Quick Reference Guide

Complete reference for oh-my-opencode-slim configuration and capabilities.

Presets
Skills
- Cartography
MCP Servers
Tools & Capabilities
Configuration

Presets

The default installer generates an OpenAI preset. To use alternative providers (Kimi, GitHub Copilot, ZAI Coding Plan), see Provider Configurations for step-by-step instructions and full config examples.

Switching Presets

Method 1: Edit Config File

Edit ~/.config/opencode/oh-my-opencode-slim.json (or .jsonc) and change the preset field:

{
  "preset": "openai"
}

Method 2: Environment Variable

Set the environment variable before running OpenCode:

export OH_MY_OPENCODE_SLIM_PRESET=openai
opencode

The environment variable takes precedence over the config file.

OpenAI Preset (Default)

Uses OpenAI models exclusively:

{
  "preset": "openai",
  "presets": {
    "openai": {
      "orchestrator": { "model": "openai/gpt-5.4", "skills": ["*"], "mcps": ["websearch"] },
      "oracle": { "model": "openai/gpt-5.4", "variant": "high", "skills": [], "mcps": [] },
      "librarian": { "model": "openai/gpt-5.4-mini", "variant": "low", "skills": [], "mcps": ["websearch", "context7", "grep_app"] },
      "explorer": { "model": "openai/gpt-5.4-mini", "variant": "low", "skills": [], "mcps": [] },
      "designer": { "model": "openai/gpt-5.4-mini", "variant": "medium", "skills": ["agent-browser"], "mcps": [] },
      "fixer": { "model": "openai/gpt-5.4-mini", "variant": "low", "skills": [], "mcps": [] }
    }
  }
}

Other Providers

For Kimi, GitHub Copilot, and ZAI Coding Plan presets, see Provider Configurations.

Skills

Skills are specialized capabilities provided by external agents and tools. Unlike MCPs which are servers, skills are prompt-based tool configurations installed via npx skills add during installation.

Recommended Skills (via npx)

Skill	Description	Assigned To
`simplify`	YAGNI code simplification expert	`orchestrator`
`agent-browser`	High-performance browser automation	`designer`

Custom Skills (bundled in repo)

Skill	Description	Assigned To
`cartography`	Repository understanding and hierarchical codemap generation	`orchestrator`

Simplify

The Minimalist's sacred truth: every line of code is a liability.

simplify is a specialized skill for complexity analysis and YAGNI enforcement. It identifies unnecessary abstractions and suggests minimal implementations.

Agent Browser

External browser automation for visual verification and testing.

agent-browser provides full high-performance browser automation capabilities. It allows agents to browse the web, interact with elements, and capture screenshots for visual state verification.

Cartography

Automated repository mapping through hierarchical codemaps.

A dedicated guide (with screenshots) lives at: docs/cartography.md.

cartography empowers the Orchestrator to build and maintain a deep architectural understanding of any codebase. Instead of reading thousands of lines of code every time, agents refer to hierarchical codemap.md files that describe the why and how of each directory.

How to use:

Just ask the Orchestrator to run cartography. It will automatically detect if it needs to initialize a new map or update an existing one.

Why it's useful:

Instant Onboarding: Help agents (and humans) understand unfamiliar codebases in seconds.
Efficient Context: Agents only read architectural summaries, saving tokens and improving accuracy.
Change Detection: Only modified folders are re-analyzed, making updates fast and efficient.
Timeless Documentation: Focuses on high-level design patterns that don't get stale.

Technical Details & Manual Control

The skill uses a background Python engine (cartographer.py) to manage state and detect changes.

How it works under the hood:

Initialize - Orchestrator analyzes repo structure and runs init to create .slim/cartography.json (hashes) and empty templates.
Map - Orchestrator spawns specialized Explorer sub-agents to fill codemaps with timeless architectural details (Responsibility, Design, Flow, Integration).
Update - On subsequent runs, the engine detects changed files and only refreshes codemaps for affected folders.

Manual Commands:

# Initialize mapping manually
python3 ~/.config/opencode/skills/cartography/scripts/cartographer.py init \
  --root . \
  --include "src/**/*.ts" \
  --exclude "**/*.test.ts"

# Check for changes since last map
python3 ~/.config/opencode/skills/cartography/scripts/cartographer.py changes --root .

# Sync hashes after manual map updates
python3 ~/.config/opencode/skills/cartography/scripts/cartographer.py update --root .

Skills Assignment

You can customize which skills each agent is allowed to use in ~/.config/opencode/oh-my-opencode-slim.json (or .jsonc).

