PenEcho turns a 20,000×20,000 canvas into a shared workspace for humans and AI
JafarNajafov · x · 2026-07-22
PenEcho is a shared 20,000×20,000 canvas where humans and AI work in the same workspace.
- You can handwrite equations, sketch diagrams, or leave partial ideas on the canvas, and the system responds next to the relevant area.
- It can solve handwritten math, continue proofs, convert rough sketches into clean diagrams, and typeset selected handwriting into text and formulas.
- Supports OpenAI, Anthropic, Kimi K3, Codex CLI, and Claude CLI.
- The local CLI modes work with an existing ChatGPT or Claude subscription, so no API key is required.
- It runs in the browser via a local Node.js server on macOS, Windows, and Linux, is open source under AGPL, and is still early with rough edges around handwriting recognition and pen input.
More from coding & agent
- Four teams independently shipped the same “LLM wiki” pattern after Karpathy’s gist — garrytan · 2026-07-22
- Greptile reviews GPT code with Claude, and Claude code with GPT — garrytan · 2026-07-22
- Claude placed a live crypto trade through Bitpanda MCP, raising latency questions — Bitches172882 · 2026-07-22
- A builder says losing coding-model access would cut productivity sharply — serrjoa · 2026-07-22
- Security agents need harsher isolation because models will cheat, search for hints and peek anywhere — banteg · 2026-07-22
- Hermes Agent v0.19.0 adds subscription controls, reasoning modes and transcript exports — Teknium · 2026-07-22