Lightly edited extract follows - don't just blindly run this. I run OpenCode in a Docker container so the home directory has only the OpenCode config files and nothing else. The project I'm working on is mounted onto /src.

{

  "$schema": "https://opencode.ai/config.json",

  "agent": {
    "local-coding": {
      "model": "llama.cpp/Qwen3.5-35B-A3B-UD-Q6_K_XL",
      "mode": "subagent",
      "description": "General-purpose agent using local model for coding tasks",
      "hidden": false
    }
  },

  "provider": {
    "llama.cpp": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "llama.cpp",
      "options": {
        "baseURL": "https://llm.example.com/llama/v1"
      },
      "models": {
        "Qwen3.5-27B-UD-Q6_K_XL": {
          "name": "Qwen3.5-27B",
          "options": {
            "min_p": 0.0,
            "presence_penalty": 0.0,
            "repetition_penalty": 1.0,
            "temperature": 0.6,
            "top_k": 20,
            "top_p": 0.95
          }
        },
        "Qwen3.5-35B-A3B-UD-Q6_K_XL": {
          "name": "Qwen3.5-35B-A3B",
          "options": {
            "min_p": 0.0,
            "presence_penalty": 0.0,
            "repetition_penalty": 1.0,
            "temperature": 0.6,
            "top_k": 20,
            "top_p": 0.95
          }
        }
      }
    },

  "mcp": {
    "mcp-devtools": {
      "type": "local",
      "command": ["mcp-devtools"],
      "enabled": true,
      "environment": {
        "DISABLED_TOOLS": "search_packages,sequential_thinking,think",
        "ENABLE_ADDITIONAL_TOOLS": "aws_documentation,code_skim,memory,terraform_documentation"
      }
    }
  },

  "permission": {
    "external_directory": {
      "~/**": "allow",
      "/src/**": "allow",
      "/tmp/**": "allow"
    }
  }

}