Hooks Overview

The best way to understand this group is not by what the code looks like, but by what actually happens at runtime.

Shared pattern

All four share the same high-level pattern:

• the plugin declares a handler
• the host later calls a named point

For example:

const next = await agent.plugins.pipeline("chat.enrich_message", value);
await agent.plugins.guard("review.require_checked", next);
await agent.plugins.effect("audit.observe", next);
const role = await agent.plugins.resolve("auth.resolve_role", {
  userId: "owner",
});

In this example, the host is what triggers execution, not the plugin by itself.

Biggest difference between them

pipeline

The key idea is: receive one value, then hand back a new value.

guard

The key idea is: allow the flow to continue, or throw and stop it.

effect

The key idea is: keep the main value untouched and only do side effects.

resolve

The key idea is: only one plugin is allowed to be the final authority for the answer.

Think of them as four kinds of questions

pipeline asks

"Should this value be transformed before the next step?"

guard asks

"Is this value allowed to continue?"

effect asks

"Now that this happened, should we log, sync, or observe something?"

resolve asks

"Who gives the final answer for this point?"

Why resolve is the easiest one to misuse

Many people instinctively write it as if several plugins can each contribute a little.

But resolve is not:

• a collaborative answer-building point

It is:

• a single-authority answer point

That makes it a good fit for things like final role lookup, final provider choice, or final routing decisions, not step-by-step enrichment.

Next reading

• Call flow
• Pipeline
• Guard
• Effect
• Resolve