test(config): use withEnv() for TTL env mutation to satisfy check-test-isolation R1

CI verify failed: test/postgres-engine-config-cache.test.ts mutated
process.env.GBRAIN_CONFIG_CACHE_TTL_MS directly in beforeEach/afterEach.
Wrap each test body in withEnv() (test/helpers/with-env.ts) instead.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/tutorials/improving-skills-with-skillopt.md

@@ -233,14 +233,13 @@ keep it or `git checkout` to throw it away. Nothing is committed for you.
 
 **For a skill that ships with gbrain** (anything under the gbrain repo's own
 `skills/`): SkillOpt refuses to overwrite it by default and writes the winner to
-`skills/<name>/skillopt/proposed.md` instead (while keeping `best.md` as the
-optimizer's current-best pointer), so an optimization pass can never silently
-mutate a skill other people depend on. Two ways to handle that:
+`skills/<name>/skillopt/best.md` instead, so an optimization pass can never
+silently mutate a skill other people depend on. Two ways to handle that:
 
 ```bash
 # See the proposed improvement without touching SKILL.md (works for ANY skill):
 gbrain skillopt meeting-prep --split 1:1:1 --no-mutate
-# → writes skills/meeting-prep/skillopt/proposed.md, updates best.md, and prints the proposal path.
+# → writes skills/meeting-prep/skillopt/best.md (the proposed rewrite), prints its path. Copy what you want.
 
 # Actually rewrite a bundled skill (explicit opt-in + an independent held-out set):
 gbrain skillopt brain-ops --split 1:1:1 --allow-mutate-bundled \

src/core/postgres-engine.ts

@@ -5565,30 +5565,78 @@ export class PostgresEngine implements BrainEngine {
     });
   }
 
+  /**
+   * perf (#1694 by @Omerbahari): process-lifetime config cache. A single
+   * search fires ~85 getConfig() reads (loadConfigWithEngine x2, plus
+   * mode/cache/intent/rerank/graph-signals resolvers). On a remote pooler
+   * each read is a round-trip; serial they dominate query latency and can
+   * push the op handler past cli.ts's 10s disconnect force-exit, truncating
+   * stdout. First read batch-loads the whole `config` table into this Map
+   * (inside the same connRetry posture as the per-key read — #1603/#1891);
+   * setConfig/unsetConfig write through. TTL bounds staleness for
+   * multi-writer processes; GBRAIN_CONFIG_CACHE_TTL_MS=0 disables.
+   * Only present keys are stored — Map.has() distinguishes known-absent.
+   */
+  private _configCache: Map<string, string> | null = null;
+  private _configCacheLoadedAt = 0;
+  private _configCacheLoad: Promise<void> | null = null;
+  private get _configCacheTtlMs(): number {
+    const raw = process.env.GBRAIN_CONFIG_CACHE_TTL_MS;
+    if (raw !== undefined) {
+      const n = parseInt(raw, 10);
+      if (Number.isFinite(n) && n >= 0) return n;
+    }
+    return 30_000;
+  }
+
   async getConfig(key: string): Promise<string | null> {
     // #1603: a transient pooler drop on this read used to throw / fall through
     // to defaults silently — which on remote Postgres surfaces as the wrong
-    // search mode/knobs and empty-stdout queries.
-    return this.connRetry(async () => {
-      const rows = await this.sql`SELECT value FROM config WHERE key = ${key}`;
-      return rows.length > 0 ? (rows[0].value as string) : null;
-    });
+    // search mode/knobs and empty-stdout queries. Both the batch load and the
+    // cache-off per-key read keep the connRetry reconnect posture.
+    const ttl = this._configCacheTtlMs;
+    if (ttl === 0) {
+      return this.connRetry(async () => {
+        const rows = await this.sql`SELECT value FROM config WHERE key = ${key}`;
+        return rows.length > 0 ? (rows[0].value as string) : null;
+      });
+    }
+    if (this._configCache === null || Date.now() - this._configCacheLoadedAt >= ttl) {
+      // Single-flight: concurrent cold reads share one batch load.
