OpenCode

OpenCode Custom Agents and Subagents: Markdown Files, Modes and @ Mentions

How do I create a custom agent or subagent in OpenCode?

Put a markdown file in .opencode/agents/ for a project or ~/.config/opencode/agents/ for every project, or add an entry under the agent key in opencode.json. The file name becomes the agent name. Set mode to subagent and call it with an @ mention or let the primary agent call it.

Built-in agents

  • build: the default primary agent with all tools enabled.
  • plan: a restricted primary agent for analysis. Edits and bash ask by default.
  • general: a subagent for multi-step work that can change files.
  • explore: a read-only subagent for finding files and searching code.

Create an agent as a markdown file

Save the file in .opencode/agents/ or ~/.config/opencode/agents/. A file named review.md creates an agent called review. The body is the system prompt.

.opencode/agents/docs-writer.md

---
description: Writes project documentation
mode: subagent
permission:
  bash: deny
---

You are a technical writer. Produce clear, well-structured docs with code examples.

Create an agent in opencode.json

opencode.json

{
  "$schema": "https://opencode.ai/config.json",
  "agent": {
    "reviewer": {
      "description": "Reviews changes for bugs and style issues",
      "mode": "subagent",
      "temperature": 0.1,
      "permission": { "edit": "deny", "bash": "ask" }
    }
  }
}

Options you can set

  • description: required. Says what the agent does and when to use it.
  • mode: primary, subagent or all. The default is all.
  • model: in provider/model-id format.
  • temperature, top_p, steps, color, hidden, disable.
  • prompt: path to a custom system prompt file.
  • permission: allow, ask or deny per tool. The older tools key is deprecated.

Generate one and use it

Run the interactive wizard to create an agent. It asks where to save it, what it should do and which permissions to grant.

Terminal

opencode agent create

Primary agents call subagents automatically based on their description. You can also mention one directly, for example: @explore find where the session config is loaded.

Get OpenCode settings changes by email

When a setting, flag or permission rule in this guide changes, it goes in the weekly AgentAtlas update, checked against the vendor docs. One email a week.

