diff --git a/docs/custom-automations.md b/docs/custom-automations.md
index fabb52f..15318f3 100644
--- a/docs/custom-automations.md
+++ b/docs/custom-automations.md
@@ -54,6 +54,11 @@ on:
   pull_request:
     types: [opened, synchronize]
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   review-by-author:
     if: |
diff --git a/docs/solutions.md b/docs/solutions.md
index 2315064..4185c70 100644
--- a/docs/solutions.md
+++ b/docs/solutions.md
@@ -27,6 +27,11 @@ on:
   pull_request:
     types: [opened, synchronize]
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   review:
     runs-on: ubuntu-latest
@@ -81,6 +86,11 @@ on:
   pull_request:
     types: [opened, synchronize, ready_for_review, reopened]
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   review:
     runs-on: ubuntu-latest
@@ -145,6 +155,11 @@ on:
       - "src/api/**"
       - "config/security.yml"
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   security-review:
     runs-on: ubuntu-latest
@@ -202,6 +217,11 @@ on:
   pull_request:
     types: [opened, synchronize]
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   external-review:
     if: github.event.pull_request.author_association == 'FIRST_TIME_CONTRIBUTOR'
@@ -260,6 +280,11 @@ on:
   pull_request:
     types: [opened, synchronize]
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   checklist-review:
     runs-on: ubuntu-latest
@@ -448,6 +473,11 @@ on:
       - "src/api/**/*.ts"
       - "src/routes/**/*.ts"
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   doc-sync:
     runs-on: ubuntu-latest
@@ -504,6 +534,11 @@ on:
   pull_request:
     types: [opened, synchronize]
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   security:
     runs-on: ubuntu-latest
diff --git a/examples/pr-review-comprehensive.yml b/examples/pr-review-comprehensive.yml
index 3002b4d..3ddc0b5 100644
--- a/examples/pr-review-comprehensive.yml
+++ b/examples/pr-review-comprehensive.yml
@@ -7,6 +7,11 @@ on:
   pull_request:
     types: [opened, synchronize, ready_for_review, reopened]
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   review-with-tracking:
     runs-on: ubuntu-latest
diff --git a/examples/pr-review-filtered-authors.yml b/examples/pr-review-filtered-authors.yml
index 0032720..26d3d93 100644
--- a/examples/pr-review-filtered-authors.yml
+++ b/examples/pr-review-filtered-authors.yml
@@ -4,6 +4,11 @@ on:
   pull_request:
     types: [opened, synchronize]
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   review-by-author:
     # Only run for PRs from specific authors
diff --git a/examples/pr-review-filtered-paths.yml b/examples/pr-review-filtered-paths.yml
index f465a4b..932d6f5 100644
--- a/examples/pr-review-filtered-paths.yml
+++ b/examples/pr-review-filtered-paths.yml
@@ -10,6 +10,11 @@ on:
       - "api/**/*.py"
       # You can add more specific patterns as needed
 
+# Prevent multiple reviews from running simultaneously on the same PR
+concurrency:
+  group: claude-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   claude-review-paths:
     runs-on: ubuntu-latest
diff --git a/src/github/validation/actor.ts b/src/github/validation/actor.ts
index 2599254..36be2ff 100644
--- a/src/github/validation/actor.ts
+++ b/src/github/validation/actor.ts
@@ -6,11 +6,11 @@
  */
 
 import type { Octokit } from "@octokit/rest";
-import type { ParsedGitHubContext } from "../context";
+import type { GitHubContext } from "../context";
 
 export async function checkHumanActor(
   octokit: Octokit,
-  githubContext: ParsedGitHubContext,
+  githubContext: GitHubContext,
 ) {
   // Fetch user information from GitHub API
   const { data: userData } = await octokit.users.getByUsername({
diff --git a/src/modes/agent/index.ts b/src/modes/agent/index.ts
index 4bcd4aa..864f4fe 100644
--- a/src/modes/agent/index.ts
+++ b/src/modes/agent/index.ts
@@ -5,6 +5,7 @@ import type { PreparedContext } from "../../create-prompt/types";
 import { prepareMcpConfig } from "../../mcp/install-mcp-server";
 import { parseAllowedTools } from "./parse-tools";
 import { configureGitAuth } from "../../github/operations/git-config";
+import { checkHumanActor } from "../../github/validation/actor";
 import type { GitHubContext } from "../../github/context";
 import { isEntityContext } from "../../github/context";
 
