refactor: align sticky comment isolation with PR #780 patterns

- Use `<!-- bot: {id} -->` header format instead of `<!-- sticky-job: -->`
- Add extractBotHeader() for cleaner header extraction
- Move header preservation to MCP server instead of modifying sanitizer
- Adopt regex-based matching with hasAnyHeader check and legacy fallback
- Use context.inputs.botId for dynamic bot ID matching
- Revert sanitizer.ts to keep security code untouched

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/github/operations/comment-logic.ts

@@ -1,4 +1,5 @@
 import { GITHUB_SERVER_URL } from "../api/config";
+import { extractBotHeader } from "./comments/common";
 
 export type ExecutionDetails = {
   total_cost_usd?: number;
@@ -79,21 +80,18 @@ export function updateCommentBody(input: CommentUpdateInput): string {
     errorDetails,
   } = input;
 
-  // Preserve sticky-job header if present
-  const stickyHeaderMatch = originalBody.match(
-    /^(<!-- sticky-job: [^\n]+ -->)\n?/,
-  );
-  const stickyHeader = stickyHeaderMatch ? stickyHeaderMatch[1] + "\n" : "";
+  // Extract and preserve bot header for sticky comment identification
+  const botHeader = extractBotHeader(originalBody);
 
   // Extract content from the original comment body
   // First, remove the "Claude Code is working…" or "Claude Code is working..." message
   const workingPattern = /Claude Code is working[…\.]{1,3}(?:\s*<img[^>]*>)?/i;
   let bodyContent = originalBody.replace(workingPattern, "").trim();
 
-  // Remove sticky-job header from body content (it's re-prepended separately)
-  bodyContent = bodyContent
-    .replace(/^<!-- sticky-job: [^\n]+ -->\n?/, "")
-    .trim();
+  // Remove bot header from body content since we'll prepend it at the end
+  if (botHeader) {
+    bodyContent = bodyContent.replace(/^<!--\s*bot:\s*\S+\s*-->\n?/, "").trim();
+  }
 
   // Check if there's a PR link in the content
   let prLinkFromContent = "";
@@ -190,7 +188,7 @@ export function updateCommentBody(input: CommentUpdateInput): string {
   }
 
   // Build the new body with blank line between header and separator
-  let newBody = `${stickyHeader}${header}${links}`;
+  let newBody = `${header}${links}`;
 
   // Add error details if available
   if (actionFailed && errorDetails) {
@@ -210,5 +208,10 @@ export function updateCommentBody(input: CommentUpdateInput): string {
   // Add the cleaned body content
   newBody += bodyContent;
 
+  // Prepend bot header if it existed in the original comment
+  if (botHeader) {
+    return (botHeader + newBody).trim();
+  }
+
   return newBody.trim();
 }

src/github/operations/comments/common.ts

@@ -21,23 +21,20 @@ export function createBranchLink(
   return `\n[View branch](${branchUrl})`;
 }
 
-export function createStickyJobHeader(jobId: string): string {
-  return `<!-- sticky-job: ${jobId} -->`;
-}
-
-export function hasStickyJobHeader(body: string, jobId: string): boolean {
-  return body.includes(createStickyJobHeader(jobId));
-}
-
 export function createCommentBody(
   jobRunLink: string,
   branchLink: string = "",
-  jobId: string = "",
+  botName: string = "",
 ): string {
-  const header = jobId ? `${createStickyJobHeader(jobId)}\n` : "";
+  const header = botName ? `<!-- bot: ${botName} -->\n` : "";
   return `${header}Claude Code is working… ${SPINNER_HTML}
 
 I'll analyze this and get back to you.
 
 ${jobRunLink}${branchLink}`;
 }
+
+export function extractBotHeader(body: string): string {
+  const match = body.match(/^(<!--\s*bot:\s*\S+\s*-->\n?)/);
+  return match?.[1] ?? "";
+}

src/github/operations/comments/create-initial.ts

@@ -6,28 +6,29 @@
  */
 
 import { appendFileSync } from "fs";
-import {
-  createJobRunLink,
-  createCommentBody,
-  hasStickyJobHeader,
-} from "./common";
+import { createJobRunLink, createCommentBody } from "./common";
 import {
   isPullRequestReviewCommentEvent,
   isPullRequestEvent,
   type ParsedGitHubContext,
 } from "../../context";
-import { CLAUDE_APP_BOT_ID } from "../../constants";
 import type { Octokit } from "@octokit/rest";
 
