OSS assets

OSS assets connect to an S3-compatible object storage endpoint (AWS S3, MinIO, Aliyun OSS, …). The asset names the endpoint and credentials only — the bucket is part of every command's target, not part of the asset.

Command syntax

<family> <verb> [target] [--flags] — family is bucket or object, verb is the operation, and target is <bucket>/<key> (no leading slash).

Every example below is literally executable as written. Optional flags are not marked with brackets; each useful combination is spelled out on its own line.

bucket

• bucket list

object

• object list backups
• object list backups/2026/
• object list backups/2026/ --max-keys=100
• object list backups/2026/ --max-keys=100 --after=2026/03/db.sql.gz
• object stat backups/2026/db.sql.gz
• object get backups/app.conf (returns the content inline, truncated to 64 KiB)
• object get backups/app.conf --max-bytes=4096
• object get backups/2026/db.sql.gz --file=/tmp/db.sql.gz (streams to a local file instead)
• object put backups/2026/db.sql.gz --file=/tmp/db.sql.gz
• object put backups/app.conf --file=/tmp/app.conf --content-type=text/plain
• object copy backups/2026/db.sql.gz --to=archive/db-2026.sql.gz
• object move backups/2026/db.sql.gz --to=archive/db-2026.sql.gz
• object delete backups/2026/old.log
• object presign backups/2026/db.sql.gz
• object presign backups/2026/db.sql.gz --expiry=600
• object presign uploads/inbox/report.pdf --method=put --expiry=600 (denied by the default policy, see Notes)

Flag reference

Every flag each verb accepts — anything else is rejected rather than ignored. Bold flags are required: omitting one does not default it, the command is rejected before it runs. Verbs not listed here take no flags at all.

• object list: --max-keys, --after
• object get: --file, --max-bytes
• object put: --file, --content-type
• object copy: --to
• object move: --to
• object presign: --expiry, --method

Flag values

Checked before any approval dialog, so a wrong value costs nothing:

• --max-keys, --max-bytes and --expiry must be plain decimal integers: 1000, not 1,000, 1_000, 1e3 or 3.0.
• --method is get or put, lower case exactly. Nothing else is accepted, and there is no case folding: GET is an error rather than a synonym. Omitting it means get, so a bare object presign requests object.presign.read.
• --expiry defaults to 3600 seconds when omitted.
• --file must be an absolute local path. The approved command string is all that identifies the file, and a relative path resolves against a working directory that is not part of it, so it would land somewhere unpredictable.
• --file and --max-bytes cannot be given together: they select two different behaviors of object get (stream the whole object to disk, or return the first bytes inline), so one of them would have to be ignored.
• --max-bytes defaults to 64 KiB and is capped at 1 MiB. A larger value is reduced to the cap rather than rejected, and truncated then reports that the object was longer.
• --max-keys is capped at 1000. A larger value is rejected, not reduced: silently returning fewer keys than asked would break --after pagination against what the caller expected to page through.
• --expiry is capped at 604800 seconds (7 days) and is also rejected rather than reduced: a longer-lived presigned URL is what S3-compatible backends refuse to sign in the first place, so a value over the cap would otherwise be approved and then fail.
• --to is a second <bucket>/<key> and follows the same rules as the target, including the requirement that it name a single object.

Not checked on this side at all — the storage service is the only thing that will reject a wrong value, after approval and a round trip:

• --content-type is passed through verbatim as the object's MIME type; omitting it lets the service decide.
• --after is a continuation cursor, not a filter: pass back the nextContinuationToken from the previous object list result to read the next page.

Results

• bucket list returns {"buckets":[…]}.
• object list returns the raw listing: prefixes (one level of "folders"), objects, plus isTruncated and nextContinuationToken for paging.
• object stat returns the object's metadata.
• object get without --file returns content together with encoding (utf-8, or base64 when the bytes are not valid UTF-8) and truncated. When truncated is true you read only the first bytes — re-run with --file rather than guessing at the rest.
• object get --file returns the byte count, the object and the local file path; object put returns the byte count and the object (bucket/key), with no file. The content never passes through the conversation either way.
• object copy, object move and object delete return {"status":"ok",…}.
• object presign returns the signed url, its method and expiresIn seconds. The URL is fully usable; the audit log stores it with the signature parameters redacted.

Approval and policy rules

Approval is granted per <action> <resource>, where resource is <bucket>/<key>:

copy and move request every one of their resources: any one of them being denied rejects the whole command, and where an allow list exists all of them must match.

Rules are written the same way, with * wildcards that do not cross / inside a key:

Notes

• Presigned PUT URLs are denied by the default policy and cannot be enabled by an allow rule: a signed upload URL moves write access outside this app entirely — anyone holding it can write that key until it expires, with no further policy, approval or audit. Use object put instead — no asset or group policy change can enable it, because the deny is a floor merged into every effective policy.
• Object keys may contain spaces; quote the whole target when they do, e.g. object stat 'mybucket/My Report.pdf'. Leading or trailing whitespace is rejected — permission rules split <action> <resource> at the first whitespace, so a padded name could never be authorized.
• Every object verb takes exactly one target and it must name a real key: object stat mybucket is rejected, because mybucket as a rule would authorize the whole bucket rather than one object. object list is the exception — listing is always by prefix, so a bare bucket name is normalized to mybucket/.
• A trailing / names the zero-byte "folder marker" object, so object delete mybucket/logs/ deletes exactly that marker. Because the same string read as a rule means the whole prefix, such an approval is never turned into a standing grant: repeating it asks again. object list is the exception — a listing approval on mybucket/logs/ does become a standing grant, because there the command and the rule cover the same range.
• Targets must not start with / or --, and the bucket is part of the target rather than of the asset — there is no per-asset default bucket.
• object copy and object move are single-object and server-side; both endpoints must be on this same asset. Use the cp tool to move data between different assets or between object storage and a server, and to copy whole prefixes.
• Unknown flags are rejected rather than ignored, so a typo such as --max_keys=100 fails instead of silently listing the default page size.
• The command line is shell-tokenized but never shell-executed: $, |, > and & produce an error rather than expanding or redirecting.
• The scope parameter is not used by OSS assets; the target names bucket and key.

Asset config (for put_asset)

Example:

put_asset(name="backups-bucket", type="oss", config={"endpoint":"s3.us-east-1.amazonaws.com","region":"us-east-1","access_key_id":"AKIAEXAMPLE","secret_access_key":"...","use_ssl":"true"})