> ## Documentation Index > Fetch the complete documentation index at: https://docs.agenticenv.ai/llms.txt > Use this file to discover all available pages before exploring further. # Hooks > Implement lifecycle hooks for PII scrubbing, retrieval filtering, and memory tenant access checks Registers hook groups across LLM, tools, retrieval, and memory lifecycle points. Hook activity logs to **stderr** with a `[hooks]` prefix so you can see when each hook fires without mixing into the assistant reply. Source: [`examples/agent_with_hooks/`](https://github.com/agenticenv/agent-sdk-go/tree/main/examples/agent_with_hooks) ## What it demonstrates | Hook | What this example does | | ---------------------------------------- | -------------------------------------------------------------------------- | | `BeforeLLM` / `AfterLLM` | Redact email addresses and SSNs from prompts and responses | | `BeforeTool` / `AfterTool` | Scrub PII from tool args and results | | `BeforeRetrieve` / `AfterRetrieve` | Prefix queries with `kb:`; drop documents containing SSNs | | `BeforeMemoryLoad` / `AfterMemoryLoad` | Require `tenant_id` in scope; wrap recalled context with a scrubbed header | | `BeforeMemoryStore` / `AfterMemoryStore` | Scrub PII before persist; audit log after store | The sample uses `WithHooks` with named hook groups. See [Hooks](/features/hooks) for every hook point and `RunMeta` fields. ## Run From `examples/`: ```bash theme={null} go run ./agent_with_hooks ``` Default: two-run demo (store memories + prefetch retrieval + tools, then recall). ```bash theme={null} go run ./agent_with_hooks "My email is alice@example.com. What is the return policy?" ``` Watch stderr for `[hooks]` lines as each hook fires. ## Expected output stdout (assistant reply): ``` Our return policy allows returns within 30 days. I've noted your query. ``` stderr (`[hooks]` lines, interleaved): ``` [hooks] BeforeLLM: redacted 0 PII items [hooks] BeforeRetrieve: prefixed query with "kb:" [hooks] AfterRetrieve: kept 3 documents (0 dropped) [hooks] AfterLLM: redacted 0 PII items ``` Sending `"My email is alice@example.com..."` triggers PII redaction and you'll see `redacted 1 PII items` in the hook output. ## Temporal Hooks are Go functions — they run in the **process that executes activities** (the worker). Register the same hook groups on both the agent starter and the worker via `HookOptions()` (or equivalent `WithHooks` calls). Group **names** are fingerprinted for drift detection; hook **logic** consistency is your responsibility. ## Learn more Hook points and RunMeta OTLP alongside hooks Before/after memory hooks Before/after retrieve hooks