fix(ai,search,cli): read embed-shim bodies once (#1610); zero-hit source hint (#1484); log swallowed vector-arm failures (#1626)

Three backlog fixes:

- #1610: voyageCompatFetch/zeroEntropyCompatFetch read the response body
  ONCE via text() + JSON.parse instead of resp.clone().json(). On bun <
  1.1.27 clone() truncates large bodies (oven-sh/bun#6348), the parse threw,
  and the catch fell back to the raw provider shape the AI SDK schema
  rejects — multi-chunk pages died with "Invalid JSON response". Every JSON
  return path now rebuilds the Response and strips the stale
  Content-Length/Content-Encoding headers. Shims exported as test seams;
  behavioral coverage simulates the truncating clone().

- #1484: a bare `gbrain query`/`search` that returns zero results on a
  multi-source brain now prints a stderr hint naming the source that was
  actually searched and how to widen scope (--source-id __all__). Fires only
  when the caller didn't scope explicitly; best-effort (lookup failure is
  silent). Default scope stays unchanged — widening to __all__ is a separate
  maintainer policy call.

- #1626: hybridSearch's text-vector arm no longer swallows failures dark.
  The arm only runs when the embedding provider probed available, so a throw
  (embed timeout, transient pooler error on the searchVector fan-out) now
  logs the reason via warnOncePerProcess while keeping the keyword
  fallback — a cross-source __all__ run can no longer collapse to
  "No results" with zero diagnostics.

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

src/cli.ts

@@ -466,6 +466,11 @@ async function main() {
     const result = JSON.parse(JSON.stringify(rawResult, bigintToStringReplacer));
     const output = formatResult(op.name, result);
     if (output) process.stdout.write(output);
+    // #1484 — invisible-miss hint: a bare query/search that hit zero results
+    // on a multi-source brain tells the user (stderr) which source it
+    // actually searched and how to widen the scope.
+    const hint = await sourceScopeHint(op.name, params, ctx.sourceId, engine, result);
+    if (hint) console.error(hint);
   } catch (e: unknown) {
     // v0.42.20.0 (codex D4): on error, set exitCode + return so the `finally`
     // STILL runs (drains every background-work sink + disconnects). A bare
@@ -837,6 +842,44 @@ async function makeContext(engine: BrainEngine, params: Record<string, unknown>)
   };
 }
 
+/**
+ * #1484 — a bare `gbrain query`/`search` silently scopes to the resolved
+ * source (usually 'default'); on a multi-source brain a zero-hit run looks
+ * identical to "the brain doesn't know this" even when the answer lives in
+ * another source. Returns a stderr hint when (a) the op is query/search,
+ * (b) it returned zero results, (c) the caller did NOT scope explicitly
+ * (--source / --source-id / --all-sources), and (d) the brain has >1
+ * registered source. Best-effort: any lookup failure returns null.
+ *
+ * Exported for tests (same import-safety contract as formatResult).
+ */
+export async function sourceScopeHint(
+  opName: string,
+  params: Record<string, unknown>,
+  sourceId: string,
+  engine: BrainEngine,
+  result: unknown,
+): Promise<string | null> {
+  if (opName !== 'query' && opName !== 'search') return null;
+  if (!Array.isArray(result) || result.length > 0) return null;
+  // Explicit scoping (flag tier) = user intent; don't second-guess it.
+  if (params.source || params.source_id || params.all_sources) return null;
+  if (sourceId === '__all__') return null;
+  try {
+    const rows = await engine.executeRaw<{ n: number }>(
+      `SELECT count(*)::int AS n FROM sources`,
+    );
+    const n = Number(rows[0]?.n ?? 0);
+    if (n <= 1) return null;
+    return (
+      `Hint: this brain has ${n} sources; you searched only "${sourceId}". ` +
+      `Retry with --source-id __all__ (all sources) or --source-id <id>.`
+    );
+  } catch {
+    return null; // hint is best-effort; never fail the query over it
+  }
+}
+
 // Exported for tests (same import-safety contract as cliAliases/printOpHelp).
 export function formatResult(opName: string, result: unknown): string {
   switch (opName) {

