Add PermissionRequest hooks support (#17563)

## Why

We need `PermissionRequest` hook support!

Also addresses:
- https://github.com/openai/codex/issues/16301
- run a script on Hook to do things like play a sound to draw attention
but actually no-op so user can still approve
- can omit the `decision` object from output or just have the script
exit 0 and print nothing
- https://github.com/openai/codex/issues/15311
  - let the script approve/deny on its own
  - external UI what will run on Hook and relay decision back to codex


## Reviewer Note

There's a lot of plumbing for the new hook, key files to review are:
- New hook added in `codex-rs/hooks/src/events/permission_request.rs`
- Wiring for network approvals
`codex-rs/core/src/tools/network_approval.rs`
- Wiring for tool orchestrator `codex-rs/core/src/tools/orchestrator.rs`
- Wiring for execve
`codex-rs/core/src/tools/runtimes/shell/unix_escalation.rs`

## What

- Wires shell, unified exec, and network approval prompts into the
`PermissionRequest` hook flow.
- Lets hooks allow or deny approval prompts; quiet or invalid hooks fall
back to the normal approval path.
- Uses `tool_input.description` for user-facing context when it helps:
  - shell / `exec_command`: the request justification, when present
  - network approvals: `network-access <domain>`
- Uses `tool_name: Bash` for shell, unified exec, and network approval
permission-request hooks.
- For network approvals, passes the originating command in
`tool_input.command` when there is a single owning call; otherwise falls
back to the synthetic `network-access ...` command.

<details>
<summary>Example `PermissionRequest` hook input for a shell
approval</summary>

```json
{
  "session_id": "<session-id>",
  "turn_id": "<turn-id>",
  "transcript_path": "/path/to/transcript.jsonl",
  "cwd": "/path/to/cwd",
  "hook_event_name": "PermissionRequest",
  "model": "gpt-5",
  "permission_mode": "default",
  "tool_name": "Bash",
  "tool_input": {
    "command": "rm -f /tmp/example"
  }
}
```

</details>

<details>
<summary>Example `PermissionRequest` hook input for an escalated
`exec_command` request</summary>

```json
{
  "session_id": "<session-id>",
  "turn_id": "<turn-id>",
  "transcript_path": "/path/to/transcript.jsonl",
  "cwd": "/path/to/cwd",
  "hook_event_name": "PermissionRequest",
  "model": "gpt-5",
  "permission_mode": "default",
  "tool_name": "Bash",
  "tool_input": {
    "command": "cp /tmp/source.json /Users/alice/export/source.json",
    "description": "Need to copy a generated file outside the workspace"
  }
}
```

</details>

<details>
<summary>Example `PermissionRequest` hook input for a network
approval</summary>

```json
{
  "session_id": "<session-id>",
  "turn_id": "<turn-id>",
  "transcript_path": "/path/to/transcript.jsonl",
  "cwd": "/path/to/cwd",
  "hook_event_name": "PermissionRequest",
  "model": "gpt-5",
  "permission_mode": "default",
  "tool_name": "Bash",
  "tool_input": {
    "command": "curl http://codex-network-test.invalid",
    "description": "network-access http://codex-network-test.invalid"
  }
}
```

</details>

## Follow-ups

- Implement the `PermissionRequest` semantics for `updatedInput`,
`updatedPermissions`, `interrupt`, and suggestions /
`permission_suggestions`
- Add `PermissionRequest` support for the `request_permissions` tool
path

