# Receive progress notifications from your AgentCore gateway Progress notifications allow MCP server targets to report incremental progress on long-running tool calls. When a tool call takes time to complete, the server can send `notifications/progress` events to keep the client informed about the operation’s status. AgentCore Gateway forwards these notifications from MCP server targets to your client as Server-Sent Events (SSE) chunks. ## Prerequisites To receive progress notifications from your gateway: + **Response streaming enabled** — Progress notifications are delivered as SSE chunks during an open connection. Set `streamingConfiguration.enableResponseStreaming` to `true` in your gateway’s `protocolConfiguration.mcp`. + **MCP server target type** — Progress notifications originate from MCP server targets. + **Client sends the `Accept` header** — The client must send `Accept: application/json, text/event-stream` so that the gateway can return a streaming (SSE) response. ## How progress notifications work When a client makes a `tools/call` request with a `progressToken` in the request parameters, the MCP server target can send `notifications/progress` events during execution. The gateway forwards these events to the client as SSE chunks before the final tool result. Each progress notification includes: + `progressToken` — Matches the token provided in the original request. + `progress` — The current progress value (numeric). + `total` — Optional total value indicating completion target. + `message` — Optional human-readable description of current status. ## Code samples **Example** Call a tool with a progress token. Set the `MCP-Protocol-Version` header to a version that your gateway supports. ``` curl -N -X POST \ https://mygateway-abcdefghij.gateway.bedrock-agentcore.us-west-2.amazonaws.com/mcp \ -H "Content-Type: application/json" \ -H "Accept: application/json, text/event-stream" \ -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \ -H "MCP-Protocol-Version: 2025-11-25" \ -d '{ "jsonrpc": "2.0", "id": "tool-call-1", "method": "tools/call", "params": { "name": "analyzeDataset", "arguments": { "datasetId": "ds-12345" }, "_meta": { "progressToken": "progress-1" } } }' ``` The gateway returns an SSE stream with progress notifications followed by the final result: ``` event: message data: {"jsonrpc":"2.0","method":"notifications/progress","params":{"progressToken":"progress-1","progress":1,"total":4,"message":"Loading dataset..."}} event: message data: {"jsonrpc":"2.0","method":"notifications/progress","params":{"progressToken":"progress-1","progress":2,"total":4,"message":"Running analysis..."}} event: message data: {"jsonrpc":"2.0","method":"notifications/progress","params":{"progressToken":"progress-1","progress":3,"total":4,"message":"Generating report..."}} event: message data: {"jsonrpc":"2.0","method":"notifications/progress","params":{"progressToken":"progress-1","progress":4,"total":4,"message":"Complete"}} event: message data: {"jsonrpc":"2.0","id":"tool-call-1","result":{"content":[{"type":"text","text":"Analysis complete. Found 3 anomalies in dataset ds-12345."}]}} ``` On version `2026-07-28`, include the `Mcp-Method` and `Mcp-Name` request-metadata headers and the `_meta` version fields in the body. Keep `progressToken` in `_meta` to opt into progress notifications. The `MCP-Protocol-Version` header must match `_meta.io.modelcontextprotocol/protocolVersion`. Your gateway’s `supportedVersions` must include `2026-07-28`. ``` curl -N -X POST \ https://mygateway-abcdefghij.gateway.bedrock-agentcore.us-west-2.amazonaws.com/mcp \ -H "Content-Type: application/json" \ -H "Accept: application/json, text/event-stream" \ -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \ -H "MCP-Protocol-Version: 2026-07-28" \ -H "Mcp-Method: tools/call" \ -H "Mcp-Name: analyzeDataset" \ -d '{ "jsonrpc": "2.0", "id": "tool-call-1", "method": "tools/call", "params": { "name": "analyzeDataset", "arguments": { "datasetId": "ds-12345" }, "_meta": { "io.modelcontextprotocol/protocolVersion": "2026-07-28", "io.modelcontextprotocol/clientInfo": { "name": "my-agent", "version": "1.0.0" }, "io.modelcontextprotocol/clientCapabilities": {}, "progressToken": "progress-1" } } }' ``` The gateway returns an SSE stream with progress notifications followed by the final result: ``` event: message data: {"jsonrpc":"2.0","method":"notifications/progress","params":{"progressToken":"progress-1","progress":1,"total":4,"message":"Loading dataset..."}} event: message data: {"jsonrpc":"2.0","method":"notifications/progress","params":{"progressToken":"progress-1","progress":2,"total":4,"message":"Running analysis..."