[codex] expose model context windows

README.md

@@ -57,6 +57,10 @@ curl -sS https://ai.ubq.fi/uos/models/capabilities \
   -H "Authorization: Bearer $UOS_AI_TOKEN"
 ```
 
+Use this endpoint, not `/v1/models`, when clients need gateway-specific fields such as reasoning support or token-window
+limits (`context_window_tokens`, `max_context_window_tokens`, and `auto_compact_token_limit_tokens`). `/v1/models` keeps
+the strict OpenAI model-object shape.
+
 Whoami (debug which auth method was used; never returns raw secrets):
 
 ```bash

scripts/codex-models.ts

@@ -209,6 +209,12 @@ const isRecord = (value: unknown): value is Record<string, unknown> =>
 
 const getString = (value: unknown): string | null => (typeof value === "string" ? value : null);
 
+const getNonNegativeInteger = (value: unknown): number | null => {
+  if (typeof value !== "number" || !Number.isFinite(value)) return null;
+  const normalized = Math.trunc(value);
+  return normalized >= 0 ? normalized : null;
+};
+
 const isHiddenCodexModel = (value: Record<string, unknown>): boolean =>
   getString(value.visibility)?.trim().toLowerCase() === "hide";
 
@@ -241,6 +247,14 @@ export const extractCodexModelsFromText = (text: string): ExtractedCodexModels |
     if (displayName) normalized.display_name = displayName;
     const description = getString(parsed.description);
     if (description) normalized.description = description;
+    for (const key of ["context_window", "max_context_window", "auto_compact_token_limit"]) {
+      if (parsed[key] === null) {
+        normalized[key] = null;
+        continue;
+      }
+      const count = getNonNegativeInteger(parsed[key]);
+      if (count !== null) normalized[key] = count;
+    }
     const defaultReasoning = getString(parsed.default_reasoning_level);
     if (defaultReasoning) normalized.default_reasoning_level = defaultReasoning;
     if (Array.isArray(parsed.supported_reasoning_levels)) {

src/admin.ts

@@ -75,6 +75,12 @@ const MAX_KV_MIGRATION_BODY_BYTES = 5 * 1024 * 1024;
 const isHiddenCodexModel = (value: Record<string, unknown>): boolean =>
   getString(value.visibility)?.trim().toLowerCase() === "hide";
 
+const normalizeNonNegativeInteger = (value: unknown): number | null => {
+  if (typeof value !== "number" || !Number.isFinite(value)) return null;
+  const normalized = Math.trunc(value);
+  return normalized >= 0 ? normalized : null;
+};
+
 const resolveDefaultModel = async (entryValue: unknown): Promise<string> => {
   const configured = typeof entryValue === "string" ? entryValue.trim() : "";
   if (configured) return configured;
@@ -611,6 +617,14 @@ const normalizeCodexModelsPayload = (value: unknown): CodexModelsSnapshot | null
     if (displayName) normalized.display_name = displayName;
     const description = getString(item.description);
     if (description) normalized.description = description;
+    for (const key of ["context_window", "max_context_window", "auto_compact_token_limit"]) {
+      if (item[key] === null) {
+        normalized[key] = null;
+        continue;
+      }
+      const count = normalizeNonNegativeInteger(item[key]);
+      if (count !== null) normalized[key] = count;
+    }
     const defaultReasoning = getString(item.default_reasoning_level);
     if (defaultReasoning) normalized.default_reasoning_level = defaultReasoning;
     if (Array.isArray(item.supported_reasoning_levels)) {

src/openai.ts

@@ -1308,6 +1308,9 @@ const normalizeModelCapabilitiesEntry = (value: unknown): Record<string, unknown
     supported_endpoints: ["/v1/chat/completions", "/v1/responses"],
     supported_reasoning_levels: reasoning.levels,
     default_reasoning_effort: reasoning.defaultLevel,
+    context_window_tokens: normalizeTokenCount(value.context_window),
+    max_context_window_tokens: normalizeTokenCount(value.max_context_window),
+    auto_compact_token_limit_tokens: normalizeTokenCount(value.auto_compact_token_limit),
   };
 };
 

static/chat.js

@@ -136,6 +136,17 @@ const mergeModelCapabilities = (models, capabilities) => {
       merged.default_reasoning_effort = defaultReasoning;
       merged.default_reasoning_level = defaultReasoning;
     }
+    for (
+      const key of [
+        "context_window_tokens",
+        "max_context_window_tokens",
+        "auto_compact_token_limit_tokens",
+      ]
+    ) {
+      if (typeof capability[key] === "number" || capability[key] === null) {
+        merged[key] = capability[key];
+      }
+    }
     return merged;
   });
 };

static/docs/llms-agents.md

@@ -135,8 +135,9 @@ backed by Codex with a ChatGPT account, so some OpenAI API model aliases may not
 Hidden Codex catalog entries such as internal review models are filtered during snapshot upload and are not exposed.
 
 Use `GET /uos/models/capabilities` for gateway-specific model metadata such as `supported_reasoning_levels`,
-`default_reasoning_effort`, `supported_endpoints`, and `upstream_provider`. This metadata is intentionally not included
-in `/v1/models` so OpenAI-compatible SDKs receive an OpenAI-shaped response.
+`default_reasoning_effort`, `context_window_tokens`, `max_context_window_tokens`, `auto_compact_token_limit_tokens`,
+`supported_endpoints`, and `upstream_provider`. This metadata is intentionally not included in `/v1/models` so
+OpenAI-compatible SDKs receive an OpenAI-shaped response.
 
