09440c85cb
LSP 3.18 allows servers to send [`MarkupContent` diagnostic messages](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.18/specification/#diagnostic), guarded by the client capability `textDocument.diagnostic.markupMessageSupport`. - Advertise `markup_message_support` only while pull diagnostics are enabled because `textDocument.diagnostic` is the pull-model capability. LSP 3.18 currently has no equivalent capability for push diagnostics: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.18/specification/#diagnosticClientCapabilities https://github.com/microsoft/language-server-protocol/issues/2246 - Handle `string | MarkupContent` messages in both push and pull diagnostic paths: markdown-kind messages populate the existing `Diagnostic::markdown` field (rendered in hover popovers and the diagnostics panel), plaintext-kind markup remains plain text, and plain string messages keep going through the adapter's `diagnostic_message_to_markdown`. - Preserve server-provided markup for code actions sent back to the originating server, avoid forwarding markup diagnostics to other servers, and render diagnostic metadata without altering the server-provided markdown. - Carry the markup kind over RPC via a new optional `LspDiagnostic.markup_message_kind` proto field so remote/collab projects round-trip `MarkupContent` messages. Depends on the lsp-types change that turns `Diagnostic.message` into a `DiagnosticMessage` enum (`string | MarkupContent`): https://github.com/zed-industries/lsp-types/pull/15 Once merged, Cargo.toml can point to the upstream commit. Note that Zed already rendered some plain-string diagnostics as Markdown through language-specific adapter hooks, including `rust-analyzer`. This adds protocol-level support for diagnostics explicitly sent as LSP 3.18 `MarkupContent`, while preserving the existing adapter fallbacks. As a result, this does not introduce a new diagnostics rendering pipeline. Server-provided Markdown is routed through the existing `Diagnostic::markdown` path, with small fixes to handle Markdown-only updates and block content correctly. ## Showcase Example from [JETLS.jl](github.com/aviatesk/JETLS.jl) (a Julia language server): > Before <img width="924" height="160" alt="Screenshot 2026-07-15 at 16 05 40" src="https://github.com/user-attachments/assets/b19fe9e3-50e3-44e4-9b4d-ac8bd438d3d6" /> > After <img width="924" height="160" alt="Screenshot 2026-07-15 at 14 13 05" src="https://github.com/user-attachments/assets/359c3382-118d-4fa6-aa91-6bd3661d3d28" /> --- Release Notes: - Added support for rendering LSP 3.18 Markdown diagnostic messages from language servers. --------- Co-authored-by: Claude Fable 5 <noreply@anthropic.com> Co-authored-by: Kirill Bulatov <mail4score@gmail.com>
Zed Server
This crate is what we run at https://collab.zed.dev.
It contains our back-end logic for collaboration, to which we connect from the Zed client via a websocket after authenticating via https://zed.dev, which is a separate repo running on Vercel.
Local Development
Database setup
Before you can run the collab server locally, you'll need to set up a zed Postgres database. Follow the steps sequentially:
- Ensure you have postgres installed. If not, install with
brew install postgresql@15. - Follow the steps on Brew's formula and verify your
$PATHcontains/opt/homebrew/opt/postgresql@15/bin. - If you hadn't done it before, create the
postgresuser withcreateuser -s postgres. - You are now ready to run the
bootstrapscript:
script/bootstrap
This script will set up the zed Postgres database, and populate it with some users. It requires internet access, because it fetches some users from the GitHub API.
The script will create several admin users, who you'll sign in as by default when developing locally. The GitHub logins for the default users are specified in the seed.default.json file.
To use a different set of admin users, create crates/collab/seed.json.
{
"admins": ["yourgithubhere"],
"channels": ["zed"]
}
Testing collaborative features locally
In one terminal, run Zed's collaboration server and the livekit dev server:
foreman start
In a second terminal, run two or more instances of Zed.
script/zed-local -2
This script starts one to four instances of Zed, depending on the -2, -3 or -4 flags. Each instance will be connected to the local collab server, signed in as a different user from seed.json or seed.default.json.
Deployment
We run two instances of collab:
- Staging (https://staging-collab.zed.dev)
- Production (https://collab.zed.dev)
Both of these run on the Kubernetes cluster hosted in Digital Ocean.
Deployment is triggered by pushing to the collab-staging (or collab-production) tag in GitHub. The best way to do this is:
./script/deploy-collab staging./script/deploy-collab production
You can tell what is currently deployed with ./script/what-is-deployed.