaces",
    "mcp"
  ],
  "updated": "2026-08-28T00:00:00.000Z",
  "published": "2026-08-28T00:00:00.000Z",
  "category": "interfaces",
  "summary": "Connect through the superseded HTTP plus SSE transport when migration compatibility is required.",
  "specLabel": "MCP 2026-07-28",
  "specification": {
    "id": "mcp",
    "revision": "2026-07-28",
    "maturity": "published",
    "role": "legacy transport",
    "authority": "MCP project / AAIF ecosystem",
    "canonicalUrl": "https://modelcontextprotocol.io/specification/2026-07-28"
  },
  "aliases": [
    "MCP SSE"
  ],
  "capabilityKind": "atomic",
  "parent": "mcp",
  "related": [],
  "relations": [],
  "highlight": false,
  "notes": [
    {
      "id": 1,
      "text": "Evidence checked 2026-08-28: the Agent Plugins compatible-client registry explicitly lists legacy MCP SSE for Grok Bot. This is registry evidence, not an independent transport test."
    },
    {
      "id": 2,
      "text": "Evidence checked 2026-08-28: Anthropic documents the `sse` transport for legacy remote Claude Code MCP servers while recommending HTTP for current servers."
    },
    {
      "id": 3,
      "text": "Evidence checked 2026-08-28: Gemini CLI documents SSE endpoints as one of its three supported MCP transport types."
    },
    {
      "id": 4,
      "text": "Evidence checked 2026-08-28: Cursor documents SSE as a supported local or remote MCP transport and distinguishes it from Streamable HTTP."
    },
    {
      "id": 5,
      "text": "Evidence checked 2026-08-28: Cline documents an explicit `sse` transport for legacy remote servers and retains SSE as the default when a remote transport type is omitted."
    },
    {
      "id": 6,
      "text": "Evidence checked 2026-08-28: Continue documents an explicit `sse` remote transport and its pinned desktop client constructs the MCP SDK SSE client transport."
    },
    {
      "id": 7,
      "text": "Evidence checked 2026-08-28: Zed's pinned transport module exposes only stdio and a single-endpoint POST-based HTTP transport; it does not implement the superseded HTTP-plus-SSE client transport."
    }
  ],
  "issues": [],
  "resources": [
    {
      "title": "Model Context Protocol specification",
      "href": "https://modelcontextprotocol.io/specification/2026-07-28",
      "kind": "spec"
    },
    {
      "id": "agent-plugins-grok-bot-client",
      "title": "Agent Plugins — Compatible clients",
      "href": "https://agent-plugins.org/compatible-clients",
      "kind": "spec",
      "publisher": "Agent Plugins",
      "evidenceType": "listed",
      "reviewedAt": "2026-08-28",
      "locator": "Grok Bot"
    },
    {
      "id": "anthropic-claude-code-mcp",
      "title": "Anthropic — Connect Claude Code to tools via MCP",
      "href": "https://code.claude.com/docs/en/mcp",
      "kind": "docs",
      "publisher": "Anthropic",
      "evidenceType": "documented",
      "reviewedAt": "2026-08-28",
      "locator": "Add a remote SSE server"
    },
    {
      "id": "google-gemini-cli-mcp-docs",
      "title": "Google — MCP servers with Gemini CLI",
      "href": "https://geminicli.com/docs/tools/mcp-server/",
      "kind": "docs",
      "publisher": "Google",
      "evidenceType": "documented",
      "reviewedAt": "2026-08-28",
      "locator": "Transport mechanisms — SSE Transport"
    },
    {
      "id": "cursor-mcp-docs",
      "title": "Cursor — Model Context Protocol",
      "href": "https://prod.cursor.com/docs/mcp",
      "kind": "docs",
      "publisher": "Cursor",
      "evidenceType": "documented",
      "reviewedAt": "2026-08-28",
      "locator": "Transport table — SSE"
    },
    {
      "id": "cline-mcp-docs",
      "title": "Cline — Model Context Protocol",
      "href": "https://docs.cline.bot/mcp/mcp-overview",
      "kind": "docs",
      "publisher": "Cline",
      "evidenceType": "documented",
      "reviewedAt": "2026-08-28",
      "locator": "SSE (Legacy); remote transport default"
    },
    {
      "id": "continue-mcp-docs",
      "title": "Continue — Model Context Protocol",
      "href": "https://docs.continue.dev/customize/deep-dives/mcp",
      "kind": "docs",
      "publisher": "Continue",
      "evidenceType": "documented",
