Fluid Chat is a free, open-source team chat tool, officially positioned as an alternative to Slack. It provides core features such as channels, direct messages, threads, emoji reactions, files, search, and presence, and supports self-hosting or using a hosted version, with users able to run it on their own Postgres. The official emphasis is that there is no per-seat pricing, no 90-day history limit, and no vendor lock-in, and all 91 features are included in the free product, with no paid tiers.
Main capabilities include: public and private channels, a channel browser, 1:1 and group direct messages for up to nine people, and threads with reply counts, stacked participant avatars, and "also send to channel." Real-time functionality is implemented through HTTP writes, WebSocket reads, and events, including typing indicators, presence, and live updates; if the socket is interrupted, the app still works. Features such as unread counts, mention badges, "new messages" dividers, and marking any message as unread help track messages; an activity feed collects mentions, thread replies, emoji reactions, and keyword hits. Files support drag-and-drop and paste upload, inline image rendering, a file list for each conversation, and files are stored in private S3-compatible storage, with a maximum of 10 MiB per file, an active file limit of 100 MiB per workspace, files retained for 15 days, and exports retained for 7 days. It provides 19 slash commands and incoming webhooks, supporting CI, alerts, and scripts to post to channels as their own app. The client provides light and dark themes, comfortable or compact density, a ⌘K quick switcher, full keyboard shortcuts, custom emoji, sidebar sections, and a drawer layout suitable for mobile phones. Search is based on Postgres full-text search and supports operators such as in:#channel, from:@person, has:file, has:link, is:pinned, before:, after:, and during:, can sort by time or relevance, and has no 90-day history wall. Governance features are available without an enterprise tier.
How to use: You can start for free in the browser, or clone the project and run it on your own Postgres. Technical dependencies: Node 20+, Postgres 14+, private S3-compatible object storage (for uploads and workspace exports); Redis is optional and only needed when running multiple app or realtime processes, in which case realtime events are distributed via Redis publish/subscribe. Passwords are hashed using Argon2, and all queries are scoped by workspace through permission helpers.Visitors are limited to the channels they have been added to. Data does not leave the user's server.
Limitations and information not provided: The official page does not mention features such as AI stock summaries, Reddit community content, or sending updates via Discord or email; no Slack importer is provided; there is no native iOS or Android app, only a mobile web drawer layout; no specific AI capabilities are mentioned.
