> ## Documentation Index
> Fetch the complete documentation index at: https://ti-mm-mycompc.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP SSE transport — /mcp/sse and /mcp/messages

> Connect AI agents to the Solana AI Gateway via Model Context Protocol SSE transport for real-time tool invocation.

The Solana AI Gateway implements the Model Context Protocol (MCP) using Server-Sent Events (SSE). Clients such as Claude Desktop and Cursor can connect to the SSE endpoint to discover and invoke gateway tools in real time. After establishing the SSE stream, the client sends JSON-RPC messages via POST to the messages endpoint using the session ID returned in the stream.

## Endpoints

### Establish SSE stream

```http theme={null}
GET /mcp/sse
```

No authentication required.

The gateway opens a long-lived SSE connection and assigns a unique `sessionId`. The first event contains the messages URL, for example `/mcp/messages?sessionId=<uuid>`.

### Send messages

```http theme={null}
POST /mcp/messages?sessionId=<uuid>
Content-Type: application/json
```

Send JSON-RPC tool invocation requests to this endpoint using the `sessionId` from the SSE stream.

## How it works

<Steps>
  <Step title="Open SSE connection">
    Send `GET /mcp/sse`. The gateway creates a session and streams events back to your client.
  </Step>

  <Step title="Read session ID">
    The gateway emits the messages endpoint URL with a unique `sessionId` query parameter.
  </Step>

  <Step title="POST tool requests">
    Send JSON-RPC `tools/call` requests to `POST /mcp/messages?sessionId=<uuid>`.
  </Step>

  <Step title="Receive responses">
    Results are streamed back over the original SSE connection as JSON-RPC responses.
  </Step>
</Steps>

## Available MCP tools

The gateway exposes the following tools over MCP. Each tool accepts the same parameters as the equivalent REST endpoint and returns structured JSON text content.

| Tool name                     | Purpose                                                       |
| ----------------------------- | ------------------------------------------------------------- |
| `get_solana_balance`          | Fetch native SOL balance with network selection.              |
| `get_solana_blockhash`        | Get the latest finalized blockhash.                           |
| `get_token_accounts`          | Scan all SPL token holdings for a wallet.                     |
| `get_recent_transactions`     | Retrieve recent transaction signatures.                       |
| `simulate_solana_transaction` | Simulate a base64 transaction before broadcast.               |
| `find_ata`                    | Derive the Associated Token Account for a wallet and mint.    |
| `token_profile`               | Get token metadata, decimals, and security/honeypot flags.    |
| `optimal_fee`                 | Get tiered priority fee recommendations.                      |
| `decode_tx`                   | Translate raw transaction logs into human-readable summaries. |

## Example: cURL SSE connection

<CodeGroup>
  ```bash Open SSE stream theme={null}
  curl -N "$GATEWAY_URL/mcp/sse"
  ```

  ```bash Send a tool call theme={null}
  # Replace <sessionId> with the value from the SSE stream
  curl -X POST "$GATEWAY_URL/mcp/messages?sessionId=<sessionId>" \
    -H "Content-Type: application/json" \
    -d '{
      "jsonrpc": "2.0",
      "id": 1,
      "method": "tools/call",
      "params": {
        "name": "get_solana_balance",
        "arguments": {
          "wallet": "Brpc8HoPo1d3Uiyo7kbERnjMqwLJJmbWxtwxHxzar6DU",
          "network": "mainnet-beta"
        }
      }
    }'
  ```
</CodeGroup>

## Example: TypeScript SSE client

```typescript TypeScript theme={null}
const eventSource = new EventSource(`${process.env.GATEWAY_URL}/mcp/sse`);

eventSource.onmessage = (event) => {
  const data = JSON.parse(event.data);
  console.log("SSE event:", data);
};

// After reading the sessionId from the first SSE event:
async function callTool(sessionId: string) {
  const res = await fetch(
    `${process.env.GATEWAY_URL}/mcp/messages?sessionId=${sessionId}`,
    {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        jsonrpc: "2.0",
        id: 1,
        method: "tools/call",
        params: {
          name: "get_solana_balance",
          arguments: {
            wallet: "Brpc8HoPo1d3Uiyo7kbERnjMqwLJJmbWxtwxHxzar6DU",
            network: "mainnet-beta",
          },
        },
      }),
    }
  );
  return await res.json();
}
```

## Errors

| Status | Meaning                                                             |
| ------ | ------------------------------------------------------------------- |
| `400`  | Missing `sessionId` on `POST /mcp/messages`.                        |
| `404`  | `MCP SSE Session not found` — the session ID is invalid or expired. |

## Notes

* SSE sessions are cleaned up automatically when the client disconnects.
* The gateway applies the same rate limits to MCP traffic as to REST traffic.
* For tool schemas and descriptions, fetch the [MCP manifest](/api-reference/mcp/manifest) first.