## Summary
Adds SDK support for the new `POST /sandboxes/{sandboxID}/fork` endpoint
(e2b-dev/infra#3202): checkpoint a running sandbox in place (briefly
paused, snapshotted with full memory state, and resumed — its ID and
expiration stay untouched) and boot `count` new sandboxes from that
snapshot.
- **spec**: adds `SandboxForkRequest` / `SandboxForkResult` schemas and
the `/sandboxes/{sandboxID}/fork` path (mirroring the infra spec); JS
and Python API clients regenerated via `make codegen`.
- **js-sdk**: `sandbox.fork(opts)` instance method and
`Sandbox.fork(sandboxId, opts)` static method. Returns
`Promise<Array<Sandbox | Error>>` — one entry per requested fork, each
either a connected `Sandbox` instance or an `Error` describing why that
fork failed to start (`Promise.allSettled`-style, matching the per-fork
results of the API). Per-fork error codes go through the same code→class
mapping as other API errors (extracted from `handleApiError` into
`apiErrorFromCode`), so e.g. a per-fork 429 (sandbox limit) surfaces as
`RateLimitError`. `SandboxForkOpts` extends the full `ConnectionOpts`
(like `SandboxConnectOpts`), so `proxy`, `logger`, `apiUrl`, etc. work
with fork-by-ID. `timeoutMs` defaults to 5 minutes like
`create`/`connect`; `count` defaults to 1 and is validated client-side
(`InvalidArgumentError` for `count < 1`); a whole-request 404 maps to
`SandboxNotFoundError` (the source sandbox is the missing resource —
same semantics as `pause`/`connect`/`setTimeout`), carrying the API
error message when present; per-fork 404 error codes map to generic
`NotFoundError` (the missing resource is fork-internal, e.g. the
snapshot).
- **python-sdk**: `sandbox.fork(timeout=..., count=...)` /
`Sandbox.fork(sandbox_id, ...)` and the `AsyncSandbox` equivalents (same
`@class_method_variant` instance/static pattern as `connect`/`pause`),
returning `List[Union[Sandbox, Exception]]`. Per-fork errors map through
the shared `api_exception_from_code` (extracted from
`handle_api_exception`). `timeout` is in seconds per Python SDK
convention; an explicit `timeout=0` is preserved. Whole-request 404
raises `SandboxNotFoundException`; per-fork 404 codes map to generic
`NotFoundException`.
- **changesets**: minor bumps for `e2b` and `@e2b/python-sdk`.
## Usage
JS:
```ts
const sandbox = await Sandbox.create()
const [fork1, fork2] = await sandbox.fork({ count: 2, timeoutMs: 60_000 })
if (fork1 instanceof Sandbox) {
await fork1.commands.run('echo "hello from fork"')
}
// or by ID
const forks = await Sandbox.fork(sandbox.sandboxId, { count: 2 })
```
Python (sync / async):
```python
sandbox = Sandbox.create()
fork1, fork2 = sandbox.fork(count=2, timeout=60)
if isinstance(fork1, Sandbox):
fork1.commands.run('echo "hello from fork"')
# or by ID
forks = Sandbox.fork(sandbox.sandbox_id, count=2)
```
```python
sandbox = await AsyncSandbox.create()
fork1, fork2 = await sandbox.fork(count=2)
```
## Notes
- The JS option is named `timeoutMs` (milliseconds) to match
`SandboxOpts.timeoutMs` / `SandboxConnectOpts.timeoutMs`; the API
receives seconds via `timeoutToSeconds` as elsewhere.
- Failed forks are returned as error **values** in the array rather than
rejected promises, so a partial failure doesn't throw away the
successful forks and there are no unhandled-rejection hazards. A
per-fork error message includes the API error code only when the API
returned one.
## Test plan
- [x] `pnpm run format`, `pnpm run lint`, `pnpm run typecheck` pass at
the repo root (`ty` diagnostics identical to baseline)
- [x] Offline tests pass: `count < 1` → `InvalidArgumentError` /
`InvalidArgumentException` in JS, Python sync, and Python async;
`handleApiError` suite passes after the `apiErrorFromCode` extraction
(plus a behavior-parity check of the Python `handle_api_exception`
refactor)
- [ ] Integration tests (single fork with FS state inheritance +
independence, multi-fork with unique IDs, fork-by-ID, fork of killed
sandbox → `SandboxNotFoundError`) are written but currently fail against
prod with 404 because the fork endpoint (e2b-dev/infra#3202) is not
deployed yet — they should pass once it lands.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Mish Ushakov
95e4dc2832