oc-ghcp-headers

[!WARNING] This is experimental software provided as-is. Use it at your own risk. Modifying request behavior may lead to degraded service, policy enforcement, or account-level actions. The authors and contributors are not responsible for any resulting account issues, restrictions, or losses.

This plugin controls the x-initiator header for GitHub Copilot requests in OpenCode.

Behavior

• First user message in a session: x-initiator is randomized between user and agent.
• Follow-up user messages: x-initiator defaults to agent, with optional chance to send user.

The plugin determines first vs follow-up by reading recent session messages and checking for prior assistant/tool activity. It explicitly ignores the current turn's pre-created user message and assistant placeholder so first-turn detection stays accurate.

If session history cannot be loaded, it fails closed to agent.

Setup

Install from npm:

bun add oc-ghcp-headers

Then enable it in ~/.config/opencode/opencode.jsonc:

{
  "plugin": ["oc-ghcp-headers"]
}

Restart OpenCode after updating config.

Configuration

Configure percentages in opencode.json / opencode.jsonc under provider.github-copilot.options:

{
  "provider": {
    "github-copilot": {
      "options": {
        "firstMessageAgentPercent": 0,
        "followupMessageAgentPercent": 100
      }
    }
  }
}

• firstMessageAgentPercent (default 0)
  • Percentage chance first message is sent as agent
  • 0 => always user
  • 10 => 10% agent, 90% user
  • 100 => always agent
• followupMessageAgentPercent (default 100)
  • Percentage chance follow-up message is sent as agent
  • 100 => always agent
  • 90 => 90% agent, 10% user
  • 0 => always user
• DEBUG_ENABLED
  • Enable/disable plugin debug logging

Scope

• Applies only to models where providerID includes github-copilot.
• This plugin only sets request headers; auth/token handling remains managed by OpenCode.

Debug Log

• Log file: /tmp/oc-ghcp-headers-debug.log
• Watch live:

tail -f /tmp/oc-ghcp-headers-debug.log

Maintainer Docs

• Publishing and release process: docs/release.md

License

• MIT. See LICENSE.

Credits

• Original custom plugin author: @Tarquinen