Opencode - ModRouter

Opencode lets you customize provider base URLs. Point each provider to the ModRouter integration that matches that provider’s SDK shape.

OpenAI-Compatible Provider

Use ModRouter’s OpenAI-compatible integration:

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "openai": {
      "options": {
        "baseURL": "https://api.modrouter.online/openai/v1",
        "apiKey": "${MODROUTER_API_KEY}"
      },
      "models": {
        "openai/gpt-4o-mini": {},
        "anthropic/claude-sonnet-4-5": {},
        "gemini/gemini-2.5-pro": {}
      }
    }
  }
}

Anthropic-Compatible Provider

If you use Opencode’s Anthropic provider, point it to ModRouter’s /anthropic integration:

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "anthropic": {
      "options": {
        "baseURL": "https://api.modrouter.online/anthropic",
        "apiKey": "${MODROUTER_API_KEY}"
      },
      "models": {
        "anthropic/claude-sonnet-4-5": {}
      }
    }
  }
}

Notes

Keep the provider config aligned with the request shape Opencode sends. OpenAI providers should use /openai/v1; Anthropic providers should use /anthropic.
Use ModRouter virtual keys for per-user budgets, rate limits, and provider access control.
Non-native models must support the tool-calling format expected by the selected Opencode provider.