}} event: message data: {"jsonrpc":"2.0","method":"notifications/progress","params":{"progressToken":"progress-1","progress":3,"total":4,"message":"Generating report..."}} event: message data: {"jsonrpc":"2.0","method":"notifications/progress","params":{"progressToken":"progress-1","progress":4,"total":4,"message":"Complete"}} event: message data: {"jsonrpc":"2.0","id":"tool-call-1","result":{"content":[{"type":"text","text":"Analysis complete. Found 3 anomalies in dataset ds-12345."}]}} ``` Set the `MCP-Protocol-Version` header to a version that your gateway supports. ``` import requests import json import sseclient gateway_url = "https://mygateway-abcdefghij.gateway.bedrock-agentcore.us-west-2.amazonaws.com/mcp" headers = { "Content-Type": "application/json", "Accept": "application/json, text/event-stream", "Authorization": "Bearer YOUR_ACCESS_TOKEN", "MCP-Protocol-Version": "2025-11-25" } # Call tool with progress token (streaming response) response = requests.post(gateway_url, headers=headers, json={ "jsonrpc": "2.0", "id": "tool-call-1", "method": "tools/call", "params": { "name": "analyzeDataset", "arguments": {"datasetId": "ds-12345"}, "_meta": {"progressToken": "progress-1"} } }, stream=True) # Process SSE events client = sseclient.SSEClient(response) for event in client.events(): data = json.loads(event.data) if data.get("method") == "notifications/progress": params = data["params"] print(f"Progress: {params['progress']}/{params.get('total', '?')} - {params.get('message', '')}") elif "result" in data: print(f"Tool result: {data['result']}") break ``` On version `2026-07-28`, add the `MCP-Protocol-Version`, `Mcp-Method`, and `Mcp-Name` headers, and include the `_meta` version fields in the request body. Keep `progressToken` in `_meta` to opt into progress notifications. Your gateway’s `supportedVersions` must include `2026-07-28`. ``` import requests import json import sseclient gateway_url = "https://mygateway-abcdefghij.gateway.bedrock-agentcore.us-west-2.amazonaws.com/mcp" headers = { "Content-Type": "application/json", "Accept": "application/json, text/event-stream", "Authorization": "Bearer YOUR_ACCESS_TOKEN", "MCP-Protocol-Version": "2026-07-28", "Mcp-Method": "tools/call", "Mcp-Name": "analyzeDataset" } # Call tool with progress token (streaming response) response = requests.post(gateway_url, headers=headers, json={ "jsonrpc": "2.0", "id": "tool-call-1", "method": "tools/call", "params": { "name": "analyzeDataset", "arguments": {"datasetId": "ds-12345"}, "_meta": { "io.modelcontextprotocol/protocolVersion": "2026-07-28", "io.modelcontextprotocol/clientInfo": {"name": "my-agent", "version": "1.0.0"}, "io.modelcontextprotocol/clientCapabilities": {}, "progressToken": "progress-1" } } }, stream=True) # Process SSE events client = sseclient.SSEClient(response) for event in client.events(): data = json.loads(event.data) if data.get("method") == "notifications/progress": params = data["params"] print(f"Progress: {params['progress']}/{params.get('total', '?')} - {params.get('message', '')}") elif "result" in data: print(f"Tool result: {data['result']}") break ``` ``` from mcp import ClientSession from mcp.client.streamable_http import streamablehttp_client import asyncio async def progress_handler(progress_token, progress, total, message=None): """Handle progress notifications.""" print(f"[{progress}/{total}] {message or ''}") async def use_progress(url, token): headers = {"Authorization": f"Bearer {token}"} async with streamablehttp_client(url=url, headers=headers) as ( read_stream, write_stream, _ ): async with ClientSession( read_stream, write_stream, progress_handler=progress_handler ) as session: await session.initialize() # Call tool with progress token - notifications handled by callback result = await session.call_tool( name="analyzeDataset", arguments={"datasetId": "ds-12345"} ) print(f"Tool result: {result}") return result asyncio.run(use_progress( url="https://mygateway-abcdefghij.gateway.bedrock-agentcore.us-west-2.amazonaws.com/mcp", token="YOUR_ACCESS_TOKEN" )) ``` ``` from mcp.client.streamable_http import streamablehttp_client from strands import Agent from strands.tools.mcp import MCPClient mcp_url = "https://mygateway-abcdefghij.gateway.bedrock-agentcore.us-west-2.amazonaws.com/mcp" access_token = "YOUR_ACCESS_TOKEN" mcp_client = MCPClient( lambda: streamablehttp_client( mcp_url, headers={"Authorization": f"Bearer {access_token}"} ) ) # Strands handles streaming and progress notifications automatically with mcp_client: agent = Agent(tools=mcp_client.list_tools_sync()) response = agent("Analyze dataset ds-12345") print(response) ```