Launch HN: Runtime (YC P26) – Sandboxed coding agents for everyone on a team

Hey HN, We're Gus and Carlos from Runtime (https://runtm.com). We're building infra that lets your whole team (including non-engineers) ship with Claude Code, Codex, and other agents without engineering having to handhold every session.

After Mentum (YC S21) was acquired, I personally shipped 4 full-stack products in 3 months using coding agents. When I tried to roll the same workflow out to the rest of the team, it fell apart: Most PRs were unmergeable slop - Every repo required an engineer doing one-off local setup. - Skills and context lived in one person's head. - There was no safe way for a PM to touch a real codebase without risking a bad deploy or a secrets leak.

Carlos comes from building agentic reconciliation systems at Modern Treasury and had a similar experience when letting his support team use devin.

We ended up building internal background agent infra but it quickly became a nightmare to mantain and develop. We built Runtime so you don't have to do this kind of thing.

Runtime work like as follows. Engineering defines the context once: system instructions, skills, and scoped integrations installable via CLI, mise, npm, or any package manager. Then Runtime snapshots your full running environment including multi-service Docker Compose setups, Kafka, Redis, seeded DBs, so it comes up in milliseconds with every server already running.

We orchestrate across sandbox providers like E2B, Daytona, EC2 or self-hosted K8s depending on your setup. Secrets are injected through our managed proxy so they never touch the agent directly, and guardrails run at the infrastructure level: command allow/deny lists, network egress controls, and RBAC scoped per human and per agent. Every session also gets a shareable preview URL, so internal builds go from sandbox to the rest of the team without needing production access.

Runtime works with whichever agent your team already uses: Claude Code, Codex, Cursor, Copilot, Gemini, Devin. You can trigger sandboxes from our web app, CLI, Slack, Linear, GitHub, or API.

One of our customers built an on-call inspector that wires PagerDuty, Sentry, and their repo so when an alert fires, the agent finds the cause and opens a PR with a unit test before anyone gets paged. Another runs a finance agent in a private Slack channel pulling from Stripe, NetSuite, and Snowflake to run reconciliations in minutes with source rows attached.

A fintech unicorn and several YC scaleups are live on Runtime, including a few teams who had built similar infrastructure internally and handed it to us to take over.

The core is open source at https://github.com/runtm-ai/runtm. Hosted version is live at https://app.runtm.com, free tier included. We're charging a flat platform fee plus compute, no token markup.

Check our demo: https://www.youtube.com/watch?v=wLwj__aEEh4

We'd love to hear how you're thinking about the infra for letting more people across your org use coding agents without creating chaos!