From d03c5017ffac9112aa37f2c3605d82756f737a79 Mon Sep 17 00:00:00 2001
From: Cesar Garcia <128240629+Chesars@users.noreply.github.com>
Date: Tue, 13 Jan 2026 19:19:47 -0300
Subject: [PATCH] fix: correct context window sizes for GPT-5 model variants
 (#18928)
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* fix: correct context window sizes for GPT-5 model variants

Updates max_input_tokens for GPT-5, GPT-5.1, and GPT-5.2 model variants
to match OpenAI's official specifications, resolving issue #18927.

Changes:
- GPT-5.1 (base, codex variants): 272k → 400k tokens
- GPT-5.1-chat variants: 272k → 128k tokens (with max_output 16,384)
- GPT-5 (base): 272k → 400k tokens
- GPT-5-chat: 272k → 128k tokens (with max_output 16,384)
- GPT-5-codex: 272k → 400k tokens
- GPT-5-mini: 272k → 400k tokens
- GPT-5-nano: 272k → 400k tokens
- GPT-5-pro: 272k → 400k tokens (max_output 272k)
- GPT-5 dated versions (2025-08-07): 272k → 400k tokens

Affected providers: OpenAI, Azure (all regions), OpenRouter

Fixes #18927

* fix: correct Azure GPT-5 context window limits to match Azure docs

Azure OpenAI has different limits than OpenAI for GPT-5 models.

Changes:
- Azure GPT-5 models: max_input_tokens 400k → 272k (Azure limit)
- Azure GPT-5 Pro: max_output_tokens 272k → 128k (Azure limit)
- OpenAI GPT-5 models: remain at 400k (correct)
- OpenRouter models: remain at 400k (routes to OpenAI)

Azure docs specify 272k input + 128k output = 400k total context.
OpenAI allows full 400k input + 128k output.

* fix: correct Azure GPT-5 max_input_tokens to 272k

Azure has explicit input limit of 272k tokens (not 400k like OpenAI).
Context window 400k = 272k input + 128k output for Azure.
OpenAI allows flexible input up to 400k (context - output).
---
 model_prices_and_context_window.json | 70 ++++++++++++++--------------
 1 file changed, 35 insertions(+), 35 deletions(-)

