## Filesystem-only auto-pause (`onTimeout` object form)
Adds an object form to the sandbox **lifecycle** `onTimeout`
(`on_timeout` in Python) that controls the snapshot kind taken when a
sandbox auto-pauses on timeout, via `keepMemory` (`keep_memory`).
`onTimeout` now accepts either the existing bare action (`'pause'` /
`'kill'`) or the object form `{ action, keepMemory }`. When `keepMemory`
is `false` (with `action: 'pause'`), a timeout auto-pause takes a
**filesystem-only** snapshot (no memory) instead of a full memory one,
so the sandbox cold-boots (reboots) from disk on resume — losing running
processes and open connections. Defaults to `true` (full memory
snapshot), so existing callers are unaffected. **The bare string form is
unchanged.**
It's the create-time / auto-pause counterpart to the explicit
`pause(keepMemory=false)` from #1465: same `keepMemory` naming, mapped
onto the `autoPauseMemory` create field.
### Type safety
The object form is a **discriminated union** on `action`: `keepMemory`
is only valid with `action: 'pause'`. Pairing it with `action: 'kill'`
is a **compile-time type error** (TS) / static error (`ty`), and is
additionally rejected at runtime (`InvalidArgumentError` /
`InvalidArgumentException`) for untyped callers.
### Behavior & validation
- `keepMemory` only applies to a `pause` action.
- **Incompatible with auto-resume** — auto-resume wakes a paused sandbox
on inbound traffic by restoring its memory snapshot in place; a
filesystem-only snapshot has no memory to restore (resuming cold-boots
it), so it must be resumed explicitly via `connect()`. Combining
`keepMemory: false` with `autoResume` is rejected client-side.
### Usage
```ts
// JS/TS — filesystem-only auto-pause on timeout
const sbx = await Sandbox.create({
lifecycle: { onTimeout: { action: 'pause', keepMemory: false } },
})
// bare string form still works (full memory snapshot)
const sbx2 = await Sandbox.create({ lifecycle: { onTimeout: 'pause' } })
```
```python
# Python
sbx = Sandbox.create(
lifecycle={"on_timeout": {"action": "pause", "keep_memory": False}}
)
```
### Changes
- `spec/openapi.yml`: `autoPauseMemory` on the create body (+
regenerated JS/Python clients).
- JS `SandboxOnTimeout` discriminated union (`'pause' | 'kill' | {
action: 'pause'; keepMemory? } | { action: 'kill' }`) and the Python
`SandboxOnTimeoutPause` / `SandboxOnTimeoutKill` TypedDicts, wired
through `createSandbox` / `_create_sandbox` (sync + async) to
`autoPauseMemory`, with the client-side guards.
- Tests: payload serialization + validation (offline, incl. the `action:
'kill'` type/runtime guard) and live cold-boot e2e in both SDKs;
changeset (`e2b` + `@e2b/python-sdk`, minor).
### Backend dependency
The live e2e tests exercise the real auto-pause→cold-boot path and
require the infra-side `autoPauseMemory` support (e2b-dev/infra#3055),
now merged and deployed.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Signed-off-by: Babis Chalios <babis.chalios@e2b.dev>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Babis Chalios
7e7e9514df