src/core/ai/gateway.ts

@@ -1000,9 +1000,24 @@ const voyageCompatFetch = (async (input: RequestInfo | URL, init?: RequestInit)
   // Voyage diverges from OpenAI in two places that break the parser:
   //   - `embedding` is a base64 string (SDK schema expects `number[]`)
   //   - `usage` lacks `prompt_tokens` (SDK schema requires it when usage present)
+  //
+  // #1610: read the body ONCE via text() and JSON.parse it. The pre-fix
+  // `await resp.clone().json()` truncated large bodies on bun < 1.1.27
+  // (oven-sh/bun#6348) — the parse threw, the catch fell back to the raw
+  // response, and multi-chunk pages died with "Invalid JSON response".
+  // Every JSON return path below rebuilds the Response so a stale
+  // Content-Length/Content-Encoding header from the original can't lie
+  // about the rewritten body.
+  const bodyText = await resp.text();
+  const rebuild = (body: string) => {
+    const headers = new Headers(resp.headers);
+    headers.delete('content-length');
+    headers.delete('content-encoding');
+    return new Response(body, { status: resp.status, statusText: resp.statusText, headers });
+  };
   try {
-    const json: any = await resp.clone().json();
-    if (!json || typeof json !== 'object') return resp;
+    const json: any = JSON.parse(bodyText);
+    if (!json || typeof json !== 'object') return rebuild(bodyText);
     let modified = false;
     if (Array.isArray(json.data)) {
       for (const item of json.data) {
@@ -1037,22 +1052,19 @@ const voyageCompatFetch = (async (input: RequestInfo | URL, init?: RequestInit)
         : 0;
       modified = true;
     }
-    if (!modified) return resp;
-    return new Response(JSON.stringify(json), {
-      status: resp.status,
-      statusText: resp.statusText,
-      headers: resp.headers,
-    });
+    if (!modified) return rebuild(bodyText);
+    return rebuild(JSON.stringify(json));
   } catch (err) {
     // OOM-cap throws MUST propagate. The catch is here for "Voyage returned
     // JSON I can't reshape" (parse error, unexpected schema) — falling back
-    // to the original response is correct in that case. Letting the
+    // to the original body is correct in that case. Letting the
     // too-large response through here would defeat the entire purpose of
     // Layer 2 (the per-embedding cap that fires when Content-Length wasn't
     // available to Layer 1).
     if (err instanceof VoyageResponseTooLargeError) throw err;
-    // If parsing/transformation fails, fall back to the original response.
-    return resp;
+    // If parsing/transformation fails, pass the original body through
+    // (rebuilt — resp's body stream is already consumed by text()).
+    return rebuild(bodyText);
   }
 }) as unknown as typeof fetch;
 
@@ -1192,9 +1204,21 @@ const zeroEntropyCompatFetch = (async (input: RequestInfo | URL, init?: RequestI
   // validates. Also map usage.total_tokens → prompt_tokens (SDK requires
   // prompt_tokens when `usage` is present — same divergence Voyage hit at
   // gateway.ts:655).
+  //
+  // #1610: read the body ONCE via text() + JSON.parse — `resp.clone().json()`
+  // truncated large bodies on bun < 1.1.27 (oven-sh/bun#6348), so the parse
+  // threw and the catch fell back to the RAW ZE `{results: ...}` shape, which
+  // the AI SDK schema rejects → "Invalid JSON response" on multi-chunk pages.
+  const bodyText = await resp.text();
+  const rebuild = (body: string) => {
+    const headers = new Headers(resp.headers);
+    headers.delete('content-length');
+    headers.delete('content-encoding');
+    return new Response(body, { status: resp.status, statusText: resp.statusText, headers });
+  };
   try {
-    const json: any = await resp.clone().json();
-    if (!json || typeof json !== 'object') return resp;
+    const json: any = JSON.parse(bodyText);
+    if (!json || typeof json !== 'object') return rebuild(bodyText);
     let modified = false;
     if (Array.isArray(json.results) && !Array.isArray(json.data)) {
       // Layer 2 OOM cap — per-embedding size. ZE returns float[] arrays,
@@ -1228,20 +1252,25 @@ const zeroEntropyCompatFetch = (async (input: RequestInfo | URL, init?: RequestI
       // SDK also expects total_tokens; ZE provides it directly.
       modified = true;
     }
-    if (!modified) return resp;
-    return new Response(JSON.stringify(json), {
-      status: resp.status,
-      statusText: resp.statusText,
-      headers: resp.headers,
-    });
+    if (!modified) return rebuild(bodyText);
+    return rebuild(JSON.stringify(json));
   } catch (err) {
     // OOM-cap throws MUST propagate. Voyage's pattern: instanceof check on
     // its own tagged class. Same here — only rethrow our own cap class.
     if (err instanceof ZeroEntropyResponseTooLargeError) throw err;
-    return resp;
+    return rebuild(bodyText);
   }
 }) as unknown as typeof fetch;
 