diff --git a/model_prices_and_context_window.json b/model_prices_and_context_window.json
index 0b97d8761fc..6d814c731dc 100644
--- a/model_prices_and_context_window.json
+++ b/model_prices_and_context_window.json
@@ -1644,7 +1644,7 @@
         "cache_read_input_token_cost": 1.4e-07,
         "input_cost_per_token": 1.38e-06,
         "litellm_provider": "azure",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 128000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -1944,7 +1944,7 @@
         "cache_read_input_token_cost": 1.25e-07,
         "input_cost_per_token": 1.25e-06,
         "litellm_provider": "azure",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 128000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -2893,7 +2893,7 @@
         "input_cost_per_token": 1.25e-06,
         "input_cost_per_token_priority": 2.5e-06,
         "litellm_provider": "azure",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -2964,7 +2964,7 @@
         "input_cost_per_token": 1.25e-06,
         "input_cost_per_token_priority": 2.5e-06,
         "litellm_provider": "azure",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "responses",
@@ -2997,7 +2997,7 @@
         "input_cost_per_token": 2.5e-07,
         "input_cost_per_token_priority": 4.5e-07,
         "litellm_provider": "azure",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "responses",
@@ -3092,9 +3092,9 @@
         "cache_read_input_token_cost": 1.25e-07,
         "input_cost_per_token": 1.25e-06,
         "litellm_provider": "azure",
-        "max_input_tokens": 272000,
-        "max_output_tokens": 128000,
-        "max_tokens": 128000,
+        "max_input_tokens": 128000,
+        "max_output_tokens": 16384,
+        "max_tokens": 16384,
         "mode": "chat",
         "output_cost_per_token": 1e-05,
         "source": "https://azure.microsoft.com/en-us/blog/gpt-5-in-azure-ai-foundry-the-future-of-ai-apps-and-agents-starts-here/",
@@ -3377,7 +3377,7 @@
         "cache_read_input_token_cost": 1.25e-07,
         "input_cost_per_token": 1.25e-06,
         "litellm_provider": "azure",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 128000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -3440,7 +3440,7 @@
         "cache_read_input_token_cost": 1.25e-07,
         "input_cost_per_token": 1.25e-06,
         "litellm_provider": "azure",
-        "max_input_tokens": 400000,
+        "max_input_tokens": 272000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "responses",
@@ -3500,7 +3500,7 @@
         "cache_read_input_token_cost": 1.75e-07,
         "input_cost_per_token": 1.75e-06,
         "litellm_provider": "azure",
-        "max_input_tokens": 400000,
+        "max_input_tokens": 272000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -3637,7 +3637,7 @@
     "azure/gpt-5.2-pro": {
         "input_cost_per_token": 2.1e-05,
         "litellm_provider": "azure",
-        "max_input_tokens": 400000,
+        "max_input_tokens": 272000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "responses",
@@ -3668,7 +3668,7 @@
     "azure/gpt-5.2-pro-2025-12-11": {
         "input_cost_per_token": 2.1e-05,
         "litellm_provider": "azure",
-        "max_input_tokens": 400000,
+        "max_input_tokens": 272000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "responses",
@@ -4684,7 +4684,7 @@
         "cache_read_input_token_cost": 1.4e-07,
         "input_cost_per_token": 1.38e-06,
         "litellm_provider": "azure",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 128000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -17470,7 +17470,7 @@
         "input_cost_per_token_flex": 6.25e-07,
         "input_cost_per_token_priority": 2.5e-06,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -17507,7 +17507,7 @@
         "input_cost_per_token": 1.25e-06,
         "input_cost_per_token_priority": 2.5e-06,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -17543,7 +17543,7 @@
         "input_cost_per_token": 1.25e-06,
         "input_cost_per_token_priority": 2.5e-06,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -17852,7 +17852,7 @@
         "input_cost_per_token_flex": 6.25e-07,
         "input_cost_per_token_priority": 2.5e-06,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -17887,9 +17887,9 @@
         "cache_read_input_token_cost": 1.25e-07,
         "input_cost_per_token": 1.25e-06,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
-        "max_output_tokens": 128000,
-        "max_tokens": 128000,
+        "max_input_tokens": 128000,
+        "max_output_tokens": 16384,
+        "max_tokens": 16384,
         "mode": "chat",
         "output_cost_per_token": 1e-05,
         "supported_endpoints": [
@@ -17951,7 +17951,7 @@
         "cache_read_input_token_cost": 1.25e-07,
         "input_cost_per_token": 1.25e-06,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "responses",
@@ -17983,7 +17983,7 @@
         "input_cost_per_token": 1.25e-06,
         "input_cost_per_token_priority": 2.5e-06,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "responses",
@@ -18046,7 +18046,7 @@
         "input_cost_per_token": 2.5e-07,
         "input_cost_per_token_priority": 4.5e-07,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "responses",
@@ -18081,7 +18081,7 @@
         "input_cost_per_token_flex": 1.25e-07,
         "input_cost_per_token_priority": 4.5e-07,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -18120,7 +18120,7 @@
         "input_cost_per_token_flex": 1.25e-07,
         "input_cost_per_token_priority": 4.5e-07,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -18158,7 +18158,7 @@
         "input_cost_per_token_flex": 2.5e-08,
         "input_cost_per_token_priority": 2.5e-06,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -18193,7 +18193,7 @@
         "input_cost_per_token": 5e-08,
         "input_cost_per_token_flex": 2.5e-08,
         "litellm_provider": "openai",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -23206,9 +23206,9 @@
         "cache_read_input_token_cost": 1.25e-07,
         "input_cost_per_token": 1.25e-06,
         "litellm_provider": "openrouter",
-        "max_input_tokens": 272000,
-        "max_output_tokens": 128000,
-        "max_tokens": 128000,
+        "max_input_tokens": 128000,
+        "max_output_tokens": 16384,
+        "max_tokens": 16384,
         "mode": "chat",
         "output_cost_per_token": 1e-05,
         "supported_modalities": [
@@ -23225,7 +23225,7 @@
         "cache_read_input_token_cost": 1.25e-07,
         "input_cost_per_token": 1.25e-06,
         "litellm_provider": "openrouter",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -23244,7 +23244,7 @@
         "cache_read_input_token_cost": 1.25e-07,
         "input_cost_per_token": 1.25e-06,
         "litellm_provider": "openrouter",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -23263,7 +23263,7 @@
         "cache_read_input_token_cost": 2.5e-08,
         "input_cost_per_token": 2.5e-07,
         "litellm_provider": "openrouter",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",
@@ -23282,7 +23282,7 @@
         "cache_read_input_token_cost": 5e-09,
         "input_cost_per_token": 5e-08,
         "litellm_provider": "openrouter",
-        "max_input_tokens": 272000,
+        "max_input_tokens": 400000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
         "mode": "chat",