OpenCode Permissions Configuration Expert

OpenCode Permissions Configuration Expert

Overview

I help configure OpenCode’s granular permission system. OpenCode has three permission modes per tool and supports pattern-based bash command allowlisting.

Permission Modes

Mode	Behavior	Use Case
"allow"	Auto-execute without prompting	Trusted operations, fast iteration
"ask"	Prompt for approval each time	Security-conscious, learning
"deny"	Block entirely	Dangerous operations

Default: OpenCode defaults to "allow" for most operations.

Configuration Hierarchy

Scope	Location	Priority
Global	~/.config/opencode/opencode.json	Lowest
Per-project	.opencode/opencode.json	Middle
Per-agent	Agent definition file	Highest

Configurable Tools

• edit - File modifications
• bash - Command execution (supports patterns!)
• skill - Skill tool access
• webfetch - Web fetching
• doom_loop - Infinite loop protection
• external_directory - Operations outside project

Bash Pattern Syntax

Wildcards:

• * = matches any characters (e.g., git * matches all git commands)
• ? = matches single character
• Specific commands override wildcards
• Last matching rule wins

Project Type Templates

Coding Project (Conservative)

{
  "permission": {
    "edit": "ask",
    "bash": {
      "npm run *": "allow",
      "npm install": "allow",
      "npm test": "allow",
      "git status": "allow",
      "git diff *": "allow",
      "git log *": "allow",
      "git add *": "ask",
      "git commit *": "ask",
      "git push *": "ask",
      "rm -rf *": "deny",
      "rm -r *": "deny",
      "*": "ask"
    },
    "webfetch": "allow",
    "external_directory": "ask"
  }
}

Media/Content Project (Read-Heavy)

{
  "permission": {
    "edit": "ask",
    "bash": {
      "ls *": "allow",
      "find *": "allow",
      "du *": "allow",
      "file *": "allow",
      "mediainfo *": "allow",
      "ffprobe *": "allow",
      "exiftool *": "allow",
      "cat *": "allow",
      "head *": "allow",
      "tail *": "allow",
      "ffmpeg *": "ask",
      "mv *": "ask",
      "cp *": "ask",
      "rm *": "deny",
      "*": "ask"
    },
    "webfetch": "allow",
    "external_directory": "ask"
  }
}

Home Automation / IoT Project

{
  "permission": {
    "edit": "ask",
    "bash": {
      "curl *": "ask",
      "wget *": "ask",
      "docker ps *": "allow",
      "docker logs *": "allow",
      "docker exec *": "ask",
      "systemctl status *": "allow",
      "systemctl restart *": "ask",
      "journalctl *": "allow",
      "ping *": "allow",
      "ssh *": "deny",
      "rm *": "deny",
      "*": "ask"
    },
    "webfetch": "allow",
    "external_directory": "deny"
  }
}

Read-Only Exploration Agent

{
  "tools": {
    "write": false,
    "edit": false
  },
  "permission": {
    "bash": {
      "ls *": "allow",
      "cat *": "allow",
      "head *": "allow",
      "tail *": "allow",
      "find *": "allow",
      "grep *": "allow",
      "wc *": "allow",
      "*": "deny"
    },
    "webfetch": "allow",
    "external_directory": "allow"
  }
}

Production-Safe (Maximum Security)

{
  "permission": {
    "edit": "ask",
    "bash": {
      "rm *": "deny",
      "rmdir *": "deny",
      "truncate *": "deny",
      "dd *": "deny",
      "mkfs *": "deny",
      "chmod 777 *": "deny",
      "curl * | sh": "deny",
      "wget * | sh": "deny",
      "sudo *": "deny",
      "*": "ask"
    },
    "external_directory": "deny",
    "doom_loop": "deny"
  }
}

Session Approval

During interactive use, the “accept always” option in the permission dialog:

• Grants “allow for session” for the pattern (first two command elements)
• Example: Approving ls /some/folder whitelists ls * for the entire session
• This means ALL ls commands will auto-approve after the first one
• Session only — does NOT persist across OpenCode restarts
• Pipelines accumulate: Approving cd dir && ls whitelists BOTH cd * AND ls *

Security consideration: Be cautious with “accept always” for risky commands. Once approved, all variations of that command will auto-execute.

Process for Creating Config

1. Identify project type - Coding, media, automation, exploration?
2. List common operations - What commands will be run frequently?
3. Identify risks - What commands could cause damage?
4. Set defaults - Usually "ask" as fallback
5. Add allowlist - Frequently used safe commands
6. Add denylist - Dangerous commands to block
7. Test - Run through typical workflow to tune

Quick Reference

{
  "$schema": "https://opencode.ai/schema.json",
  "permission": {
    "edit": "ask|allow|deny",
    "bash": {
      "safe-command": "allow",
      "risky-command *": "ask",
      "dangerous *": "deny",
      "*": "ask"
    },
    "webfetch": "allow",
    "skill": "allow",
    "doom_loop": "ask",
    "external_directory": "ask"
  }
}

See Also

• Full permissions documentation
• Tool comparison