Previously the gateway was just fire and forget which lead to a race
condition when you immediately tried to access the mcp server, changed
the template to launch a daemon with healthcheck.
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> Start MCP gateway synchronously with error checks and bump default MCP
template to `mcp-gateway-v0-2` across JS and Python SDKs.
>
> - **MCP Gateway startup**:
> - JS (`packages/js-sdk/src/sandbox/index.ts`): Start `mcp-gateway`
without background mode; validate exit code and throw on failure.
> - Python Async (`packages/python-sdk/e2b/sandbox_async/main.py`):
Await `mcp-gateway` start, remove background/timeout flags; raise on
non-zero exit.
> - Python Sync (`packages/python-sdk/e2b/sandbox_sync/main.py`): Run
`mcp-gateway` synchronously; check exit code and raise on failure.
> - **Defaults**:
> - Update `default_mcp_template` from `mcp-gateway-v0-1` to
`mcp-gateway-v0-2` in JS and Python SDKs.
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
79e431c78bf384c970a5b1fede55071116a089c5. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->
Jonas Scholz
1a51777cc0