# Open External Dependencies

Things the packaging/signing design assumes exist but doesn't own or
fully specify — needed before implementation:

- **FEC HTTP service** for the MR one-way hop — assumed already available,
  ~1GB chunks, not built as part of this design.
- **Existing S3 handover interface spec** — a separate, already-established
  convention elsewhere in this environment for mapping S3 user object
  metadata (`x-amz-meta-*` headers) to NiFi attributes via a regular
  expression, plus a flag indicating whether the attribute set exceeded
  S3's ~2KB metadata limit (in which case it falls back to this design's
  JSON trailer). The exact regex pattern and flag/tag name are **not**
  reproduced in the packaging/signing spec — need to source that document
  before implementation.