diff --git a/src/sse/services/auth.ts b/src/sse/services/auth.ts
index a261dfe065..d206825a68 100644
--- a/src/sse/services/auth.ts
+++ b/src/sse/services/auth.ts
@@ -927,6 +927,8 @@ export { readHeaderValue, type AuthRequestHeaders } from "./headerReader.ts";
 const PROVIDER_SEARCH_PAIRS: string[][] = [
   ["nvidia", "nvidia_nim"],
   ["kimi-coding", "kimi-coding-apikey"],
+  // The model layer canonicalizes `agy/` to `antigravity`, but the Antigravity
+  // CLI card stores its connection under `agy`. Same account, either id serves.
   ["antigravity", "agy"],
 ];
 /**
diff --git a/tests/unit/8779-agy-prefix-credential-lookup.test.ts b/tests/unit/8779-agy-prefix-credential-lookup.test.ts
new file mode 100644
index 0000000000..446f1e708b
--- /dev/null
+++ b/tests/unit/8779-agy-prefix-credential-lookup.test.ts
@@ -0,0 +1,98 @@
+/**
+ * #8779 -- an `agy/` request must find the connection the user actually
+ * authorized, which is stored under `agy`.
+ *
+ * The model layer deliberately canonicalizes the `agy/` prefix to
+ * `antigravity` (#8013 aligned the official clients and the callable catalog,
+ * and DEFAULT_MODEL_ALIAS_SEED ships `gemini-3.1-pro -> agy/gemini-pro-agent`
+ * on that assumption). The connections layer does the opposite: the Antigravity
+ * CLI card writes its row under `agy`.
+ *
+ * Those two are individually intentional and jointly broken. An operator whose
+ * only Antigravity connections came from the CLI card gets
+ * "No credentials for antigravity" on every request. A deployment that also has
+ * `antigravity` rows never sees it -- the lookup finds those instead and the
+ * `agy` rows simply go unused, which is why this survived in production.
+ *
+ * Fixed by pairing the two ids in PROVIDER_SEARCH_PAIRS, the mechanism that
+ * already exists for exactly this (nvidia/nvidia_nim, #922).
+ */
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-8779-agy-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const providersDb = await import("../../src/lib/db/providers.ts");
+const auth = await import("../../src/sse/services/auth.ts");
+const model = await import("../../open-sse/services/model.ts");
+
+async function resetStorage() {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+}
+
+async function seedOnly(provider: string) {
+  await resetStorage();
+  await providersDb.createProviderConnection({
+    provider,
+    authType: "oauth",
+    email: `${provider}@example.test`,
+    accessToken: `tok-${provider}`,
+    isActive: true,
+    testStatus: "active",
+    priority: 1,
+  });
+}
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+test("the agy/ prefix still canonicalizes to antigravity (#8013 unchanged)", () => {
+  const parsed = model.parseModel("agy/gemini-3-pro");
+  assert.equal(parsed.provider, "antigravity");
+  assert.equal(parsed.providerAlias, "agy");
+});
+
+test("an agy/ request finds credentials when only agy connections exist", async () => {
+  await seedOnly("agy");
+
+  // The real path: parse the model string, then ask for the credentials of
+  // whatever provider the parse produced. Before the fix this returned null
+  // and logged "No credentials for antigravity".
+  const parsed = model.parseModel("agy/gemini-3-pro");
+  const creds = await auth.getProviderCredentials(parsed.provider as string);
+
+  assert.ok(
+    creds,
+    `no credentials for "${parsed.provider}" -- the agy row the CLI card wrote ` +
+      `is unreachable, which is #8779`
+  );
+});
+
+test("the pair works in the other direction too", async () => {
+  await seedOnly("antigravity");
+  const creds = await auth.getProviderCredentials("agy");
+  assert.ok(creds, "an antigravity row must serve an agy lookup");
+});
+
+test("each id still finds its own rows", async () => {
+  await seedOnly("agy");
+  assert.ok(await auth.getProviderCredentials("agy"));
+
+  await seedOnly("antigravity");
+  assert.ok(await auth.getProviderCredentials("antigravity"));
+});
+
+test("the pair does not make unrelated providers findable", async () => {
+  await seedOnly("agy");
+  // gemini shares the upstream vendor but not the account; it must stay empty.
+  assert.equal(await auth.getProviderCredentials("gemini"), null);
+});