 Observed integration behavior:
 
@@ -330,8 +331,8 @@ Defaults can be managed via `/admin/defaults` (admin auth required). When no mod
 uses the first model in the current Codex model snapshot. If neither a configured default nor a snapshot is available,
 no-model requests fail with `503` instead of fetching a live fallback catalog.
 
-`GET /uos/models/capabilities` is the endpoint to inspect reasoning support programmatically. `/v1/models` remains
-OpenAI-compatible and does not include reasoning metadata.
+`GET /uos/models/capabilities` is the endpoint to inspect reasoning support and token-window limits programmatically.
+`/v1/models` remains OpenAI-compatible and does not include gateway metadata.
 
 ## Ignored parameters and warnings
 

tests/admin-auth.test.ts

@@ -102,6 +102,9 @@ Deno.test("admin codex auth stores CLI model snapshot as source of truth", async
           models: [{
             slug: "gpt-5.5",
             display_name: "GPT-5.5",
+            context_window: 272000,
+            max_context_window: 1000000,
+            auto_compact_token_limit: null,
             supported_reasoning_levels: ["low", "medium", "high", "xhigh"],
           }, {
             slug: "codex-auto-review",
@@ -120,11 +123,23 @@ Deno.test("admin codex auth stores CLI model snapshot as source of truth", async
     assert.equal(fetchUrls.length, 1);
 
     const stored = kvStore.get(keyToString(["ubq_ai", "codex_models"])) as
-      | { source?: string; client_version?: string; models?: Array<{ slug?: string }> }
+      | {
+        source?: string;
+        client_version?: string;
+        models?: Array<{
+          slug?: string;
+          context_window?: number;
+          max_context_window?: number;
+          auto_compact_token_limit?: number | null;
+        }>;
+      }
       | undefined;
     assert.equal(stored?.source, "codex_cli");
     assert.equal(stored?.client_version, "0.126.0");
     assert.deepEqual(stored?.models?.map((model) => model.slug), ["gpt-5.5"]);
+    assert.equal(stored?.models?.[0]?.context_window, 272000);
+    assert.equal(stored?.models?.[0]?.max_context_window, 1000000);
+    assert.equal(stored?.models?.[0]?.auto_compact_token_limit, null);
   } finally {
     globalThis.fetch = originalFetch;
   }

tests/codex-models.test.ts

@@ -95,11 +95,14 @@ let vendorRoot;
 
 Deno.test("extractCodexModelsFromText parses slugs and reasoning levels", () => {
   const text =
-    'codex_cli_rs/0.99.0 {"slug":"gpt-5.2-codex","supported_reasoning_levels":[{"effort":"low"},{"effort":"high"}]}';
+    'codex_cli_rs/0.99.0 {"slug":"gpt-5.2-codex","context_window":272000,"max_context_window":1000000,"auto_compact_token_limit":null,"supported_reasoning_levels":[{"effort":"low"},{"effort":"high"}]}';
   const extracted = extractCodexModelsFromText(text);
   assert.ok(extracted);
   assert.equal(extracted?.clientVersion, "0.99.0");
   assert.equal(extracted?.models[0]?.slug, "gpt-5.2-codex");
+  assert.equal(extracted?.models[0]?.context_window, 272000);
+  assert.equal(extracted?.models[0]?.max_context_window, 1000000);
+  assert.equal(extracted?.models[0]?.auto_compact_token_limit, null);
   assert.deepEqual(extracted?.models[0]?.supported_reasoning_levels, ["low", "high"]);
 });
 

tests/openai-compat.test.ts

@@ -21,6 +21,9 @@ kvStore.set(keyToString(TEST_CODEX_MODELS_KEY), {
   models: [{
     slug: DEFAULT_TEST_MODEL,
     display_name: "GPT-5 Fixture Default",
+    context_window: 272000,
+    max_context_window: 1000000,
+    auto_compact_token_limit: null,
     default_reasoning_level: "medium",
     supported_reasoning_levels: ["low", "medium", "high", "xhigh"],
   }],
@@ -475,6 +478,9 @@ Deno.test("openai: model capabilities are exposed outside /v1 model objects", as
       supported_endpoints?: string[];
       supported_reasoning_levels?: string[];
       default_reasoning_effort?: string | null;
+      context_window_tokens?: number | null;
+      max_context_window_tokens?: number | null;
+      auto_compact_token_limit_tokens?: number | null;
     }>;
   };
   assert.equal(payload.object, "list");
@@ -485,6 +491,9 @@ Deno.test("openai: model capabilities are exposed outside /v1 model objects", as
   assert.equal(model.upstream_provider, "codex_chatgpt");
   assert.deepEqual(model.supported_reasoning_levels, ["low", "medium", "high", "xhigh"]);
   assert.equal(model.default_reasoning_effort, "medium");
+  assert.equal(model.context_window_tokens, 272000);
+  assert.equal(model.max_context_window_tokens, 1000000);
+  assert.equal(model.auto_compact_token_limit_tokens, null);
   assert.ok(model.supported_endpoints?.includes("/v1/chat/completions"));
   assert.ok(model.supported_endpoints?.includes("/v1/responses"));
 });