Runtime changelog, 26 September 2026

What shipped in Runtime Cloud on 26 September 2026: security fixes across the account; single sign-on through OIDC; bucket mounts work again; paid means paid and kept; faster starts, pauses and wakes; outbound traffic has a price; a calmer console; fast commands keep all their output; withruntime 0.7.1; your account opens straight away; and a smaller MCP tool list.

Security fixes across the account

A read-only key still lists a sandbox's previews but no longer receives a private preview's token. Webhooks and telemetry exports are made, changed and deleted by an owner's or admin's key, and every key still lists them. A deleted or replaced private registry password is erased, as is every one when an account closes. Support asked through a read-only key sees only what that key can. See security and observability.

Single sign-on through OIDC

Okta, Entra ID and Google Workspace connections by OIDC can be saved and used, as SAML ones could. See single sign-on.

Bucket mounts work again

Bucket mounts work again, and a custom domain under a suffix such as co.uk is told to set A and AAAA records at its apex, not a CNAME.

Paid means paid and kept

Paid-only features follow a top-up that was not refunded or charged back in full, and a refund of a top-up that earned matching credit is smaller by any of that credit already spent. See pricing.

Faster starts, pauses and wakes

Runtime now keeps machines of the most common sandbox shapes started ahead of time, and the servers keep memory ready for sandboxes that start or grow at once. Measured through the public API: a new sandbox runs its first Python command 374 ms after the create request at the median (495 ms p95, down from 981 ms), a pause takes 207 ms, a paused sandbox runs its next command 980 ms after the call that wakes it, and a preview visit to one answers in 0.77 s, down from 3.99 s. See speed for every figure and the samples.

Outbound traffic has a price

Inbound traffic stays free, and each account's first 100 GiB out a month is free. Past it, what sandboxes send to the internet costs $0.02 per GB, fixed in each new sandbox's quote. Replies served through previews, custom domains and TCP ports, traffic to your own network, and trial sandboxes are not charged, and sandboxes made before today keep free traffic for their whole life. GET /v1/usage shows the month so far under outbound. See pricing.

A calmer console

Home is your whole account on three sheets: your sandboxes' CPU hour by hour for the last day, this month's cost by product, and Worth a look, which names sandboxes costing money while doing little and offers Pause for an idle one. Sandboxes, a sandbox's page, Images, Volumes and Settings are redrawn to match, and the sidebar holds everything, with your account and your menu in one place at its top.

Fast commands keep all their output

A command that writes faster than it is read now waits for its reader from its first byte instead of losing what came before: 4 MiB written at once came back whole in every run, where before about half the runs lost up to three quarters of it. See running commands.

withruntime 0.7.1

Code written for E2B no longer gets lost output back looking whole: when part of a command's output was dropped before it was read, the result says truncated and a warning names it. runtime login now names the account it connected to. Update with npm i withruntime@latest or pip install -U withruntime.

Your account opens straight away

A new account now lands in the full console. Home shows the setup prompt for your coding agent until the agent connects, and keys, billing and settings are in the menu from the first visit. Hide the prompt if you would rather start on your own.

A smaller MCP tool list

An agent connected to Runtime's MCP server now reads 45 tools instead of 80, in 61,754 characters instead of 80,808, before its first call. A product's rarer verbs share one tool that takes an action: runtime_volume_get is now runtime_volume with "action": "get". The first-session tools keep their names. The old names answer until the next release and say what replaces them; see renamed tools.