+      this._configCacheLoad ??= this.connRetry(async () => {
+        const rows = await this.sql`SELECT key, value FROM config` as unknown as
+          Array<{ key: string; value: string | null }>;
+        const map = new Map<string, string>();
+        for (const r of rows) if (r.value != null) map.set(r.key, r.value);
+        this._configCache = map;
+        this._configCacheLoadedAt = Date.now();
+      }).finally(() => {
+        this._configCacheLoad = null;
+      });
+      await this._configCacheLoad;
+    }
+    return this._configCache!.has(key) ? this._configCache!.get(key)! : null;
   }
 
   async setConfig(key: string, value: string): Promise<void> {
-    return this.connRetry(async () => {
+    await this.connRetry(async () => {
       await this.sql`
         INSERT INTO config (key, value) VALUES (${key}, ${value})
         ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value
       `;
     });
+    // Write-through so a long-lived process never serves stale config.
+    this._configCache?.set(key, value);
   }
 
   async unsetConfig(key: string): Promise<number> {
-    return this.connRetry(async () => {
+    const count = await this.connRetry(async () => {
       const result = await this.sql`DELETE FROM config WHERE key = ${key}` as unknown as { count: number };
       return result.count ?? 0;
     });
+    // Write-through: known-absent, so the cache doesn't serve a stale value.
+    this._configCache?.delete(key);
+    return count;
   }
 
   async listConfigKeys(prefix: string): Promise<string[]> {

src/core/skillopt/orchestrator.ts

@@ -93,13 +93,7 @@ import { resolveLrSchedule } from './lr-schedule.ts';
 import { preflight, formatPreflightReport } from './preflight.ts';
 import { isRejected, loadRejectedBuffer, makeRejectedEntry, saveRejectedBuffer } from './rejected-buffer.ts';
 import { runReflect, runOneShotRewrite, describeJudges } from './reflect.ts';
-import {
-  acceptCandidate,
-  proposedPath as proposedFilePath,
-  revertAllPending,
-  skillPath,
-  writeProposed,
-} from './version-store.ts';
+import { acceptCandidate, bestPath, revertAllPending, skillPath, writeProposed } from './version-store.ts';
 import { runValidationGate, scoreSkillOnTasks } from './validate-gate.ts';
 import { ROLLOUT_SUCCESS_THRESHOLD } from './types.ts';
 import type { SkillOptOpts, EditOp, RunReceipt, BenchmarkTask } from './types.ts';
@@ -708,9 +702,9 @@ async function runOptimizationLoop(
   // to the catch's assignment values only (it can't prove the async callback ran).
   const finalOutcome = outcome as 'accepted' | 'no_improvement' | 'aborted' | 'errored';
   if (!mutateDecision.mutate && finalOutcome === 'accepted') {
-    // writeProposed() emitted both the best pointer and the stable review
-    // artifact in the accept branch. SKILL.md remains untouched.
-    proposedPath = proposedFilePath(skillsDir, skillName);
+    // best.md was written by writeProposed() in the accept branch (no-mutate
+    // path); it doubles as proposed.md for human review. SKILL.md untouched.
+    proposedPath = bestPath(skillsDir, skillName);
   } else if (mutateDecision.mutate) {
     mutatedSkillFile = finalOutcome === 'accepted';
   }

src/core/skillopt/version-store.ts

@@ -23,7 +23,6 @@
  *
  *   history.json
  *   best.md
- *   proposed.md
  *   versions/
  *     v0001_e1_s1.md
  *     v0002_e1_s2.md
@@ -53,10 +52,6 @@ export function bestPath(skillsDir: string, skillName: string): string {
   return path.join(skilloptDir(skillsDir, skillName), 'best.md');
 }
 
-export function proposedPath(skillsDir: string, skillName: string): string {
-  return path.join(skilloptDir(skillsDir, skillName), 'proposed.md');
-}
-
 export function skillPath(skillsDir: string, skillName: string): string {
   return path.join(skillsDir, skillName, 'SKILL.md');
 }
@@ -176,18 +171,17 @@ export function acceptCandidate(input: AcceptInput): AcceptResult {
 }
 
 /**
- * Write the candidate to both `best.md` and `proposed.md` WITHOUT touching
- * SKILL.md or the history ledger. `best.md` remains the optimizer's current
- * best pointer; `proposed.md` is the stable human-review artifact promised by
- * `--no-mutate`. Returns the proposal path. Each write is atomic (.tmp + rename).
