Proto Codegen

Local @temporalio/proto codegen

The published @temporalio/proto package often lags the protos we develop against. This tool regenerates a drop-in @temporalio/proto from current temporalio/api protos so you can build and preview the UI against unreleased fields locally.

This is a local dev unblock, not a shipped dependency. The generated output, the pnpm override that activates it, and the ui-server go.mod bump are all local-only — none of them are committed. A feature must not merge to main relying on an unreleased proto; wait until the fields ship in a released @temporalio/proto (and go.temporal.io/api for the ui-server), then delete the local setup with --reset.

Only the tooling is committed: scripts/generate-temporal-proto.ts, this skill, the .gitignore entry, and the protobufjs-cli devDep. vendor/temporalio-proto/ is gitignored.

Commands

pnpm generate:proto --help    # full option list

pnpm generate:proto                        # generate from the latest temporalio/api main
pnpm generate:proto --ref v1.63.3          # generate from a specific tag, branch, or commit SHA
pnpm generate:proto --sync-ui-server       # also bump server/go.mod + rebuild the ui-server to match
pnpm generate:proto --sync-ui-server --ui-server-version v1.63.3   # pin the ui-server go module version
pnpm generate:proto --reset                # undo everything: remove override, delete vendor, revert go.mod, reinstall

A normal run generates vendor/temporalio-proto/, injects the @temporalio/proto override into package.json (a local, uncommitted change), and runs pnpm install. Do not commit the override or the vendored output. When you're done previewing, pnpm generate:proto --reset returns the working tree to the clean, main-matching state.

The two-part bump

Field names/values only line up if two things are on the same proto revision, because gRPC matches by field number — a mismatch silently drops values or renames fields:

1. UI TypeScript types — the generated @temporalio/proto (this tool).
2. The ui-server (server/go.mod) — the grpc-gateway that decodes gRPC into the JSON the UI receives; its baked-in descriptors decide the wire field names.

--sync-ui-server does both: generate the types, then go get go.temporal.io/api@<version> + make build in server/. Restart pnpm dev:local-temporal afterward. Both changes are local-only; --reset reverts them.

Version-axis caveat: the TS types come from a temporalio/api git ref, while the ui-server pins a go.temporal.io/api release tag — no exact 1:1 mapping, so --sync-ui-server defaults to @latest (the practical match for main). If a field still looks wrong, confirm the release tag contains the ref you generated from.

Consuming the generated types

Import as usual — the local override makes these resolve to the generated package:

import type { temporal, google } from '@temporalio/proto';

Only temporal.* and google.* are generated (not coresdk.*, unused here). For enum fields that arrive over REST/JSON as SCREAMING_SNAKE strings, derive a string union from the proto enum so it can't drift:

type ActivityExecutionStatus =
  keyof typeof import('@temporalio/proto').temporal.api.enums.v1.ActivityExecutionStatus;

Note: while previewing with the override active, these resolve to the unreleased shape. Committed code must still compile against the published package, so don't reference fields that only exist in the unreleased protos until they ship.