Syntax:

Syntax	Description	Example
`"*"`	All installed skills	`["*"]`
`"!item"`	Exclude specific skill	`["*", "!agent-browser"]`
Explicit list	Only listed skills	`["simplify"]`
`"!*"`	Deny all skills	`["!*"]`

Rules:

* expands to all available skills
!item excludes specific skills
Conflicts (e.g., ["a", "!a"]) → deny wins (principle of least privilege)
Empty list [] → no skills allowed

Example Configuration:

{
  "presets": {
    "my-preset": {
      "orchestrator": {
        "skills": ["*", "!agent-browser"]
      },
      "designer": {
        "skills": ["agent-browser", "simplify"]
      }
    }
  }
}

MCP Servers

Built-in Model Context Protocol servers (enabled by default):

MCP	Purpose	URL
`websearch`	Real-time web search via Exa AI	`https://mcp.exa.ai/mcp`
`context7`	Official library documentation	`https://mcp.context7.com/mcp`
`grep_app`	GitHub code search via grep.app	`https://mcp.grep.app`

MCP Permissions

Control which agents can access which MCP servers using per-agent allowlists:

Agent	Default MCPs
`orchestrator`	`websearch`
`designer`	none
`oracle`	none
`librarian`	`websearch`, `context7`, `grep_app`
`explorer`	none
`fixer`	none

Configuration & Syntax

You can configure MCP access in your plugin configuration file: ~/.config/opencode/oh-my-opencode-slim.json (or .jsonc).

Per-Agent Permissions

Control which agents can access which MCP servers using the mcps array in your preset. The syntax is the same as for skills:

Syntax	Description	Example
`"*"`	All MCPs	`["*"]`
`"!item"`	Exclude specific MCP	`["*", "!context7"]`
Explicit list	Only listed MCPs	`["websearch", "context7"]`
`"!*"`	Deny all MCPs	`["!*"]`

Rules:

* expands to all available MCPs
!item excludes specific MCPs
Conflicts (e.g., ["a", "!a"]) → deny wins
Empty list [] → no MCPs allowed

Example Configuration:

{
  "presets": {
    "my-preset": {
      "orchestrator": {
        "mcps": ["websearch"]
      },
      "librarian": {
        "mcps": ["websearch", "context7", "grep_app"]
      },
      "oracle": {
        "mcps": ["*", "!websearch"]
      }
    }
  }
}

Global Disabling

You can disable specific MCP servers globally by adding them to the disabled_mcps array at the root of your config object.

Tools & Capabilities

Tmux Integration

Watch your agents work in real-time. When the Orchestrator launches sub-agents or initiates background tasks, new tmux panes automatically spawn showing each agent's live progress. No more waiting in the dark.

Quick Setup

Enable tmux integration in oh-my-opencode-slim.json (or .jsonc):

   {
     "tmux": {
       "enabled": true,
       "layout": "main-vertical",
       "main_pane_size": 60
     }
   }

Run OpenCode inside tmux: bash tmux opencode

Layout Options

Layout	Description
`main-vertical`	Your session on the left (60%), agents stacked on the right
`main-horizontal`	Your session on top (60%), agents stacked below
`tiled`	All panes in equal-sized grid
`even-horizontal`	All panes side by side
`even-vertical`	All panes stacked vertically

Detailed Guide: For complete tmux integration documentation, troubleshooting, and advanced usage, see Tmux Integration

Background Tasks

The plugin provides tools to manage asynchronous work:

Tool	Description
`background_task`	Launch an agent in a new session (`sync=true` blocks, `sync=false` runs in background)
`background_output`	Fetch the result of a background task by ID
`background_cancel`	Abort running tasks

LSP Tools

Language Server Protocol integration for code intelligence:

Tool	Description
`lsp_goto_definition`	Jump to symbol definition
`lsp_find_references`	Find all usages of a symbol across the workspace
`lsp_diagnostics`	Get errors/warnings from the language server
`lsp_rename`	Rename a symbol across all files

Built-in LSP Servers: OpenCode includes pre-configured LSP servers for 30+ languages (TypeScript, Python, Rust, Go, etc.). See the official documentation for the full list and requirements.

Code Search Tools

Fast code search and refactoring:

Tool	Description
`grep`	Fast content search using ripgrep
`ast_grep_search`	AST-aware code pattern matching (25 languages)
`ast_grep_replace`	AST-aware code refactoring with dry-run support

Formatters

OpenCode automatically formats files after they're written or edited using language-specific formatters.

Built-in Formatters: Includes support for Prettier, Biome, gofmt, rustfmt, ruff, and 20+ others. See the official documentation for the complete list.

Configuration

Files You Edit

File	Purpose
`~/.config/opencode/opencode.json`	OpenCode core settings
`~/.config/opencode/oh-my-opencode-slim.json` or `.jsonc`	Plugin settings (agents, tmux, MCPs)
`.opencode/oh-my-opencode-slim.json` or `.jsonc`	Project-local plugin overrides (optional)

💡 JSONC Support: Configuration files support JSONC format (JSON with Comments). Use .jsonc extension to enable comments and trailing commas. If both .jsonc and .json exist, .jsonc takes precedence.

Prompt Overriding

You can customize agent prompts by creating markdown files in ~/.config/opencode/oh-my-opencode-slim/:

With no preset, prompt files are loaded directly from this directory.
With preset set (for example test), the plugin first checks ~/.config/opencode/oh-my-opencode-slim/{preset}/, then falls back to the root prompt directory.

