feat: add agent mode for automation scenarios (#337)

* feat: add agent mode for automation scenarios

- Add agent mode that always triggers without checking for mentions
- Implement Mode interface with support for mode-specific tool configuration
- Add getAllowedTools() and getDisallowedTools() methods to Mode interface
- Simplify tests by combining related test cases
- Update documentation and examples to include agent mode
- Fix TypeScript imports to prevent circular dependencies

Agent mode is designed for automation and workflow_dispatch scenarios
where Claude should always run without requiring trigger phrases.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Minor update to readme (from @main to @beta)

* Since workflow_dispatch isn't in the base action, update the examples accordingly

* minor formatting issue

* Update to say beta instead of main

* Fix missed tracking comment to be false

---------

Co-authored-by: km-anthropic <km-anthropic@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>

src/modes/agent/index.ts

@@ -0,0 +1,42 @@
+import type { Mode } from "../types";
+
+/**
+ * Agent mode implementation.
+ *
+ * This mode is designed for automation and workflow_dispatch scenarios.
+ * It always triggers (no checking), allows highly flexible configurations,
+ * and works well with override_prompt for custom workflows.
+ *
+ * In the future, this mode could restrict certain tools for safety in automation contexts,
+ * e.g., disallowing WebSearch or limiting file system operations.
+ */
+export const agentMode: Mode = {
+  name: "agent",
+  description: "Automation mode that always runs without trigger checking",
+
+  shouldTrigger() {
+    return true;
+  },
+
+  prepareContext(context, data) {
+    return {
+      mode: "agent",
+      githubContext: context,
+      commentId: data?.commentId,
+      baseBranch: data?.baseBranch,
+      claudeBranch: data?.claudeBranch,
+    };
+  },
+
+  getAllowedTools() {
+    return [];
+  },
+
+  getDisallowedTools() {
+    return [];
+  },
+
+  shouldCreateTrackingComment() {
+    return false;
+  },
+};

src/modes/registry.ts

@@ -5,17 +5,17 @@
  *
  * To add a new mode:
  * 1. Add the mode name to VALID_MODES below
- * 2. Create the mode implementation in a new directory (e.g., src/modes/review/)
+ * 2. Create the mode implementation in a new directory (e.g., src/modes/new-mode/)
  * 3. Import and add it to the modes object below
  * 4. Update action.yml description to mention the new mode
  */
 
-import type { Mode } from "./types";
-import { tagMode } from "./tag/index";
+import type { Mode, ModeName } from "./types";
+import { tagMode } from "./tag";
+import { agentMode } from "./agent";
 
 export const DEFAULT_MODE = "tag" as const;
-export const VALID_MODES = ["tag"] as const;
-export type ModeName = (typeof VALID_MODES)[number];
+export const VALID_MODES = ["tag", "agent"] as const;
 
 /**
  * All available modes.
@@ -23,6 +23,7 @@ export type ModeName = (typeof VALID_MODES)[number];
  */
 const modes = {
   tag: tagMode,
+  agent: agentMode,
 } as const satisfies Record<ModeName, Mode>;
 
 /**

src/modes/types.ts

@@ -1,5 +1,6 @@
 import type { ParsedGitHubContext } from "../github/context";
-import type { ModeName } from "./registry";
+
+export type ModeName = "tag" | "agent";
 
 export type ModeContext = {
   mode: ModeName;
@@ -20,9 +21,9 @@ export type ModeData = {
  * Each mode defines its own behavior for trigger detection, prompt generation,
  * and tracking comment creation.
  *
- * Future modes might include:
- * - 'review': Optimized for code reviews without tracking comments
- * - 'freeform': For automation with no trigger checking
+ * Current modes include:
+ * - 'tag': Traditional implementation triggered by mentions/assignments
+ * - 'agent': For automation with no trigger checking
  */
 export type Mode = {
   name: ModeName;
@@ -39,13 +40,12 @@ export type Mode = {
   prepareContext(context: ParsedGitHubContext, data?: ModeData): ModeContext;
 
   /**
-   * Returns additional tools that should be allowed for this mode
-   * (base GitHub tools are always included)
+   * Returns the list of tools that should be allowed for this mode
    */
   getAllowedTools(): string[];
 
   /**
-   * Returns tools that should be disallowed for this mode
+   * Returns the list of tools that should be disallowed for this mode
    */
   getDisallowedTools(): string[];