Add genai-prices to dev deps and a basic test

pyproject.toml

@@ -104,6 +104,7 @@ dev = [
     "pytest-xdist>=3.6.1",
     # Needed for PyCharm users
     "pip>=25.2",
+    "genai-prices>=0.0.22",
 ]
 lint = ["mypy>=1.11.2", "pyright>=1.1.390", "ruff>=0.6.9"]
 docs = [

tests/test_usage_limits.py

@@ -2,8 +2,10 @@
 import operator
 import re
 from datetime import timezone
+from decimal import Decimal
 
 import pytest
+from genai_prices import Usage as GenaiPricesUsage, calc_price
 from inline_snapshot import snapshot
 
 from pydantic_ai import Agent, RunContext, UsageLimitExceeded
@@ -22,6 +24,11 @@
 pytestmark = pytest.mark.anyio
 
 
+def test_genai_prices():
+    usage = GenaiPricesUsage(input_tokens=100, output_tokens=50)
+    assert calc_price(usage, model_ref='gpt-4o').total_price == snapshot(Decimal('0.00075'))
+
+
 def test_request_token_limit() -> None:
     test_agent = Agent(TestModel())