txaion-model-pricing 0.1.0

Cross-provider AI model pricing for Python

Txaion Model Pricing

Lightweight, cross-provider model pricing for Python.

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Txaion Model Pricing is a lightweight Python package for querying cross-provider model information and calculating USD costs for input, output, and cached-input tokens.

Developed and maintained by Txaion.

The current version is 0.1.0 and requires Python 3.10 or later.

Installation

Install the package from the project directory:

python -m pip install .

Install the development dependencies for testing and building:

python -m pip install -e ".[dev]"

Quick start

from txaion_model_pricing import calculate_cost, count_models, get_model_details

print(count_models())

input_cost = calculate_cost("gpt-4o", 1_000_000, "input")
output_cost = calculate_cost("gpt-4o", 1_000_000, "output")
cached_cost = calculate_cost("gpt-4o", 1_000_000, "cached")

print(input_cost)   # Decimal("2.5000000")
print(output_cost)  # Decimal("10.00000")
print(cached_cost)  # Decimal("1.25000000")

details = get_model_details("gpt-4o")
print(details["max_input_tokens"])

All costs are returned as decimal.Decimal values. The package does not round results or perform currency conversion.

Public API

count_models() -> int

Returns the number of models in the bundled snapshot. Metadata entries such as sample_spec are excluded.

calculate_cost(model, tokens, token_type) -> Decimal

Calculates the USD cost using the model's per-token price:

• input maps to input_cost_per_token
• output maps to output_cost_per_token
• cached maps to cache_read_input_token_cost

tokens must be a non-negative integer. If the requested price field is unavailable, the package does not treat the cost as zero or fall back to a different price.

get_model_details(model) -> dict

Returns a deep copy of the model data. Modifying the returned value does not affect the package's internal cache.

Error handling

All domain-specific exceptions inherit from ModelPriceError:

from txaion_model_pricing import (
    InvalidTokenCountError,
    InvalidTokenTypeError,
    NotFound,
    PriceUnavailableError,
    calculate_cost,
)

try:
    cost = calculate_cost("unknown-model", 1_000, "input")
except NotFound:
    ...
except PriceUnavailableError:
    ...
except (InvalidTokenCountError, InvalidTokenTypeError):
    ...

Price data

The package includes a pinned snapshot of the LiteLLM model price and context-window data. The source commit, retrieval time, and SHA-256 checksum are recorded in src/txaion_model_pricing/data_source.json. See THIRD_PARTY_NOTICES.md for third-party attribution and licensing information.

Maintainers must specify an immutable commit SHA or tag when updating the snapshot:

python scripts/update_prices.py <commit-or-tag>

The update tool downloads and validates the JSON before atomically replacing the snapshot and its metadata. Moving refs such as main, master, and latest are rejected.

Limitations

• Version 0.1.0 only calculates token-based input, output, and cached-input costs.
• Image, audio, search, tool-call, session, and storage pricing are not supported by calculate_cost().
• Model providers may change their prices at any time. Results depend on the bundled snapshot and may not match current provider pricing. Verify official provider prices before using the results for billing or budget enforcement.

Development

ruff check .
pytest
python -m build

License

This project and the vendored LiteLLM data are redistributed under the MIT License. See LICENSE and THIRD_PARTY_NOTICES.md for details.