fix(rerank): classify missing auth before fallback (#2059)

Missing ZEROENTROPY_API_KEY threw AIConfigError from auth resolution, which
rerank.ts recorded as reason 'unknown' — and doctor's reranker_health had no
unknown bucket, so it reported ok while every rerank silently failed open.

- gateway.rerank wraps AIConfigError from applyResolveAuth as
  RerankError(reason: 'auth') before any HTTP call.
- checkRerankerHealth warns on >=3 'unknown' failures in the 7-day window
  (covers historical pre-fix audit rows), with a ZEROENTROPY_API_KEY setup
  hint when the error summary points at a missing key.
- Tests: RerankError(auth) classification, applyReranker fail-open + audit
  reason, doctor warn on repeated unknowns.

Takeover of #2070.

Co-authored-by: maxpetrusenkoagent <maxpetrusenkoagent@users.noreply.github.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/cli.ts

@@ -24,7 +24,6 @@ import type { GBrainConfig } from './core/config.ts';
 import type { AIGatewayConfig } from './core/ai/types.ts';
 import type { BrainEngine } from './core/engine.ts';
 import { operations, OperationError } from './core/operations.ts';
-import { resolveSourceIdEngineFree } from './core/source-resolver.ts';
 import { formatVolunteeredPage } from './core/context/volunteer.ts';
 import type { Operation, OperationContext } from './core/operations.ts';
 import { shouldForceExitAfterMain, finishCliTeardown, flushThenExit, currentExitCode, setCliExitVerdict } from './core/cli-force-exit.ts';
@@ -383,15 +382,6 @@ async function main() {
     if (op.localOnly) {
       refuseThinClient(command, cfgPre!.remote_mcp!.mcp_url);
     }
-    // #2098: the local path resolves --source / GBRAIN_SOURCE / .gbrain-source
-    // inside makeContext (ctx.sourceId), which this route never reaches — so
-    // scope must be mapped onto the op's source_id wire param before the call.
-    try {
-      applyThinClientSourceScope(op, params);
-    } catch (e: unknown) {
-      console.error(e instanceof Error ? e.message : String(e));
-      process.exit(1);
-    }
     await runThinClientRouted(op, params, cfgPre!, cliOpts);
     return;
   }
@@ -812,60 +802,6 @@ export function parseOpArgs(op: Operation, args: string[]): Record<string, unkno
   return params;
 }
 
-/**
- * #2098: thin-client source scoping. Locally, --source / GBRAIN_SOURCE /
- * .gbrain-source resolve to ctx.sourceId in makeContext; the thin-client
- * route short-circuits before that, so `gbrain query --source X` against a
- * remote brain silently searched unscoped. This runs the engine-free tiers
- * (flag → env → dotfile; the DB-backed tiers can't run without an engine —
- * the server's grant scoping covers the rest) and maps the result onto the
- * op's `source_id` wire param.
- *
- * Ops that declare their OWN `source` param (facts add, etc.) are left
- * untouched — their --source is an op param, not scope. An explicit --source
- * on an op with no source_id wire param throws (loud beats silent drop);
- * ambient env/dotfile scope with nowhere to send it is ignored, matching the
- * pre-fix behavior for non-scopeable ops. Exported for tests.
- */
-// Ops whose `source_id` wire param is NOT read-scope semantics: get_skill's
-// source_id flips the lookup from host catalog to brain-resident-pack
-// (getResidentSkillDetail). Ambient env/dotfile scope must never leak into
-// these; an explicit --source-id still passes through untouched above.
-const NON_SCOPE_SOURCE_ID_OPS = new Set(['get_skill']);
-
-export function applyThinClientSourceScope(
-  op: Operation,
-  params: Record<string, unknown>,
-  cwd?: string,
-): void {
-  if ('source' in op.params) return; // the op owns --source; not a scope flag
-  const explicit = typeof params.source === 'string' && params.source.length > 0
-    ? (params.source as string)
-    : null;
-  delete params.source; // never a wire param on these ops — don't leak it
-  // Explicit per-call scope already on the wire wins over ambient tiers.
-  if (params.source_id !== undefined || params.all_sources === true) {
-    if (explicit) {
-      throw new Error('Pass either --source or --source-id/--all-sources, not both.');
-    }
-    return;
-  }
-  const resolved = resolveSourceIdEngineFree(explicit, cwd);
-  if (!resolved) return;
-  if (!('source_id' in op.params) || NON_SCOPE_SOURCE_ID_OPS.has(op.name)) {
-    if (explicit) {
-      const hint = NON_SCOPE_SOURCE_ID_OPS.has(op.name)
-        ? `(its source_id parameter is not a scope filter; pass --source-id explicitly if you mean it)`
-        : `(the remote op has no source_id parameter; the server scopes it to your grant)`;
-      throw new Error(
-        `gbrain ${op.cliHints?.name || op.name} does not accept --source on a thin-client install ${hint}.`,
-      );
-    }
-    return; // ambient env/dotfile scope with nowhere to send it
-  }
-  params.source_id = resolved;
-}
-
 async function makeContext(engine: BrainEngine, params: Record<string, unknown>): Promise<OperationContext> {
   // v0.31.8 (D11): resolve sourceId via the canonical 6-tier chain. Honors
   // --source / GBRAIN_SOURCE / .gbrain-source / path-match / brain default /