      "reviewedAt": "2026-08-28",
      "locator": "How to use Server-Sent Events transport"
    },
    {
      "id": "continue-mcp-client-source",
      "title": "Continue source — MCP desktop client at 5522c6f",
      "href": "https://github.com/continuedev/continue/blob/5522c6f44ca0ac3528b37244818fbfa39b5af470/core/context/mcp/MCPConnection.ts",
      "kind": "docs",
      "publisher": "Continue",
      "evidenceType": "documented",
      "reviewedAt": "2026-08-28",
      "locator": "SSEClientTransport"
    },
    {
      "id": "zed-mcp-transport-source",
      "title": "Zed source — MCP transport module at e3adf43",
      "href": "https://github.com/zed-industries/zed/blob/e3adf43f37d7a2a9c165a78b255d293b0848d2d0/crates/context_server/src/transport.rs",
      "kind": "docs",
      "publisher": "Zed Industries",
      "evidenceType": "documented",
      "reviewedAt": "2026-08-28",
      "locator": "exported stdio and HTTP transports"
    },
    {
      "id": "zed-mcp-http-source",
      "title": "Zed source — MCP HTTP transport at e3adf43",
      "href": "https://github.com/zed-industries/zed/blob/e3adf43f37d7a2a9c165a78b255d293b0848d2d0/crates/context_server/src/transport/http.rs",
      "kind": "docs",
      "publisher": "Zed Industries",
      "evidenceType": "documented",
      "reviewedAt": "2026-08-28",
      "locator": "single-endpoint POST transport"
    }
  ],
  "support": [
    {
      "harness": "claude-cli",
      "versions": [
        {
          "track": "current",
          "status": "yes",
          "noteIds": [
            2
          ],
          "target": {
            "kind": "dated-documentation",
            "revision": "current Claude Code MCP documentation",
            "observedAt": "2026-08-28"
          },
          "environmentProfile": "local-default",
          "qualifiers": [
            {
              "type": "transport",
              "value": "SSE is retained for legacy compatibility; Anthropic recommends the HTTP transport where the server supports it"
            }
          ],
          "evidence": [
            {
              "resourceId": "anthropic-claude-code-mcp",
              "type": "documented",
              "observedAt": "2026-08-28"
            }
          ]
        }
      ]
    },
    {
      "harness": "cursor",
      "versions": [
        {
          "track": "current",
          "status": "yes",
          "noteIds": [
            4
          ],
          "target": {
            "kind": "dated-documentation",
            "revision": "current Cursor MCP documentation observed 2026-08-28",
            "observedAt": "2026-08-28"
          },
          "environmentProfile": "local-default",
          "qualifiers": [
            {
              "type": "transport",
              "value": "SSE remains supported for compatibility, while Cursor separately documents Streamable HTTP for current HTTP endpoints"
            }
          ],
          "evidence": [
            {
              "resourceId": "cursor-mcp-docs",
              "type": "documented",
              "observedAt": "2026-08-28"
            }
          ]
        }
      ]
    },
    {
      "harness": "gemini-cli",
      "versions": [
        {
          "track": "current",
          "status": "yes",
          "noteIds": [
            3
          ],
          "target": {
            "kind": "dated-documentation",
            "revision": "Gemini CLI MCP documentation updated 2026-06-18",
            "observedAt": "2026-08-28"
          },
          "environmentProfile": "local-default",
          "qualifiers": [
            {
              "type": "transport",
              "value": "SSE endpoints can use headers or OAuth; new deployments should prefer Streamable HTTP where available"
            }
          ],
          "evidence": [
            {
              "resourceId": "google-gemini-cli-mcp-docs",
              "type": "documented",
              "observedAt": "2026-08-28"
            }
          ]
        }
      ]
    },
    {
      "harness": "grok-bot-desktop",
      "versions": [
        {
          "track": "current",
          "status": "yes",
          "noteIds": [
            1
          ],
