Codeflash

0.20.5 verified Mon Apr 27 auth: no python

Codeflash is an AI-powered tool that automatically optimizes Python code for performance. It analyzes code, runs test suites, and generates performance improvements with minimal user intervention. Current version: 0.20.5, active development with weekly releases.

pip install codeflash

Common errors

error ModuleNotFoundError: No module named 'codeflash' ↓

cause Codeflash not installed or installed in wrong environment.

fix

Run pip install codeflash in the correct Python environment (e.g., virtualenv).

error RunCodeflashError: Authentication failed. Please set CODEFLASH_API_KEY. ↓

cause API key not provided.

fix

Set environment variable CODEFLASH_API_KEY with your API key from https://app.codeflash.ai.

error ValueError: Function must have type hints ↓

cause Codeflash requires functions to have type annotations.

fix

Add type hints to the function parameters and return value.

error UnsupportedPythonVersionError: Python 3.8 is not supported ↓

cause Codeflash requires Python >=3.9.

fix

Upgrade Python to version 3.9 or later.

Warnings

breaking In v0.17.0, the API changed from `codeflash.optimize` to `codeflash.run_codeflash`. Old code using `import codeflash.optimize` will break. ↓

fix Update imports to `from codeflash import run_codeflash`.

gotcha Codeflash requires an API key set via `CODEFLASH_API_KEY` environment variable. Without it, `run_codeflash` raises an authentication error. ↓

fix Set `CODEFLASH_API_KEY` in your environment or pass `api_key` parameter.

deprecated The `verbose` parameter in `run_codeflash` is deprecated since v0.19.0 and will be removed in v0.21.0. Use `logging` level instead. ↓

fix Remove `verbose` parameter and configure Python logging: `logging.basicConfig(level=logging.INFO)`.

gotcha Codeflash only supports Python 3.9 and above. Installing on older Python versions will fail with a `Requires-Python` error. ↓

fix Ensure Python >=3.9 is used.

Imports

run_codeflash
```
from codeflash import run_codeflash
```
CodeOptimizer
wrong
```
from codeflash.optimizer import CodeOptimizer
```
correct
```
from codeflash import CodeOptimizer
```
CodeOptimizer is directly exposed in the top-level module as of 0.20.x

Quickstart

Initialize Codeflash with API key and optimize a function.

from codeflash import run_codeflash

# Example: optimize a simple function
def slow_function(n: int) -> int:
    total = 0
    for i in range(n):
        total += i
    return total

# Run codeflash optimization (requires CODEFLASH_API_KEY env var)
optimized_code = run_codeflash(slow_function, api_key=os.environ.get('CODEFLASH_API_KEY', ''))
print(optimized_code)