Tools - Hexel Studio

A tool is a callable integration that lets an agent act on an external system. Tools are organized into toolkits and made available through the Tool Gateway, which handles credentials and execution.

Key concepts

Term	Meaning
Tool	A single callable action (e.g., “send email”).
Toolkit	A provider-scoped grouping of related tools.
Connected account	An authorized credential for a provider.
Binding	A mapping that grants an agent access to a toolkit’s tools.

Available toolkits

Toolkit	Examples
Gmail	Send email, read inbox, search messages.
Google Sheets	Read, write, and update spreadsheet data.
Slack	Post messages, read channels, manage threads.
GitHub	Create issues, open PRs, read repositories.
Jira	Create and update tickets, search issues.
WhatsApp	Send messages, read conversations.

How it works

Connect account (OAuth) → Bind toolkit to agent → Agent discovers and executes tools at runtime

You connect an account once via a managed OAuth flow.
You bind a toolkit to an agent so it can use those tools.
At runtime, the agent discovers available tools and the Tool Gateway resolves credentials automatically.

Example

from hexel import Hexel

client = Hexel(api_key="YOUR_API_KEY")

# Discover available toolkits and tools
toolkits = client.tools.list_toolkits()
tools = client.tools.list_tools(toolkit="GMAIL")

# Execute a tool
result = client.tools.execute(
    tool_slug="GMAIL_SEND_EMAIL",
    input={"to": "user@example.com", "subject": "Hello", "body": "Hi there"},
)

Tool Gateway Overview

The full tool integration model.

Connected Accounts

Authorize providers with OAuth.

Bindings

Grant agents access to tools.

Executing Tools

Run tools synchronously or asynchronously.

Next steps

Continue to Knowledge & Memory.

​Key concepts

​Available toolkits

​How it works

​Example

​Related pages