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/hooks/src/schema.rs

@@ -15,6 +15,8 @@ use std::path::PathBuf;
 const GENERATED_DIR: &str = "generated";
 const POST_TOOL_USE_INPUT_FIXTURE: &str = "post-tool-use.command.input.schema.json";
 const POST_TOOL_USE_OUTPUT_FIXTURE: &str = "post-tool-use.command.output.schema.json";
+const PERMISSION_REQUEST_INPUT_FIXTURE: &str = "permission-request.command.input.schema.json";
+const PERMISSION_REQUEST_OUTPUT_FIXTURE: &str = "permission-request.command.output.schema.json";
 const PRE_TOOL_USE_INPUT_FIXTURE: &str = "pre-tool-use.command.input.schema.json";
 const PRE_TOOL_USE_OUTPUT_FIXTURE: &str = "pre-tool-use.command.output.schema.json";
 const SESSION_START_INPUT_FIXTURE: &str = "session-start.command.input.schema.json";
@@ -69,6 +71,8 @@ pub(crate) struct HookUniversalOutputWire {
 pub(crate) enum HookEventNameWire {
     #[serde(rename = "PreToolUse")]
     PreToolUse,
+    #[serde(rename = "PermissionRequest")]
+    PermissionRequest,
     #[serde(rename = "PostToolUse")]
     PostToolUse,
     #[serde(rename = "SessionStart")]
@@ -109,6 +113,58 @@ pub(crate) struct PostToolUseCommandOutputWire {
     pub hook_specific_output: Option<PostToolUseHookSpecificOutputWire>,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+#[serde(deny_unknown_fields)]
+#[schemars(rename = "permission-request.command.output")]
+pub(crate) struct PermissionRequestCommandOutputWire {
+    #[serde(flatten)]
+    pub universal: HookUniversalOutputWire,
+    #[serde(default)]
+    pub hook_specific_output: Option<PermissionRequestHookSpecificOutputWire>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+#[serde(deny_unknown_fields)]
+pub(crate) struct PermissionRequestHookSpecificOutputWire {
+    pub hook_event_name: HookEventNameWire,
+    #[serde(default)]
+    pub decision: Option<PermissionRequestDecisionWire>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+#[serde(deny_unknown_fields)]
+pub(crate) struct PermissionRequestDecisionWire {
+    pub behavior: PermissionRequestBehaviorWire,
+    /// Reserved for a future input-rewrite capability.
+    ///
+    /// PermissionRequest hooks currently fail closed if this field is present.
+    #[serde(default)]
+    pub updated_input: Option<Value>,
+    /// Reserved for a future permission-rewrite capability.
+    ///
+    /// PermissionRequest hooks currently fail closed if this field is present.
+    #[serde(default)]
+    pub updated_permissions: Option<Value>,
+    #[serde(default)]
+    pub message: Option<String>,
+    /// Reserved for future short-circuiting semantics.
+    ///
+    /// PermissionRequest hooks currently fail closed if this field is `true`.
+    #[serde(default)]
+    pub interrupt: bool,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+pub(crate) enum PermissionRequestBehaviorWire {
+    #[serde(rename = "allow")]
+    Allow,
+    #[serde(rename = "deny")]
+    Deny,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
 #[serde(rename_all = "camelCase")]
 #[serde(deny_unknown_fields)]
@@ -181,6 +237,34 @@ pub(crate) struct PreToolUseCommandInput {
     pub tool_use_id: String,
 }
 
+#[derive(Debug, Clone, Serialize, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+#[serde(deny_unknown_fields)]
+pub(crate) struct PermissionRequestToolInput {
+    pub command: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub description: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, JsonSchema)]
+#[serde(deny_unknown_fields)]
+#[schemars(rename = "permission-request.command.input")]
+pub(crate) struct PermissionRequestCommandInput {
+    pub session_id: String,
+    /// Codex extension: expose the active turn id to internal turn-scoped hooks.
+    pub turn_id: String,
+    pub transcript_path: NullableString,
+    pub cwd: String,
+    #[schemars(schema_with = "permission_request_hook_event_name_schema")]
+    pub hook_event_name: String,
+    pub model: String,
+    #[schemars(schema_with = "permission_mode_schema")]
+    pub permission_mode: String,
+    #[schemars(schema_with = "permission_request_tool_name_schema")]
+    pub tool_name: String,
+    pub tool_input: PermissionRequestToolInput,
+}
+
 #[derive(Debug, Clone, Serialize, JsonSchema)]
 #[serde(rename_all = "camelCase")]
 #[serde(deny_unknown_fields)]
@@ -358,6 +442,14 @@ pub fn write_schema_fixtures(schema_root: &Path) -> anyhow::Result<()> {
         &generated_dir.join(POST_TOOL_USE_OUTPUT_FIXTURE),
         schema_json::<PostToolUseCommandOutputWire>()?,
     )?;
+    write_schema(
+        &generated_dir.join(PERMISSION_REQUEST_INPUT_FIXTURE),
+        schema_json::<PermissionRequestCommandInput>()?,
+    )?;
+    write_schema(
+        &generated_dir.join(PERMISSION_REQUEST_OUTPUT_FIXTURE),
+        schema_json::<PermissionRequestCommandOutputWire>()?,
+    )?;
     write_schema(
         &generated_dir.join(PRE_TOOL_USE_INPUT_FIXTURE),
         schema_json::<PreToolUseCommandInput>()?,
@@ -461,10 +553,18 @@ fn pre_tool_use_hook_event_name_schema(_gen: &mut SchemaGenerator) -> Schema {
     string_const_schema("PreToolUse")
 }
 
