How do I install the Diff4 skill?

Run npx skillmds@latest add djyde/diff4 in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Diff4 safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Diff4?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Diff4 free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

djyde (@djyde) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Diff4 by djyde — Agent Skill

Name: Diff4
Author: djyde

File contents

diff4 - Encrypted Diff & File Sharing

diff4 encrypts diffs and files client-side (AES-256-GCM) before uploading. The server never sees plaintext. Recipients need the passphrase to decrypt.

Prerequisites

diff4 must be installed and available on PATH. Use npm i -g @diff4/cli to install.
A passphrase must be configured (see setup below)

Commands

Share the latest commit diff

diff4 git-latest

Runs git diff HEAD~1, encrypts the result, and uploads. Use when the user says "preview my last commit" or "send the latest diff."

Share staged changes

diff4 git-staged

Runs git diff --staged, encrypts, and uploads. Use when the user says "preview my staged changes" or "send what's about to be committed."

Share arbitrary files

diff4 files path/to/file1.ts path/to/file2.ts

Reads each file (UTF-8 text only), bundles them as JSON, encrypts, and uploads. Supports any number of paths (relative or absolute).

Key management

diff4 key-gen [key] - Generate or set the encryption passphrase
diff4 key-get - Print the current passphrase

Options

All upload commands (git-latest, git-staged, files) accept:

Flag	Description
`-s, --server <url>`	Override the diff4 server URL. Default: `https://diff4.com` (or `DIFF4_SERVER` env var)
`-p, --passphrase <key>`	Override the passphrase for this command only. Default: `DIFF4_PASSPHRASE` env var

Gotchas

Empty diffs fail gracefully. git-latest and git-staged will error if there is nothing to share.
Binary files are not supported. diff4 files reads files as UTF-8 text.
Server is configurable. Self-hosted instances can be set via DIFF4_SERVER env var or -s flag.
The passphrase must be shared out-of-band. diff4 only encrypts — recipients need the same passphrase to decrypt.
key-gen updates existing keys. If DIFF4_PASSPHRASE already exists in the shell config, key-gen replaces it in-place.

Typical workflow

User asks to see a diff or files
Verify setup: run diff4 key-get (if it fails, run diff4 key-gen and tell user to source their rc file)
Run the appropriate command (git-latest, git-staged, or files <paths>)
Return the URL from the response to the user
Remind the user that recipients need the passphrase to decrypt

---name: diff4description: Preview git diffs and files using the diff4 CLI. Use when the user wants to see code changes, review files content securely via diff4---# diff4 - Encrypted Diff & File Sharingdiff4 encrypts diffs and files client-side (AES-256-GCM) before uploading. The server never sees plaintext. Recipients need the passphrase to decrypt.## Prerequisites- `diff4` must be installed and available on PATH. Use `npm i -g @diff4/cli` to install.- A passphrase must be configured (see setup below)## Commands### Share the latest commit diff```diff4 git-latest```Runs `git diff HEAD~1`, encrypts the result, and uploads. Use when the user says "preview my last commit" or "send the latest diff."### Share staged changes```diff4 git-staged```Runs `git diff --staged`, encrypts, and uploads. Use when the user says "preview my staged changes" or "send what's about to be committed."### Share arbitrary files```diff4 files path/to/file1.ts path/to/file2.ts```Reads each file (UTF-8 text only), bundles them as JSON, encrypts, and uploads. Supports any number of paths (relative or absolute).### Key management- `diff4 key-gen [key]` - Generate or set the encryption passphrase- `diff4 key-get` - Print the current passphrase## OptionsAll upload commands (`git-latest`, `git-staged`, `files`) accept:| Flag | Description ||------|-------------|| `-s, --server <url>` | Override the diff4 server URL. Default: `https://diff4.com` (or `DIFF4_SERVER` env var) || `-p, --passphrase <key>` | Override the passphrase for this command only. Default: `DIFF4_PASSPHRASE` env var |## Gotchas- **Empty diffs fail gracefully.** `git-latest` and `git-staged` will error if there is nothing to share.- **Binary files are not supported.** `diff4 files` reads files as UTF-8 text.- **Server is configurable.** Self-hosted instances can be set via `DIFF4_SERVER` env var or `-s` flag.- **The passphrase must be shared out-of-band.** diff4 only encrypts — recipients need the same passphrase to decrypt.- **key-gen updates existing keys.** If `DIFF4_PASSPHRASE` already exists in the shell config, key-gen replaces it in-place.## Typical workflow1. User asks to see a diff or files2. Verify setup: run `diff4 key-get` (if it fails, run `diff4 key-gen` and tell user to source their rc file)3. Run the appropriate command (`git-latest`, `git-staged`, or `files <paths>`)4. Return the URL from the response to the user5. Remind the user that recipients need the passphrase to decrypt

Frequently asked questions

Diff4