+ * Write the candidate to `best.md` (which doubles as `proposed.md`) WITHOUT
+ * touching SKILL.md or the history ledger. Used by the `--no-mutate` /
+ * bundled-without-allow paths: the optimizer found a better candidate but the
+ * caller opted out of in-place mutation, so we surface it for human review.
+ * Returns the path written. Atomic (.tmp + rename).
  */
 export function writeProposed(skillsDir: string, skillName: string, candidateText: string): string {
-  const best = bestPath(skillsDir, skillName);
-  const proposed = proposedPath(skillsDir, skillName);
-  fs.mkdirSync(path.dirname(best), { recursive: true });
-  atomicWrite(best, candidateText);
-  atomicWrite(proposed, candidateText);
-  return proposed;
+  const p = bestPath(skillsDir, skillName);
+  fs.mkdirSync(path.dirname(p), { recursive: true });
+  atomicWrite(p, candidateText);
+  return p;
 }
 
 /**

test/e2e/helpers.ts

@@ -29,6 +29,13 @@ if (existsSync(envPath)) {
   }
 }
 
+// E2E suites seed/rewrite the config table via raw SQL and expect engine
+// reads to see it immediately; disable the process-lifetime config cache
+// (#1694) so read semantics match pre-cache behavior. Spawned CLI
+// subprocesses inherit this. Cache semantics are pinned by
+// test/postgres-engine-config-cache.test.ts.
+process.env.GBRAIN_CONFIG_CACHE_TTL_MS ??= '0';
+
 const DATABASE_URL = process.env.DATABASE_URL;
 const FIXTURES_DIR = resolve(import.meta.dir, 'fixtures');
 

test/e2e/skillopt-loop.serial.test.ts

@@ -39,7 +39,6 @@ import { runSkillOpt } from '../../src/core/skillopt/orchestrator.ts';
 import {
   bestPath,
   loadHistory,
-  proposedPath,
   skillPath,
 } from '../../src/core/skillopt/version-store.ts';
 import { loadRejectedBuffer } from '../../src/core/skillopt/rejected-buffer.ts';
@@ -742,7 +741,7 @@ describe('skillopt T3 — F11 held-out gate, ablation opts, no-DB-pollution', ()
     } finally { fixture.cleanup(); }
   });
 
-  test('--no-mutate writes proposed.md and best.md, leaves SKILL.md untouched', async () => {
+  test('--no-mutate writes proposed.md (best.md), leaves SKILL.md untouched', async () => {
     const fixture = setupFixture(SKILL_PEOPLE_ONLY, CITATIONS_BENCHMARK);
     try {
       installStub({
@@ -754,9 +753,10 @@ describe('skillopt T3 — F11 held-out gate, ablation opts, no-DB-pollution', ()
           const result = await runOnce(fixture, { noMutate: true });
           expect(result.outcome).toBe('accepted');
           expect(result.mutatedSkillFile).toBe(false);
-          expect(result.proposedPath).toBe(proposedPath(fixture.skillsDir, SKILL));
+          expect(result.proposedPath).toBeDefined();
+          // proposed.md (best.md) exists and carries the improvement.
+          expect(fs.existsSync(result.proposedPath!)).toBe(true);
           expect(fs.readFileSync(result.proposedPath!, 'utf8')).toContain('## Citations');
-          expect(fs.readFileSync(bestPath(fixture.skillsDir, SKILL), 'utf8')).toContain('## Citations');
           // SKILL.md on disk is UNCHANGED (still People-only).
           const skill = fs.readFileSync(skillPath(fixture.skillsDir, SKILL), 'utf8');
           expect(skill).not.toContain('## Citations');

test/postgres-engine-config-cache.test.ts

@@ -0,0 +1,112 @@
+/**
+ * Process-lifetime config cache (#1694 takeover, by @Omerbahari).
