From d652ee367769120193f54e4c7ed8d425fd696cce Mon Sep 17 00:00:00 2001
From: AaronG <kyh1618@outlook.com>
Date: Wed, 4 Nov 2026 08:04:15 +0800
Subject: [PATCH] fix(cost-map): add azure_ai/claude-mythos-5-1 entry

`azure_ai/claude-mythos-5-1` had no entry in the model cost map, so the
provider lookup rejected it (the bare `claude-mythos-5-1` belongs to the
`anthropic` provider). `cost_per_token()` raised `ModelNotMappedError` and the
proxy recorded zero spend for a model that actually bills.

Add the dedicated `azure_ai/` entry, reusing Anthropic's published per-model
token rates (per the Microsoft Foundry docs: Foundry uses Anthropic's published
rates), and mirroring the existing `azure_ai/claude-*` layout.

Add a regression test that resolves the entry via `get_model_info` and asserts
non-zero input/output costs from `cost_per_token` (no credentials needed).

Fixes #49865
---
 model_prices_and_context_window.json          | 34 ++++++++++++++++-
 .../test_azure_ai_mythos_cost_map.py          | 37 +++++++++++++++++++
 2 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100644 tests/unit_tests/test_azure_ai_mythos_cost_map.py

diff --git a/model_prices_and_context_window.json b/model_prices_and_context_window.json
index be93d6fcd9b..e8f6677e628 100644
--- a/model_prices_and_context_window.json
+++ b/model_prices_and_context_window.json
@@ -3833,7 +3833,39 @@
         "prompt_cache_min_tokens": 4096,
         "source": "https://learn.microsoft.com/en-us/azure/foundry/openai/concepts/model-retirement-schedule"
     },
-    "azure_ai/claude-opus-4-5": {
+    "azure_ai/claude-mythos-5-1": {
+        "litellm_provider": "azure_ai",
+        "mode": "chat",
+        "max_input_tokens": 1000000,
+        "max_output_tokens": 128000,
+        "input_cost_per_token": 1e-05,
+        "output_cost_per_token": 5e-05,
+        "input_cost_per_token_batches": 5e-06,
+        "output_cost_per_token_batches": 2.5e-05,
+        "cache_creation_input_token_cost": 1.25e-05,
+        "cache_creation_input_token_cost_above_1hr": 2e-05,
+        "cache_creation_input_token_cost_batches": 6.25e-06,
+        "cache_read_input_token_cost": 2.5e-07,
+        "cache_read_input_token_cost_batches": 1.25e-07,
+        "prompt_cache_min_tokens": 512,
+        "supports_function_calling": true,
+        "supports_vision": true,
+        "supports_pdf_input": true,
+        "supports_prompt_caching": true,
+        "supports_reasoning": true,
+        "supports_response_schema": true,
+        "supports_tool_choice": true,
+        "supports_computer_use": true,
+        "supports_assistant_prefill": false,
+        "supports_sampling_params": false,
+        "supports_adaptive_thinking": true,
+        "supports_xhigh_reasoning_effort": true,
+        "supports_max_reasoning_effort": true,
+        "supports_output_config": true,
+        "supports_native_structured_output": true,
+        "source": "https://platform.claude.com/docs/en/about-claude/pricing"
+  },
+  "azure_ai/claude-opus-4-5": {
         "deprecation_date": "2026-11-24",
         "cache_creation_input_token_cost": 6.25e-06,
         "cache_creation_input_token_cost_above_1hr": 1e-05,
diff --git a/tests/unit_tests/test_azure_ai_mythos_cost_map.py b/tests/unit_tests/test_azure_ai_mythos_cost_map.py
new file mode 100644
index 00000000000..17d506b8c8b
--- /dev/null
+++ b/tests/unit_tests/test_azure_ai_mythos_cost_map.py
@@ -0,0 +1,37 @@
+"""
+Regression test for https://github.com/BerriAI/litellm/issues/49865
+
+`azure_ai/claude-mythos-5-1` had no entry in the model cost map. The bare
+`claude-mythos-5-1` entry belongs to the `anthropic` provider and is rejected by
+the azure_ai provider lookup, so `cost_per_token()` raised `ModelNotMappedError`
+and the proxy recorded zero spend for a model that actually bills.
+
+This test asserts the dedicated azure_ai entry resolves and returns non-zero
+input/output costs, mirroring the issue's reproduction (no credentials needed).
+"""
+import pytest
+
+from litellm import cost_per_token, get_model_info
+
+
+def test_azure_ai_claude_mythos_5_1_get_model_info():
+    info = get_model_info("claude-mythos-5-1", custom_llm_provider="azure_ai")
+    assert info["litellm_provider"] == "azure_ai"
+    assert info["input_cost_per_token"] > 0
+    assert info["output_cost_per_token"] > 0
+
+
+def test_azure_ai_claude_mythos_5_1_cost_per_token():
+    spend = cost_per_token(
+        model="claude-mythos-5-1",
+        custom_llm_provider="azure_ai",
+        prompt_tokens=1271,
+        completion_tokens=389,
+    )
+    try:
+        prompt_cost, completion_cost = spend
+    except (TypeError, ValueError):
+        prompt_cost = spend["prompt_cost"]
+        completion_cost = spend["completion_cost"]
+    assert prompt_cost > 0
+    assert completion_cost > 0