Catches the mistakes coding agents repeat before they merge: a pull-request gate with no model call and no API key.
Short answer: Mutating external POST/PUT requests send Idempotency-Key. Without an idempotency key a retried POST creates the thing twice.
Group: API and network robustness. Status: stable. Generated from the rule definitions; do not edit by hand.
Playground: https://brevio.pro/tools/agent-guard-playground?rule=R10.2
Idempotency key transmission: mutating external POST/PUT requests send Idempotency-Key.
Without an idempotency key a retried POST creates the thing twice.
await fetch(url, { method: 'POST', body });
await fetch(url, { method: 'POST', body, headers: { 'Idempotency-Key': key } });
A person can silence one finding with brevio-core: ignore R10.2 -- reason on the line or the line above. Without the reason it does not count. An agent cannot silence it: the agent hook and the MCP tools never honour the comment, and a pull request that adds one is reported until a reviewer allows it. Fixing the code is still the better answer.
To change what the rule flags, edit its definition in dev_rules.py or code_rules/__init__.py. That is a code change and is reviewed like one.