stegstr

# Stegstr

Stegstr hides Nostr messages and arbitrary payloads inside PNG images using steganography. Users embed their feed (posts, DMs, JSON) into images and share them; recipients use Detect to load the hidden content. No registration, works offline.

## When to use this skill

- User wants to **decode** (extract) hidden data from a PNG that contains Stegstr data.
- User wants to **embed** a payload into a cover PNG (e.g. Nostr bundle, JSON, text).
- User mentions steganography, Nostr-in-images, Stegstr, hiding data in images, or secret messages in photos.
- User needs programmatic access for automation, scripts, or AI agents.

## CLI (headless)

Build the CLI from the Stegstr repo:

```bash
git clone https://github.com/brunkstr/Stegstr.git
cd Stegstr/src-tauri
cargo build --release --bin stegstr-cli
```

Binary: `target/release/stegstr-cli` (or `stegstr-cli.exe` on Windows).

### Decode (extract payload)

```bash
stegstr-cli decode image.png
```

Writes raw payload to stdout. Valid UTF-8 JSON is printed as text; otherwise `base64:<data>`. Exit 0 on success.

### Detect (decode + decrypt app bundle)

```bash
stegstr-cli detect image.png
```

Decodes and decrypts; prints Nostr bundle JSON `{ "version": 1, "events": [...] }`.

### Embed (hide payload in image)

```bash
stegstr-cli embed cover.png -o out.png --payload "text or JSON"
stegstr-cli embed cover.png -o out.png --payload @bundle.json
stegstr-cli embed cover.png -o out.png --payload @bundle.json --encrypt
```

Use `--payload @file` to load from file. Use `--encrypt` so any Stegstr user can detect. Use `--payload-base64 <base64>` for binary payloads.

### Post (create kind 1 note bundle)

```bash
stegstr-cli post "Your message here" --output bundle.json
stegstr-cli post "Message" --privkey-hex <64-char-hex> --output bundle.json
```

Creates a Nostr bundle; use `stegstr-cli embed` to hide it in an image.

## Example workflow

```bash
# Create a post bundle
stegstr-cli post "Hello from OpenClaw" --output bundl...

# Stegstr (ClawHub Skill)

Embed and decode hidden messages in PNG images. Steganographic Nostr client—works offline, no registration.

## Quick install

Requires [Rust](https://rustup.rs) and git.

```bash
git clone https://github.com/brunkstr/Stegstr.git
cd Stegstr/src-tauri && cargo build --release --bin stegstr-cli
```

Binary: `target/release/stegstr-cli` (Windows: `stegstr-cli.exe`)

Or use the optional `install.sh` script for a one-step install to `~/.local/bin`.

## Usage

| Command | Description |
|---------|-------------|
| `stegstr-cli decode image.png` | Extract raw payload from image |
| `stegstr-cli detect image.png` | Decode + decrypt, print bundle JSON |
| `stegstr-cli embed cover.png -o out.png --payload @bundle.json --encrypt` | Hide payload in image |
| `stegstr-cli post "message" --output bundle.json` | Create Nostr note bundle |

See [SKILL.md](./SKILL.md) for full documentation and examples.

## Links

- [stegstr.com](https://stegstr.com)
- [GitHub](https://github.com/brunkstr/Stegstr)
- [CLI docs](https://www.stegstr.com/wiki/cli.html)
- [For AI agents](https://www.stegstr.com/wiki/for-agents.html)