feat(server): cache getPullRequestStatus with TTL and in-flight dedup

Adds @isaacs/ttlcache to avoid repeated gh CLI calls for the same
working directory. Concurrent lookups for the same cwd share a single
in-flight promise. Cache expires after 30s by default.

package-lock.json

@@ -35318,6 +35318,7 @@
         "@deepgram/sdk": "^3.4.0",
         "@getpaseo/highlight": "0.1.37",
         "@getpaseo/relay": "0.1.37",
+        "@isaacs/ttlcache": "^2.1.4",
         "@modelcontextprotocol/sdk": "^1.20.1",
         "@opencode-ai/sdk": "1.2.6",
         "@sctg/sentencepiece-js": "^1.1.0",
@@ -35360,6 +35361,15 @@
         "vitest": "^3.2.4"
       }
     },
+    "packages/server/node_modules/@isaacs/ttlcache": {
+      "version": "2.1.4",
+      "resolved": "https://registry.npmjs.org/@isaacs/ttlcache/-/ttlcache-2.1.4.tgz",
+      "integrity": "sha512-7kMz0BJpMvgAMkyglums7B2vtrn5g0a0am77JY0GjkZZNetOBCFn7AG7gKCwT0QPiXyxW7YIQSgtARknUEOcxQ==",
+      "license": "BlueOak-1.0.0",
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "packages/server/node_modules/@modelcontextprotocol/sdk": {
       "version": "1.20.1",
       "resolved": "https://registry.npmjs.org/@modelcontextprotocol/sdk/-/sdk-1.20.1.tgz",

packages/server/package.json

@@ -65,6 +65,7 @@
     "@deepgram/sdk": "^3.4.0",
     "@getpaseo/highlight": "0.1.37",
     "@getpaseo/relay": "0.1.37",
+    "@isaacs/ttlcache": "^2.1.4",
     "@modelcontextprotocol/sdk": "^1.20.1",
     "@opencode-ai/sdk": "1.2.6",
     "@sctg/sentencepiece-js": "^1.1.0",

packages/server/src/utils/checkout-git.test.ts

@@ -1,9 +1,19 @@
 import { describe, it, expect, beforeEach, afterEach } from "vitest";
 import { execSync } from "child_process";
-import { mkdtempSync, rmSync, writeFileSync, realpathSync, mkdirSync, symlinkSync } from "fs";
+import {
+  mkdtempSync,
+  rmSync,
+  writeFileSync,
+  readFileSync,
+  realpathSync,
+  mkdirSync,
+  symlinkSync,
+} from "fs";
 import { join } from "path";
 import { tmpdir } from "os";
 import {
+  __resetPullRequestStatusCacheForTests,
+  __setPullRequestStatusCacheTtlForTests,
   commitAll,
   getCheckoutDiff,
   getCheckoutShortstat,
@@ -38,6 +48,10 @@ function initRepo(): { tempDir: string; repoDir: string } {
   return { tempDir, repoDir };
 }
 
+function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
 describe("checkout git utilities", () => {
   let tempDir: string;
   let repoDir: string;
@@ -48,9 +62,11 @@ describe("checkout git utilities", () => {
     tempDir = setup.tempDir;
     repoDir = setup.repoDir;
     paseoHome = join(tempDir, "paseo-home");
+    __resetPullRequestStatusCacheForTests();
   });
 
   afterEach(() => {
+    __resetPullRequestStatusCacheForTests();
     rmSync(tempDir, { recursive: true, force: true });
   });
 
@@ -681,6 +697,167 @@ const x = 1;
     }
   });
 