@@ -77,7 +78,14 @@ export const agentMode: Mode = {
     return false;
   },
 
-  async prepare({ context, githubToken }: ModeOptions): Promise<ModeResult> {
+  async prepare({
+    context,
+    octokit,
+    githubToken,
+  }: ModeOptions): Promise<ModeResult> {
+    // Check if actor is human (prevents bot-triggered loops)
+    await checkHumanActor(octokit.rest, context);
+
     // Configure git authentication for agent mode (same as tag mode)
     if (!context.inputs.useCommitSigning) {
       // Use bot_id and bot_name from inputs directly
diff --git a/test/modes/agent.test.ts b/test/modes/agent.test.ts
index 16e3796..25bf844 100644
--- a/test/modes/agent.test.ts
+++ b/test/modes/agent.test.ts
@@ -145,12 +145,12 @@ describe("Agent Mode", () => {
         users: {
           getAuthenticated: mock(() =>
             Promise.resolve({
-              data: { login: "test-user", id: 12345 },
+              data: { login: "test-user", id: 12345, type: "User" },
             }),
           ),
           getByUsername: mock(() =>
             Promise.resolve({
-              data: { login: "test-user", id: 12345 },
+              data: { login: "test-user", id: 12345, type: "User" },
             }),
           ),
         },
@@ -187,6 +187,65 @@ describe("Agent Mode", () => {
       process.env.GITHUB_REF_NAME = originalRefName;
   });
 
+  test("prepare method rejects bot actors without allowed_bots", async () => {
+    const contextWithPrompts = createMockAutomationContext({
+      eventName: "workflow_dispatch",
+    });
+    contextWithPrompts.actor = "claude[bot]";
+    contextWithPrompts.inputs.allowedBots = "";
+
+    const mockOctokit = {
+      rest: {
+        users: {
+          getByUsername: mock(() =>
+            Promise.resolve({
+              data: { login: "claude[bot]", id: 12345, type: "Bot" },
+            }),
+          ),
+        },
+      },
+    } as any;
+
+    await expect(
+      agentMode.prepare({
+        context: contextWithPrompts,
+        octokit: mockOctokit,
+        githubToken: "test-token",
+      }),
+    ).rejects.toThrow(
+      "Workflow initiated by non-human actor: claude (type: Bot)",
+    );
+  });
+
+  test("prepare method allows bot actors when in allowed_bots list", async () => {
+    const contextWithPrompts = createMockAutomationContext({
+      eventName: "workflow_dispatch",
+    });
+    contextWithPrompts.actor = "dependabot[bot]";
+    contextWithPrompts.inputs.allowedBots = "dependabot";
+
+    const mockOctokit = {
+      rest: {
+        users: {
+          getByUsername: mock(() =>
+            Promise.resolve({
+              data: { login: "dependabot[bot]", id: 12345, type: "Bot" },
+            }),
+          ),
+        },
+      },
+    } as any;
+
+    // Should not throw - bot is in allowed list
+    await expect(
+      agentMode.prepare({
+        context: contextWithPrompts,
+        octokit: mockOctokit,
+        githubToken: "test-token",
+      }),
+    ).resolves.toBeDefined();
+  });
+
   test("prepare method creates prompt file with correct content", async () => {
     const contextWithPrompts = createMockAutomationContext({
       eventName: "workflow_dispatch",
@@ -199,12 +258,12 @@ describe("Agent Mode", () => {
         users: {
           getAuthenticated: mock(() =>
             Promise.resolve({
-              data: { login: "test-user", id: 12345 },
+              data: { login: "test-user", id: 12345, type: "User" },
             }),
           ),
           getByUsername: mock(() =>
             Promise.resolve({
-              data: { login: "test-user", id: 12345 },
+              data: { login: "test-user", id: 12345, type: "User" },
             }),
           ),
         },