+function escapeRegex(str: string): string {
+  return str.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+}
+
 export async function createInitialComment(
   octokit: Octokit,
   context: ParsedGitHubContext,
 ) {
   const { owner, repo } = context.repository;
-  const jobId = context.inputs.jobId;
+  const botIdentifier = context.inputs.useStickyComment
+    ? context.inputs.jobId
+    : "";
 
   const jobRunLink = createJobRunLink(owner, repo, context.runId);
-  const initialBody = createCommentBody(jobRunLink, "", jobId);
+  const initialBody = createCommentBody(jobRunLink, "", botIdentifier);
 
   try {
     let response;
@@ -37,6 +38,7 @@ export async function createInitialComment(
       context.isPR &&
       isPullRequestEvent(context)
     ) {
+      // Use pagination to fetch all comments (handles PRs with 30+ comments)
       const comments = await octokit.paginate(
         octokit.rest.issues.listComments,
         {
@@ -48,15 +50,41 @@ export async function createInitialComment(
       );
 
       const existingComment = comments.find((comment) => {
-        if (jobId) {
-          return hasStickyJobHeader(comment.body ?? "", jobId);
+        // Must be from the correct bot user
+        const idMatch = comment.user?.id === Number(context.inputs.botId);
+        if (!idMatch) return false;
+
+        if (botIdentifier) {
+          // Check for our hidden header (case-insensitive, whitespace-tolerant)
+          const headerPattern = new RegExp(
+            `<!--\\s*bot:\\s*${escapeRegex(botIdentifier)}\\s*-->`,
+            "i",
+          );
+          const hasOurHeader = headerPattern.test(comment.body || "");
+
+          // Check if comment has ANY bot header
+          const hasAnyHeader = /<!--\s*bot:\s*\S+\s*-->/.test(
+            comment.body || "",
+          );
+
+          // If comment has a header, ONLY match if it's ours
+          if (hasAnyHeader) {
+            return hasOurHeader;
+          }
+
+          // Legacy comments (no header): match if it looks like a Claude comment
+          const isClaudeComment =
+            comment.body?.includes("Claude Code is working") ||
+            comment.body?.includes("View job run");
+
+          return isClaudeComment;
         }
-        // Fallback for backward compat when no jobId is available
-        const idMatch = comment.user?.id === CLAUDE_APP_BOT_ID;
+
+        // Fallback when no botIdentifier: match any Claude-looking comment
         const botNameMatch =
           comment.user?.type === "Bot" &&
           comment.user?.login.toLowerCase().includes("claude");
-        return idMatch || botNameMatch;
+        return botNameMatch;
       });
 
       if (existingComment) {

src/github/operations/comments/update-with-branch.ts

@@ -33,11 +33,10 @@ export async function updateTrackingComment(
     branchLink = createBranchLink(owner, repo, branch);
   }
 
-  const updatedBody = createCommentBody(
-    jobRunLink,
-    branchLink,
-    context.inputs.jobId,
-  );
+  const botIdentifier = context.inputs.useStickyComment
+    ? context.inputs.jobId
+    : "";
+  const updatedBody = createCommentBody(jobRunLink, branchLink, botIdentifier);
 
   // Update the existing comment with the branch link
   try {

src/github/utils/sanitizer.ts

@@ -97,9 +97,4 @@ export function redactGitHubTokens(content: string): string {
 }
 
 export const stripHtmlComments = (content: string) =>
-  content.replace(/<!--[\s\S]*?-->/g, (match) => {
-    if (match.startsWith("<!-- sticky-job:")) {
-      return match;
-    }
-    return "";
-  });
+  content.replace(/<!--[\s\S]*?-->/g, "");

src/mcp/github-comment-server.ts

@@ -5,6 +5,7 @@ import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"
 import { z } from "zod";
 import { GITHUB_API_URL } from "../github/api/config";
 import { Octokit } from "@octokit/rest";
+import { extractBotHeader } from "../github/operations/comments/common";
 import { updateClaudeComment } from "../github/operations/comments/update-claude-comment";
 import { sanitizeContent } from "../github/utils/sanitizer";
 
@@ -55,13 +56,31 @@ server.tool(
       const isPullRequestReviewComment =
         eventName === "pull_request_review_comment";
 
+      // Fetch current comment to preserve the bot header for sticky comment functionality
+      const currentComment = isPullRequestReviewComment
+        ? await octokit.rest.pulls.getReviewComment({
+            owner,
+            repo,
+            comment_id: commentId,
+          })
+        : await octokit.rest.issues.getComment({
+            owner,
+            repo,
+            comment_id: commentId,
+          });
+
+      // Extract bot header if present (e.g., "<!-- bot: claude-code-review -->")
+      const botHeader = extractBotHeader(currentComment.data.body || "");
+
+      // Sanitize then prepend header to preserve sticky comment identification
       const sanitizedBody = sanitizeContent(body);
+      const bodyWithHeader = botHeader + sanitizedBody;
 
       const result = await updateClaudeComment(octokit, {
         owner,
         repo,
         commentId,
-        body: sanitizedBody,
+        body: bodyWithHeader,
         isPullRequestReviewComment,
       });
 

test/comment-logic.test.ts

@@ -444,11 +444,11 @@ describe("updateCommentBody", () => {
     });
   });
 
