# Biome Enforcement > Use this skill when a task touches code, tests, Biome config, or generated artifacts and Biome must remain the final remediation and enforcement pass using the required JSON changed-files command. - Skill: `mwillbanks/biome-enforcement` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add mwillbanks/biome-enforcement` - Raw SKILL.md: https://api.skillmd.com/api/skills/mwillbanks/biome-enforcement/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Productivity - License: Apache-2.0 - Author: mwillbanks (https://skillmd.com/u/mwillbanks) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/mwillbanks/biome-enforcement --- # Biome Enforcement This skill governs how agents should work with **Biome as a repository enforcement tool**. It still preserves the core rule from the prior skill: - Biome is primarily a **final remediation and enforcement pass** - the required final command remains fixed - the remediation loop remains mandatory - post-Biome build and test re-validation still occurs only when Biome changed files This skill is broader than a single final step. Agents should also use it when they need to: - reason about whether a task is Biome-relevant - interpret Biome JSON diagnostics - decide whether generated output belongs in ignore rules - update Biome configuration safely - distinguish source issues from tool-noise issues before the final pass Operational details for how Biome works are defined in: ``` references/biome.md ``` Agents must consult that reference when executing this skill. --- ## Concern Ownership This skill owns **Biome-specific execution policy**. It takes precedence whenever the task involves: - Biome command selection - Biome diagnostic interpretation - Biome remediation sequencing - Biome ignore-path decisions - post-Biome validation rules Repository-wide standards skills may still govern adjacent concerns, but they should defer to this skill for Biome behavior. --- ## When This Skill Must Be Used Activate this skill whenever a task: - modifies source code - modifies tests - adds or removes files in Biome-managed areas - changes `biome.json`, related workspace config, or scripts that affect Biome usage - creates new directories or generated output that may need ignore handling - requires interpretation of Biome diagnostics or JSON reporter output - completes an implementation that must be validated before handoff In practice, this means **most coding tasks that touch Biome-managed files** should consult this skill, even if Biome itself is only executed at the end. --- ## Execution Timing Biome must run as the **final enforcement routine after implementation and normal validation are already complete**. Agents may consult this skill earlier for planning, config awareness, or ignore-path triage, but they should not turn Biome into a continuous edit-loop tool. Correct order: 1. Complete implementation 2. Run repository-native validation before Biome such as build, typecheck, and tests 3. Run the Biome remediation loop 4. If Biome modified files: - re-run the same build and test validation that was already used 5. Declare the task complete --- ## Required Final Command Always run Biome using the following command: ```bash biome check --write --unsafe --changed --no-errors-on-unmatched --files-ignore-unknown=true --reporter=json ``` Requirements: - JSON reporter **must always be used** - the command must run against **changed files** - autofix must be enabled - this exact invocation remains the required final enforcement command Do not substitute alternative reporters or command structures. --- ## Broader Biome Responsibilities This skill is not limited to "run one command at the end." Agents should also apply it when working with: - Biome config updates - Biome ignore rules - parser or config failures surfaced by Biome - lint-rule remediation strategy - repository changes that expand or shrink the set of files Biome should own These activities support the final enforcement pass. They do not replace it. --- ## Remediation Loop If Biome reports errors: 1. Parse the JSON output 2. Convert diagnostics into a remediation task list 3. Resolve the issues 4. Run the Biome command again Repeat until **Biome reports zero errors**. Full remediation workflow details are defined in: ``` references/biome.md ``` --- ## Ignore Path Responsibilities If the task introduces **generated artifacts or machine-produced output**, the agent must determine whether those paths should be ignored by Biome. Examples may include: - test artifacts - playwright output - coverage reports - generated snapshots - build output - tool-generated directories Guidance for determining when ignore paths are appropriate is defined in: ``` references/biome.md ``` Agents must **not add ignore rules for real source code issues**. --- ## Final Validation Requirement Work is **not complete** until all of the following are true: - Biome reports zero errors from the required command - if Biome made changes, the repository-native build and test commands used earlier succeed again - no new Biome noise remains in the changed scope - any newly introduced generated output is either ignored appropriately or intentionally Biome-managed --- ## Agent Responsibility Agents must treat Biome as a **mandatory repository enforcement mechanism**. For any coding task: - consult this skill when Biome-related decisions are required - run the required Biome command before completion - use the JSON reporter - follow the remediation loop - re-run build and test validation **only if Biome modifies files** Agents should consult the reference document for operational details when executing this skill.