Release workflow@5.4.0 · vercel/workflow

@workflow/core@5.4.0

#5048 e1bce44 @pranaygp - Awaiting run.returnValue of a child run from the workflow that started it now suspends on one system hook per parent, which each child resumes when it finishes, instead of polling inside a step.
#5226 50d425f @pranaygp - Removed: reading response.body with getReader(), values() or for await inside workflow functions (added in 5.3.0) throws again. Use response.json(), response.text() or response.arrayBuffer(), or make the request and read the response in a step function. If you assigned globalThis.fetch = fetch to run AI SDK calls in a workflow function, move those calls into a step function, or use AI SDK's WorkflowAgent for agents.
#5238 50a61e7 @pranaygp - Rename the start() option hook to experimental_hook, and enable it by default on the Postgres and Vercel Worlds. WORKFLOW_POSTGRES_EXPERIMENTAL_START_HOOK and WORKFLOW_VERCEL_EXPERIMENTAL_START_HOOK are removed, along with the EXPERIMENTAL_START_HOOK_ENV exports; the capability is only used when a caller passes experimental_hook to start().

#5243 9bed0a7 @pranaygp - workflow health now gives its local server check the --timeout it was run with instead of a fixed 5 seconds, and reports a server that answered with an error status as such rather than as unreachable.

#5190 f98fca1 @prha - Take over a Hook token claim lock left by a dead process at once, instead of after 30 seconds, and create claim and in-band fence locks with their owner recorded in one atomic step. Continue to recognize directory locks written by earlier world-local releases.
#5189 a4123ba @prha - Create a hook whose interrupted hook_created left its token claim naming an event slot another event has since taken, instead of reporting it as already created while no creation exists.

#5048 e1bce44 @pranaygp - Awaiting run.returnValue of a child run from the workflow that started it now suspends on one system hook per parent, which each child resumes when it finishes, instead of polling inside a step.
#5238 50a61e7 @pranaygp - Rename the start() option hook to experimental_hook, and enable it by default on the Postgres and Vercel Worlds. WORKFLOW_POSTGRES_EXPERIMENTAL_START_HOOK and WORKFLOW_VERCEL_EXPERIMENTAL_START_HOOK are removed, along with the EXPERIMENTAL_START_HOOK_ENV exports; the capability is only used when a caller passes experimental_hook to start().

#5238 50a61e7 @pranaygp - Rename the start() option hook to experimental_hook, and enable it by default on the Postgres and Vercel Worlds. WORKFLOW_POSTGRES_EXPERIMENTAL_START_HOOK and WORKFLOW_VERCEL_EXPERIMENTAL_START_HOOK are removed, along with the EXPERIMENTAL_START_HOOK_ENV exports; the capability is only used when a caller passes experimental_hook to start().
#5058 c805b90 @bluepegasus123 - Honor the caller's abort signal when runs.waitForTerminalStatus falls back to a plain run read.

#5228 8e90367 @mitul-s - Render the trace viewer’s Wake Up Sleep and Resolve Hook actions as standard text-only secondary buttons, without the nested Actions card, and keep their labels stable while they run.

#5063 11a904f @joelfickson - Export workflowSerdeComputedPropertyPattern alongside the other workflow pattern regexes.

#5063 11a904f @joelfickson - Run the Turbopack workflow loader on files that use static [WORKFLOW_SERIALIZE] computed keys (such as @ai-sdk/openai models), fixing "Class … not found" errors in steps.

#5243 9bed0a7 @pranaygp - Coalesce workflow rebuilds requested while one is running in Nitro dev. A burst of file changes now triggers at most one follow-up rebuild instead of one per change, so the dev server settles sooner.

#5211 6291260 @atinux - Upgrade @nuxt/kit to 4.6.3 to pick up the fix for CVE-2026-71314.