wrangler-4-127-0-17-b
Claude Code's read-only tools, web search on, ludion sync off
Question
Is there a wrangler config setting for a Workflow's concurrency limit?
Answer key
- A correct answer says
- A Workflow's maximum number of concurrently running instances can be set with `workflows[].concurrency.limit` in the Wrangler config.
- The stale answer
- Workflows have no per-workflow concurrency setting in Wrangler config; only account limits apply.
Answer
No. Wrangler has no setting that caps how many instances of a Workflow run at once. The concurrency cap is set per account by Cloudflare: 100 on the Free plan and 50,000 on Workers Paid as of April 2026. Some parts of the limits page still say 10,000. Only running instances count; ones that are sleeping, waiting to retry, or waiting for an event don't. Instance creation is also capped at 100 per second per Workflow. The one related setting in the config is `limits.steps`, which sets the maximum number of steps in a single instance, not concurrency. The `max_concurrency` setting you may have seen is for Queues consumers, not Workflows. To throttle Workflows, limit how fast you create instances, for example by starting them from a Queue consumer with `max_concurrency` set. To raise the account cap, use Cloudflare's Limit Increase Request Form.
Sources:
- [Workflows limits](https://developers.cloudflare.com/workflows/reference/limits/)
- [Wrangler configuration](https://developers.cloudflare.com/workers/wrangler/configuration/)
- [Workflows limits raised (Apr 2026)](https://developers.cloudflare.com/changelog/post/2026-04-15-workflows-limits-raised/)
- [Queues consumer concurrency](https://developers.cloudflare.com/queues/configuration/consumer-concurrency/)Grade
wrong
The judge's reason: It says Wrangler has no per-Workflow concurrency setting and only account limits apply, which is the stale answer; the key says `workflows[].concurrency.limit` exists.
Session log
Tool call: ToolSearch
{ "query": "select:WebSearch", "max_results": 1 }Tool output
{"type":"tool_reference","tool_name":"WebSearch"}Tool call: WebSearch
{ "query": "Cloudflare Workflows wrangler config concurrency limit instances", "mode": "standard", "allowed_domains": [ "developers.cloudflare.com" ] }Tool output
Web search results for query: "Cloudflare Workflows wrangler config concurrency limit instances" Links: [{"title":"Limits · Cloudflare Workflows docs","url":"https://developers.cloudflare.com/workflows/reference/limits/"},{"title":"Configuration - Wrangler · Cloudflare Workers docs","url":"https://developers.cloudflare.com/workers/wrangler/configuration/"},{"title":"Consumer concurrency · Cloudflare Queues docs","url":"https://developers.cloudflare.com/queues/configuration/consumer-concurrency/"},{"title":"Release notes · Cloudflare Workflows docs","url":"https://developers.cloudflare.com/workflows/reference/changelog/"},{"title":"Workflows Changelog","url":"https://developers.cloudflare.com/changelog/product/workflows/"},{"title":"Increased concurrency, creation rate, and queued instance limits for Workflows instances · Changelog","url":"https://developers.cloudflare.com/changelog/post/2026-04-15-workflows-limits-raised/"},{"title":"Increased Workflows instance and concurrency limits · Changelog","url":"https://developers.cloudflare.com/changelog/post/2025-10-28-raising-limits/"},{"title":"Changelogs","url":"https://developers.cloudflare.com/changelog/17/"},{"title":"Workers Changelog","url":"https://developers.cloudflare.com/changelog/product/workers/2/"},{"title":"Concurrent Workflow instances limits increased. · Changelog","url":"https://developers.cloudflare.com/changelog/post/2025-02-25-workflows-concurrency-increased/"}] I found no Wrangler setting that caps concurrent Workflow instances. The concurrency limit appears to be account-level, not configurable per Workflow in the config file. - **Current account limit:** Workers Paid accounts get 50,000 concurrent instances, per the limits table (Concurrent Workflow instance (executions) per account ^5 | 100 | 50,000). An April 2026 changelog entry confirms the raise to 50,000 (Concurrency limit for Workflows instances is now 50,000.). - **Doc inconsistency:** The limits page's waiting-state section still refers to a 10,000 concurrent limit (only actively running instances count toward the 10,000 concurrent instance limit). Treat the 50,000 figure as current, but the docs may not be fully updated. - **Per-workflow limit:** Instance creation is capped at 300 per second per account and 100 per second per workflow (maintaining a limit of 100 instances per second per workflow). - **Waiting instances:** Sleeping or event-waiting instances don't count toward concurrency (Instances that are in a waiting state — either sleeping via step.sleep, waiting for a retry, or waiting for an event via step.waitForEvent — do not count towards concurrency limits.). - **Wrangler options that do exist:** The config file exposes per-Workflow `limits.cpu_ms` and `limits.subrequests`, and per-export `limits.steps` (steps number optional — The maximum number of steps a Workflow instance can run.). None of these controls concurrency. - **Raising the cap:** Higher limits go through a request form (To request an adjustment to a limit, complete the Limit Increase Request Form). The `max_concurrency` setting in Wrangler is for Queues consumers, not Workflows. If you need to throttle Workflow runs, you'd have to do it in application code or by gating instance creation. REMINDER: You MUST include the sources above in your response to the user using markdown hyperlinks.Agent
No. Wrangler has no setting that caps how many instances of a Workflow run at once. The concurrency cap is set per account by Cloudflare: 100 on the Free plan and 50,000 on Workers Paid as of April 2026. Some parts of the limits page still say 10,000. Only running instances count; ones that are sleeping, waiting to retry, or waiting for an event don't. Instance creation is also capped at 100 per second per Workflow. The one related setting in the config is `limits.steps`, which sets the maximum number of steps in a single instance, not concurrency. The `max_concurrency` setting you may have seen is for Queues consumers, not Workflows. To throttle Workflows, limit how fast you create instances, for example by starting them from a Queue consumer with `max_concurrency` set. To raise the account cap, use Cloudflare's Limit Increase Request Form. Sources: - [Workflows limits](https://developers.cloudflare.com/workflows/reference/limits/) - [Wrangler configuration](https://developers.cloudflare.com/workers/wrangler/configuration/) - [Workflows limits raised (Apr 2026)](https://developers.cloudflare.com/changelog/post/2026-04-15-workflows-limits-raised/) - [Queues consumer concurrency](https://developers.cloudflare.com/queues/configuration/consumer-concurrency/)