fix: Remote MCP type shows 'connected' but silently fails to register tools

Description

When configuring an MCP server with "type": "remote", OpenCode shows the server as "connected" in the MCP status, but tools are silently not registered and unavailable. There is no error message in the UI or logs indicating the failure.

This is different from previously fixed issues #834 and #1595, which produced clear error messages like "MCP server failed to start".

Steps to Reproduce

Configure a remote MCP server using SSE endpoint in ~/.config/opencode/opencode.json:

{
  "mcp": {
    "exa": {
      "type": "remote",
      "url": "https://mcp.exa.ai/mcp?exaApiKey=YOUR_KEY"
    }
  }
}

Start OpenCode TUI
Check MCP status - shows "connected" (green checkmark)
Try to use any Exa tools - they are not available
Check logs at ~/.local/share/opencode/log/ - no error messages about Exa

Expected Behavior

Either:

Tools should be registered and available when status shows "connected"
OR an error message should be displayed when tool registration fails

Actual Behavior

MCP status shows "connected" (implying success)
Tools are silently not registered
No error in UI or logs
User has no indication anything is wrong until they try to use the tools

Workaround

Using "type": "local" with npx works correctly:

{
  "mcp": {
    "exa": {
      "type": "local",
      "command": ["npx", "-y", "exa-mcp-server"],
      "environment": {
        "EXA_API_KEY": "your-key"
      }
    }
  }
}

Environment

OpenCode version: 1.1.25
OS: macOS 15.7.4 (Darwin arm64)
MCP server tested: Exa (https://mcp.exa.ai/mcp)

Related Issues

Remote MCP servers using Server-Sent Events (SSE) fail to start with 'UnknownError Server error' #834 - Remote MCP servers using SSE fail to start (CLOSED - had clear error messages)
MCP remote servers not configurable as expected #1595 - MCP remote servers not configurable (CLOSED - had clear error messages)

This issue is distinct because the connection appears to succeed but tool registration silently fails.

Suggested Fix

When type: "remote" connection completes, verify that tools were actually registered. If tool registration fails, either:

Display an error message to the user
Update the MCP status to indicate partial failure
Log a warning with troubleshooting guidance

This issue might be a duplicate of or related to an existing issue. Please check:

MCP servers showing as disabled #8990: MCP servers showing as disabled - Similar issue where MCP servers appear configured but don't work properly (v1.1.24+)

Also note that there have been recent infrastructure improvements:

Exa MCP endpoint (mcp.exa.ai) timing out while REST API works #6878: Exa MCP endpoint previously had timeout and connectivity issues, which may be related to remote MCP server problems
fix(mcp): connection hangs with non-standard SSE/HTTP servers which causes opencode to hang #8406: Remote MCP servers can hang with non-standard SSE/HTTP - timeout/connection handling could cause silent failures

These issues may provide context for debugging the silent tool registration failure you're experiencing.

I encountered similar error as well:

Side Note: I tested these MCP's about two days ago and they functioned properly except for the fact that my ZAI dashboard never saw the MCP tool usage. This was using the same configuration below but without the oauth config option being present.

Global opencode.jsonc :

{
    "$schema": "https://opencode.ai/config.json",
    "mcp": {
        "zread": {
            "type": "remote",
            "url": "https://api.z.ai/api/mcp/zread/mcp",
            "enabled": true,
            "oauth": false,
            "headers": {
                "Authorization": "Bearer your_api_key"
            }
        }
    }
}

Logs containing mcp:

INFO  2026-01-23T18:55:57 +1ms service=mcp key=zread type=remote found
INFO  2026-01-23T18:55:57 +0ms service=server method=GET path=/mcp request
INFO  2026-01-23T18:55:57 +1ms service=server status=started method=GET path=/mcp request
INFO  2026-01-23T18:55:58 +506ms service=server status=completed duration=846 method=GET path=/mcp request

Receiving similar error on my end.

To stay organized issues are automatically closed after 90 days of no activity. If the issue is still relevant please open a new one.

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fix: Remote MCP type shows 'connected' but silently fails to register tools #9425

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fix: Remote MCP type shows 'connected' but silently fails to register tools #9425

Description

Description

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github-actions commented on Jan 19, 2026

socrabytes commented on Jan 23, 2026

vxnuaj commented on Feb 12, 2026

github-actions commented on Apr 14, 2026

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