# Session Summary: Upload Pipeline & Filesystem Consolidation

Date: 2026-03-01

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## Summary

This session consolidated the file system architecture and resolved issues in the upload pipeline from browser to agent.

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## Filesystem Architecture

Game server filesystem operations are handled exclusively by the agent. The API proxies all requests — it never touches the filesystem directly.

Capabilities documented:

- Read (list, stat, read, download)
- Write (server.properties, config/*.toml, config/*.json, config/*.properties)
- Delete (constrained to mods-removed/, mods-uploaded/, logs/)
- Upload (mods/*.jar, world/datapacks/*.zip)
- Revert (shadow backup restore)

Shadow backups created on first write. 7-day retention, 6h cleanup cycle.

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## Provenance Tracking

`.zlh_metadata.json` written after every upload:

```json
{
  "mods/sodium.jar": {
    "source": "user",
    "uploaded_at": "2026-03-01T22:37:01Z"
  }
}
```

`stat` responses include `source: "user" | null`. No curated inference implemented.

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## Upload Transport Fix (API Layer)

Uploads initially failed with `502` errors when proxied from the API to the agent.

Root cause:
The Node API upload proxy was forwarding `Content-Length` incorrectly while streaming the request body.

Resolution:
The upload route now uses a raw Node `http.request` stream:

- `req.pipe(proxyReq)`
- `proxyRes.pipe(res)`
- `Content-Type` preserved
- `Content-Length` not forwarded
- Upload timeout extended to 5 minutes

This allows large multipart uploads to stream directly from the client → API → agent without buffering.