> ## Documentation Index
> Fetch the complete documentation index at: https://praison.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Hook Runner • Rust AI Agent SDK
> HookRunner: Hook runner for executing hooks in a workflow
# HookRunner
> Defined in the [**hooks**](../modules/hooks) module.
Rust AI Agent SDK
Hook runner for executing hooks in a workflow
```mermaid theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
%%{init: {'theme': 'base', 'themeVariables': { 'primaryColor': '#8B0000', 'primaryTextColor': '#fff', 'primaryBorderColor': '#710101', 'lineColor': '#189AB4', 'secondaryColor': '#189AB4', 'tertiaryColor': '#fff' }}}%%
graph TD
event["Event Trigger"] --> hook["Hook: HookRunner"]
hook --> decision{"Decision"}
decision -- "Allow" --> proc["Process"]
decision -- "Deny" --> block["Block"]
style hook fill:#189AB4,color:#fff
style event fill:#8B0000,color:#fff
style proc fill:#8B0000,color:#fff
style block fill:#8B0000,color:#fff
```
## Fields
| Name | Type | Description |
| ---------- | ------------------------- | ----------- |
| `registry` | `Arc<HookRegistry>` | - |
## Methods
### `new`
```rust theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
fn new(registry: HookRegistry) -> Self
```
Create a new hook runner
**Parameters:**
| Name | Type |
| ---------- | -------------- |
| `registry` | `HookRegistry` |
### `before_tool`
```rust theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
fn before_tool(
&self,
session_id: &str,
tool_name: &str,
args: serde_json::Value,
) -> Result
```
Run before-tool hooks
**Parameters:**
| Name | Type |
| ------------ | ------------------- |
| `session_id` | `&str` |
| `tool_name` | `&str` |
| `args` | `serde_json::Value` |
### `after_tool`
```rust theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
fn after_tool(
&self,
session_id: &str,
tool_name: &str,
result: serde_json::Value,
) -> Result
```
Run after-tool hooks
**Parameters:**
| Name | Type |
| ------------ | ------------------- |
| `session_id` | `&str` |
| `tool_name` | `&str` |
| `result` | `serde_json::Value` |
### `before_agent`
```rust theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
fn before_agent(
&self,
session_id: &str,
agent_name: &str,
message: &str,
) -> Result
```
Run before-agent hooks
**Parameters:**
| Name | Type |
| ------------ | ------ |
| `session_id` | `&str` |
| `agent_name` | `&str` |
| `message` | `&str` |
### `after_agent`
```rust theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
fn after_agent(
&self,
session_id: &str,
agent_name: &str,
response: &str,
) -> Result
```
Run after-agent hooks
**Parameters:**
| Name | Type |
| ------------ | ------ |
| `session_id` | `&str` |
| `agent_name` | `&str` |
| `response` | `&str` |
### `on_error`
```rust theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
fn on_error(&self, session_id: &str, error: &str) -> Result
```
Run on-error hooks
**Parameters:**
| Name | Type |
| ------------ | ------ |
| `session_id` | `&str` |
| `error` | `&str` |
## Source
`praisonai/src/hooks/mod.rs` at line 461
***
## Related Documentation