-  describe("sticky-job header preservation", () => {
-    it("should preserve sticky-job header through comment update", () => {
+  describe("bot header preservation", () => {
+    it("should preserve bot header through comment update", () => {
       const input: CommentUpdateInput = {
         currentBody:
-          "<!-- sticky-job: claude-review -->\nClaude Code is working…\n\nI'll analyze this and get back to you.\n\n[View job run](https://github.com/owner/repo/actions/runs/123)",
+          "<!-- bot: claude-review -->\nClaude Code is working…\n\nI'll analyze this and get back to you.\n\n[View job run](https://github.com/owner/repo/actions/runs/123)",
         actionFailed: false,
         executionDetails: { duration_ms: 30000 },
         jobUrl: "https://github.com/owner/repo/actions/runs/123",
@@ -456,11 +456,25 @@ describe("updateCommentBody", () => {
       };
 
       const result = updateCommentBody(input);
-      expect(result).toStartWith("<!-- sticky-job: claude-review -->\n");
+      expect(result).toStartWith("<!-- bot: claude-review -->\n");
       expect(result).toContain("Claude finished @test-user's task");
     });
 
-    it("should work without sticky-job header", () => {
+    it("should preserve bot header with different bot names", () => {
+      const input: CommentUpdateInput = {
+        currentBody:
+          "<!-- bot: claude-docs-review -->\nClaude Code is working...",
+        actionFailed: false,
+        executionDetails: { duration_ms: 30000 },
+        jobUrl: "https://github.com/owner/repo/actions/runs/123",
+        triggerUsername: "user",
+      };
+
+      const result = updateCommentBody(input);
+      expect(result).toStartWith("<!-- bot: claude-docs-review -->");
+    });
+
+    it("should work without bot header", () => {
       const input: CommentUpdateInput = {
         currentBody:
           "Claude Code is working…\n\nI'll analyze this and get back to you.",
@@ -471,8 +485,37 @@ describe("updateCommentBody", () => {
       };
 
       const result = updateCommentBody(input);
-      expect(result).not.toContain("sticky-job");
+      expect(result).not.toContain("<!-- bot:");
       expect(result).toContain("Claude finished @test-user's task");
     });
+
+    it("should preserve bot header when action fails", () => {
+      const input: CommentUpdateInput = {
+        currentBody: "<!-- bot: claude-review -->\nClaude Code is working…",
+        actionFailed: true,
+        executionDetails: { duration_ms: 10000 },
+        jobUrl: "https://github.com/owner/repo/actions/runs/123",
+        errorDetails: "Something went wrong",
+      };
+
+      const result = updateCommentBody(input);
+      expect(result).toStartWith("<!-- bot: claude-review -->");
+      expect(result).toContain("**Claude encountered an error after 10s**");
+    });
+
+    it("should not preserve bot header if not at start of comment", () => {
+      const input: CommentUpdateInput = {
+        currentBody:
+          "Some text before\n<!-- bot: claude-review -->\nClaude Code is working…",
+        actionFailed: false,
+        executionDetails: { duration_ms: 5000 },
+        jobUrl: "https://github.com/owner/repo/actions/runs/123",
+        triggerUsername: "testuser",
+      };
+
+      const result = updateCommentBody(input);
+      expect(result.startsWith("<!-- bot:")).toBe(false);
+      expect(result).toContain("**Claude finished");
+    });
   });
 });

test/sanitizer.test.ts

@@ -361,26 +361,7 @@ describe("stripHtmlComments (legacy)", () => {
     );
   });
 
-  it("should preserve sticky-job headers", () => {
-    expect(stripHtmlComments("<!-- sticky-job: claude-review -->Text")).toBe(
-      "<!-- sticky-job: claude-review -->Text",
-    );
-  });
-
-  it("should preserve sticky-job headers while stripping other comments", () => {
-    const input =
-      "<!-- sticky-job: my-job -->\n<!-- hidden prompt -->Hello World";
-    expect(stripHtmlComments(input)).toBe(
-      "<!-- sticky-job: my-job -->\nHello World",
-    );
-  });
-});
-
-describe("sanitizeContent with sticky-job headers", () => {
-  it("should preserve sticky-job headers through full sanitization", () => {
-    const content = "<!-- sticky-job: claude-review -->\nSome response text";
-    const sanitized = sanitizeContent(content);
-    expect(sanitized).toContain("<!-- sticky-job: claude-review -->");
-    expect(sanitized).toContain("Some response text");
+  it("should strip all HTML comments including bot headers", () => {
+    expect(stripHtmlComments("<!-- bot: claude-review -->Text")).toBe("Text");
   });
 });