Determinstically set up PR branch

entry

@@ -39511,7 +39511,7 @@ async function reportProgress({ body }) {
   }
   const issueNumber = ctx.payload.event.issue_number;
   if (issueNumber === void 0) {
-    throw new Error("cannot create progress comment: no issue_number found in the payload event");
+    return void 0;
   }
   const result = await ctx.octokit.rest.issues.createComment({
     owner: ctx.owner,
@@ -39679,6 +39679,12 @@ var init_comment = __esm({
       parameters: ReportProgress,
       execute: contextualize(async ({ body }) => {
         const result = await reportProgress({ body });
+        if (!result) {
+          return {
+            success: false,
+            message: "cannot create progress comment: no issue_number found in the payload event. this may occur for workflow_dispatch events or when there is no associated issue/PR. if you need to comment on a specific issue or PR, use create_issue_comment with an explicit issueNumber."
+          };
+        }
         return {
           success: true,
           ...result
@@ -124233,7 +124239,8 @@ function $(cmd, args3, options) {
   const result = spawnSync4(cmd, args3, {
     stdio: ["ignore", "pipe", "pipe"],
     encoding,
-    cwd: options?.cwd
+    cwd: options?.cwd,
+    env: options?.env ? { ...process.env, ...options.env } : void 0
   });
   const stdout = result.stdout ?? "";
   const stderr = result.stderr ?? "";
@@ -124719,6 +124726,7 @@ var PullRequestTool = tool({
 // mcp/prInfo.ts
 init_out4();
 init_cli();
+init_github();
 init_shared3();
 var PullRequestInfo = type({
   pull_number: type.number.describe("The pull request number to fetch")
@@ -124743,7 +124751,10 @@ var PullRequestInfoTool = tool({
     const headRepo = data.head.repo.full_name;
     const isFork = headRepo !== baseRepo;
     log.info(`Checking out PR #${pull_number} using gh pr checkout`);
-    $("gh", ["pr", "checkout", pull_number.toString()]);
+    const token = getGitHubInstallationToken();
+    $("gh", ["pr", "checkout", pull_number.toString()], {
+      env: { GH_TOKEN: token }
+    });
     log.info(`Fetching base branch: origin/${baseBranch}`);
     $("git", ["fetch", "origin", baseBranch, "--depth=20"]);
     const currentBranch = $("git", ["rev-parse", "--abbrev-ref", "HEAD"], { log: false }).trim();
@@ -125103,6 +125114,7 @@ init_github();
 // utils/setup.ts
 import { execSync } from "node:child_process";
 init_cli();
+init_github();
 function setupGitConfig() {
   const repoDir = process.cwd();
   log.info("\u{1F527} Setting up git configuration...");
@@ -125150,9 +125162,10 @@ function setupGitBranch(payload) {
     const prNumber = payload.event.issue_number;
     try {
       log.debug(`Checking out PR #${prNumber} using gh pr checkout`);
-      execSync(`gh pr checkout ${prNumber}`, {
+      const token = getGitHubInstallationToken();
+      $("gh", ["pr", "checkout", prNumber.toString()], {
         cwd: repoDir,
-        stdio: "pipe"
+        env: { GH_TOKEN: token }
       });
       log.info(`\u2713 Successfully checked out PR branch: ${branch}`);
       return;

external.ts

@@ -193,7 +193,6 @@ interface FixReviewEvent extends BasePayloadEvent {
   review_id: number;
   /** "all" to fix all comments, or specific comment IDs to fix */
   comment_ids: number[] | "all";
-  branch: string;
 }
 
 interface UnknownEvent extends BasePayloadEvent {

mcp/comment.ts

@@ -177,7 +177,8 @@ export async function reportProgress({ body }: { body: string }): Promise<
   // no existing comment - create one
   const issueNumber = ctx.payload.event.issue_number;
   if (issueNumber === undefined) {
-    throw new Error("cannot create progress comment: no issue_number found in the payload event");
+    // cannot create comment without issue_number (e.g., workflow_dispatch events)
+    return undefined;
   }
 
   const result = await ctx.octokit.rest.issues.createComment({
@@ -207,6 +208,16 @@ export const ReportProgressTool = tool({
   execute: contextualize(async ({ body }) => {
     const result = await reportProgress({ body });
 
