diff --git a/docs-site/src/content/docs/guides/model-routing.md b/docs-site/src/content/docs/guides/model-routing.md
index b9f1a6b34da..ac8e6ae62bb 100644
--- a/docs-site/src/content/docs/guides/model-routing.md
+++ b/docs-site/src/content/docs/guides/model-routing.md
@@ -91,6 +91,10 @@ Routing and catalog visibility are separate controls:
   deliberately inert for them.
 - `provider.disabled: true` removes that provider from catalog discovery. Explicit
   `provider/model` requests fail, and `defaultModel` / `models[]` scans skip it.
+- Routed catalog rows are cloned from the Codex-native template, so native-only delivery flags are
+  stripped during normalization: `supports_websockets`, `supports_reasoning_summaries`, and
+  `supports_experimental_context`. A routed provider never inherits the experimental-context
+  contract; inheriting it made Codex compact after nearly every step on long routed threads.
 - `providerContextCaps` applies per-provider Codex-visible context caps. `contextCapValue` is the
   dashboard default (350,000 by default), but it does nothing by itself until a provider is
   present in `providerContextCaps`. Changing the dashboard value updates every enabled cap
diff --git a/src/codex/catalog/parsing.ts b/src/codex/catalog/parsing.ts
index fd9a4db1784..d802284aeef 100644
--- a/src/codex/catalog/parsing.ts
+++ b/src/codex/catalog/parsing.ts
@@ -803,6 +803,13 @@ export function normalizeRoutedCatalogEntry(
   delete entry.multi_agent_reasoning_effort;
   delete entry.use_responses_lite;
   delete entry.supports_websockets;
+  // Routed rows cloned from native templates must not inherit OpenAI-only experimental context
+  // delivery. Codex reads the flag as "this model accepts experimental context history" and drives
+  // its context-management cadence from it, so a third-party provider that never negotiated it gets
+  // a compact-after-every-step loop instead (observed on a routed DeepSeek row: 1,600+ compactions
+  // in a single thread). Nothing re-applies the field from provider metadata during this step, so
+  // the row leaves this normalization without it.
+  delete entry.supports_experimental_context;
   /*
    * Tier metadata is stripped from routed rows because a row cloned from a native template
    * would otherwise hand a third-party provider OpenAI's tiers.
diff --git a/tests/e2e-style/phase100-native-parity.test.ts b/tests/e2e-style/phase100-native-parity.test.ts
index 04088ace30d..abe4f8e51b2 100644
--- a/tests/e2e-style/phase100-native-parity.test.ts
+++ b/tests/e2e-style/phase100-native-parity.test.ts
@@ -18,6 +18,7 @@ function nativeTemplate(): Record<string, unknown> {
     multi_agent_version: "v2",
     use_responses_lite: true,
     supports_websockets: true,
+    supports_experimental_context: true,
     web_search_tool_type: "text_and_image",
     supports_search_tool: true,
     supported_reasoning_levels: [
@@ -88,6 +89,7 @@ describe("Phase 100 Codex-native parity smoke", () => {
     expect(routed).not.toHaveProperty("model_messages");
     expect(routed).not.toHaveProperty("use_responses_lite");
     expect(routed).not.toHaveProperty("supports_websockets");
+    expect(routed).not.toHaveProperty("supports_experimental_context");
 
     const parsed = parseRequest({
       model: "opencode-go/deepseek-v4-flash",