agentsbox

Tool-search facade for MCP servers (OpenCode + pi integrations).

agentsbox implements the "tool search tool" pattern for MCP: instead of loading every MCP tool schema into the agent context up-front, it exposes a small set of agentsbox_* tools that search and execute MCP server tools on-demand.

Installation

NPM Package

npm install -g agentsbox

After installation via npm, initialize the configuration:

agentsbox init

This creates the config directory under $XDG_CONFIG_HOME/agentsbox (usually ~/.config/agentsbox).

Setup Integration

OpenCode

agentsbox setup opencode

Installs the plugin by copying dist/opencode.js to ~/.config/opencode/plugins/agentsbox.js (auto-loaded by OpenCode).

pi

agentsbox setup pi

Installs extension by symlinking to ~/.pi/agent/extensions/agentsbox (auto-loaded by pi).

What Gets Created

Initialization creates under $XDG_CONFIG_HOME/agentsbox (usually ~/.config/agentsbox):

• config.jsonc – minimal config scaffold
• agentsbox.schema.json – JSON schema for validation
• skill/agentsbox/ – bundled skill for agents

With OpenCode

After agentsbox setup opencode, the plugin is automatically loaded by OpenCode. The plugin exposes:

• agentsbox_search_bm25
• agentsbox_search_regex
• agentsbox_execute
• agentsbox_status
• agentsbox_perf
• agentsbox_test

With pi

After agentsbox setup pi, the extension is available in the pi agent system. The bundled skill at skill/agentsbox/ provides guidelines for agents using these tools.

What It Does

Instead of exposing all MCP server tools to the LLM context, agentsbox provides only 6 stable tools:

| Tool | Description | |------|-------------| | agentsbox_search_bm25 | Search tools by natural language query | | agentsbox_search_regex | Search tools by regex pattern on tool names | | agentsbox_execute | Execute a discovered tool by toolId | | agentsbox_status | Get status (servers, tools, health) | | agentsbox_perf | Get performance metrics | | agentsbox_test | Test all tools with minimal inputs |

The Problem: Context Bloat

Without agentsbox, LLMs see all MCP tools with full schemas:

{
  "tools": [
    { "name": "time_get_current_time", "description": "...", "parameters": {...} },
    { "name": "brave_web_search", "description": "...", "parameters": {...} },
    { "name": "tavily_search", "description": "...", "parameters": {...} },
    ... (dozens more)
  ]
}

The Solution: Search-First Pattern

With agentsbox, the LLM sees only 6 tools and discovers others on-demand:

User: "Search the web for AI news"
    ↓
LLM calls: agentsbox_search_bm25({ text: "web search" })
    ↓
Returns: [ "brave_web_search", "tavily_search" ] + schemas
    ↓
LLM calls: agentsbox_execute({ toolId: "brave_web_search", arguments: "{...}" })

Configuration

Config Path

• Default: ~/.config/agentsbox/config.jsonc
• Override: export AGENTSBOX_CONFIG=/path/to/config.jsonc

Config Format

Full reference in CONFIG.md. Minimal example:

{
  "$schema": "./agentsbox.schema.json",
  "mcp": {
    "time": {
      "type": "local",
      "command": ["uvx", "mcp-server-time"]
    },
    "tavily": {
      "type": "remote",
      "url": "https://mcp.tavily.com/mcp/",
      "headers": {
        "Authorization": "Bearer {env:TAVILY_API_KEY}"
      }
    }
  },
  "settings": {
    "defaultLimit": 5,
    "initMode": "eager",
    "connection": {
      "connectTimeout": 5000,
      "requestTimeout": 30000,
      "retryAttempts": 2,
      "retryDelay": 1000
    }
  }
}

Environment Variable Interpolation

Use {env:VAR_NAME} anywhere in config:

{
  "mcp": {
    "my-server": {
      "type": "remote",
      "url": "{env:MCP_SERVER_URL}",
      "headers": {
        "Authorization": "Bearer {env:API_TOKEN}"
      }
    }
  }
}

Development

# Lint and format
bun run check
bun run check:fix

# Type checking
bun run typecheck

# Run tests
bun test
bun test --coverage

# Benchmarks
bun run bench

Project Structure

agentsbox/
├── src/
│   ├── catalog/       # Tool catalog + types
│   ├── config/        # Config loading + validation
│   ├── mcp-client/    # MCP client manager (local/remote)
│   ├── search/        # BM25 + regex search
│   ├── profiler/      # Performance metrics
│   ├── runtime.ts     # Core runtime (tool registration)
│   ├── plugin.ts      # OpenCode plugin implementation
│   ├── pi.ts          # pi extension implementation
│   └── cli.ts         # CLI (init/setup commands)
├── docs/
│   └── ARCHITECTURE.md    # Architecture deep-dive
├── DEVELOPMENT.md     # Contributor guide
├── QUICKSTART.md      # Detailed usage guide
├── skill/agentsbox/   # Bundled skill for agents
└── dist/              # Built output

Documentation

| Document | Description | |----------|-------------| | README.md | This file – project overview | | QUICKSTART.md | Detailed usage guide with examples | | DEVELOPMENT.md | Contributor guide | | ARCHITECTURE.md | Architecture deep-dive | | CONFIG.md | Configuration reference | | AGENTS.md | Guidelines for coding agents using agentsbox | | llms.txt | Compressed context for LLMs | | TESTING.md | Testing guide | | RELEASE.md | Release process |

License

MIT

Related

• Model Context Protocol (MCP)
• OpenCode
• pi