picoclaw/docs/reference/tools-api.md

Tools API Documentation

Overview

PicoClaw's tools system provides a extensible way for the AI agent to interact with the host system, web, hardware, and external services. Tools are registered in a centralized ToolRegistry and can be exposed to LLM providers via JSON Schema definitions.

Architecture

Tool Interface

All tools implement the base Tool interface (pkg/tools/registry.go):

type Tool interface {
    Name() string
    Description() string
    Parameters() map[string]any  // JSON Schema
    Execute(ctx context.Context, args map[string]any) *ToolResult
}

Optional interfaces for enhanced behavior:

• AsyncExecutor - Tools that support async execution with callback
• mediaStoreAware - Tools that need access to media storage
• PromptMetadataProvider - Tools that provide prompt layer/slot metadata

Tool Registry

The ToolRegistry (pkg/tools/registry.go) manages all tools:

• Core Tools: Registered with Register(tool) - always available, no TTL
• Hidden Tools: Registered with RegisterHidden(tool) - have TTL (Time To Live), can be promoted
• Tool Definitions: GetDefinitions() returns JSON Schema for LLM providers
• Provider Format: ToProviderDefs() converts to provider-specific format (OpenAI, Anthropic, etc.)

Tool Execution Flow

1. Tool called by agent with arguments
2. Arguments validated against tool's JSON Schema
3. Channel/ChatID context injected into ctx
4. Execute() or ExecuteAsync() called
5. Result normalized and returned as ToolResult
6. Panics recovered to prevent agent crashes

Available Tools

Filesystem Tools

Tool Name	Description	Category	Config Key
read_file	Read file content from workspace or allowed paths	filesystem	read_file
write_file	Create or overwrite files within workspace	filesystem	write_file
list_dir	Inspect directories and enumerate files	filesystem	list_dir
edit_file	Apply targeted edits to existing files	filesystem	edit_file
append_file	Append content to end of existing file	filesystem	append_file

Implementation: pkg/tools/fs/ package

• Path validation against workspace restrictions
• Symlink resolution to prevent escaping workspace
• Configurable allow/deny path patterns
• Max file size limit: 64KB (configurable via MaxReadFileSize)

Expected Arguments (example for read_file):

{
  "path": "/path/to/file.txt",
  "workspace": "/workspace"  // injected automatically
}

Shell/Exec Tool

Tool Name	Description	Category	Config Key
exec	Run shell commands in workspace sandbox	filesystem	exec

Implementation: pkg/tools/shell.go

• Security: Deny patterns block dangerous commands:
  • rm -rf, dd, shutdown, reboot, chmod, chown, sudo
  • Command substitution: $(...), backticks
  • Pipe to shell: \| sh, \| bash
• Session Management: Persistent shell sessions via SessionManager
• Timeout: Configurable command timeout
• Working Directory: Restricted to workspace by default

Expected Arguments:

{
  "command": "ls -la",
  "workdir": "/workspace",  // optional
  "timeout": 30  // seconds, optional
}

Automation Tools

Tool Name	Description	Category	Config Key
cron	Schedule one-time or recurring tasks	automation	cron

Implementation: pkg/tools/cron.go

• Schedule reminders, shell commands, and jobs
• One-time or recurring (cron expression support)

Expected Arguments:

{
  "action": "add",  // add, list, remove
  "schedule": "0 9 * * *",  // cron format or "in 5m"
  "command": "echo 'reminder'",  // optional
  "message": "Daily reminder"  // optional
}

Web Tools

Tool Name	Description	Category	Config Key
web_search	Search the web using configured providers	web	web
web_fetch	Fetch and summarize webpage contents	web	web_fetch

Web Search Providers (configured in tools.web):

• Sogou - Chinese search engine
• DuckDuckGo - Privacy-focused search
• Brave Search - Independent search (requires API key)
• Tavily - AI-optimized search (requires API key)
• Perplexity - AI search engine (requires API key)
• SearXNG - Metasearch engine (self-hosted)
• GLM Search - Chinese AI search (requires API key)
• Baidu Search - Chinese search engine (requires API key)

Web Search Expected Arguments:

{
  "query": "latest AI news",
  "max_results": 5,  // optional, default varies by provider
  "provider": "brave"  // optional, uses default
}

Web Fetch Expected Arguments:

{
  "url": "https://example.com",
  "max_chars": 10000  // optional
}

Communication Tools

Tool Name	Description	Category	Config Key
message	Send follow-up message to active chat	communication	message
send_file	Send file or media to active chat	communication	send_file

Implementation: pkg/tools/integration_facade.go → pkg/tools/integration/

Message Tool Expected Arguments:

{
  "text": "Hello from the agent!",
  "channel": "telegram",  // injected from context
  "chat_id": "123456"  // injected from context
}

Send File Expected Arguments:

{
  "path": "/workspace/report.pdf",
  "caption": "Here's your file"  // optional
}

Skills Tools

Tool Name	Description	Category	Config Key
find_skills	Search external skill registries	skills	find_skills
install_skill	Install skill from registry	skills	install_skill

Dependencies: Requires skills config to be enabled

Find Skills Expected Arguments:

{
  "query": "pdf",
  "limit": 10  // optional
}

Install Skill Expected Arguments:

{
  "name": "pdf-tools",
  "source": "registry-url"  // optional
}

Agent/Subagent Tools

Tool Name	Description	Category	Config Key
spawn	Launch background subagent for delegated work	agents	spawn
spawn_status	Query status of spawned subagents	agents	spawn_status

