Skill: brunkstr/stegstr (version 1.0.1)

--- name: stegstr summary: Embed and decode hidden messages in PNG images. Steganographic Nostr client for hiding data in images—works offline, no registration. description: Decode and embed Stegstr payloads in PNG images. Use when the user needs to extract hidden Nostr data from a Stegstr image, encode a payload into a cover PNG, or work with steganographic social networking (Nostr-in-images). Supports CLI (stegstr-cli decode, detect, embed, post) for scripts and AI agents. license: MIT tags: steganography, nostr, images, crypto, integration, file-management, automation, cli install: requirements: | - Rust (latest stable) - https://rustup.rs - Git steps: | 1. git clone https://github.com/brunkstr/Stegstr.git 2. cd Stegstr/src-tauri && cargo build --release --bin stegstr-cli 3. Binary: target/release/stegstr-cli (Windows: stegstr-cli.exe) permissions: - filesystem metadata: homepage: https://stegstr.com for-agents: https://www.stegstr.com/wiki/for-agents.html repo: https://github.com/brunkstr/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 bundle.json # Embed into a cover image (encrypted for any Stegstr user) stegstr-cli embed cover.png -o stego.png --payload @bundle.json --encrypt # Recipient detects and extracts stegstr-cli detect stego.png ``` ## Image format PNG only (lossless). JPEG or other lossy formats will corrupt the hidden data. ## Payload format - **Magic:** `STEGSTR` (7 bytes ASCII) - **Length:** 4 bytes, big-endian - **Payload:** UTF-8 JSON or raw bytes (desktop app encrypts; CLI can embed raw or `--encrypt`) Decrypted bundle: `{ "version": 1, "events": [ ... Nostr events ... ] }`. Schema: [bundle.schema.json](https://raw.githubusercontent.com/brunkstr/Stegstr/main/schema/bundle.schema.json). ## Links - **agents.txt:** https://www.stegstr.com/agents.txt - **For agents:** https://www.stegstr.com/wiki/for-agents.html - **CLI docs:** https://www.stegstr.com/wiki/cli.html - **Downloads:** https://github.com/brunkstr/Stegstr/releases/latest


Security scan verdicts — ClawScan: clean | static analysis: clean | VirusTotal: clean | SkillSpector: suspicious (CRITICAL)