/oh-my-opencode-slim

name: oh-my-opencode-slim
description: Configure and improve oh-my-opencode-slim for the current user. Use when users want to tune agents, models, prompts, custom agents, skills, MCPs, presets, or plugin behavior. Also use when recurring workflow friction suggests a safe config or prompt improvement.

oh-my-opencode-slim Configuration Skill

You help users configure, customize, and safely improve their oh-my-opencode-slim setup.

The goal is not just to answer configuration questions. When useful, help the user make their agent system better for future runs: tune models, adjust agent prompts, add focused custom agents, enable or restrict tools, and document restart requirements.

When to Use

Use this skill when the user asks about or is likely to benefit from changes to:

• `~/.config/opencode/oh-my-opencode-slim.json` or `.jsonc`
• `.opencode/` or `~/.config/opencode/` plugin/agent configuration
• agent models, variants, presets, or provider routing
• orchestrator delegation behavior or specialist-agent prompts
• custom agents under `agents.<name>`
• custom agent `prompt` and `orchestratorPrompt` blocks
• skills, MCP permissions, tool access, or disabled agents
• background orchestration, session reuse, multiplexer panes, or deepwork
• recurring workflow friction that could be fixed by a prompt/config change

Also use it proactively, with restraint, when a session reveals a repeatable improvement opportunity. Example: if the user repeatedly asks the same agent to follow a project-specific rule, suggest adding that rule to a prompt or config.

What Is Possible

oh-my-opencode-slim is configured through a plugin config file, usually:

~/.config/opencode/oh-my-opencode-slim.json

or:

~/.config/opencode/oh-my-opencode-slim.jsonc

Concrete files agents should know:

| Path | Use | |---|---| | `~/.config/opencode/opencode.json` | OpenCode core config: plugin registration and providers | | `~/.config/opencode/oh-my-opencode-slim.jsonc` | User plugin config with comments/trailing commas; takes precedence over `.json` | | `~/.config/opencode/oh-my-opencode-slim.json` | User plugin config generated by installer | | `<project>/.opencode/oh-my-opencode-slim.json` | Project-local plugin overrides checked before user config | | `~/.config/opencode/oh-my-opencode-slim/{agent}.md` | Full prompt replacement for a built-in agent | | `~/.config/opencode/oh-my-opencode-slim/{agent}_append.md` | Append-only prompt tuning for a built-in agent | | `~/.config/opencode/oh-my-opencode-slim/{preset}/{agent}.md` | Preset-specific full prompt replacement | | `~/.config/opencode/oh-my-opencode-slim/{preset}/{agent}_append.md` | Preset-specific append-only prompt tuning | | `~/.config/opencode/skills/<skill-name>/SKILL.md` | Installed skill prompt payload |

Built-in agent prompt file names are exact agent names:

• `orchestrator.md` / `orchestrator_append.md`
• `oracle.md` / `oracle_append.md`
• `librarian.md` / `librarian_append.md`
• `explorer.md` / `explorer_append.md`
• `designer.md` / `designer_append.md`
• `fixer.md` / `fixer_append.md`
• `observer.md` / `observer_append.md`
• `council.md` / `council_append.md`

Prefer `{agent}_append.md` for small behavior tuning. Use `{agent}.md` only when the user intentionally wants to replace the bundled prompt entirely.

Prompt override lookup order:

1. If a `preset` is active, check `~/.config/opencode/oh-my-opencode-slim/{preset}/` first. 2. Fall back to `~/.config/opencode/oh-my-opencode-slim/`. 3. If both `{agent}.md` and `{agent}_append.md` exist, the replacement prompt is loaded first and the append file is added after it. 4. If no prompt files exist, the built-in prompt from the plugin package is used.

Common customizations:

• **Switch presets**: choose which generated or custom preset is active.
• **Tune models**: assign different models/variants per agent.
• **Limit costs**: use cheaper models for `explorer`, `librarian`, and `fixer`.
• **Improve quality**: use stronger models for `orchestrator`, `oracle`, or

design-heavy `designer` work.

• **Control skills**: set `skills` per agent with `['*']`, explicit names, or

exclusions like `['*', '!codemap']`.

• **Control MCPs**: set `mcps` per agent with the same allow/exclude style.
• **Enable optional agents**: remove agents from `disabled_agents` and configure

an appropriate model, such as a vision-capable `observer`.

• **Add custom agents**: define focused specialists under `agents.<name>`.
• **Tune prompts**: override or extend an agent's prompt for local workflow

preferences.

• **Guide delegation**: add `orchestratorPrompt` for custom agents so the

Orchestrator knows when to call them and when not to.

Important schema boundary:

• Built-in agents (`orchestrator`, `oracle`, `librarian`, `explorer`,

`designer`, `fixer`, `observer`, `council`) can set models, variants, skills, MCPs, options, and display names in config.

• Built-in agent `prompt` and `orchestratorPrompt` fields are **not** supported

in `oh-my-opencode-slim.json[c]`; use markdown prompt override files instead.

• Unknown keys under top-level `agents` are custom agents. Custom agents may use

`prompt` and `orchestratorPrompt` directly in config.

Config Shapes

Tune a built-in agent model/skills/MCPs

Edit the active preset under `presets.<preset>.<agent>`:

{
  "preset": "openai",
  "presets": {
    "openai": {
      "orchestrator": {
        "model": "openai/gpt-5.6-terra",
        "variant": "high",
        "skills": ["*"],
        "mcps": ["*", "!context7"]
      },
      "librarian": {
        "model": "openai/gpt-5.6-luna",
        "variant": "low",
        "skills": [],
        "mcps": ["context7", "gh_grep"]
      }
    }
  }
}

Append instructions to a built-in prompt

Create, for example:

~/.config/opencode/oh-my-opencode-slim/orchestrator_append.md

or for only the `openai` preset:

~/.config/opencode/oh-my-opencode-slim/openai/orc