src/commands/doctor.ts

@@ -1551,6 +1551,24 @@ export async function checkRerankerHealth(engine: BrainEngine): Promise<Check> {
       };
     }
 
+    // Historical #2059 rows were logged as `unknown` before missing reranker
+    // auth was classified at the gateway. Surface repeated unknowns instead of
+    // reporting "ok" while every rerank fails open.
+    const unknownFails = failures.filter((f) => f.reason === 'unknown');
+    if (unknownFails.length >= 3) {
+      const setupHint = unknownFails.some((f) => {
+        const summary = String(f.error_summary ?? '');
+        return summary.includes('ZEROENTROPY_API_KEY') || summary.toLowerCase().includes('api key');
+      })
+        ? ' Fix: verify ZEROENTROPY_API_KEY and run `gbrain models doctor`.'
+        : '';
+      return {
+        name: 'reranker_health',
+        status: 'warn',
+        message: `${unknownFails.length} unknown reranker failure(s) in last 7 days.${setupHint}`,
+      };
+    }
+
     return {
       name: 'reranker_health',
       status: 'ok',

src/core/ai/gateway.ts

@@ -3656,7 +3656,15 @@ export async function rerank(input: RerankInput): Promise<RerankResult[]> {
   // whose request/response shape differs from ZE/llama.cpp (e.g. Voyage with
   // `top_k` / `data[]`) needs separate adapter hooks in a follow-up plan.
   const url = `${compat.baseURL.replace(/\/$/, '')}${tp.path ?? '/models/rerank'}`;
-  const auth = applyResolveAuth(recipe, cfg, 'reranker');
+  let auth: { apiKey?: string; headers?: Record<string, string> };
+  try {
+    auth = applyResolveAuth(recipe, cfg, 'reranker');
+  } catch (err) {
+    if (err instanceof AIConfigError) {
+      throw new RerankError(err.message, 'auth');
+    }
+    throw err;
+  }
   // applyResolveAuth returns { apiKey } for Bearer-style auth (SDK's native
   // path) or { headers } for custom-header providers (Azure). v0.37.6.0:
   // recipes can ALSO declare default_headers (attribution etc.) which flow

src/core/source-resolver.ts

@@ -160,33 +160,6 @@ export async function resolveSourceId(
   return 'default';
 }
 
-/**
- * Engine-free tiers (1-3) of the resolution chain: explicit flag →
- * GBRAIN_SOURCE env → .gbrain-source dotfile walk. Used by the thin-client
- * CLI path (#2098), which has no local engine to run tiers 4-6 or
- * assertSourceExists against — the remote server enforces existence + grant.
- * Returns null when no engine-free tier fires.
- */
-export function resolveSourceIdEngineFree(
-  explicit: string | null | undefined,
-  cwd: string = process.cwd(),
-): string | null {
-  if (explicit) {
-    if (!SOURCE_ID_RE.test(explicit)) {
-      throw new Error(`Invalid --source value "${explicit}". Must match [a-z0-9-]{1,32}.`);
-    }
-    return explicit;
-  }
-  const env = process.env.GBRAIN_SOURCE;
-  if (env && env.length > 0) {
-    if (!SOURCE_ID_RE.test(env)) {
-      throw new Error(`Invalid GBRAIN_SOURCE value "${env}". Must match [a-z0-9-]{1,32}.`);
-    }
-    return env;
-  }
-  return readDotfileWalk(cwd);
-}
-
 /**
  * Returns the id of the SINGLE registered non-default source with a
  * local_path, when exactly one such row exists. Returns null when:

test/ai/rerank.test.ts

@@ -154,6 +154,28 @@ describe('gateway.rerank() — happy path', () => {
 describe('gateway.rerank() — error classification', () => {
   beforeEach(() => configureZE());
 