+/**
+ * Test-only seams (#1610): the compat shims are module-private closures;
+ * exporting them lets tests drive the response-rewrite paths behaviorally
+ * (truncating clone(), stale Content-Length) without a live provider.
+ * Same pattern as __getShrinkStateForTests.
+ */
+export const __voyageCompatFetchForTests = voyageCompatFetch;
+export const __zeroEntropyCompatFetchForTests = zeroEntropyCompatFetch;
+
 /**
  * Generic asymmetric-embedding shim for openai-compatible recipes that
  * ship no compat fetch of their own (llama-server, litellm, ollama, ...).

src/core/search/hybrid.ts

@@ -1323,8 +1323,18 @@ export async function hybridSearch(
       if (effectiveModality === 'both' && imageVectorList !== null) {
         vectorLists = [...vectorLists, imageVectorList];
       }
-    } catch {
-      // Embedding failure is non-fatal, fall back to keyword-only
+    } catch (err) {
+      // Embedding/vector failure is non-fatal — fall back to keyword-only —
+      // but say WHY (#1626): this arm only runs when the embedding provider
+      // probed available, so a throw here is a real failure (embed timeout,
+      // transient pooler error on the searchVector fan-out). Pre-fix the bare
+      // catch made a cross-source `--source __all__` run silently collapse to
+      // keyword-only/"No results" with zero diagnostics.
+      warnOncePerProcess(
+        'hybrid-vector-arm-failed',
+        `[gbrain] vector arm failed (fail-open, keyword-only fallback): ` +
+          `${err instanceof Error ? err.message : String(err)}`,
+      );
     }
   }
 

