OpenCode

OpenCode is an open-source terminal coding agent. Its instructions are AGENTS.md; skills, agents, and commands live in .opencode folders in the project and in ~/.config/opencode.

Select it in Settings ▸ AI ▸ Coding agent.

What Marginal lists

Section	In the workspace	In your home folder
AGENTS.md	AGENTS.md and CLAUDE.md, in the root and in any subfolder	~/.config/opencode/AGENTS.md, ~/.claude/CLAUDE.md
SKILLS	.opencode/skills/*/SKILL.md (or skill/), .claude/skills/*/SKILL.md, .agents/skills/*/SKILL.md, in the root and in any subfolder	~/.config/opencode/skills (or skill), ~/.claude/skills, ~/.agents/skills
AGENTS	.opencode/agents/**/*.md (or agent/), in the root and in any subfolder	~/.config/opencode/agents/**/*.md (or agent/)
COMMANDS	.opencode/commands/**/*.md (or command/), in the root and in any subfolder	~/.config/opencode/commands/**/*.md (or command/)

OpenCode has no rules folder, so there is no RULES section. Extra instruction files come from the instructions key of opencode.json instead, and Marginal does not read that key.

OPENCODE_CONFIG_DIR, when set in the environment Marginal was launched from, replaces ~/.config/opencode. The ~/.claude and ~/.agents folders stay where they are.

Agents and commands nested in subfolders are named by the path: team/reviewer, /team/review.

How OpenCode uses these files

• AGENTS.md is collected from the current directory up to the git worktree root, every match on that chain. CLAUDE.md is consulted only when no AGENTS.md exists anywhere on the chain. Globally, the first of ~/.config/opencode/AGENTS.md and ~/.claude/CLAUDE.md that exists is used. When OpenCode reads a file, it also injects the nearest AGENTS.md above that file, which is why nested ones matter.
• Skills are SKILL.md files with a required name and description. The .claude/skills and .agents/skills folders are read for compatibility; OPENCODE_DISABLE_CLAUDE_CODE_SKILLS=1 turns the first off. Precedence, lowest to highest: built-in, .claude/skills, .agents/skills, the global folder, .opencode/skills, then the skills array in the config.
• Agents are markdown with a front matter description (required), mode (primary, subagent, or all), model, permission, and more; the body is the prompt. The older mode/ and modes/ folders are still discovered as primary agents.
• Commands are markdown with an optional description, agent, model, and subtask in the front matter; the body is the template, with $ARGUMENTS, $1…$n, and shell substitutions. A command named like a built-in overrides it.

Both the singular and plural folder names are accepted; the documentation recommends plural. Every .opencode folder from the current directory up to the worktree root is a config directory, so Marginal looks for them in every folder of the workspace.

OpenCode V2, in beta, keeps the same folders but recognises only AGENTS.md for instructions and renames several config keys to plural.

Not listed

opencode.json and opencode.jsonc (project and global), tui.json, plugins and custom tools (.ts, .js), themes, and the managed configuration under /Library/Application Support/opencode, /etc/opencode, or %ProgramData%\opencode.

Checked against the OpenCode documentation and source on 1 September 2026.