diff --git a/open-sse/executors/antigravity.ts b/open-sse/executors/antigravity.ts
index 426003c552..d819a5c92d 100644
--- a/open-sse/executors/antigravity.ts
+++ b/open-sse/executors/antigravity.ts
@@ -22,7 +22,11 @@ import {
 import { persistCreditBalance, getAllPersistedCreditBalances } from "@/lib/db/creditBalance";
 import { setConnectionRateLimitUntil } from "@/lib/db/providers";
 import { getMitmAlias } from "@/lib/db/models";
-import { getExplicitModelOutputCap } from "@/lib/modelCapabilities";
+import {
+  MAX_ANTIGRAVITY_OUTPUT_TOKENS,
+  resolveAntigravityOutputCap,
+} from "./antigravityOutputCap.ts";
+export { MAX_ANTIGRAVITY_OUTPUT_TOKENS } from "./antigravityOutputCap.ts";
 import { ensureAntigravityProjectAssigned } from "../services/antigravityProjectBootstrap.ts";
 import { persistDiscoveredAntigravityProjectId } from "../services/antigravityProjectPersist.ts";
 import {
@@ -279,57 +283,6 @@ async function cleanModelName(model: string, modelIdOverride?: string): Promise<
   return clean;
 }
 
-/**
- * Fallback ceiling on `generationConfig.maxOutputTokens` for Antigravity
- * Cloud Code, used when the model is unknown to the catalogue.
- *
- * Ports decolua/9router#779 (lukmanfauzie): VS Code GitHub Copilot Chat in
- * Agent mode regularly requests 32K–65K output tokens, which the Antigravity
- * backend rejects with HTTP 400 "Invalid Argument". 16384 was the ceiling
- * confirmed safe at the time, via successful 200 OK runs with
- * claude-sonnet-4-6 and gemini-pro-agent across both Ask and Agent modes.
- *
- * Both of those models are catalogue-known today, so neither one reaches this
- * constant anymore: they get their own declared limit via
- * `resolveAntigravityOutputCap` (65536 and 65535, respectively). The higher
- * limit holds against the live upstream. A gemini-3.6-flash-high request came
- * back with completion_tokens 16754 and finish_reason "stop", which exceeds
- * 16384 on its own and so cannot be an artifact of thinking-token accounting.
- *
- * Note also that #779 was reported against Copilot Chat in Agent mode, a path
- * that does not reach this executor, so 16384 arrived with that port rather
- * than from a limit measured here. Beware of re-deriving it from a running
- * instance: the clamp below rewrites maxOutputTokens before the request
- * leaves, so a build still carrying a low constant measures its own clamp and
- * reports it as an upstream ceiling.
- */
-export const MAX_ANTIGRAVITY_OUTPUT_TOKENS = 16384;
-
-/**
- * The output ceiling this specific model accepts, or the conservative
- * fallback above when the id is not in the catalogue.
- *
- * The declared limits are not uniform: most Antigravity models publish
- * 65535 or 65536, but gpt-oss-120b-medium publishes 32768. A single global
- * ceiling either starves the first group or lets an oversized request
- * through to the second, so the number has to come from the model.
- */
-function resolveAntigravityOutputCap(modelId: string | null | undefined): number {
-  const id = typeof modelId === "string" ? modelId.trim() : "";
-  if (!id) return MAX_ANTIGRAVITY_OUTPUT_TOKENS;
-  try {
-    const declared = getExplicitModelOutputCap({ provider: "antigravity", model: id });
-    return typeof declared === "number" && Number.isFinite(declared) && declared > 0
-      ? declared
-      : MAX_ANTIGRAVITY_OUTPUT_TOKENS;
-  } catch {
-    // DB not available (build phase, transient error) -- fall through to the
-    // conservative fallback, the same guard cleanModelName uses above for
-    // its own MITM alias lookup.
-    return MAX_ANTIGRAVITY_OUTPUT_TOKENS;
-  }
-}
-
 function applyAntigravityGenerationDefaults(
   request: Record<string, unknown>,
   modelId?: string | null
diff --git a/open-sse/executors/antigravityOutputCap.ts b/open-sse/executors/antigravityOutputCap.ts
new file mode 100644
index 0000000000..c3d173cd92
--- /dev/null
+++ b/open-sse/executors/antigravityOutputCap.ts
@@ -0,0 +1,52 @@
+import { getExplicitModelOutputCap } from "@/lib/modelCapabilities";
+
+/**
+ * Fallback ceiling on `generationConfig.maxOutputTokens` for Antigravity
+ * Cloud Code, used when the model is unknown to the catalogue.
+ *
+ * Ports decolua/9router#779 (lukmanfauzie): VS Code GitHub Copilot Chat in
+ * Agent mode regularly requests 32K–65K output tokens, which the Antigravity
+ * backend rejects with HTTP 400 "Invalid Argument". 16384 was the ceiling
+ * confirmed safe at the time, via successful 200 OK runs with
+ * claude-sonnet-4-6 and gemini-pro-agent across both Ask and Agent modes.
+ *
+ * Both of those models are catalogue-known today, so neither one reaches this
+ * constant anymore: they get their own declared limit via
+ * `resolveAntigravityOutputCap` (65536 and 65535, respectively). The higher
+ * limit holds against the live upstream. A gemini-3.6-flash-high request came
+ * back with completion_tokens 16754 and finish_reason "stop", which exceeds
+ * 16384 on its own and so cannot be an artifact of thinking-token accounting.
+ *
+ * Note also that #779 was reported against Copilot Chat in Agent mode, a path
+ * that does not reach this executor, so 16384 arrived with that port rather
+ * than from a limit measured here. Beware of re-deriving it from a running
+ * instance: the clamp below rewrites maxOutputTokens before the request
+ * leaves, so a build still carrying a low constant measures its own clamp and
+ * reports it as an upstream ceiling.
+ */
+export const MAX_ANTIGRAVITY_OUTPUT_TOKENS = 16384;
+
+/**
+ * The output ceiling this specific model accepts, or the conservative
+ * fallback above when the id is not in the catalogue.
+ *
+ * The declared limits are not uniform: most Antigravity models publish
+ * 65535 or 65536, but gpt-oss-120b-medium publishes 32768. A single global
+ * ceiling either starves the first group or lets an oversized request
+ * through to the second, so the number has to come from the model.
+ */
+export function resolveAntigravityOutputCap(modelId: string | null | undefined): number {
+  const id = typeof modelId === "string" ? modelId.trim() : "";
+  if (!id) return MAX_ANTIGRAVITY_OUTPUT_TOKENS;
+  try {
+    const declared = getExplicitModelOutputCap({ provider: "antigravity", model: id });
+    return typeof declared === "number" && Number.isFinite(declared) && declared > 0
+      ? declared
+      : MAX_ANTIGRAVITY_OUTPUT_TOKENS;
+  } catch {
+    // DB not available (build phase, transient error) -- fall through to the
+    // conservative fallback, the same guard cleanModelName uses above for
+    // its own MITM alias lookup.
+    return MAX_ANTIGRAVITY_OUTPUT_TOKENS;
+  }
+}