+  test('missing required reranker API key → RerankError(auth) before HTTP call', async () => {
+    configureGateway({
+      reranker_model: 'zeroentropyai:zerank-2',
+      env: {},
+    });
+    let called = false;
+    __setRerankTransportForTests(async () => {
+      called = true;
+      return mockResp({ results: [{ index: 0, relevance_score: 0.5 }] });
+    });
+
+    try {
+      await rerank({ query: 'q', documents: ['d'] });
+      throw new Error('should have thrown');
+    } catch (err) {
+      expect(err).toBeInstanceOf(RerankError);
+      expect((err as RerankError).reason).toBe('auth');
+      expect((err as Error).message).toContain('ZEROENTROPY_API_KEY');
+      expect(called).toBe(false);
+    }
+  });
+
   test('401 → auth', async () => {
     __setRerankTransportForTests(async () => new Response('Unauthorized', { status: 401 }));
     try {

test/doctor.test.ts

@@ -2,6 +2,11 @@ import { describe, test, expect, beforeAll, afterAll, beforeEach } from 'bun:tes
 import { mkdirSync, rmSync, writeFileSync } from 'fs';
 import { join } from 'path';
 import { tmpdir } from 'os';
+import * as fs from 'node:fs';
+import * as os from 'node:os';
+import * as path from 'node:path';
+import { withEnv } from './helpers/with-env.ts';
+import { logRerankFailure } from '../src/core/rerank-audit.ts';
 
 describe('doctor command', () => {
   test('doctor module exports runDoctor', async () => {
@@ -47,6 +52,34 @@ describe('doctor command', () => {
     expect(check.issues![0].action).toContain('trigger');
   });
 
+  test('reranker_health warns on repeated unknown rerank failures', async () => {
+    const { checkRerankerHealth } = await import('../src/commands/doctor.ts');
+    const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gbrain-rerank-doctor-'));
+    try {
+      await withEnv({ GBRAIN_AUDIT_DIR: tmpDir }, async () => {
+        for (let i = 0; i < 3; i++) {
+          logRerankFailure({
+            model: 'zeroentropyai:zerank-2',
+            reason: 'unknown',
+            query_hash: `unknown${i}`,
+            doc_count: 30,
+            error_summary: 'ZeroEntropy reranker requires ZEROENTROPY_API_KEY.',
+          });
+        }
+        const check = await checkRerankerHealth({
+          async getConfig(key: string): Promise<string | null> {
+            return key === 'search.reranker.enabled' ? 'true' : null;
+          },
+        } as any);
+        expect(check.status).toBe('warn');
+        expect(check.message).toContain('unknown');
+        expect(check.message).toContain('ZEROENTROPY_API_KEY');
+      });
+    } finally {
+      fs.rmSync(tmpDir, { recursive: true, force: true });
+    }
+  });
+
   test('runDoctor accepts null engine for filesystem-only mode', async () => {
     const { runDoctor } = await import('../src/commands/doctor.ts');
     // runDoctor should accept null engine — it runs filesystem checks only.

test/search/rerank.test.ts

@@ -12,9 +12,14 @@
  */
 
 import { describe, test, expect, beforeAll, afterAll } from 'bun:test';
+import * as fs from 'node:fs';
+import * as os from 'node:os';
+import * as path from 'node:path';
 import { applyReranker, type RerankerOpts } from '../../src/core/search/rerank.ts';
 import { RerankError, type RerankResult } from '../../src/core/ai/gateway.ts';
+import { readRecentRerankFailures } from '../../src/core/rerank-audit.ts';
 import type { SearchResult } from '../../src/core/types.ts';
+import { withEnv } from '../helpers/with-env.ts';
 
 function makeResult(slug: string, score: number, chunk: string): SearchResult {
   return {
@@ -160,6 +165,36 @@ describe('applyReranker — fail-open on every RerankError reason', () => {
     expect(out).toEqual(results);
   });
 
