# Open WebUI 0.13.1 adds Tether, a desktop companion app, and coding agents as models; 0.13.2 fixes HTTP chats

Canonical: https://theagenticweekly.com/news/open-webui-v0-13-1 · Evidence: Reported · First seen: 2026-11-08 11:58 UTC · Source published: 2026-11-08 11:53 UTC · Brief published: 2026-11-08 13:03 UTC · Updated: 2026-11-08 13:03 UTC · Author: Agentic Weekly

> Open WebUI 0.13.1, released November 8, 2026, introduces Tether, "the new desktop companion app for macOS, Windows and Linux that ties your own computer to Open WebUI." The notes also say the release contains security fixes and that "rolling updates are not supported"; same-day 0.13.2 then fixed chats that stalled over plain HTTP.

## What changed

- Tether is a new desktop companion for macOS, Windows and Linux. The notes say you sign in once and the computer appears under Your devices, so models and coding agents can work in your real files; it connects out (no ports to open) and unused sessions expire after 90 days by default (SESSION_EXPIRES_IN).
- Coding agents as models: on an Open Terminal that offers agents, Claude Code, Codex and Pi now appear in the model picker. You can chat with them or call them by voice and approve their tool requests; each conversation uses one agent, and those chats cannot be regenerated, continued or edited and resent.
- The notes say tool chats cost less because citation instructions, memory, skills and attached knowledge are no longer rewritten on every tool round, so providers can prompt-cache that prefix. A new Auto permission mode (off by default) lets a review model run a call only when it judges no confirmation is needed.
- Breaking defaults: with native function calling, attached files are no longer preloaded (models read them with file tools). Unless you saved your own values, RAG_TOP_K and RAG_TOP_K_RERANKER default to 10 from 3, and CHUNK_SIZE to 1024 from 1000. Side chats are now saved; they were always temporary in 0.13.0.
- Files whose extracted text is shorter than 50,000 characters (RAG_FULL_TEXT_CHAR_THRESHOLD, set in admin Documents settings) are included in full instead of through retrieval. On large screens, chats can split into resizable panes, and each chat's open tabs and layout are saved per user on the server.
- Upgrade notes: 0.13.1 has unlisted security fixes and schema changes, so rolling updates are not supported. Same-day 0.13.2 fixed chats, comments and Markdown editing that stalled over plain HTTP with "crypto.randomUUID is not a function", and made the Allow Side Chat switch visible when Temporary Chat is off.

## In the source's words

> "Tether is the new desktop companion app for macOS, Windows and Linux that ties your own computer to Open WebUI."
> (Open WebUI v0.13.1 release notes, https://github.com/open-webui/open-webui/releases/tag/v0.13.1)

> "We strongly recommend updating all deployments as soon as possible to have the latest security fixes in place."
> (Open WebUI v0.13.1 release notes, https://github.com/open-webui/open-webui/releases/tag/v0.13.1)

> "If you are running a multi-worker, multi-server, or load-balanced deployment, all instances must be updated simultaneously, rolling updates are not supported and will cause application failures due to schema incompatibility."
> (Open WebUI v0.13.1 release notes, https://github.com/open-webui/open-webui/releases/tag/v0.13.1)

## Early verdict

Self-hosters should upgrade to 0.13.2 for the security fixes and the HTTP chat patch, but back up the database first and plan a full, not rolling, update on multi-instance setups. Anyone using file attachments with native function calling should check the new Preload files default. (Basis: Based only on the v0.13.1 and v0.13.2 release notes as read on November 8, 2026; we have not run either release.)

## What we have not verified

- We did not install 0.13.1, 0.13.2 or the Tether desktop app, or try coding agents in the model picker.
- The security fixes are not listed in the changelog, so we cannot say what they cover or how severe they are.
- We did not measure the prompt-cache cost reduction the notes claim for tool chats.

## Timeline

- Source published: 2026-11-08 11:53 UTC
- First seen by our watcher: 2026-11-08 11:58 UTC (via GitHub releases: open-webui/open-webui)
- Brief published: 2026-11-08 13:03 UTC

## Sources

- [Open WebUI v0.13.1 release notes (GitHub)](https://github.com/open-webui/open-webui/releases/tag/v0.13.1) (primary source) (fetched 2026-11-08)
- [Open WebUI v0.13.2 release notes (GitHub)](https://github.com/open-webui/open-webui/releases/tag/v0.13.2) (fetched 2026-11-08)

## Related

- [Open WebUI: verdict and setup guide](https://theagenticweekly.com/tools/open-webui)
- [Alternatives to Open WebUI](https://theagenticweekly.com/alternatives/open-webui)
- [All news briefs](https://theagenticweekly.com/news)
- [This week's releases](https://theagenticweekly.com/this-week)
- [New AI models this week](https://theagenticweekly.com/models/this-week)

## How to cite

Agentic Weekly, "Open WebUI 0.13.1 adds Tether, a desktop companion app, and coding agents as models; 0.13.2 fixes HTTP chats", published 2026-11-08 13:03 UTC, https://theagenticweekly.com/news/open-webui-v0-13-1