## assay.s3
S3-compatible object storage with AWS Signature V4 authentication.
Client: `s3.client({endpoint="...", region="...", access_key="...", secret_key="...", path_style=true})`.
Works with AWS S3, Cloudflare R2, iDrive e2, MinIO, and any S3-compatible provider.
### Buckets
- `c.buckets:create(bucket)` -> true -- Create a new bucket
- `c.buckets:delete(bucket)` -> true -- Delete a bucket
- `c.buckets:list()` -> `[{name, creation_date}]` -- List all buckets
- `c.buckets:exists(bucket)` -> bool -- Check if bucket exists
### Objects
- `c.objects:put(bucket, key, body, opts?)` -> true -- Upload object. `opts`: `{content_type}`
- `c.objects:get(bucket, key)` -> string|nil -- Download object content (nil if 404)
- `c.objects:delete(bucket, key)` -> true -- Delete an object
- `c.objects:list(bucket, opts?)` -> `{objects, is_truncated, next_continuation_token, key_count}` -- List objects. `opts`: `{prefix, max_keys, continuation_token}`. Each object: `{key, size, last_modified}`
- `c.objects:head(bucket, key)` -> `{status, headers}`|nil -- Get object metadata (nil if 404)
- `c.objects:copy(src_bucket, src_key, dst_bucket, dst_key)` -> true -- Copy object between buckets
Example:
```lua
local s3 = require("assay.s3")
local c = s3.client({
endpoint = "https://s3.us-east-1.amazonaws.com",
region = "us-east-1",
access_key = env.get("AWS_ACCESS_KEY_ID"),
secret_key = env.get("AWS_SECRET_ACCESS_KEY"),
})
c.objects:put("my-bucket", "data/report.json", json.encode({status = "complete"}))
local content = c.objects:get("my-bucket", "data/report.json")
```