+    if (!result) {
+      // gracefully handle case where no comment can be created
+      // this happens for workflow_dispatch events or when there's no associated issue/PR
+      return {
+        success: false,
+        message:
+          "cannot create progress comment: no issue_number found in the payload event. this may occur for workflow_dispatch events or when there is no associated issue/PR. if you need to comment on a specific issue or PR, use create_issue_comment with an explicit issueNumber.",
+      };
+    }
+
     return {
       success: true,
       ...result,

mcp/prInfo.ts

@@ -1,6 +1,4 @@
 import { type } from "arktype";
-import { log } from "../utils/cli.ts";
-import { $ } from "../utils/shell.ts";
 import { contextualize, tool } from "./shared.ts";
 
 export const PullRequestInfo = type({
@@ -9,7 +7,8 @@ export const PullRequestInfo = type({
 
 export const PullRequestInfoTool = tool({
   name: "get_pull_request",
-  description: "Retrieve PR information. Automatically fetches and checks out the PR branch.",
+  description:
+    "Retrieve PR information (metadata only). PR branch is already checked out during setup.",
   parameters: PullRequestInfo,
   execute: contextualize(async ({ pull_number }, ctx) => {
     const pr = await ctx.octokit.rest.pulls.get({
@@ -20,38 +19,8 @@ export const PullRequestInfoTool = tool({
 
     const data = pr.data;
 
-    const baseBranch = data.base.ref;
-    const headBranch = data.head.ref;
-
-    if (!baseBranch) {
-      throw new Error(`Base branch not found for PR #${pull_number}`);
-    }
-
     // detect fork PRs - head repo differs from base repo
-    const baseRepo = data.base.repo.full_name;
-    const headRepo = data.head.repo.full_name;
-    const isFork = headRepo !== baseRepo;
-
-    // use gh pr checkout which handles fork PRs automatically
-    // it adds the fork as a remote if needed and checks out the PR branch
-    log.info(`Checking out PR #${pull_number} using gh pr checkout`);
-    $("gh", ["pr", "checkout", pull_number.toString()]);
-
-    // fetch base branch for diff comparison
-    log.info(`Fetching base branch: origin/${baseBranch}`);
-    $("git", ["fetch", "origin", baseBranch, "--depth=20"]);
-
-    // get current git status for summary
-    const currentBranch = $("git", ["rev-parse", "--abbrev-ref", "HEAD"], { log: false }).trim();
-    const currentSha = $("git", ["rev-parse", "HEAD"], { log: false }).trim();
-    const baseSha = $("git", ["rev-parse", `origin/${baseBranch}`], { log: false }).trim();
-
-    // build summary
-    const summary = `PR branch has been fetched and checked out:
-- Base branch: \`origin/${baseBranch}\` (${baseSha.substring(0, 7)})
-- PR branch: \`${headBranch}\` (checked out locally, ${currentSha.substring(0, 7)})
-- Current branch: \`${currentBranch}\`
-- View diff: \`git diff origin/${baseBranch}...HEAD\``;
+    const isFork = data.head.repo.full_name !== data.base.repo.full_name;
 
     return {
       number: data.number,
@@ -60,10 +29,9 @@ export const PullRequestInfoTool = tool({
       state: data.state,
       draft: data.draft,
       merged: data.merged,
-      base: baseBranch,
-      head: headBranch,
+      base: data.base.ref,
+      head: data.head.ref,
       isFork,
-      summary,
     };
   }),
 });

utils/setup.ts

@@ -2,7 +2,7 @@ import { execSync } from "node:child_process";
 import { existsSync, rmSync } from "node:fs";
 import type { Payload } from "../external.ts";
 import { log } from "./cli.ts";
-import type { RepoContext } from "./github.ts";
+import { getGitHubInstallationToken, type RepoContext } from "./github.ts";
 import { $ } from "./shell.ts";
 
 export interface SetupOptions {
@@ -95,62 +95,28 @@ export function setupGitAuth(ctx: {
 }
 