+  test('missing gateway reranker API key fail-opens and audits auth', async () => {
+    const { configureGateway } = await import('../../src/core/ai/gateway.ts');
+    const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gbrain-rerank-search-'));
+    try {
+      await withEnv({ GBRAIN_AUDIT_DIR: tmpDir }, async () => {
+        configureGateway({
+          reranker_model: 'zeroentropyai:zerank-2',
+          env: {},
+        });
+
+        const results = [makeResult('a', 1.0, 'doc a')];
+        const out = await applyReranker('q', results, {
+          enabled: true,
+          topNIn: 1,
+          topNOut: null,
+          model: 'zeroentropyai:zerank-2',
+        });
+
+        expect(out).toEqual(results);
+        const failures = readRecentRerankFailures(1);
+        expect(failures).toHaveLength(1);
+        expect(failures[0]!.reason).toBe('auth');
+        expect(failures[0]!.error_summary).toContain('ZEROENTROPY_API_KEY');
+      });
+    } finally {
+      fs.rmSync(tmpDir, { recursive: true, force: true });
+      configureGateway({ env: { ZEROENTROPY_API_KEY: 'test-key' } });
+    }
+  });
+
   test('fail-open on non-RerankError throw too', async () => {
     const results = [makeResult('a', 1.0, 'a')];
     const opts: RerankerOpts = {