test/ai/compat-fetch-body-read.serial.test.ts

@@ -0,0 +1,115 @@
+/**
+ * #1610 — Voyage/ZeroEntropy compat shims must read the response body ONCE
+ * via text() instead of `resp.clone().json()`.
+ *
+ * On bun < 1.1.27, Response.clone() truncates large bodies (oven-sh/bun#6348):
+ * the clone().json() parse threw, the shim's catch fell back to the ORIGINAL
+ * response — whose wire shape (ZE `{results: ...}`, Voyage base64 embeddings)
+ * the AI SDK's openai-compatible Zod schema rejects — and multi-chunk pages
+ * failed with "Invalid JSON response".
+ *
+ * These tests simulate the truncating clone() and assert the shims still
+ * return the fully rewritten body. They also pin that the rewritten Response
+ * does NOT carry the original (now stale) Content-Length header, which lied
+ * about the rewritten body's size (gateway.ts previously copied
+ * `headers: resp.headers` verbatim).
+ */
+
+import { afterEach, describe, expect, test } from 'bun:test';
+import {
+  __voyageCompatFetchForTests,
+  __zeroEntropyCompatFetchForTests,
+} from '../../src/core/ai/gateway.ts';
+
+const origFetch = globalThis.fetch;
+afterEach(() => {
+  globalThis.fetch = origFetch;
+});
+
+/** Build a Response whose clone() truncates the body (bun < 1.1.27 behavior). */
+function truncatingCloneResponse(body: string): Response {
+  const headers = {
+    'content-type': 'application/json',
+    // Deliberately stale after any rewrite: the original wire body's length.
+    'content-length': String(Buffer.byteLength(body)),
+  };
+  const resp = new Response(body, { status: 200, headers });
+  (resp as any).clone = () =>
+    new Response(body.slice(0, 32), { status: 200, headers });
+  return resp;
+}
+
+describe('voyageCompatFetch — single body read (#1610)', () => {
+  test('rewrites base64 embeddings even when clone() truncates the body', async () => {
+    const floats = new Float32Array([0.5, 0.25, -1]);
+    const b64 = Buffer.from(floats.buffer).toString('base64');
+    const wireBody = JSON.stringify({
+      object: 'list',
+      data: [{ object: 'embedding', embedding: b64, index: 0 }],
+      model: 'voyage-3',
+      usage: { total_tokens: 7 },
+    });
+    globalThis.fetch = (async () => truncatingCloneResponse(wireBody)) as unknown as typeof fetch;
+
+    const out = await __voyageCompatFetchForTests('https://api.voyageai.com/v1/embeddings', {
+      method: 'POST',
+      body: JSON.stringify({ input: ['hello'], model: 'voyage-3' }),
+      headers: { 'content-type': 'application/json' },
+    });
+
+    const json: any = await out.json();
+    expect(Array.from(json.data[0].embedding)).toEqual([0.5, 0.25, -1]);
+    expect(json.usage.prompt_tokens).toBe(7);
+    // Stale Content-Length from the wire body must not survive the rewrite.
+    expect(out.headers.get('content-length')).toBeNull();
+    expect(out.headers.get('content-encoding')).toBeNull();
+  });
+});
+
+describe('zeroEntropyCompatFetch — single body read (#1610)', () => {
+  test('rewrites {results} → {data} even when clone() truncates the body', async () => {
+    const wireBody = JSON.stringify({
+      results: [{ embedding: [0.1, 0.2] }, { embedding: [0.3, 0.4] }],
+      usage: { total_bytes: 42, total_tokens: 9 },
+    });
+    let fetchedUrl = '';
+    globalThis.fetch = (async (url: string | URL | Request) => {
+      fetchedUrl = String(url);
+      return truncatingCloneResponse(wireBody);
+    }) as unknown as typeof fetch;
+
+    const out = await __zeroEntropyCompatFetchForTests('https://api.zeroentropy.dev/v1/embeddings', {
+      method: 'POST',
+      body: JSON.stringify({ input: ['hello'], model: 'zembed-1' }),
+      headers: { 'content-type': 'application/json' },
+    });
+
+    expect(fetchedUrl.endsWith('/v1/models/embed')).toBe(true);
+    const json: any = await out.json();
+    // The AI SDK schema requires {data: [{embedding, index}]} — the raw ZE
+    // {results} fallback is exactly the pre-fix "Invalid JSON response".
+    expect(json.results).toBeUndefined();
+    expect(json.data).toHaveLength(2);
+    expect(json.data[0]).toEqual({ object: 'embedding', embedding: [0.1, 0.2], index: 0 });
+    expect(json.data[1].index).toBe(1);
+    expect(json.usage.prompt_tokens).toBe(9);
+    expect(out.headers.get('content-length')).toBeNull();
+  });
+
+  test('non-JSON body falls back to the original bytes (rebuilt, still readable)', async () => {
+    const wireBody = 'plain text, not json';
+    globalThis.fetch = (async () =>
+      new Response(wireBody, {
+        status: 200,
+        headers: { 'content-type': 'application/json' },
+      })) as unknown as typeof fetch;
+
+    const out = await __zeroEntropyCompatFetchForTests('https://api.zeroentropy.dev/v1/embeddings', {
+      method: 'POST',
+      body: JSON.stringify({ input: ['hello'] }),
+    });
+    // Body was consumed by the shim's single read; the fallback must
+    // rebuild a readable Response rather than return the drained original.
+    expect(await out.text()).toBe(wireBody);
+  });
+});

test/ai/zeroentropy-compat-fetch.test.ts

@@ -98,16 +98,18 @@ describe('zeroEntropyCompatFetch — OOM caps', () => {
     expect(src).toMatch(/MAX_ZEROENTROPY_RESPONSE_BYTES\s*=\s*256\s*\*\s*1024\s*\*\s*1024/);
   });
 