Sources

OpenCode: Agents

More on OpenCode

OpenCode standards support

More OpenCode guides

Other guides

Cursor: allow all terminal commandsClaude Code: allow commands without promptsClaude Code permissions: allow, ask and deny rules, rule syntax and allowed toolsCodex CLI: approval and sandbox modesGemini CLI: YOLO mode, auto_edit and allowing specific shell commandsCursor Privacy Mode: telemetry, training and data retentionClaude Code telemetry and data retention: what is sent and how to turn it offGemini CLI: turn off usage statistics and telemetryCLAUDE.md: where it goes, how it loads, and how it works with AGENTS.mdClaude Code hooks: format on save, block risky edits, get notifiedClaude Code subagents: create one, limit its tools, and call itAdd MCP servers to Cursor with mcp.json: Keep files out of Cursor with .cursorignore: Configure Codex with config.toml: Configure Gemini CLI with settings.json: Add MCP servers to Claude Code (claude mcp add, .mcp.json, scopes): Claude Code custom slash commands and skills (SKILL.md): GitHub Copilot custom instructions: Adding MCP servers to GitHub Copilot: Claude Code settings.json: file locations, precedence, and key settingsClaude Code plugins and marketplaces: install, create, and shareGemini CLI extensions and custom commands: Cline Rules: workspace, global, and conditional rulesKiro steering files: .kiro/steering, inclusion modes, and AGENTS.mdZed agent: instruction files, MCP servers, tool permissions, and ACP agentsCursor CLI: install, headless mode, permissions and CIAider: CONVENTIONS.md, .aider.conf.yml and API keysJunie guidelines, MCP and the Action Allowlist: Amp AGENTS.md, settings.json and MCP: Configure Goose extensions, hints, recipes and permissions: Customize OpenHands with skills, AGENTS.md, setup.sh and MCP: Configure Factory Droid CLI: AGENTS.md, settings.json, autonomy, custom droids and MCPConfigure Qwen Code: settings.json, providers, QWEN.md, MCP and approval modesCursor hooks: hooks.json, beforeShellExecution, afterFileEdit and exit codesCursor sandbox: sandbox.json, network allowlist and run modesCursor settings: settings.json, Cursor Settings and the ~/.cursor config filesCursor browser agent: @browser, browser automation and approval modesCursor subagents: .cursor/agents, frontmatter, built-in Explore, Bash and BrowserCursor telemetry and OpenTelemetry export (Privacy Mode, OTLP, Analytics API): Cursor rules setup: project, user and Team Rules, .mdc frontmatter, globs and AGENTS.mdClaude Code headless mode: claude -p, --output-format json, --bare and CI flagsClaude Code statusline: custom status bar in settings.json with context %, cost and git branchClaude Code /model: switch models, aliasesClaude Code /cost and /usage: check token spend, usage limits and reduce costsClaude Code VS Code extension: install, shortcuts, settings and /ideCodex AGENTS.md: global, project and override instruction files explainedCodex MCP servers: codex mcp add and [mcp_servers] in config.tomlCodex sandbox modes: read-only, workspace-write, danger-full-access and network accesscodex exec: run Codex non-interactively in scripts and CI with JSON outputCodex skills: create SKILL.md, skill folder locations and $skill invocationGEMINI.md in Gemini CLI: context file locations, imports and /memoryGemini CLI MCP servers: gemini mcp add and mcpServers in settings.jsonGemini CLI custom slash commands: TOML files, {{args}}, !{shell} and @{file}Gemini CLI headless mode: gemini -p, JSON output and exit codes for scripts and CIGemini CLI sandbox: enable Docker, Podman, macOS Seatbelt or gVisorcopilot-setup-steps.yml: set up the GitHub Copilot cloudGitHub Copilot CLI permissions: --allow-tool, --deny-tool, --allow-all-tools and trusted directoriesGitHub Copilot custom agents: .github/agents/*.agent.md profiles, tools and frontmatterGitHub Copilot code review settings: automatic PR reviews, rulesets, effort level and approvalsCline MCP Setup: cline_mcp_settings.json for Local and Remote ServersCline Auto Approve and YOLO Mode: Run Commands and Edits Without PromptsCline Skills: SKILL.md Location, Format and Slash Command UseAmp MCP Setup: amp mcp add, amp.mcpServers and Workspace ApprovalAmp AGENTS.md: File Locations, @ Mentions and Glob-Scoped GuidanceAmp Skills: SKILL.md Folders, amp skill add and Search OrderKiro MCP Setup: .kiro/settings/mcp.json, autoApprove and OAuthKiro Hooks: .kiro/hooks JSON, PreToolUse, PostFileSave and StopKiro Permissions: permissions.yaml Allow, Ask and Deny RulesFactory Droid MCP Setup: droid mcp add, mcp.json Locations and /mcpFactory Droid Hooks: hooks.json, PreToolUse Matchers and Exit CodesFactory Droid Custom Droids (Subagents): .factory/droids Markdown FilesJunie MCP Setup: .junie/mcp/mcp.json for CLI and /mcp CommandJunie Brave Mode and Action Allowlist: Auto-Approve Commands in Junie CLIJunie Custom Slash Commands: .junie/commands Markdown Files and Argumentsgoose .goosehints and AGENTS.md: Global and Project Instructionsgoose Permission Modes: GOOSE_MODE auto, approve, smart_approve and chatgoose Recipes: recipe.yaml Format, Parameters and goose run --recipeZed Agent Tool Permissions: Auto-Approve Terminal Commands with tool_permissionsUse Claude, Codex and Gemini CLI in Zed: External Agents and agent_serversZed with Ollama, LM Studio and llama.cpp: Local Model Setup and Context Length

Reviewed Oct 13, 2026. Settings change often; the linked vendor docs are the source of truth.