optimclaw/examples/wasm-tools/slack

Slack WASM Tool

A standalone WASM component that provides Slack integration for IronClaw. This serves as both a functional tool and a template for building custom WASM tools.

Features

• send_message: Send messages to channels or threads
• list_channels: List channels the bot has access to
• get_channel_history: Retrieve recent messages from a channel
• post_reaction: Add emoji reactions to messages
• get_user_info: Get information about Slack users

Prerequisites

1. Rust toolchain with WASM target:

   rustup target add wasm32-wasip2
   

2. cargo-component for building WASM components:

   cargo install cargo-component
   

3. Slack Bot Token with the following OAuth scopes:

   • chat:write - Send messages
   • channels:read - List public channels
   • channels:history - Read channel history
   • groups:read - List private channels
   • groups:history - Read private channel history
   • reactions:write - Add reactions
   • users:read - Get user information

Building

cd examples/wasm-tools/slack
cargo component build --release

The compiled WASM component will be at:

target/wasm32-wasip2/release/slack_tool.wasm

Installation

Option A: File-based (Development)

Copy the WASM and capabilities files to the agent's tools directory:

mkdir -p ~/.ironclaw/tools
cp target/wasm32-wasip2/release/slack_tool.wasm ~/.ironclaw/tools/slack.wasm
cp slack.capabilities.json ~/.ironclaw/tools/

Option B: Database Storage (Production)

Use the agent CLI or API to store the tool:

ironclaw tool install \
  --name slack \
  --wasm target/wasm32-wasip2/release/slack_tool.wasm \
  --capabilities slack.capabilities.json

Configuration

Store your Slack bot token as a secret:

ironclaw secret set slack_bot_token "xoxb-your-token-here"

Or via SQL:

INSERT INTO secrets (user_id, name, encrypted_value, key_salt)
VALUES ('your_user_id', 'slack_bot_token', ...);

Usage Examples

Send a Message

{
  "action": "send_message",
  "channel": "#general",
  "text": "Hello from IronClaw!"
}

Reply in a Thread

{
  "action": "send_message",
  "channel": "C1234567890",
  "text": "This is a thread reply",
  "thread_ts": "1234567890.123456"
}

List Channels

{
  "action": "list_channels",
  "limit": 50
}

Get Channel History

{
  "action": "get_channel_history",
  "channel": "C1234567890",
  "limit": 10
}

Add a Reaction

{
  "action": "post_reaction",
  "channel": "C1234567890",
  "timestamp": "1234567890.123456",
  "emoji": "thumbsup"
}

Get User Info

{
  "action": "get_user_info",
  "user_id": "U1234567890"
}

Security Model

This tool runs in a sandboxed WASM environment with strict capability controls:

1. HTTP Allowlist: Can only access slack.com/api/*
2. Credential Injection: The bot token is injected by the host runtime; the WASM code never sees it
3. Rate Limiting: 50 requests/minute, 1000 requests/hour
4. No Filesystem Access: Cannot read/write files except through workspace capability
5. No Network Access: Beyond the allowlisted endpoints

Capabilities File

The slack.capabilities.json file declares what this tool needs:

{
  "http": {
    "allowlist": [
      { "host": "slack.com", "path_prefix": "/api/", "methods": ["GET", "POST"] }
    ],
    "credentials": {
      "slack_bot_token": {
        "secret_name": "slack_bot_token",
        "location": { "type": "bearer" },
        "host_patterns": ["slack.com"]
      }
    },
    "rate_limit": { "requests_per_minute": 50, "requests_per_hour": 1000 }
  },
  "secrets": {
    "allowed_names": ["slack_bot_token"]
  }
}

Building Your Own Tool

Use this as a template for creating new WASM tools:

1. Copy this directory
2. Update Cargo.toml with your tool name
3. Modify src/types.rs with your action types
4. Implement API calls in src/api.rs
5. Update the action dispatch in src/lib.rs
6. Create your *.capabilities.json file
7. Build with cargo component build --release

Key Files

• Cargo.toml - Rust package config with WASM target
• src/lib.rs - WIT bindings and main dispatch
• src/types.rs - Request/response types
• src/api.rs - API implementation
• *.capabilities.json - Security capabilities declaration

WIT Interface

Tools implement the sandboxed-tool world from wit/tool.wit:

world sandboxed-tool {
    import host;   // log, http-request, secret-exists, etc.
    export tool;   // execute, schema, description
}

Troubleshooting

"Slack bot token not configured"

Ensure you've stored the secret:

ironclaw secret set slack_bot_token "xoxb-..."

"Endpoint not in allowlist"

Check that slack.capabilities.json includes the endpoint you're trying to access.

"Rate limit exceeded"

The tool has a default rate limit of 50 requests/minute. Wait and retry.

Build errors

Ensure you have the WASM target and cargo-component installed:

rustup target add wasm32-wasip2
cargo install cargo-component

License

MIT OR Apache-2.0