Render just removed its AI sandbox time limit — and Vercel still has a 24-hour cap

Render is taking on Vercel with AI sandboxes that can run indefinitely, along with new tools for managing long-running agent workflows and shared storage.

Announced Wednesday, the launch removes Render’s previous 30-day continuous runtime limit on paid workspace plans. Vercel caps individual sandbox sessions at 24 hours, while Render says its environments can suspend when idle and resume with their files, memory and running processes intact.

Render founder and CEO Anurag Goel, a former Stripe engineer and head of risk, built the platform as an alternative to AWS without the same infrastructure complexity. Now he’s extending that approach to AI agents, combining sandboxes, durable workflows, and shared storage with the applications and databases they depend on.

Not everything is ready yet. Credential brokering will initially be available only to selected customers, private networking for sandboxes is still in development, and Render has yet to settle how its shared storage will handle simultaneous writes to the same file.

Sandboxes that resume mid-task

With this launch, Render sandboxes can stay active through a multi-day codebase migration or while an agent tests an entire application.

The bigger difference comes when a sandbox needs to resume work. Vercel limits uninterrupted sessions to 24 hours, and while persistent sandboxes can restart, their running processes start over.

Render takes a different approach. A sandbox “suspends when it goes idle and wakes on the next command with its files and memory intact, so the agent picks up mid-task instead of rebuilding its state,” the company tells The New Stack.

“suspends when it goes idle and wakes on the next command with its files and memory intact, so the agent picks up mid-task instead of rebuilding its state.”

Credentials that never enter

One of the launch’s security features is credential brokering, which attaches credentials to an agent’s outbound requests as they leave the sandbox so that secrets never enter it.

Pressed on whether that sets Render apart from Vercel, which already offers scoped credentials for agents through its Connect service and has been pushing its own vendors toward short-lived credentials, the company does not claim an edge.

Credential brokering “is not a competitive differentiator” and “is rapidly becoming table stakes,” Render tells The New Stack, calling it “a feature we believe users of Render will appreciate having access to, rather than one users of other platforms will migrate for.”

Render tells The New Stack, it is “turning credential brokering on for small groups of customers first to make sure the experience meets our quality bar” before expanding in the coming weeks, while every developer in the beta gets outbound controls that can “block all traffic from a sandbox or allow only the domains you list.”

The company’s larger argument is that the sandbox matters less than everything around it. Developers choose Render over Vercel, the company contends, because an agent usually has to run inside a larger product and do heavy background work that needs an API staying up and holding its database connections, along with background workers, cron jobs, and the database itself.

Compute flexibility, less complexity

Vercel started with the frontend and serverless functions and is strong there; Render allows, but the company tells The New Stack that Vercel’s “underlying ‘fluid compute’ model is inflexible and inefficient for running the compute-heavy backend workloads that agentic applications depend on,” noting that a single function “tops out at 2 CPUs and 4 GB of RAM,” a ceiling that applies to Vercel Functions rather than its sandboxes.

Render tells The New Stack, it “gives developers the compute flexibility of AWS but takes the complexity off their plate.” Cristian Herrera, CTO of OCMI, which considered Vercel while moving away from AWS, tells Render that “Vercel is a different story,” adding that “if you need to do anything outside of Next.js, you’re fighting the platform.”

“if you need to do anything outside of Next.js, you’re fighting the platform.”

Vercel acknowledged The New Stack’s request for comment but had not provided a statement by publication time.

Workflows that survive crashes

Render’s new Durable Workflows let developers resume long-running jobs after a failure without starting over. Developers can write workflows in Python or TypeScript, with individual tasks running for up to 24 hours. Render “saves the result of every step as it finishes,” the company tells The New Stack. If a process crashes, the workflow can resume on a new machine using those saved results, so “model calls, payments, and database writes that have already succeeded don’t run again.”

A risk remains if a process crashes after a payment goes through but before the result is saved. Render recommends using idempotency keys to prevent duplicate charges or database writes. Shared Filesystems let sandboxes and workflow tasks access the same persistent files, even after the compute that created them shuts down.

Render says the feature is designed for “many agents reading the same repo or dataset, with each one writing its own output.” But handling “concurrent writes to the same file, including locking and conflict resolution, is something we’re still studying,” the company tells The New Stack.

Render says AWS and Vercel are “the two platforms new users most often tell us they’re leaving today, citing complexity and cost as major factors,” the company tells The New Stack. Render doesn’t yet have figures showing how many customers have migrated from Vercel.

Render says AWS and Vercel are “the two platforms new users most often tell us they’re leaving today”

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