Fluid Chat

Fluid Chat is presented as a free, open source alternative to Slack. It can be used as a hosted service or self-hosted against your own Postgres database. The page states it has no per-seat pricing, no 90-day message history limit, and no vendor lock-in. It describes realtime messaging with WebSocket updates and optional Redis fan-out, Postgres full-text search with operators, file uploads to S3-compatible storage with stated size limits, slash commands and incoming webhooks, and administration features such as roles, per-channel retention, data exports, and an audit log. Stated requirements include Node 20+, Postgres 14+, and S3-compatible storage; native iOS and Android apps are not provided. The page notes a Slack importer is not yet built.

Key features

• Public and private channels, channel browser, 1:1 and group DMs up to nine people
• Threads with reply counts, participant facepiles and also send to channel
• Realtime typing indicators, presence and live updates over WebSocket
• Unread counts, mention badges, and an activity feed
• File uploads up to 10 MiB each and 100 MiB active files per workspace, with inline image rendering
• Pins, saved messages to Later, reminders and scheduled sends
• Nineteen slash commands and incoming webhooks
• Postgres full-text search with operators such as in:, from:, has:file, has:link, is:pinned, before:, after:, during:
• Light and dark themes, keyboard shortcuts, custom emoji, and a responsive drawer layout for phones
• Roles (owner, admin, member, guest), per-channel retention settings, JSONL and CSV data exports, and an audit log
• Docker Compose or source-based installation

Best suited for

• Teams wanting a self-hosted Slack alternative with their own data
• Organizations seeking unlimited message history without per-seat charges
• Developers who want to read, extend, or contribute to open source team chat software

Pricing

Free. The page states self-hosted or hosted use is $0 with no per-seat charge, no credit card, and no trial expiry.