Local Temporal Dev Setup

To develop against a local build of the Temporal server, you need two things running in separate terminals.

Terminal 1 — Temporal server (from your local temporal repo)

Navigate to your local clone of the temporalio/temporal repo and start the server:

make start

This builds and starts the server with SQLite in-memory. If you want a specific branch, check it out first:

git checkout <branch-name>
make bins  # safe to run even if already built — outputs "Nothing to be done" and exits cleanly
make start

The server runs gRPC on port 7233 and HTTP on 7243.

Terminal 2 — UI dev server (this repo)

From this repo, use the local-temporal script instead of the default dev script:

pnpm dev:local-temporal

This loads .env.local-temporal which points the UI at the local server instead of spinning up its own.

Why not pnpm dev?

pnpm dev (aliased to pnpm dev:ui-server) starts a bundled Temporal server alongside the UI. pnpm dev:local-temporal skips that and connects to whatever is already running on the configured ports.

Keeping the ui-server in sync with the Temporal server branch

This is critical when working on unreleased features. The ui-server (server/) is a separate Go binary that acts as a grpc-gateway — it decodes HTTP/JSON into proto messages and forwards them to the Temporal server over gRPC. Its proto descriptors are baked in at compile time from its own server/go.mod.

If the Temporal server branch uses a newer go.temporal.io/api version than server/go.mod, the ui-server will reject any new HTTP fields as "unknown field" before the request ever reaches the Temporal server.

When switching to a Temporal branch with API changes:

1. Check what go.temporal.io/api version the Temporal server branch uses:

   grep "go.temporal.io/api" ~/code/temporal/go.mod

2. Update server/go.mod to match:

   cd server
   go get go.temporal.io/api@<version>

3. Rebuild the ui-server binary:

   go build -o ui-server ./cmd/server

4. Then restart pnpm dev:local-temporal to pick up the new binary.