diff --git a/src/lib/memory/embedding/index.ts b/src/lib/memory/embedding/index.ts
index 0033e6c9e6..2713847d7c 100644
--- a/src/lib/memory/embedding/index.ts
+++ b/src/lib/memory/embedding/index.ts
@@ -1,6 +1,7 @@
 import {
   EMBEDDING_PROVIDERS,
   buildDynamicEmbeddingProvider,
+  getEmbeddingDimension,
   type EmbeddingProviderNodeRow,
 } from "@omniroute/open-sse/config/embeddingRegistry.ts";
 import { getProviderCredentials } from "@/sse/services/auth";
@@ -40,6 +41,31 @@ function makeSignature(
   return `${source ?? "null"}:${model ?? "null"}:${dim ?? "null"}`;
 }
 
+/**
+ * Look up a remote model's vector size from the embedding registry.
+ * Returns null when the model is unknown / has no recorded dimensions so
+ * callers can keep the lazy-probe path (#8074).
+ */
+function resolveRemoteDimensions(model: string): number | null {
+  const dim = getEmbeddingDimension(model);
+  return typeof dim === "number" ? dim : null;
+}
+
+/** Build the remote EmbeddingResolution used by both explicit + auto paths. */
+function remoteResolution(model: string, reasonPrefix: string): EmbeddingResolution {
+  const dimensions = resolveRemoteDimensions(model);
+  return {
+    source: "remote",
+    model,
+    dimensions,
+    signature: makeSignature("remote", model, dimensions),
+    reason:
+      dimensions !== null
+        ? `${reasonPrefix}: ${model} (dim=${dimensions})`
+        : `${reasonPrefix}: ${model} (dim=unknown, will probe at embed time)`,
+  };
+}
+
 /**
  * Resolve which embedding source is active for the given settings (D4).
  * Pure: no heavy I/O. Provider key check done via synchronous registry lookup.
@@ -61,14 +87,9 @@ export function resolveEmbeddingSource(settings: MemorySettingsExtended): Embedd
     }
     // We can't do async here, so we report it as potentially available
     // and the caller will attempt embed + get no_key error on failure.
-    // For resolution purposes, mark as remote (will fail at embed time if no key).
-    return {
-      source: "remote",
-      model,
-      dimensions: null,
-      signature: makeSignature("remote", model, null),
-      reason: `remote provider configured: ${model}`,
-    };
+    // Dimensions come from the embedding registry when known so sqlite-vec
+    // can create `vec_memories` before the first embed (#8074).
+    return remoteResolution(model, "remote provider configured");
   }
 
   if (source === "static") {
@@ -123,13 +144,8 @@ export function resolveEmbeddingSource(settings: MemorySettingsExtended): Embedd
         // We defer the actual hasKey check to listEmbeddingProviders (async).
         // For resolveEmbeddingSource (sync), we report "possibly remote" when model is set.
         // If no key, embed will return EmbeddingError{reason:"no_key"}.
-        return {
-          source: "remote",
-          model: providerModel,
-          dimensions: null,
-          signature: makeSignature("remote", providerModel, null),
-          reason: `auto: provider ${providerId} configured`,
-        };
+        // Dimensions are resolved from the registry when known (#8074).
+        return remoteResolution(providerModel, `auto: provider ${providerId} configured`);
       }
     }
 
diff --git a/src/lib/memory/reindex.ts b/src/lib/memory/reindex.ts
index 1b9175fb5b..da7317b10a 100644
--- a/src/lib/memory/reindex.ts
+++ b/src/lib/memory/reindex.ts
@@ -50,9 +50,21 @@ export async function runReindexBatch(
     return { processed: 0, errors: 0 };
   }
 
-  // Ensure the vector table is ready before processing
+  // Ensure the vector table is ready before processing. ensureReady() returns
+  // `{ ready: false }` (without throwing) when dimensions are still unknown —
+  // abort the batch in that case so we don't burn embed credits upserting into
+  // a missing `vec_memories` table (#8074).
   try {
-    await vec.ensureReady(resolution);
+    const ready = await vec.ensureReady(resolution);
+    if (!ready.ready) {
+      log.warn("memory.reindex.ensure_ready.skipped", {
+        reason: ready.reason,
+        pending: queue.length,
+        model: resolution.model,
+        dimensions: resolution.dimensions,
+      });
+      return { processed: 0, errors: 0 };
+    }
   } catch (err: unknown) {
     log.warn("memory.reindex.ensure_ready.fail", {
       error: sanitizeErrorMessage(err instanceof Error ? err.message : String(err)),
diff --git a/tests/unit/memory-embedding-resolve.test.ts b/tests/unit/memory-embedding-resolve.test.ts
index 7a38d6d0af..590ee309b1 100644
--- a/tests/unit/memory-embedding-resolve.test.ts
+++ b/tests/unit/memory-embedding-resolve.test.ts
@@ -93,6 +93,57 @@ describe("resolveEmbeddingSource", () => {
     assert.strictEqual(res.model, "openai/text-embedding-3-small");
   });
 
+  // #8074 — remote resolution must surface registry dimensions so sqlite-vec
+  // can create `vec_memories` before the first embed/upsert.
+  it("explicit 'remote' + known registry model => dimensions from embeddingRegistry (#8074)", () => {
+    const res = resolveEmbeddingSource(
+      makeSettings({
+        embeddingSource: "remote",
+        embeddingProviderModel: "openai/text-embedding-3-small",
+      })
+    );
+    assert.strictEqual(res.dimensions, 1536);
+    assert.ok(
+      res.signature.endsWith(":1536"),
+      `signature should include dim=1536, got: ${res.signature}`
+    );
+    assert.ok(
+      res.reason.includes("dim=1536"),
+      `reason should mention dim=1536, got: ${res.reason}`
+    );
+  });
+
+  it("auto + known nvidia model => dimensions from embeddingRegistry (#8074)", () => {
+    const res = resolveEmbeddingSource(
+      makeSettings({
+        embeddingSource: "auto",
+        embeddingProviderModel: "nvidia/nv-embedqa-e5-v5",
+      })
+    );
+    assert.strictEqual(res.source, "remote");
+    assert.strictEqual(res.dimensions, 1024);
+    assert.ok(
+      res.signature.endsWith(":1024"),
+      `signature should include dim=1024, got: ${res.signature}`
+    );
+  });
+
+  it("explicit 'remote' + unknown custom model => dimensions null (lazy probe) (#8074)", () => {
+    const res = resolveEmbeddingSource(
+      makeSettings({
+        embeddingSource: "remote",
+        // Not in EMBEDDING_PROVIDERS — keep the lazy-probe path.
+        embeddingProviderModel: "openai-compatible-local/my-custom-embed",
+      })
+    );
+    assert.strictEqual(res.source, "remote");
+    assert.strictEqual(res.dimensions, null);
+    assert.ok(
+      res.reason.includes("dim=unknown"),
+      `reason should mention dim=unknown, got: ${res.reason}`
+    );
+  });
+
   it("explicit 'static' + staticEnabled=true => source static", () => {
     const res = resolveEmbeddingSource(
       makeSettings({