          "target": {
            "kind": "hosted-observation",
            "revision": "2026-08-28 Agent Plugins compatible-client listing",
            "observedAt": "2026-08-28"
          },
          "environmentProfile": "hosted-default",
          "qualifiers": [
            {
              "type": "runtime",
              "value": "superseded transport support is registry-listed and was not independently tested by Can My Agent Use"
            },
            {
              "type": "policy",
              "value": "organization server and network allowlists can block a remote server"
            }
          ],
          "evidence": [
            {
              "resourceId": "agent-plugins-grok-bot-client",
              "type": "listed",
              "observedAt": "2026-08-28"
            }
          ]
        }
      ]
    },
    {
      "harness": "cline",
      "versions": [
        {
          "track": "current",
          "status": "yes",
          "noteIds": [
            5
          ],
          "target": {
            "kind": "dated-documentation",
            "revision": "current Cline MCP documentation observed 2026-08-28",
            "observedAt": "2026-08-28"
          },
          "environmentProfile": "local-default",
          "qualifiers": [
            {
              "type": "transport",
              "value": "SSE is retained for legacy compatibility; Cline recommends explicit Streamable HTTP for current remote servers"
            }
          ],
          "evidence": [
            {
              "resourceId": "cline-mcp-docs",
              "type": "documented",
              "observedAt": "2026-08-28"
            }
          ]
        }
      ]
    },
    {
      "harness": "continue",
      "versions": [
        {
          "track": "current",
          "status": "yes",
          "noteIds": [
            6
          ],
          "target": {
            "kind": "dated-documentation",
            "revision": "Continue source commit 5522c6f44ca0 and current documentation observed 2026-08-28",
            "observedAt": "2026-08-28"
          },
          "environmentProfile": "local-default",
          "qualifiers": [
            {
              "type": "transport",
              "value": "SSE is an explicit legacy remote transport and remains separate from Continue's Streamable HTTP path"
            }
          ],
          "evidence": [
            {
              "resourceId": "continue-mcp-docs",
              "type": "documented",
              "observedAt": "2026-08-28"
            },
            {
              "resourceId": "continue-mcp-client-source",
              "type": "documented",
              "observedAt": "2026-08-28"
            }
          ]
        }
      ]
    },
    {
      "harness": "zed-agent",
      "versions": [
        {
          "track": "current",
          "status": "no",
          "noteIds": [
            7
          ],
          "target": {
            "kind": "dated-documentation",
            "revision": "Zed source commit e3adf43f37d7 observed 2026-08-28",
            "observedAt": "2026-08-28"
          },
          "environmentProfile": "local-default",
          "qualifiers": [
            {
              "type": "transport",
              "value": "SSE response bodies on Zed's POST-based Streamable HTTP path do not constitute the superseded dedicated HTTP-plus-SSE transport"
            }
          ],
          "evidence": [
            {
              "resourceId": "zed-mcp-transport-source",
              "type": "documented",
              "observedAt": "2026-08-28"
            },
            {
              "resourceId": "zed-mcp-http-source",
              "type": "documented",
              "observedAt": "2026-08-28"
            }
          ]
        }
      ]
    }
  ],
  "html": "/features/mcp-legacy-sse",
  "markdown": "/features/mcp-legacy-sse.md",
  "json": "/api/v1/features/mcp-legacy-sse.json",
  "body": "Connect through the superseded HTTP plus SSE transport when migration compatibility is required.\n\nThe Grok Bot cell is registry-listed for migration compatibility. New deployments should prefer the current transport where the server supports it."
}