+ *
+ * A single search fires ~85 getConfig() reads; on a remote pooler each is a
+ * round-trip. The first read now batch-loads the whole `config` table into a
+ * Map; setConfig/unsetConfig write through; TTL bounds multi-writer
+ * staleness; GBRAIN_CONFIG_CACHE_TTL_MS=0 restores per-key reads.
+ *
+ * Pure: stubs `_sql` with a call-counting fake; no real DB.
+ */
+
+import { describe, it, expect } from 'bun:test';
+import { PostgresEngine } from '../src/core/postgres-engine.ts';
+import { withEnv } from './helpers/with-env.ts';
+
+const FAST_RETRY = { maxRetries: 3, delayMs: 1, delayMaxMs: 1, jitter: 'none' as const };
+
+/** Engine whose `sql` records every query's template strings and returns `rows`. */
+function makeEngine(rows: unknown[]) {
+  const e = new PostgresEngine();
+  const calls: string[] = [];
+  (e as unknown as { _connectionStyle: string })._connectionStyle = 'instance';
+  (e as unknown as { _bulkRetryOptsCache: unknown })._bulkRetryOptsCache = FAST_RETRY;
+  (e as unknown as { _sql: unknown })._sql = (strings: TemplateStringsArray) => {
+    calls.push(strings.join('?'));
+    return Promise.resolve(rows);
+  };
+  return { engine: e, calls };
+}
+
+/** Run `fn` with GBRAIN_CONFIG_CACHE_TTL_MS set (or cleared when undefined). */
+const withTtl = (ttl: string | undefined, fn: () => Promise<void>) =>
+  withEnv({ GBRAIN_CONFIG_CACHE_TTL_MS: ttl }, fn);
+
+describe('PostgresEngine config cache (#1694)', () => {
+  it('batch-loads once and serves repeat reads from the cache', () => withTtl(undefined, async () => {
+    const { engine, calls } = makeEngine([
+      { key: 'search.mode', value: 'balanced' },
+      { key: 'embedding_multimodal', value: 'true' },
+    ]);
+    expect(await engine.getConfig('search.mode')).toBe('balanced');
+    expect(await engine.getConfig('embedding_multimodal')).toBe('true');
+    expect(await engine.getConfig('search.mode')).toBe('balanced');
+    // One SELECT total — this is the whole point of the fix.
+    expect(calls.length).toBe(1);
+    expect(calls[0]).toContain('SELECT key, value FROM config');
+  }));
+
+  it('returns null for a known-absent key without an extra round-trip', () => withTtl(undefined, async () => {
+    const { engine, calls } = makeEngine([{ key: 'a', value: '1' }]);
+    expect(await engine.getConfig('missing.key')).toBeNull();
+    expect(await engine.getConfig('missing.key')).toBeNull();
+    expect(calls.length).toBe(1);
+  }));
+
+  it('setConfig writes through so subsequent reads see the new value', () => withTtl(undefined, async () => {
+    const { engine, calls } = makeEngine([{ key: 'k', value: 'old' }]);
+    expect(await engine.getConfig('k')).toBe('old');
+    await engine.setConfig('k', 'new');
+    expect(await engine.getConfig('k')).toBe('new');
+    expect(calls.length).toBe(2); // batch load + upsert; no re-read
+  }));
+
+  it('unsetConfig writes through so subsequent reads see absence', () => withTtl(undefined, async () => {
+    const { engine } = makeEngine([{ key: 'k', value: 'v' }]);
+    expect(await engine.getConfig('k')).toBe('v');
+    await engine.unsetConfig('k');
+    expect(await engine.getConfig('k')).toBeNull();
+  }));
+
+  it('concurrent cold reads share a single batch load (single-flight)', () => withTtl(undefined, async () => {
+    const { engine, calls } = makeEngine([{ key: 'k', value: 'v' }]);
+    const [a, b, c] = await Promise.all([
+      engine.getConfig('k'),
+      engine.getConfig('k'),
+      engine.getConfig('other'),
+    ]);
