wrangler configures a per-workflow concurrency limit
Introduced 2026-08-27 · score 0.96
HOW TO USE IT
When deploying a Workflow with Wrangler, set `concurrency.limit` to a positive integer in its `workflows[]` entry. The limit is persisted on deploy and enforced server-side; it is ignored in local development.
{
"workflows": [
{
"binding": "MY_WORKFLOW",
"name": "my-workflow",
"class_name": "MyWorkflow",
"concurrency": { "limit": 10 }
}
]
}WHY THIS HELPS
Set a maximum number of Workflow instances that can run concurrently for a workflow deployed with Wrangler.
REQUIREMENTS AND LIMITATIONS
- Version: 4.127.0
- workflows[].concurrency.limit: Positive integer maximum number of Workflow instances that can run concurrently. The `concurrency` object is optional; when set, specify `limit`.
- The limit is validated as a positive integer.
- Concurrency is ignored in local development.
- Docs conflict: The current Wrangler configuration page documents Workflow binding fields but does not list `concurrency`; it does not state different behavior. https://developers.cloudflare.com/workers/wrangler/configuration/
FIRST-PARTY EVIDENCE
- https://github.com/cloudflare/workers-sdk/releases/tag/wrangler%404.127.0
- https://github.com/cloudflare/workers-sdk/releases/tag/wrangler@4.127.0
Check the installed version and the source before using it. Entry JSON