Overview
Jern Cloud is a governed cloud coding agent launched in September 2026 that reframes autonomous coding around trust and reviewability rather than maximum autonomy. You install its GitHub App on selected repositories, open a session, and describe the work; Jern then runs each message as one attempt on a fresh isolated machine under a policy pinned for the whole session, with a hard token cap and encrypted evidence, and finally opens a pull request for human review. Nothing runs on your laptop, and critically no credential ever reaches the agent process — checkout, evidence upload, model inference, and publication each use a separate short-lived credential held by the runner, whose only network route is the inference gateway. The repository’s baseline decides which paths can change and which commands run without asking; the runner verifies that digest before starting and it cannot change for the life of the session. Tokens are counted by the gateway from the provider’s own response, and wall-clock, process count, output size, and attempts are all capped. Every attempt’s exact trace is encrypted with AES-256-GCM before reaching the database and can be opened from any assistant turn, with retention you control. Work ends on an isolated branch as a pull request your branch protection and reviewers govern — Jern never merges. It is open-source under Apache-2.0 and supports bring-your-own Anthropic, OpenAI, Gemini, or Fireworks keys.
Key Features
- Policy pinned by digest — allowed paths and commands verified before the agent starts and frozen for the session
- No credential in the agent — separate short-lived credentials for checkout, evidence, inference, and publish; only the inference gateway is reachable
- Hard, gateway-metered caps — tokens counted from the provider’s own response, plus wall-clock, process, output, and attempt limits
- Encrypted evidence — every attempt trace AES-256-GCM encrypted, retrievable, with retention you set
- Immutable environment — image and setup command pinned by revision; mid-session environment changes are impossible
- Review-only exit — changes land as a pull request on an isolated branch; Jern never merges or deploys
Pricing
| Plan | Price | For |
|---|---|---|
| Free trial | $0 | 30 days of full access per workspace |
| Workspace | $19/mo | Per workspace after trial; up to 10 repos and team members, BYOK |
| Runtime | Apache-2.0 | Self-host the open-source agent runtime |
Comparison
Compared to GitHub Copilot, Jern removes the agent from your machine and replaces inline autonomy with repository-pinned policy and encrypted evidence, which reviewers can audit after the fact. Against Claude Code, Jern’s sessions are isolated and credential-free by construction, at the cost of being cloud-run rather than local. If you want a local, open-source coding agent you fully control, OpenCode is the closer fit, but it does not provide Jern’s governed, PR-only workflow out of the box.