Continue MCP SSE Issues: Connection Drops, Streaming, and Retries

Having trouble with Continue's SSE connection to Corcava MCP? This Continue-specific troubleshooting guide helps you fix SSE disconnects, streaming failures, and connection issues. Learn how to validate your config, check network/proxy settings, and implement recommended retry behavior.

Understanding SSE in Continue

Continue uses Server-Sent Events (SSE) for remote MCP servers. SSE provides real-time streaming but can be sensitive to network conditions:

How SSE Works in Continue

• Persistent connection: Maintains long-lived connection to MCP server
• Streaming responses: Server streams responses as they're generated
• Unidirectional (server→client): SSE streams data from server to client only; clients must use separate HTTP requests or WebSockets to send data back
• Network sensitive: More sensitive to network issues than HTTP polling

Common SSE Issues

Connection Drops

• Symptom: SSE connection established but then drops unexpectedly
• Causes:
  • Network instability
  • Proxy timeouts
  • Firewall closing idle connections
  • Server-side connection limits

Streaming Failures

• Symptom: Connection works but streaming responses are incomplete or corrupted
• Causes:
  • Proxy buffering SSE streams
  • Network packet loss
  • Client-side buffer issues

Connection Refused

• Symptom: Cannot establish SSE connection at all
• Causes:
  • Invalid endpoint URL
  • Network/firewall blocking SSE
  • Server not accessible
  • Authentication failure

Step 1: Validate Continue Configuration

First, ensure your Continue config is correct for SSE:

Correct SSE Config Format

Valid Continue Config

{
  "mcpServers": {
    "corcava": {
      "url": "https://app.corcava.com/mcp",
      "transport": "sse",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Key points:

• URL must be HTTPS (SSE requires secure connection)
• Transport should be "sse" (explicit or default)
• Authorization header must be correctly formatted

Config Validation Checklist

• ✅ Config file is valid JSON (see Config JSON Errors)
• ✅ URL is correct: https://app.corcava.com/mcp
• ✅ Transport is "sse" (or omitted, defaults to SSE for remote)
• ✅ Authorization header has "Bearer " prefix
• ✅ API key is active and not revoked

Step 2: Check Network and Proxy Settings

SSE connections can be blocked or interfered with by network infrastructure:

Network Diagnostics

Test SSE Endpoint

curl -N -H "Authorization: Bearer YOUR_API_KEY" \
  https://app.corcava.com/mcp

The -N flag disables buffering, useful for testing SSE streams. If this fails, there may be network/proxy issues.

Proxy Issues with SSE

Corporate Proxy Problems

Corporate proxies often interfere with SSE:

• Buffering: Proxies may buffer SSE streams, breaking real-time behavior
• Timeouts: Proxies may close idle SSE connections
• Filtering: Some proxies block SSE connections entirely

Fix: Use VPN, configure proxy exceptions, or contact IT to whitelist SSE connections

Firewall Rules

Required for SSE:

• Outbound HTTPS (port 443) to app.corcava.com
• Long-lived connections allowed (SSE keeps connection open)
• No connection timeout too short (SSE connections can be idle)

Step 3: Handle Connection Drops

SSE connections can drop. Implement retry logic:

Recommended Retry Behavior

Retry Strategy for SSE Drops

1. Immediate retry: If connection drops, retry immediately (may be transient)
2. Exponential backoff: If immediate retry fails, wait 2 seconds, then 4 seconds
3. Max retries: 3 attempts before reporting error
4. Reconnect: Re-establish SSE connection from scratch

Continue Automatic Retries

Continue may automatically retry SSE connections. Check Continue settings for:

• Automatic reconnection enabled
• Retry delay settings
• Max retry attempts

Step 4: Verify SSE Connection

Use this simple verification workflow to test your SSE connection:

Simple Verification Workflow

1. Check connection status: Look for SSE connection indicator in Continue
2. Test tool listing: Ask "What MCP tools are available?"
3. Test simple call: Try "List my projects" (read-only, fast)
4. Monitor connection: Watch for connection drops during operation
5. Check logs: Review Continue logs for SSE errors

Expected Behavior

When SSE is working correctly:

• Connection indicator shows "connected" or "active"
• Tools appear in available tools list
• Tool calls complete successfully
• Responses stream in real-time (if supported)
• No connection drop errors in logs

Step 5: Troubleshoot Streaming Issues

If connection works but streaming is problematic:

Streaming Failure Symptoms

Incomplete Responses

• Symptom: Tool calls return partial data or cut off mid-response
• Fix: Check for proxy buffering, increase client buffer size, or use HTTP polling instead

Delayed Responses

• Symptom: Responses arrive but with significant delay
• Fix: Check network latency, verify proxy isn't buffering, test from different network

Corrupted Data

• Symptom: Responses contain malformed JSON or incomplete data
• Fix: Check for packet loss, verify network stability, try reconnecting

Step 6: Alternative: Use HTTP Polling

If SSE continues to have issues, some MCP clients support HTTP polling as an alternative:

SSE vs HTTP Polling

If SSE is unreliable in your environment:

• HTTP polling may be more stable (though less efficient)
• Check Continue documentation for polling transport option
• Polling works better through corporate proxies
• Trade-off: Less real-time but more reliable

Quick Fix Checklist

Before Escalating

• ✅ Config file is valid JSON with correct SSE format
• ✅ URL is correct and uses HTTPS
• ✅ API key is active and correctly formatted
• ✅ Tested network connection (curl test works)
• ✅ Checked for proxy interference
• ✅ Verified firewall allows long-lived HTTPS connections
• ✅ Continue has been restarted after config changes
• ✅ Checked Continue logs for specific error messages

Related Troubleshooting

• Connection Failed - Diagnose general connection issues
• Timeouts - Fix timeout issues that affect SSE
• Continue Setup - Review Continue MCP setup guide
• Troubleshooting Index - Browse all troubleshooting guides