# Add License Header

> Add the project's canonical SPDX license header to source files that don't already have one. Use when asked to add a license header to a file or directory of files.

- Skill: `sociotechnica-org/add-license-header-4` (Agent Skill)
- Install (CLI): `npx skillmds@latest add sociotechnica-org/add-license-header-4`
- Raw SKILL.md: https://api.skillmd.com/api/skills/sociotechnica-org/add-license-header-4/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: sociotechnica-org (https://skillmd.com/u/sociotechnica-org)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/sociotechnica-org/add-license-header-4

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# Add License Header

## Procedure

1. Identify target files from the user's request -- either a single path or
   all source files under a given directory.

2. For each target file, read its first 20 lines and check whether the string
   `SPDX-License-Identifier` is already present.

3. If the header is already present, **skip that file**. Never add a second
   header to a file that already has one.

4. If no header is present, insert this exact two-line header at **line 1** of
   the file -- above all existing content, including shebangs, comments, or
   blank lines:

   ```
   // SPDX-License-Identifier: Apache-2.0
   // Copyright (c) 2026 Acme Corp
   ```

5. After processing all files, report which files were changed and which were
   skipped (already had a header).

## Constraints

- **Never duplicate a header.** If `SPDX-License-Identifier` already appears
  in the first 20 lines, the file is considered done -- do not touch it.
- **Always insert at the very top.** The header must be the first content in
  the file, above any shebang (`#!`), existing comment, or code. Do not place
  it after existing content.