Dependencies: Requires subagent config to be enabled

Spawn Tool Expected Arguments:

{
  "task": "Research latest AI papers",
  "model": "gpt-4",  // optional
  "max_tokens": 2000,  // optional
  "temperature": 0.7,  // optional
  "async": true  // optional, run in background
}

Spawn Status Expected Arguments:

{
  "task_id": "abc123"  // optional, returns specific task or all
}

Hardware Tools

Tool Name	Description	Category	Config Key	Platform
i2c	Interact with I2C devices	hardware	i2c	Linux only
spi	Interact with SPI devices	hardware	spi	Linux only
serial	Interact with serial ports	hardware	serial	Linux/macOS/Windows

Implementation: pkg/tools/hardware_facade.go → pkg/tools/hardware/

I2C Expected Arguments:

{
  "action": "read",  // read, write
  "bus": "/dev/i2c-1",
  "address": 0x48,
  "register": 0x00,  // optional
  "data": [0x01, 0x02]  // for write
}

Serial Expected Arguments:

{
  "port": "/dev/ttyUSB0",
  "baud": 9600,
  "data": "hello"  // string or bytes
}

Discovery Tools (Hidden, TTL-based)

Tool Name	Description	Category	Config Key
tool_search_tool_regex	Discover hidden MCP tools by regex	discovery	mcp.discovery.use_regex
tool_search_tool_bm25	Discover hidden MCP tools by semantics	discovery	mcp.discovery.use_bm25

Dependencies: Requires mcp and mcp.discovery to be enabled

Backend API Endpoints

Base URL

http://localhost:<port>/api

Tool Management

List All Tools

GET /api/tools

Response:

{
  "tools": [
    {
      "name": "read_file",
      "description": "Read file content from the workspace",
      "category": "filesystem",
      "config_key": "read_file",
      "status": "enabled",  // enabled, disabled, blocked
      "reason_code": ""  // e.g., "requires_skills"
    }
  ]
}

Enable/Disable Tool

PUT /api/tools/{name}/state

Request Body:

{
  "enabled": true
}

Response:

{
  "status": "ok"
}

Web Search Configuration

Get Web Search Config

GET /api/tools/web-search-config

Response:

{
  "provider": "auto",  // auto, sogou, duckduckgo, brave, tavily, etc.
  "current_service": "brave",
  "prefer_native": false,
  "proxy": "",
  "providers": [
    {
      "id": "brave",
      "label": "Brave Search",
      "configured": true,
      "current": true,
      "requires_auth": true
    }
  ],
  "settings": {
    "brave": {
      "enabled": true,
      "max_results": 10,
      "api_key_set": true
    }
  }
}

Update Web Search Config

PUT /api/tools/web-search-config

Request Body:

{
  "provider": "brave",
  "prefer_native": false,
  "proxy": "",
  "settings": {
    "brave": {
      "enabled": true,
      "max_results": 10,
      "api_key": "BSA...",  // or "api_keys": ["key1", "key2"]
      "base_url": ""  // optional for self-hosted
    }
  }
}

Tool Result Structure

Tools return *ToolResult with the following fields:

type ToolResult struct {
    ForLLM      string        // Text returned to LLM for processing
    ForUser     string        // Text shown to end user in chat
    MediaURLs   []string      // Media attachment URLs (media:// or http://)
    IsError     bool          // Whether execution failed
    Async       bool          // True if running asynchronously
    Err         error         // Underlying Go error (not serialized to JSON)
}

MCP (Model Context Protocol) Integration

PicoClaw exposes tools via MCP server (pkg/mcp/manager.go):

• External MCP servers can be integrated
• Tools from MCP servers appear as hidden tools with TTL
• Discovery tools (tool_search_tool_regex, tool_search_tool_bm25) make hidden tools available
• MCP manager handles tool execution via isolated command transport

MCP Tool Discovery Flow:

1. MCP server registered with PicoClaw
2. Tools exposed as hidden (TTL=0, not visible to LLM)
3. Agent uses tool_search_tool_regex or tool_search_tool_bm25
4. Matching tools promoted (TTL set >0)
5. Promoted tools appear in next LLM context

Configuration

Tools configured in config.json under tools section:

{
  "tools": {
    "read_file": {"enabled": true},
    "write_file": {"enabled": true},
    "exec": {"enabled": true},
    "web": {
      "enabled": true,
      "provider": "brave",
      "brave": {
        "enabled": true,
        "max_results": 10,
        "api_keys": ["BSA..."]
      }
    },
    "mcp": {
      "enabled": true,
      "discovery": {
        "enabled": true,
        "use_regex": true,
        "use_bm25": false
      }
    }
  }
}

Security Considerations

1. Path Restrictions: Filesystem tools restrict access to workspace by default
2. Shell Command Filtering: Dangerous commands blocked via regex patterns
3. Tool TTL: Hidden tools auto-expire to prevent context bloat
4. Media Store: File paths converted to media:// URLs for safe transport
5. Panic Recovery: Tool panics recovered to prevent agent crashes
6. Symlink Resolution: Prevents escaping workspace via symlinks

Tool Registration Example

// Register a core tool (always available)
registry.Register(tools.NewReadFileTool(workspace, true, 64*1024))

// Register a hidden tool (TTL-based)
registry.RegisterHidden(tools.NewRegexSearchTool(registry, 5, 10))

// Promote hidden tools (make them available to LLM)
registry.PromoteTools([]string{"tool_search_tool_regex"}, 10)  // TTL=10 turns