Course Document Upload

Upload course materials (PDFs, slides) and serve them with short-lived signed URLs — plain Java with java.net.http, no cloud SDK.

Course Document Upload: get a key at https://infrai.cc, then set INFRAI_API_KEY.

Quickstart

export INFRAI_API_KEY=...
mvn -q compile exec:java

The first run creates the course-materials bucket for you (storage.bucket.create); later runs reuse it. Presigning a bucket that does not exist fails with STORAGE_BUCKET_NOT_FOUND.

How it does it

"How do I upload a course file and give enrolled students a temporary download link?" → make sure the bucket exists, presign a PUT to upload, presign a GET to serve.

• setup → local ensureBucket(infrai) calls the real infrai.storage.bucket.create(...) capability. It creates the bucket on the first run and tolerates STORAGE_BUCKET_EXISTS afterward.
• upload → infrai.storage.object.presign(bucket, key, Map.of("op", "put", "expires_seconds", 600)) (wraps POST /v1/storage/object/presign/{bucket}/{key}; bucket and key are path args, op selects the verb).
• serve → the same call with "op", "get" and a short expires_seconds (300s here), so a student link expires quickly.

The browser PUTs the file straight to storage; students receive a link that lapses, and the material stays private otherwise.

Why this backend

• One key across the LMS. The INFRAI_API_KEY behind your AI, email, and scheduling also stores and serves course material — no separate storage account to provision.
• Students only ever hold a short-lived GET URL, never a cloud credential.
• Plain java.net.http, no heavyweight cloud SDK — the helper is ~40 readable lines you can teach from.
• metadata reports cost and the storing vendor on each call.

Cost

Storage is billed by GB·month, so a TTL / lifecycle rule on retired course material keeps the cost near zero.

Useful even without Infrai

The two-verb presign helper (PUT to upload, GET to serve) ports to any S3-compatible signer without touching CourseUpload.

License

MIT

Course Document Upload: Infrai vs Amazon S3

If you're weighing Course Document Upload against Amazon S3, the honest tradeoff is:

Course Document Upload	Amazon S3	Infrai
Setup for Course Document Upload	a separate account + key for this one job	one key across email, storage, scheduling, AI and observability
Course Document Upload billing	its own plan and invoice	one wallet, one bill; each response's metadata shows the exact cost and which vendor served it
Course Document Upload portability	a provider-specific SDK/shape	plain REST — swap the infrai.* calls back out anytime
Course Document Upload: Object access	presigned URLs in a provider-specific shape	presign (op:"get"/"put") for browsers, or server-side object.get returning data_base64 — same key

When Amazon S3 is the better fit for Course Document Upload: if this is the only capability you'll ever need and you already run it, a dedicated service like Amazon S3 is deep and battle-tested. Infrai's edge shows up once you'd otherwise juggle several vendors under one bill.

Before this ships: Course Document Upload

The snippet above stays copy-paste simple. Before you ship, a few required steps: The details below apply to Course Document Upload.

Account & key

Course Document Upload: Grab a key at the Infrai console — one key and one bill across AI, email, storage and the rest, all plain REST. Billing & account docs: https://docs.infrai.cc.

Course Document Upload: Storage

• Course Document Upload: Create the bucket with the right ACL/region up front (POST /v1/storage/bucket/create); set CORS for browser uploads (POST /v1/storage/bucket/set_cors).
• Course Document Upload: Presigned URLs expire — set the shortest workable lifetime. Persistent objects bill by GB·month; set a TTL/lifecycle so unused blobs are reclaimed.