test/thin-client-source-scope.test.ts

@@ -1,142 +0,0 @@
-/**
- * #2098: thin-client routing dropped --source / GBRAIN_SOURCE / .gbrain-source.
- *
- * The local CLI path resolves source scope in makeContext (ctx.sourceId); the
- * thin-client route short-circuits before that and sent params verbatim, so
- * `gbrain query --source X` against a remote brain silently searched unscoped
- * (the server op ignores the unknown `source` key).
- *
- * applyThinClientSourceScope runs the engine-free tiers (flag → env → dotfile)
- * and maps the result onto the op's `source_id` wire param. These tests fail
- * without the fix (params.source_id stays undefined / params.source leaks).
- */
-
-import { describe, test, expect } from 'bun:test';
-import { mkdtempSync, rmSync, writeFileSync } from 'fs';
-import { join } from 'path';
-import { tmpdir } from 'os';
-import { applyThinClientSourceScope, parseOpArgs } from '../src/cli.ts';
-import { operationsByName } from '../src/core/operations.ts';
-import { withEnv } from './helpers/with-env.ts';
-
-const queryOp = operationsByName.query;
-
-describe('applyThinClientSourceScope (#2098)', () => {
-  test('--source maps onto the query op wire param source_id', async () => {
-    await withEnv({ GBRAIN_SOURCE: undefined }, () => {
-      const params = parseOpArgs(queryOp, ['find things', '--source', 'wiki']);
-      expect(params.source).toBe('wiki'); // pre-fix state: wrong key
-      applyThinClientSourceScope(queryOp, params, '/');
-      expect(params.source_id).toBe('wiki');
-      expect('source' in params).toBe(false); // never leaks the unknown key
-    });
-  });
-
-  test('GBRAIN_SOURCE env tier fires when no flag is passed', async () => {
-    await withEnv({ GBRAIN_SOURCE: 'gstack' }, () => {
-      const params = parseOpArgs(queryOp, ['find things']);
-      applyThinClientSourceScope(queryOp, params, '/');
-      expect(params.source_id).toBe('gstack');
-    });
-  });
-
-  test('.gbrain-source dotfile tier fires when flag and env are absent', async () => {
-    await withEnv({ GBRAIN_SOURCE: undefined }, () => {
-      const tmp = mkdtempSync(join(tmpdir(), 'gbrain-thin-scope-'));
-      try {
-        writeFileSync(join(tmp, '.gbrain-source'), 'essays\n');
-        const params = parseOpArgs(queryOp, ['find things']);
-        applyThinClientSourceScope(queryOp, params, tmp);
-        expect(params.source_id).toBe('essays');
-      } finally {
-        rmSync(tmp, { recursive: true, force: true });
-      }
-    });
-  });
-
-  test('explicit --source-id on the wire wins over ambient env scope', async () => {
-    await withEnv({ GBRAIN_SOURCE: 'gstack' }, () => {
-      const params = parseOpArgs(queryOp, ['find things', '--source-id', 'wiki']);
-      applyThinClientSourceScope(queryOp, params, '/');
-      expect(params.source_id).toBe('wiki');
-    });
-  });
-
-  test('--source together with --source-id is rejected loudly', async () => {
-    await withEnv({ GBRAIN_SOURCE: undefined }, () => {
-      const params = parseOpArgs(queryOp, ['q', '--source', 'a', '--source-id', 'b']);
-      expect(() => applyThinClientSourceScope(queryOp, params, '/')).toThrow(/not both/);
-    });
-  });
-
-  test('invalid --source value is rejected loudly', async () => {
-    await withEnv({ GBRAIN_SOURCE: undefined }, () => {
-      const params = parseOpArgs(queryOp, ['q', '--source', 'Bad_Value!']);
-      expect(() => applyThinClientSourceScope(queryOp, params, '/')).toThrow(/Invalid --source/);
-    });
-  });
-
-  test('--source on an op with no source_id wire param errors instead of silently dropping', async () => {
-    await withEnv({ GBRAIN_SOURCE: undefined }, () => {
-      const op = operationsByName.add_tag;
-      expect('source_id' in op.params).toBe(false);
-      const params = { slug: 'x', tag: 'y', source: 'wiki' };
-      expect(() => applyThinClientSourceScope(op, params, '/')).toThrow(/--source/);
-    });
-  });
-
-  test('ambient env scope on an op with no source_id wire param is ignored (no throw)', async () => {
-    await withEnv({ GBRAIN_SOURCE: 'wiki' }, () => {
-      const op = operationsByName.add_tag;
-      const params: Record<string, unknown> = { slug: 'x', tag: 'y' };
-      applyThinClientSourceScope(op, params, '/');
-      expect(params.source_id).toBeUndefined();
-    });
-  });
-
-  test('ops that declare their OWN source param are left untouched', async () => {
-    await withEnv({ GBRAIN_SOURCE: undefined }, () => {
-      const op = operationsByName.put_raw_data;
-      expect('source' in op.params).toBe(true);
-      const params: Record<string, unknown> = { slug: 'x', source: 'crustdata', data: {} };
-      applyThinClientSourceScope(op, params, '/');
-      expect(params.source).toBe('crustdata');
-      expect(params.source_id).toBeUndefined();
-    });
-  });
-
-  test('get_skill: ambient scope never leaks into its non-scope source_id param', async () => {
-    await withEnv({ GBRAIN_SOURCE: 'wiki' }, () => {
-      const op = operationsByName.get_skill;
-      expect('source_id' in op.params).toBe(true); // has the param, but it is a mode switch
-      const params: Record<string, unknown> = { name: 'ingest' };
-      applyThinClientSourceScope(op, params, '/');
-      expect(params.source_id).toBeUndefined(); // would flip host catalog → brain-pack lookup
-    });
-  });
-
-  test('get_skill: explicit --source errors instead of masquerading as --source-id', async () => {
-    await withEnv({ GBRAIN_SOURCE: undefined }, () => {
-      const op = operationsByName.get_skill;
-      const params: Record<string, unknown> = { name: 'ingest', source: 'wiki' };
-      expect(() => applyThinClientSourceScope(op, params, '/')).toThrow(/--source-id/);
-    });
-  });
-
-  test('get_skill: explicit --source-id passes through untouched', async () => {
-    await withEnv({ GBRAIN_SOURCE: 'gstack' }, () => {
-      const op = operationsByName.get_skill;
-      const params: Record<string, unknown> = { name: 'ingest', source_id: 'wiki' };
-      applyThinClientSourceScope(op, params, '/');
-      expect(params.source_id).toBe('wiki');
-    });
-  });
-
-  test('no scope from any tier leaves params unchanged', async () => {
-    await withEnv({ GBRAIN_SOURCE: undefined }, () => {
-      const params = parseOpArgs(queryOp, ['find things']);
-      applyThinClientSourceScope(queryOp, params, '/');
-      expect(params.source_id).toBeUndefined();
-    });
-  });
-});