+  it("caches PR status results for duplicate lookups", async () => {
+    execSync("git checkout -b feature", { cwd: repoDir });
+    execSync("git remote add origin https://github.com/getpaseo/paseo.git", { cwd: repoDir });
+
+    const fakeBinDir = join(tempDir, "fake-bin-gh-cache-hit");
+    const callCountPath = join(tempDir, "gh-call-count.txt");
+    mkdirSync(fakeBinDir);
+    const gitPath = execSync("command -v git", { stdio: "pipe" }).toString().trim();
+    symlinkSync(gitPath, join(fakeBinDir, "git"));
+    writeFileSync(callCountPath, "0\n");
+    writeFileSync(
+      join(fakeBinDir, "gh"),
+      [
+        "#!/usr/bin/env bash",
+        "set -euo pipefail",
+        `count_file=${JSON.stringify(callCountPath)}`,
+        'if [[ "${1-}" == "--version" ]]; then',
+        '  echo "gh version 2.0.0"',
+        "  exit 0",
+        "fi",
+        'args="$*"',
+        'if [[ "$args" == "pr view --json url,title,state,baseRefName,headRefName,mergedAt" ]]; then',
+        '  count="$(cat "$count_file")"',
+        '  printf "%s\\n" "$((count + 1))" > "$count_file"',
+        '  echo \'{"url":"https://github.com/getpaseo/paseo/pull/123","title":"Ship feature","state":"OPEN","baseRefName":"main","headRefName":"feature","mergedAt":null}\'',
+        "  exit 0",
+        "fi",
+        'echo "unexpected gh args: $args" >&2',
+        "exit 1",
+        "",
+      ].join("\n"),
+      "utf8",
+    );
+    execSync(`chmod +x ${join(fakeBinDir, "gh")}`);
+
+    const originalPath = process.env.PATH;
+    process.env.PATH = `${fakeBinDir}:${originalPath ?? ""}`;
+    try {
+      const first = await getPullRequestStatus(repoDir);
+      const second = await getPullRequestStatus(repoDir);
+      expect(first).toEqual(second);
+      expect(first.status?.url).toContain("/pull/123");
+      expect(readFileSync(callCountPath, "utf8").trim()).toBe("1");
+    } finally {
+      if (originalPath === undefined) {
+        delete process.env.PATH;
+      } else {
+        process.env.PATH = originalPath;
+      }
+    }
+  });
+
+  it("expires cached PR status after the TTL", async () => {
+    execSync("git checkout -b feature", { cwd: repoDir });
+    execSync("git remote add origin https://github.com/getpaseo/paseo.git", { cwd: repoDir });
+
+    const fakeBinDir = join(tempDir, "fake-bin-gh-cache-expiry");
+    const callCountPath = join(tempDir, "gh-call-count-expiry.txt");
+    mkdirSync(fakeBinDir);
+    const gitPath = execSync("command -v git", { stdio: "pipe" }).toString().trim();
+    symlinkSync(gitPath, join(fakeBinDir, "git"));
+    writeFileSync(callCountPath, "0\n");
+    writeFileSync(
+      join(fakeBinDir, "gh"),
+      [
+        "#!/usr/bin/env bash",
+        "set -euo pipefail",
+        `count_file=${JSON.stringify(callCountPath)}`,
+        'if [[ "${1-}" == "--version" ]]; then',
+        '  echo "gh version 2.0.0"',
+        "  exit 0",
+        "fi",
+        'args="$*"',
+        'if [[ "$args" == "pr view --json url,title,state,baseRefName,headRefName,mergedAt" ]]; then',
+        '  count="$(cat "$count_file")"',
+        '  next="$((count + 1))"',
+        '  printf "%s\\n" "$next" > "$count_file"',
+        '  printf \'{"url":"https://github.com/getpaseo/paseo/pull/%s","title":"Ship feature","state":"OPEN","baseRefName":"main","headRefName":"feature","mergedAt":null}\\n\' "$next"',
+        "  exit 0",
+        "fi",
+        'echo "unexpected gh args: $args" >&2',
+        "exit 1",
+        "",
+      ].join("\n"),
+      "utf8",
+    );
+    execSync(`chmod +x ${join(fakeBinDir, "gh")}`);
+
+    const originalPath = process.env.PATH;
+    process.env.PATH = `${fakeBinDir}:${originalPath ?? ""}`;
+    __setPullRequestStatusCacheTtlForTests(50);
+    try {
+      const first = await getPullRequestStatus(repoDir);
+      await sleep(80);
+      const second = await getPullRequestStatus(repoDir);
+      expect(first.status?.url).toContain("/pull/1");
+      expect(second.status?.url).toContain("/pull/2");
+      expect(readFileSync(callCountPath, "utf8").trim()).toBe("2");
+    } finally {
+      if (originalPath === undefined) {
+        delete process.env.PATH;
+      } else {
+        process.env.PATH = originalPath;
+      }
+    }
+  });
+
+  it("dedupes concurrent PR status lookups for the same cwd", async () => {
+    execSync("git checkout -b feature", { cwd: repoDir });
+    execSync("git remote add origin https://github.com/getpaseo/paseo.git", { cwd: repoDir });
+
+    const fakeBinDir = join(tempDir, "fake-bin-gh-cache-concurrent");
+    const callCountPath = join(tempDir, "gh-call-count-concurrent.txt");
+    mkdirSync(fakeBinDir);
+    const gitPath = execSync("command -v git", { stdio: "pipe" }).toString().trim();
+    symlinkSync(gitPath, join(fakeBinDir, "git"));
+    writeFileSync(callCountPath, "0\n");
+    writeFileSync(
+      join(fakeBinDir, "gh"),
+      [
+        "#!/usr/bin/env bash",
+        "set -euo pipefail",
+        `count_file=${JSON.stringify(callCountPath)}`,
+        'if [[ "${1-}" == "--version" ]]; then',
+        '  echo "gh version 2.0.0"',
+        "  exit 0",
+        "fi",
+        'args="$*"',
+        'if [[ "$args" == "pr view --json url,title,state,baseRefName,headRefName,mergedAt" ]]; then',
+        '  count="$(cat "$count_file")"',
+        '  printf "%s\\n" "$((count + 1))" > "$count_file"',
+        "  sleep 0.2",
+        '  echo \'{"url":"https://github.com/getpaseo/paseo/pull/123","title":"Ship feature","state":"OPEN","baseRefName":"main","headRefName":"feature","mergedAt":null}\'',
+        "  exit 0",
+        "fi",
+        'echo "unexpected gh args: $args" >&2',
+        "exit 1",
+        "",
+      ].join("\n"),
+      "utf8",
+    );
+    execSync(`chmod +x ${join(fakeBinDir, "gh")}`);
+
+    const originalPath = process.env.PATH;
+    process.env.PATH = `${fakeBinDir}:${originalPath ?? ""}`;
+    try {
+      const [first, second] = await Promise.all([
+        getPullRequestStatus(repoDir),
+        getPullRequestStatus(repoDir),
+      ]);
+      expect(first).toEqual(second);
+      expect(readFileSync(callCountPath, "utf8").trim()).toBe("1");
+    } finally {
+      if (originalPath === undefined) {
+        delete process.env.PATH;
+      } else {
+        process.env.PATH = originalPath;
+      }
+    }
+  });
+
   it("returns typed MergeConflictError on merge conflicts", async () => {
     const conflictFile = join(repoDir, "conflict.txt");
     writeFileSync(conflictFile, "base\n");

