feat: add flexible bot access control with allowed_bots option (#117)

* feat: skip permission check for GitHub App bot users

GitHub Apps (users ending with [bot]) now bypass permission checks
as they have their own authorization mechanism.

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

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

* feat: add allow_bot_users option to control bot user access

- Add allow_bot_users input parameter (default: false)
- Modify checkHumanActor to optionally allow bot users
- Add comprehensive tests for bot user handling
- Improve security by blocking bot users by default

This change prevents potential prompt injection attacks from bot users
while providing flexibility for trusted bot integrations.

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

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

* docs: mark bot user support feature as completed in roadmap

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

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

* refactor: move allowedBots parameter to context object

Move allowedBots from function parameter to context.inputs to maintain
consistency with other input handling throughout the codebase.

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

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

* docs: update README for bot user support feature

Add documentation for the new allowed_bots parameter that enables
bot users to trigger Claude actions with granular control.

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

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

* fix: add missing allowedBots property in permissions test

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

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

* fix: update bot name format to include [bot] suffix in tests and docs

- Update test cases to use correct bot actor names with [bot] suffix
- Update documentation example to show correct bot name format
- Align with GitHub's actual bot naming convention

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

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

* feat: normalize bot names for allowed_bots validation

- Strip [bot] suffix from both actor names and allowed bot list for comparison
- Allow both "dependabot" and "dependabot[bot]" formats in allowed_bots input
- Display normalized bot names in error messages for consistency
- Add comprehensive test coverage for both naming formats

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

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

---------

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

src/github/context.ts

@@ -77,6 +77,7 @@ type BaseContext = {
     useStickyComment: boolean;
     additionalPermissions: Map<string, string>;
     useCommitSigning: boolean;
+    allowedBots: string;
   };
 };
 
@@ -136,6 +137,7 @@ export function parseGitHubContext(): GitHubContext {
         process.env.ADDITIONAL_PERMISSIONS ?? "",
       ),
       useCommitSigning: process.env.USE_COMMIT_SIGNING === "true",
+      allowedBots: process.env.ALLOWED_BOTS ?? "",
     },
   };
 

src/github/validation/actor.ts

@@ -21,9 +21,42 @@ export async function checkHumanActor(
 
   console.log(`Actor type: ${actorType}`);
 
+  // Check bot permissions if actor is not a User
   if (actorType !== "User") {
+    const allowedBots = githubContext.inputs.allowedBots;
+
+    // Check if all bots are allowed
+    if (allowedBots.trim() === "*") {
+      console.log(
+        `All bots are allowed, skipping human actor check for: ${githubContext.actor}`,
+      );
+      return;
+    }
+
+    // Parse allowed bots list
+    const allowedBotsList = allowedBots
+      .split(",")
+      .map((bot) =>
+        bot
+          .trim()
+          .toLowerCase()
+          .replace(/\[bot\]$/, ""),
+      )
+      .filter((bot) => bot.length > 0);
+
+    const botName = githubContext.actor.toLowerCase().replace(/\[bot\]$/, "");
+
+    // Check if specific bot is allowed
+    if (allowedBotsList.includes(botName)) {
+      console.log(
+        `Bot ${botName} is in allowed list, skipping human actor check`,
+      );
+      return;
+    }
+
+    // Bot not allowed
     throw new Error(
-      `Workflow initiated by non-human actor: ${githubContext.actor} (type: ${actorType}).`,
+      `Workflow initiated by non-human actor: ${botName} (type: ${actorType}). Add bot to allowed_bots list or use '*' to allow all bots.`,
     );
   }
 

src/github/validation/permissions.ts

@@ -17,6 +17,12 @@ export async function checkWritePermissions(
   try {
     core.info(`Checking permissions for actor: ${actor}`);
 
+    // Check if the actor is a GitHub App (bot user)
+    if (actor.endsWith("[bot]")) {
+      core.info(`Actor is a GitHub App: ${actor}`);
+      return true;
+    }
+
     // Check permissions directly using the permission endpoint
     const response = await octokit.repos.getCollaboratorPermissionLevel({
       owner: repository.owner,