File	Purpose
`{agent}.md`	Replaces the default prompt entirely
`{agent}_append.md`	Appends to the default prompt

Example:

~/.config/opencode/oh-my-opencode-slim/
  ├── test/
  │   ├── orchestrator.md      # Preset-specific override (preferred)
  │   └── explorer_append.md
  ├── orchestrator.md          # Custom orchestrator prompt
  ├── orchestrator_append.md   # Append to default orchestrator prompt
  ├── explorer.md
  ├── explorer_append.md
  └── ...

Usage:

Create {agent}.md to completely replace an agent's default prompt
Create {agent}_append.md to add custom instructions to the default prompt
Both files can exist simultaneously - the replacement takes precedence
When preset is set, {preset}/{agent}.md and {preset}/{agent}_append.md are checked first
If neither file exists, the default prompt is used

This allows you to fine-tune agent behavior without modifying the source code.

JSONC Format (JSON with Comments)

The plugin supports JSONC format for configuration files, allowing you to:

Add single-line comments (//)
Add multi-line comments (/* */)
Use trailing commas in arrays and objects

File Priority:

oh-my-opencode-slim.jsonc (preferred if exists)
oh-my-opencode-slim.json (fallback)

Example JSONC Configuration:

{
  // Use preset for development
  "preset": "openai",

  /* Presets definition - customize agent models here */
  "presets": {
    "openai": {
      // Fast models for quick iteration
      "oracle": { "model": "openai/gpt-5.4" },
      "explorer": { "model": "openai/gpt-5.4-mini" },
    },
  },

  "tmux": {
    "enabled": true,  // Enable for monitoring
    "layout": "main-vertical",
  },
}

Plugin Config (`oh-my-opencode-slim.json` or `oh-my-opencode-slim.jsonc`)

The installer generates this file with the OpenAI preset by default. You can manually customize it to mix and match models from any provider. See Provider Configurations for examples.

Option Reference

Option	Type	Default	Description
`preset`	string	-	Name of the preset to use (e.g., `"openai"`, `"kimi"`)
`presets`	object	-	Named preset configurations containing agent mappings
`presets.<name>.<agent>.model`	string	-	Model ID for the agent (e.g., `"openai/gpt-5.4"`)
`presets.<name>.<agent>.temperature`	number	-	Temperature setting (0-2) for the agent
`presets.<name>.<agent>.variant`	string	-	Agent variant for reasoning effort (e.g., `"low"`, `"medium"`, `"high"`)
`presets.<name>.<agent>.skills`	string[]	-	Array of skill names the agent can use (`"*"` for all, `"!item"` to exclude)
`presets.<name>.<agent>.mcps`	string[]	-	Array of MCP names the agent can use (`"*"` for all, `"!item"` to exclude)
`tmux.enabled`	boolean	`false`	Enable tmux pane spawning for sub-agents
`tmux.layout`	string	`"main-vertical"`	Layout preset: `main-vertical`, `main-horizontal`, `tiled`, `even-horizontal`, `even-vertical`
`tmux.main_pane_size`	number	`60`	Main pane size as percentage (20-80)
`disabled_mcps`	string[]	`[]`	MCP server IDs to disable globally (e.g., `"websearch"`)

quick-reference.md 15 KB

History Raw

Quick Reference Guide

Table of Contents

Presets

Switching Presets

OpenAI Preset (Default)

Other Providers

Skills

Recommended Skills (via npx)

Custom Skills (bundled in repo)

Simplify

Agent Browser

Cartography

Skills Assignment

MCP Servers

MCP Permissions

Configuration & Syntax

Tools & Capabilities

Tmux Integration

Quick Setup

Layout Options

Background Tasks

LSP Tools

Code Search Tools

Formatters

Configuration

Files You Edit

Prompt Overriding

JSONC Format (JSON with Comments)

Plugin Config (`oh-my-opencode-slim.json` or `oh-my-opencode-slim.jsonc`)

Option Reference

quick-reference.md 15 KB History Raw

Quick Reference Guide

Table of Contents

Presets

Switching Presets

OpenAI Preset (Default)

Other Providers

Skills

Recommended Skills (via npx)

Custom Skills (bundled in repo)

Simplify

Agent Browser

Cartography

Skills Assignment

MCP Servers

MCP Permissions

Configuration & Syntax

Tools & Capabilities

Tmux Integration

Quick Setup

Layout Options

Background Tasks

LSP Tools

Code Search Tools

Formatters

Configuration

Files You Edit

Prompt Overriding

JSONC Format (JSON with Comments)

Plugin Config (oh-my-opencode-slim.json or oh-my-opencode-slim.jsonc)

Option Reference

quick-reference.md 15 KB

History Raw

Plugin Config (`oh-my-opencode-slim.json` or `oh-my-opencode-slim.jsonc`)