**3 issues found** across 3 files Confidence score: **3/5** - There is concrete user-facing risk: action events are only emitted for local executions, so the new `on("action")` API is silently non-functional in API mode (`packages/core/lib/v3/v3.ts`). - Self-heal retry failures/timeouts can return/throw without emitting a terminal error action event, leaving subscribers with a started action and no terminal state (`packages/core/lib/v3/handlers/actHandler.ts`). - Overall risk is moderate due to medium-severity eventing gaps that can break consumers’ expectations about action lifecycle notifications. - Pay close attention to `packages/core/lib/v3/handlers/actHandler.ts`, `packages/core/lib/v3/v3.ts`, `packages/core/lib/v3/types/public/methods.ts` - action event emission and schema consistency.

Prompt for AI agents (all issues)

```text Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately. P2: Self-heal retry failures and timeouts return/throw without emitting an `error` action event, leaving a started action without a terminal event for subscribers. P2: Action events are only emitted for local executions; API/BROWSERBASE `act()` calls bypass ActHandler and StagehandAPIClient has no event bus. This makes the new `on("action")` API silently non-functional in API mode, causing inconsistent behavior across environments. P3: The `url` field is defined in the `ActionEvent` interface but is never populated in the implementation. Either remove this unused field, or populate it with `page.url()` when emitting action events to provide the promised functionality. ```

Architecture diagram

```mermaid sequenceDiagram participant User as User Code participant SH as Stagehand (V3) participant Bus as internal: bus (EventEmitter) participant AH as ActHandler participant PW as Playwright / Browser Note over User, Bus: Setup Phase User->>SH: NEW: on("action", callback) SH->>Bus: Register listener Note over User, PW: Execution Phase User->>SH: act(description) SH->>AH: execute action logic AH->>Bus: NEW: emit "action" (phase: "start") Bus-->>User: Trigger callback with ActionEvent AH->>PW: performUnderstudyMethod() alt Action Success PW-->>AH: success AH->>Bus: NEW: emit "action" (phase: "complete") Bus-->>User: Trigger callback else Action Failure PW-->>AH: error (e.g. selector not found) AH->>Bus: NEW: emit "action" (phase: "error", error: msg) Bus-->>User: Trigger callback opt Self-Heal Enabled AH->>AH: Request fallback selector via LLM Note over AH, Bus: CHANGED: Retry flow also emits events AH->>Bus: NEW: emit "action" (phase: "start") [retry] AH->>PW: performUnderstudyMethod() with new selector alt Retry Success PW-->>AH: success AH->>Bus: NEW: emit "action" (phase: "complete") else Retry Failure PW-->>AH: error Note right of AH: Final failure returned to Stagehand end end end AH-->>SH: Return ActResult SH-->>User: Result (success/failure) ```

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