simplify: remove workflow_dispatch/schedule from create-prompt

- Remove workflow_dispatch and schedule event handling from create-prompt
  since agent mode doesn't use the standard prompt generation flow
- Enforce mode compatibility at selection time in the registry instead
  of runtime validation in tag mode
- Add explanatory comment in agent mode about why prompt file is needed
- Update tests to reflect simplified event handling

This reduces code duplication and makes the separation between tag mode
(entity-based events) and agent mode (automation events) clearer.

src/create-prompt/index.ts

@@ -350,24 +350,6 @@ export function prepareContext(
       };
       break;
 
-    case "workflow_dispatch":
-      eventData = {
-        eventName: "workflow_dispatch",
-        isPR: false,
-        ...(baseBranch && { baseBranch }),
-        ...(claudeBranch && { claudeBranch }),
-      };
-      break;
-
-    case "schedule":
-      eventData = {
-        eventName: "schedule",
-        isPR: false,
-        ...(baseBranch && { baseBranch }),
-        ...(claudeBranch && { claudeBranch }),
-      };
-      break;
-
     default:
       throw new Error(`Unsupported event type: ${eventName}`);
   }
@@ -430,18 +412,6 @@ export function getEventTypeAndContext(envVars: PreparedContext): {
           : `pull request event`,
       };
 
-    case "workflow_dispatch":
-      return {
-        eventType: "WORKFLOW_DISPATCH",
-        triggerContext: `workflow dispatch event`,
-      };
-
-    case "schedule":
-      return {
-        eventType: "SCHEDULE",
-        triggerContext: `scheduled automation event`,
-      };
-
     default:
       throw new Error(`Unexpected event type`);
   }

src/create-prompt/types.ts

@@ -88,20 +88,6 @@ type PullRequestEvent = {
   baseBranch?: string;
 };
 
-type WorkflowDispatchEvent = {
-  eventName: "workflow_dispatch";
-  isPR?: false;
-  baseBranch?: string;
-  claudeBranch?: string;
-};
-
-type ScheduleEvent = {
-  eventName: "schedule";
-  isPR?: false;
-  baseBranch?: string;
-  claudeBranch?: string;
-};
-
 // Union type for all possible event types
 export type EventData =
   | PullRequestReviewCommentEvent
@@ -111,9 +97,7 @@ export type EventData =
   | IssueOpenedEvent
   | IssueAssignedEvent
   | IssueLabeledEvent
-  | PullRequestEvent
-  | WorkflowDispatchEvent
-  | ScheduleEvent;
+  | PullRequestEvent;
 
 // Combined type with separate eventData field
 export type PreparedContext = CommonFields & {

src/entrypoints/prepare.ts

@@ -34,7 +34,7 @@ async function run() {
     }
 
     // Step 4: Get mode and check trigger conditions
-    const mode = getMode(context.inputs.mode);
+    const mode = getMode(context.inputs.mode, context);
     const containsTrigger = mode.shouldTrigger(context);
 
     // Set output for action.yml to check

src/modes/agent/index.ts

@@ -53,7 +53,10 @@ export const agentMode: Mode = {
       recursive: true,
     });
 
-    // Write the prompt - either override_prompt, direct_prompt, or a minimal default
+    // Write the prompt file - the base action requires a prompt_file parameter,
+    // so we must create this file even though agent mode typically uses
+    // override_prompt or direct_prompt. If neither is provided, we write
+    // a minimal prompt with just the repository information.
     const promptContent =
       context.inputs.overridePrompt ||
       context.inputs.directPrompt ||

src/modes/registry.ts

@@ -13,6 +13,7 @@
 import type { Mode, ModeName } from "./types";
 import { tagMode } from "./tag";
 import { agentMode } from "./agent";
+import type { ParsedGitHubContext } from "../github/context";
 
 export const DEFAULT_MODE = "tag" as const;
 export const VALID_MODES = ["tag", "agent"] as const;
@@ -27,12 +28,13 @@ const modes = {
 } as const satisfies Record<ModeName, Mode>;
 
 /**
- * Retrieves a mode by name.
+ * Retrieves a mode by name and validates it can handle the event type.
  * @param name The mode name to retrieve
+ * @param context The GitHub context to validate against
  * @returns The requested mode
- * @throws Error if the mode is not found
+ * @throws Error if the mode is not found or cannot handle the event
  */
-export function getMode(name: ModeName): Mode {
+export function getMode(name: ModeName, context: ParsedGitHubContext): Mode {
   const mode = modes[name];
   if (!mode) {
     const validModes = VALID_MODES.join("', '");
@@ -40,6 +42,18 @@ export function getMode(name: ModeName): Mode {
       `Invalid mode '${name}'. Valid modes are: '${validModes}'. Please check your workflow configuration.`,
     );
   }
+
+  // Validate mode can handle the event type
+  if (
+    name === "tag" &&
+    (context.eventName === "workflow_dispatch" ||
+      context.eventName === "schedule")
+  ) {
+    throw new Error(
+      `Tag mode cannot handle ${context.eventName} events. Use 'agent' mode for automation events.`,
+    );
+  }
+
   return mode;
 }
 

src/modes/tag/index.ts

@@ -53,17 +53,6 @@ export const tagMode: Mode = {
   }: ModeOptions): Promise<ModeResult> {
     // Tag mode handles entity-based events (issues, PRs, comments)
 
-    // Validate this mode can handle the event
-    if (
-      context.eventName === "workflow_dispatch" ||
-      context.eventName === "schedule"
-    ) {
-      throw new Error(
-        `Tag mode cannot handle ${context.eventName} events. ` +
-          `Use 'agent' mode for automation events.`,
-      );
-    }
-
     // Check if actor is human
     await checkHumanActor(octokit.rest, context);