packages/server/src/utils/checkout-git.ts

@@ -3,6 +3,7 @@ import { promisify } from "util";
 import { resolve, dirname, basename } from "path";
 import { realpathSync } from "fs";
 import { open as openFile, stat as statFile } from "fs/promises";
+import { TTLCache } from "@isaacs/ttlcache";
 import type { ParsedDiffFile } from "../server/utils/diff-highlighter.js";
 import { parseAndHighlightDiff } from "../server/utils/diff-highlighter.js";
 import { isPaseoOwnedWorktreeCwd } from "./worktree.js";
@@ -16,6 +17,40 @@ const READ_ONLY_GIT_ENV: NodeJS.ProcessEnv = {
 };
 
 const SMALL_OUTPUT_MAX_BUFFER = 20 * 1024 * 1024; // 20MB
+const DEFAULT_PULL_REQUEST_STATUS_CACHE_TTL_MS = 30_000;
+const PULL_REQUEST_STATUS_CACHE_MAX = 1_000;
+
+let pullRequestStatusCacheTtlMs = DEFAULT_PULL_REQUEST_STATUS_CACHE_TTL_MS;
+let pullRequestStatusCache = createPullRequestStatusCache(pullRequestStatusCacheTtlMs);
+const pullRequestStatusInFlight = new Map<string, Promise<PullRequestStatusResult>>();
+
+function createPullRequestStatusCache(ttlMs: number) {
+  return new TTLCache<string, PullRequestStatusResult>({
+    ttl: ttlMs,
+    max: PULL_REQUEST_STATUS_CACHE_MAX,
+    checkAgeOnGet: true,
+  });
+}
+
+function getPullRequestStatusCacheKey(cwd: string): string {
+  return resolve(cwd);
+}
+
+export function __resetPullRequestStatusCacheForTests(): void {
+  pullRequestStatusCache.clear();
+  pullRequestStatusCache.cancelTimer();
+  pullRequestStatusCacheTtlMs = DEFAULT_PULL_REQUEST_STATUS_CACHE_TTL_MS;
+  pullRequestStatusCache = createPullRequestStatusCache(pullRequestStatusCacheTtlMs);
+  pullRequestStatusInFlight.clear();
+}
+
+export function __setPullRequestStatusCacheTtlForTests(ttlMs: number): void {
+  pullRequestStatusCache.clear();
+  pullRequestStatusCache.cancelTimer();
+  pullRequestStatusCacheTtlMs = ttlMs;
+  pullRequestStatusCache = createPullRequestStatusCache(ttlMs);
+  pullRequestStatusInFlight.clear();
+}
 
 async function execGit(
   command: string,
@@ -1807,6 +1842,31 @@ export async function createPullRequest(
 }
 
 export async function getPullRequestStatus(cwd: string): Promise<PullRequestStatusResult> {
+  const cacheKey = getPullRequestStatusCacheKey(cwd);
+  const cached = pullRequestStatusCache.get(cacheKey);
+  if (cached) {
+    return cached;
+  }
+
+  const existing = pullRequestStatusInFlight.get(cacheKey);
+  if (existing) {
+    return existing;
+  }
+
+  const lookup = getPullRequestStatusUncached(cwd)
+    .then((status) => {
+      pullRequestStatusCache.set(cacheKey, status);
+      return status;
+    })
+    .finally(() => {
+      pullRequestStatusInFlight.delete(cacheKey);
+    });
+
+  pullRequestStatusInFlight.set(cacheKey, lookup);
+  return lookup;
+}
+
+async function getPullRequestStatusUncached(cwd: string): Promise<PullRequestStatusResult> {
   await requireGitRepo(cwd);
   const head = await getCurrentBranch(cwd);
   if (!head) {