+fn permission_request_hook_event_name_schema(_gen: &mut SchemaGenerator) -> Schema {
+    string_const_schema("PermissionRequest")
+}
+
 fn pre_tool_use_tool_name_schema(_gen: &mut SchemaGenerator) -> Schema {
     string_const_schema("Bash")
 }
 
+fn permission_request_tool_name_schema(_gen: &mut SchemaGenerator) -> Schema {
+    string_const_schema("Bash")
+}
+
 fn user_prompt_submit_hook_event_name_schema(_gen: &mut SchemaGenerator) -> Schema {
     string_const_schema("UserPromptSubmit")
 }
@@ -516,10 +616,13 @@ fn default_continue() -> bool {
 
 #[cfg(test)]
 mod tests {
+    use super::PERMISSION_REQUEST_INPUT_FIXTURE;
+    use super::PERMISSION_REQUEST_OUTPUT_FIXTURE;
     use super::POST_TOOL_USE_INPUT_FIXTURE;
     use super::POST_TOOL_USE_OUTPUT_FIXTURE;
     use super::PRE_TOOL_USE_INPUT_FIXTURE;
     use super::PRE_TOOL_USE_OUTPUT_FIXTURE;
+    use super::PermissionRequestCommandInput;
     use super::PostToolUseCommandInput;
     use super::PreToolUseCommandInput;
     use super::SESSION_START_INPUT_FIXTURE;
@@ -544,6 +647,12 @@ mod tests {
             POST_TOOL_USE_OUTPUT_FIXTURE => {
                 include_str!("../schema/generated/post-tool-use.command.output.schema.json")
             }
+            PERMISSION_REQUEST_INPUT_FIXTURE => {
+                include_str!("../schema/generated/permission-request.command.input.schema.json")
+            }
+            PERMISSION_REQUEST_OUTPUT_FIXTURE => {
+                include_str!("../schema/generated/permission-request.command.output.schema.json")
+            }
             PRE_TOOL_USE_INPUT_FIXTURE => {
                 include_str!("../schema/generated/pre-tool-use.command.input.schema.json")
             }
@@ -585,6 +694,8 @@ mod tests {
         for fixture in [
             POST_TOOL_USE_INPUT_FIXTURE,
             POST_TOOL_USE_OUTPUT_FIXTURE,
+            PERMISSION_REQUEST_INPUT_FIXTURE,
+            PERMISSION_REQUEST_OUTPUT_FIXTURE,
             PRE_TOOL_USE_INPUT_FIXTURE,
             PRE_TOOL_USE_OUTPUT_FIXTURE,
             SESSION_START_INPUT_FIXTURE,
@@ -615,6 +726,11 @@ mod tests {
                 .expect("serialize post tool use input schema"),
         )
         .expect("parse post tool use input schema");
+        let permission_request: Value = serde_json::from_slice(
+            &schema_json::<PermissionRequestCommandInput>()
+                .expect("serialize permission request input schema"),
+        )
+        .expect("parse permission request input schema");
         let user_prompt_submit: Value = serde_json::from_slice(
             &schema_json::<UserPromptSubmitCommandInput>()
                 .expect("serialize user prompt submit input schema"),
@@ -625,7 +741,13 @@ mod tests {
         )
         .expect("parse stop input schema");
 
-        for schema in [&pre_tool_use, &post_tool_use, &user_prompt_submit, &stop] {
+        for schema in [
+            &pre_tool_use,
+            &permission_request,
+            &post_tool_use,
+            &user_prompt_submit,
+            &stop,
+        ] {
             assert_eq!(schema["properties"]["turn_id"]["type"], "string");
             assert!(
                 schema["required"]