feat(eve-sandbox): add a Coder workspace backend for Vercel's eve framework

[ThomasK33]

What

Adds @coder/ai-sdk-eve-sandbox, a fourth package implementing Vercel eve's SandboxBackend contract so an eve agent runs its sandbox (bash/read_file/write_file/glob/grep) inside a real, long-lived Coder workspace instead of an ephemeral microVM.

// agent/sandbox.ts
import { defineSandbox } from "eve/sandbox";
import { createCoderSandboxBackend } from "@coder/ai-sdk-eve-sandbox";

export default defineSandbox({
  backend: createCoderSandboxBackend({ create: { template: "docker", preset: "Large" } }),
});

How it works

• Thin adapter over @coder/ai-sdk-sandbox: reuses createCoderWorkspace (get-or-create, wait-for-ready, $HOME resolution, preset validation) + CoderCliTransport + CoderWorkspaceSession, and adapts the result to eve's SandboxSession. Only resolvePath/removePath/setNetworkPolicy are net-new.
• eve and @coder/ai-sdk-sandbox both build their I/O surface on the AI SDK's Experimental_SandboxSession, so the exec/file layer maps over directly.
• eve is a type-only peer dependency — the package imports no eve runtime values, so the repo's pinned ai/@ai-sdk/* chain is untouched (pnpm added eve to minimumReleaseAgeExclude).

Coder-specific behavior (documented in the README)

• prewarm is a no-op — Coder templates are server-side Terraform, so there's no build-time capture and seedFiles aren't baked.
• dispose defaults to keep (leave the workspace running for fast reattach). stop/delete apply only to per-session workspaces this backend provisions; an explicitly-named (borrowed) workspace is never torn down.
• setNetworkPolicy can't enforce egress, so it throws on anything but allow-all unless allowUnsafeNetworkPolicy is set (credential-brokering flows such as eve's GitHub channel are unsupported here).
• removePath guards against empty / working-dir / root targets to avoid a stray rm -rf.

Testing

• 17 mock-transport unit tests — no live Coder or eve runtime required.
• pnpm check (oxfmt + oxlint + typecheck across all 5 packages), pnpm build, publint, and attw all pass.

Notes / follow-ups

• eve is in public beta (eve@0.11.5) and its sandbox interfaces may change before GA — this is a v1 adapter against a moving target.
• Not yet exercised end-to-end against a live Coder deployment + eve app (the unit tests mock the transport).
• Possible deeper follow-up: re-base both createCoderWorkspace and this backend on a shared, harness-free transport core so the package wouldn't transitively need @ai-sdk/harness types.
• Wires the package into release-please, the root publint/attw scripts, and the PR-title scope allowlist.

🤖 Generated with Claude Code