-  test('Layer 1: Content-Length pre-check before resp.clone().json()', async () => {
+  test('Layer 1: Content-Length pre-check before the body is read', async () => {
     const src = await Bun.file(GATEWAY_PATH).text();
     // Find the zeroEntropyCompatFetch block bounds, then assert ordering
-    // within it (mirroring the voyage cap test pattern).
+    // within it (mirroring the voyage cap test pattern). #1610 moved the
+    // body read from `resp.clone().json()` to a single `resp.text()` (bun
+    // < 1.1.27 truncates clone()d bodies, oven-sh/bun#6348).
     const zeFetchStart = src.indexOf('const zeroEntropyCompatFetch');
     expect(zeFetchStart).toBeGreaterThan(0);
-    const block = src.slice(zeFetchStart, zeFetchStart + 8000);
+    const block = src.slice(zeFetchStart, zeFetchStart + 9000);
 
     const preCheckIdx = block.indexOf("resp.headers.get('content-length')");
-    const jsonParseIdx = block.indexOf('await resp.clone().json()');
+    const jsonParseIdx = block.indexOf('const bodyText = await resp.text()');
     expect(preCheckIdx).toBeGreaterThan(0);
     expect(jsonParseIdx).toBeGreaterThan(0);
     // The pre-check MUST appear before the JSON parse — Voyage's lesson

test/cli-source-scope-hint.test.ts

@@ -0,0 +1,61 @@
+/**
+ * #1484 — invisible-miss hint. A bare `gbrain query` resolves to a single
+ * source (usually 'default'); on a multi-source brain a zero-hit run gave no
+ * signal that the answer might live in another source. sourceScopeHint
+ * returns the stderr hint exactly when: query/search op + zero results +
+ * no explicit scoping param + >1 registered source.
+ */
+
+import { describe, expect, test } from 'bun:test';
+import { sourceScopeHint } from '../src/cli.ts';
+import type { BrainEngine } from '../src/core/engine.ts';
+
+function fakeEngine(sourceCount: number, fail = false): BrainEngine {
+  return {
+    executeRaw: async () => {
+      if (fail) throw new Error('sources table missing');
+      return [{ n: sourceCount }];
+    },
+  } as unknown as BrainEngine;
+}
+
+describe('sourceScopeHint (#1484)', () => {
+  test('fires on a bare zero-hit query against a multi-source brain', async () => {
+    const hint = await sourceScopeHint('query', {}, 'default', fakeEngine(3), []);
+    expect(hint).toContain('3 sources');
+    expect(hint).toContain('"default"');
+    expect(hint).toContain('--source-id __all__');
+  });
+
+  test('fires for search too', async () => {
+    const hint = await sourceScopeHint('search', {}, 'wiki', fakeEngine(2), []);
+    expect(hint).toContain('"wiki"');
+  });
+
+  test('silent when results were found', async () => {
+    expect(await sourceScopeHint('query', {}, 'default', fakeEngine(3), [{ slug: 'a' }])).toBeNull();
+  });
+
+  test('silent when the caller scoped explicitly', async () => {
+    expect(await sourceScopeHint('query', { source_id: 'wiki' }, 'wiki', fakeEngine(3), [])).toBeNull();
+    expect(await sourceScopeHint('query', { source: 'wiki' }, 'wiki', fakeEngine(3), [])).toBeNull();
+    expect(await sourceScopeHint('query', { all_sources: true }, '__all__', fakeEngine(3), [])).toBeNull();
+  });
+
+  test('silent when the resolved scope is already __all__', async () => {
+    expect(await sourceScopeHint('query', {}, '__all__', fakeEngine(3), [])).toBeNull();
+  });
+
+  test('silent on a single-source brain', async () => {
+    expect(await sourceScopeHint('query', {}, 'default', fakeEngine(1), [])).toBeNull();
+  });
+
+  test('silent for non-search ops and non-array results', async () => {
+    expect(await sourceScopeHint('get_stats', {}, 'default', fakeEngine(3), [])).toBeNull();
+    expect(await sourceScopeHint('query', {}, 'default', fakeEngine(3), { rows: [] })).toBeNull();
+  });
+
+  test('best-effort: sources lookup failure returns null, never throws', async () => {
+    expect(await sourceScopeHint('query', {}, 'default', fakeEngine(3, true), [])).toBeNull();
+  });
+});

