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Action Hubs

What is an Action Hub?​

An Action Hub is a small onchain contract that defines a rule once (for example, a per‑token monthly budget) and then creates many Action Builders that follow that rule. The hub is the policy parent and the builders are the concrete “do this now” children.

Pre‑approving a hub in Canon Guard means every builder it creates can use the short delay. You don’t need to pre‑approve each child.

When to use a hub​

You should consider using a hub when you find yourself repeating the same action pattern with only minor changes, such as varying the token or amount, and you want a single place to enforce limits or policies. Hubs are also valuable if you need provenance, meaning you want to be able to prove that a specific builder was genuinely created by your hub. If you want to pre-approve an entire group of related actions so they all benefit from the short delay in Canon Guard, a hub is the right tool.

What you get​

By using a hub, you define one policy that governs many compliant builders, ensuring consistency and simplifying management. The hub maintains a built-in registry, so it can always prove which builders are its legitimate children. This setup also streamlines pre-approval: You only need to approve the hub once, and all its children automatically inherit the short delay.

How it works​

  • The hub creates children (action builders) that encode exactly what to run
  • Each child remembers who created it (its parent hub)
  • When you queue a child in Canon Guard, Canon Guard checks the parent; if it’s an approved hub, the short delay applies

Example: Capped token transfers​

You want to cap token outflows per month and keep routine transfers fast.

  • Deploy a Capped Token Transfers Hub configured with your Safe, recipient, allowed tokens, per‑token caps, and a monthly epoch
  • Pre‑approve the hub in Canon Guard for a time window
  • When you need a transfer, ask the hub to create a child for “send X of token T to recipient”
  • Queue the child in Canon Guard, owners approve onchain, and after the short delay the transfer executes

What runs under the hood:

  • First, the child asks the hub to update internal accounting and will revert if the monthly cap would be exceeded
  • Then it transfers the tokens to the recipient
  • On a new month, the hub resets usage so the budget starts fresh

For reference, see contracts/action-hubs/ and contracts/actions-builders/.