Synapsdex

AI writing assistant for X (Twitter): drafts replies, reposts and posts that you review, edit and post yourself.

Synapsdex is a free, open source AI writing assistant that lives inside X (Twitter) and helps you draft sharper replies, reposts and posts. You always review, edit and post everything yourself. Open any post, pick an angle, and Synapsdex drafts ready-to-use options in seconds, grounded in the post you are actually looking at. WHAT IT DOES Reads the post in front of you (text, metrics, community note) and drafts contextual replies, not generic filler. 12 strategic angles (“archetypes”): challenge it, build on it, fact-check it, make it funny, ask a sharp question, and more. Create unlimited angles of your own. 9 actions built in: Reply, Repost, Post, Counter, Question, TL;DR, Predict and more. Hooks generator: 5 scroll-stopping opening lines for your own posts. Personas: write in the style of a public figure whose name you type. Built-in filters: banned words and a reply-opportunity score, to spend your time where it counts. TWO WAYS TO GENERATE Use your own AI API key (OpenAI, Anthropic and compatible providers) for the best quality. Or use the built-in no-key mode to start instantly. SAFE BY DESIGN No automation that risks your account: it never auto-posts, auto-likes or auto-follows. No X API. It only reads what is on your screen and lets you paste drafts into X’s composer yourself. Your settings stay on your device. Generation requests go only to the AI provider you chose. FREE AND OPEN SOURCE Synapsdex is completely free, with no limits, no account and no card. Everything is unlocked for everyone. It is also open source under the AGPL-3.0 license, so you can read, fork and contribute to the code on GitHub: https://github.com/emmgr23/synapsdex Questions, feedback or feature requests? Join our Discord: https://discord.com/invite/hHcq8gewtD