Knowledge BaseBindings

Hook Bindings

Hook binding is the runtime-local execution family in MergeSafe. It is the right fit when the real action should run through a product-native callable function or hook path instead of a direct request-driven route.

On this page

What Hook binding is When Hook is the right choice What Hook binding assumes Common caveats

What Hook binding is

A Hook binding resolves a callable path from the page or runtime context, invokes it with mapped input, and validates the output against the tool schema.

This makes Hook a better fit for product-native orchestration and page-local logic than for plain route calls.

When Hook is the right choice

The real execution path already exists as an explicit callable function or hook in the product.
The tool should stay inside the page or runtime context rather than making a direct HTTP request.
The product team wants to expose a controlled callable surface without pretending every frontend behavior is automatically tool-safe.

What Hook binding assumes

The hook or callable path actually exists and can be resolved at runtime.
The implementation source matches what the binding expects to call.
Any registry or discovery behavior needed by the runtime is present in the page environment.

Common caveats

Missing or unregistered hooks will fail execution.
Source mismatch can break the binding even when the tool shape looks valid.
Depending on implementation details, DOM or runtime discovery can matter.
Hook does not mean arbitrary frontend behavior becomes a reliable tool automatically.