 /**
- * Setup git branch based on payload event context
- * Automatically checks out the appropriate branch before agent execution
+ * Setup git branch based on payload event context.
+ * For PR events, uses `gh pr checkout` which handles fork PRs automatically.
+ * For non-PR events, stays on the default branch.
  */
 export function setupGitBranch(payload: Payload): void {
-  const branch = payload.event.branch;
-  const repoDir = process.cwd();
-
-  if (!branch) {
-    log.debug("No branch specified in payload, using default branch");
+  // only checkout for PR events - use issue_number directly (no dependency on branch field)
+  if (payload.event.is_pr !== true || !payload.event.issue_number) {
+    log.debug("Not a PR event, staying on default branch");
     return;
   }
 
-  log.info(`🌿 Setting up git branch: ${branch}`);
+  const prNumber = payload.event.issue_number;
+  const repoDir = process.cwd();
 
-  // if this is a PR-related event, use gh pr checkout which handles fork PRs automatically
-  if (payload.event.is_pr === true && payload.event.issue_number) {
-    const prNumber = payload.event.issue_number;
-    try {
-      // gh pr checkout handles fork PRs by setting up remotes automatically
-      log.debug(`Checking out PR #${prNumber} using gh pr checkout`);
-      execSync(`gh pr checkout ${prNumber}`, {
-        cwd: repoDir,
-        stdio: "pipe",
-      });
+  log.info(`🌿 Checking out PR #${prNumber}...`);
 
-      log.info(`✓ Successfully checked out PR branch: ${branch}`);
-      return;
-    } catch (error) {
-      // if gh pr checkout fails, fall back to branch name fetch
-      log.debug(
-        `gh pr checkout failed, falling back to branch name fetch: ${error instanceof Error ? error.message : String(error)}`
-      );
-    }
-  }
+  // gh pr checkout handles fork PRs by setting up remotes automatically
+  const token = getGitHubInstallationToken();
+  $("gh", ["pr", "checkout", prNumber.toString()], {
+    cwd: repoDir,
+    env: { GH_TOKEN: token },
+  });
 
-  // fallback: fetch by branch name (for non-PR contexts or if PR ref fetch failed)
-  try {
-    log.debug(`Fetching branch from origin: ${branch}`);
-    execSync(`git fetch origin ${branch}`, {
-      cwd: repoDir,
-      stdio: "pipe",
-    });
-
-    // checkout the branch, creating local tracking branch
-    log.debug(`Checking out branch: ${branch}`);
-    execSync(`git checkout -B ${branch} origin/${branch}`, {
-      cwd: repoDir,
-      stdio: "pipe",
-    });
-
-    log.info(`✓ Successfully checked out branch: ${branch}`);
-  } catch (error) {
-    // if git operations fail, log warning but don't fail the action
-    // the agent might still be able to work with the default branch
-    log.warning(
-      `Failed to checkout branch ${branch}: ${error instanceof Error ? error.message : String(error)}`
-    );
-  }
+  log.info(`✓ Successfully checked out PR #${prNumber}`);
 }

utils/shell.ts

@@ -14,6 +14,7 @@ interface ShellOptions {
     | "ucs2"
     | "utf16le";
   log?: boolean;
+  env?: Record<string, string>;
   onError?: (result: { status: number; stdout: string; stderr: string }) => void;
 }
 
@@ -36,6 +37,7 @@ export function $(cmd: string, args: string[], options?: ShellOptions): string {
     stdio: ["ignore", "pipe", "pipe"],
     encoding,
     cwd: options?.cwd,
+    env: options?.env ? { ...process.env, ...options.env } : undefined,
   });
 
   const stdout = result.stdout ?? "";