code-patterns

Code Patterns

Style

• Ruff: 120-char lines, 4-space indent, target-version = "py313"; import sorting enabled — run uv run ruff format src/ && uv run ruff check src/.
• Type hints everywhere; pathlib.Path for all file paths (never strings); Pydantic BaseModel for all config/data structures.
• Naming: snake_case files/functions, PascalCase classes, _private methods, UPPER_SNAKE constants, config classes end in Config.

Configuration

class MyHandlerConfig(BaseHandlerConfig, MyAgentConfig):
    exclude_feature: bool = Field(default=False, description="Exclude feature")  # description feeds CLI --help

• Every Field needs a description — CLI arguments are generated from it (--exclude-feature, store_true, default None = "not specified").
• Load order: Pydantic defaults < .ai/config.yaml (dot-notation section keys) < CLI args, merged with merge_dicts().
• Env vars in src/config.py: required → os.environ["KEY"]; optional → os.getenv("KEY", "default") with int()/float()/str_to_bool() conversion.

Async and concurrency

• All handler/agent operations are async; handlers implement async def handle(self).
• Bounded concurrency: use WorkerPool from src/utils/worker_pool.py (WorkerPool(max_workers=0) = CPU count) for many tasks; asyncio.gather(*tasks, return_exceptions=True) for a fixed small set.
• Always isolate errors: check each result with isinstance(result, Exception), log with exc_info=True, continue.

Error handling

• Partial success is acceptable: warn and continue if some agents fail; raise ValueError only on complete failure.
• Guarantee cleanup with try/finally (e.g., cronjob project cleanup).
• Inside agent tools, raise ModelRetry (from pydantic_ai) for recoverable errors — file not found, permission denied.

Logging and tracing

from utils import Logger

Logger.init(logs_dir)                      # once per execution, before any use
Logger.info("Agent completed", {"total_tokens": usage.total_tokens})  # structured dict payload
Logger.error("Failed", exc_info=True)      # always exc_info=True for errors