test/hybrid-vector-arm-warn.serial.test.ts

@@ -0,0 +1,62 @@
+/**
+ * #1626 — hybridSearch's text-vector arm must not fail DARK.
+ *
+ * The arm only runs when the embedding provider probed available, so a throw
+ * inside it (embed timeout, transient pooler error on searchVector) is a real
+ * failure. Pre-fix, a bare `catch {}` swallowed it and the run silently
+ * collapsed to keyword-only — under `--source __all__` on a strained pooler
+ * that read as a non-deterministic "No results". The fix logs the swallowed
+ * reason via warnOncePerProcess while keeping the keyword fallback.
+ */
+
+import { afterAll, beforeAll, describe, expect, test } from 'bun:test';
+import { PGLiteEngine } from '../src/core/pglite-engine.ts';
+import { hybridSearch } from '../src/core/search/hybrid.ts';
+import { __setEmbedTransportForTests } from '../src/core/ai/gateway.ts';
+import { _resetWarnOnceForTests } from '../src/core/utils.ts';
+
+let engine: PGLiteEngine;
+const origWarn = console.warn;
+
+beforeAll(async () => {
+  engine = new PGLiteEngine();
+  await engine.connect({});
+  await engine.initSchema();
+  await engine.putPage('people/alice-example', {
+    type: 'person',
+    title: 'Alice Example',
+    compiled_truth: 'Alice Example is a test person for the vector-arm warn test.',
+  });
+});
+
+afterAll(async () => {
+  console.warn = origWarn;
+  __setEmbedTransportForTests(null);
+  await engine.disconnect();
+});
+
+describe('hybridSearch vector-arm failure telemetry (#1626)', () => {
+  test('embed failure logs the swallowed reason and falls back to keyword', async () => {
+    _resetWarnOnceForTests();
+    // Installing a transport makes isAvailable('embedding') true (test-seam
+    // fast path), so the vector arm RUNS — and then throws.
+    __setEmbedTransportForTests(() => {
+      throw new Error('pooler exploded mid-fanout');
+    });
+    const warnings: string[] = [];
+    console.warn = (...args: unknown[]) => {
+      warnings.push(args.map(String).join(' '));
+    };
+    try {
+      const results = await hybridSearch(engine, 'alice');
+      // Keyword fallback still returns results — fail-open preserved.
+      expect(results.some((r) => r.slug === 'people/alice-example')).toBe(true);
+    } finally {
+      console.warn = origWarn;
+      __setEmbedTransportForTests(null);
+    }
+    const armWarnings = warnings.filter((w) => w.includes('vector arm failed'));
+    expect(armWarnings).toHaveLength(1);
+    expect(armWarnings[0]).toContain('pooler exploded mid-fanout');
+  });
+});

test/voyage-response-cap.test.ts

@@ -34,7 +34,7 @@ describe('v0.31.8 — voyage Content-Length pre-check + per-item cap', () => {
     expect(source).toMatch(/MAX_VOYAGE_RESPONSE_BYTES\s*=\s*256\s*\*\s*1024\s*\*\s*1024/);
   });
 
-  test('Layer 1: Content-Length pre-check fires BEFORE resp.clone().json() (D10 OOM defense)', async () => {
+  test('Layer 1: Content-Length pre-check fires BEFORE the body is read (D10 OOM defense)', async () => {
     const source = await Bun.file(new URL('../src/core/ai/gateway.ts', import.meta.url)).text();
     // Anchor relative to the post-fetch handler block. The function declaration
     // contains an OUTBOUND request body section earlier; we want to verify
@@ -47,8 +47,10 @@ describe('v0.31.8 — voyage Content-Length pre-check + per-item cap', () => {
     // doesn't pin to comment text.
     const preCheckIdx = inboundBlock.indexOf("resp.headers.get('content-length')");
     // Use the full lvalue assignment so the match doesn't accidentally hit
-    // comment text that mentions `await resp.clone().json()` for context.
-    const jsonParseIdx = inboundBlock.indexOf('const json: any = await resp.clone().json()');
+    // comment text that mentions the body read for context. (#1610 moved the
+    // read from `resp.clone().json()` to a single `resp.text()` — bun <
+    // 1.1.27 truncates clone()d bodies, oven-sh/bun#6348.)
+    const jsonParseIdx = inboundBlock.indexOf('const bodyText = await resp.text()');
     expect(preCheckIdx).toBeGreaterThan(0);
     expect(jsonParseIdx).toBeGreaterThan(0);
     // The pre-check MUST appear before the JSON parse — otherwise the OOM