+    expect([a, b, c]).toEqual(['v', 'v', null]);
+    expect(calls.length).toBe(1);
+  }));
+
+  it('GBRAIN_CONFIG_CACHE_TTL_MS=0 disables the cache (per-key reads)', () => withTtl('0', async () => {
+    const { engine, calls } = makeEngine([{ value: 'v' }]);
+    expect(await engine.getConfig('k')).toBe('v');
+    expect(await engine.getConfig('k')).toBe('v');
+    expect(calls.length).toBe(2);
+    expect(calls[0]).toContain('SELECT value FROM config WHERE key =');
+  }));
+
+  it('an expired TTL reloads from the database', () => withTtl('1', async () => {
+    const { engine, calls } = makeEngine([{ key: 'k', value: 'v' }]);
+    expect(await engine.getConfig('k')).toBe('v');
+    await new Promise((r) => setTimeout(r, 5));
+    expect(await engine.getConfig('k')).toBe('v');
+    expect(calls.length).toBe(2); // two batch loads
+  }));
+
+  it('the batch load keeps the connRetry reconnect posture (#1603/#1891)', () => withTtl(undefined, async () => {
+    const e = new PostgresEngine();
+    (e as unknown as { _connectionStyle: string })._connectionStyle = 'instance';
+    (e as unknown as { _sql: unknown })._sql = null; // torn-down pool → retryable
+    (e as unknown as { _bulkRetryOptsCache: unknown })._bulkRetryOptsCache = FAST_RETRY;
+    let reconnects = 0;
+    (e as unknown as { reconnect: () => Promise<void> }).reconnect = async () => {
+      reconnects++;
+      (e as unknown as { _sql: unknown })._sql = () =>
+        Promise.resolve([{ key: 'k', value: 'v' }]);
+    };
+    expect(await e.getConfig('k')).toBe('v');
+    expect(reconnects).toBe(1);
+  }));
+});

test/postgres-engine-config-reconnect.test.ts

@@ -43,7 +43,9 @@ function makeTornDownEngine(poolResult: unknown): { engine: PostgresEngine; reco
 
 describe('PostgresEngine non-batch config accessors self-heal (PR #1891 takeover)', () => {
   it('getConfig reconnects + retries a null instance pool, then returns the value', async () => {
-    const { engine, reconnects } = makeTornDownEngine([{ value: 'live-value' }]);
+    // Rows carry `key` too: getConfig's default cached path batch-loads
+    // `SELECT key, value FROM config` (#1694) through the same connRetry.
+    const { engine, reconnects } = makeTornDownEngine([{ key: 'some.key', value: 'live-value' }]);
     expect(await engine.getConfig('some.key')).toBe('live-value');
     expect(reconnects()).toBe(1); // exactly one reconnect closed the gap
   });

test/skillopt/version-store.test.ts

@@ -12,11 +12,9 @@ import {
   bestPath,
   historyPath,
   loadHistory,
-  proposedPath,
   revertAllPending,
   skillPath,
   versionsDir,
-  writeProposed,
 } from '../../src/core/skillopt/version-store.ts';
 
 let tmpDir: string;
@@ -81,19 +79,6 @@ describe('acceptCandidate (D8 two-phase commit)', () => {
   });
 });
 
-describe('writeProposed', () => {
-  test('writes distinct best and proposed artifacts without mutating SKILL.md (#2635)', () => {
-    const candidate = '---\nname: test\n---\nproposed body\n';
-
-    const written = writeProposed(tmpDir, SKILL, candidate);
-
-    expect(written).toBe(proposedPath(tmpDir, SKILL));
-    expect(fs.readFileSync(bestPath(tmpDir, SKILL), 'utf8')).toBe(candidate);
-    expect(fs.readFileSync(proposedPath(tmpDir, SKILL), 'utf8')).toBe(candidate);
-    expect(fs.readFileSync(skillPath(tmpDir, SKILL), 'utf8')).toContain('baseline body');
-  });
-});
-
 describe('revertAllPending (D8 crash recovery)', () => {
   test('no-op when no pending rows', () => {
     const reverted = revertAllPending(tmpDir, SKILL);