Command line

s3lens api calls one JSON-RPC method on a running S3 Lens server and prints its result. It is the shell form of the protocol, not an S3 client: every method in the revision 1 reference is available, with the same names and parameters.

Methods are subcommands

Each / in a wire method name is one subcommand level, and each parameter is a long flag in kebab case:

s3lens api provider list
s3lens api object list --provider-id dev --bucket-name photos --prefix 2026/ --limit 50
s3lens api object tags get --provider-id dev --bucket-name photos --key a.jpg
s3lens api bucket policy status get --provider-id dev --bucket-name photos

s3lens api --help lists the method groups, s3lens api object --help lists the methods in one group, and s3lens api object list --help describes every parameter. The tree is generated from the protocol schema, so it always matches the server build it ships with.

Parameter values

Parameter type	Flag value
String	Verbatim
Integer, number, boolean	Parsed; --limit many is a usage error
Enumeration	One of the values shown under [possible values: …]
Object, array, or free-form JSON	A JSON document: --tags '{"env":"prod"}'
Base64 content (--content-base64)	Base64 text, or @path to read and encode a file

A value that starts with @ is read from that file: base64 parameters receive the file’s bytes encoded, JSON parameters receive the parsed document, and other strings receive the file’s UTF-8 text.

--input PATH supplies a complete parameters object from a file, or from standard input with --input -; flags then override individual members. This is the natural form for nested parameters such as an API Key scope:

s3lens api api-key create --input - <<'INPUT'
{
  "name": "media automation",
  "expiresAt": "2026-12-31T00:00:00Z",
  "scope": { "rules": [{ "actions": ["objects:list"], "resources": [{ "type": "all" }] }] }
}
INPUT

Parameters are checked against the protocol before anything is sent, so a missing or mistyped value fails locally with the server’s own wording.

Server and credential

Setting	Flag	Environment variable	Default
Server	--server URL	S3LENS_SERVER	http://127.0.0.1:8085
Credential	--credential SECRET	S3LENS_CREDENTIAL	none

--server is the server’s origin; the command calls /rpc beneath it. The credential is sent as a bearer token and may be an s3l_ak_… API Key or a native session credential. An unauthenticated server needs neither. The credential is never printed.

export S3LENS_SERVER=https://s3lens.example.com
export S3LENS_CREDENTIAL=s3l_ak_REPLACE_WITH_THE_ISSUED_SECRET
s3lens api provider list

Output and exit status

Standard output carries the method result and nothing else, pretty-printed on a terminal and on one line when piped, so jq needs no unwrapping:

s3lens api provider list | jq -r '.providers[].id'
s3lens api object get --provider-id dev --bucket-name photos --key a.jpg | jq -r .contentBase64 | base64 -d > a.jpg

Outcome	Standard output	Standard error	Exit
Result	The result	—	0
JSON-RPC error from the server	The error object (code, message, data)	One line	1
Usage error, invalid parameters, unreachable server, missing credential	—	One line	2

--envelope prints the complete JSON-RPC response envelope instead of the bare result or error. --schema prints the method’s parameter and result JSON Schemas without calling it.

Listings and notifications

--paginate follows nextCursor on any method with a cursor parameter and prints one result per page, newline-delimited:

s3lens api object list --provider-id dev --bucket-name photos --paginate | jq -r '.objects[].key'

--notify sends the notification form of a method that has one (server/ping); nothing is printed and no result is expected. A method’s long help says whether --paginate or --notify applies.

Object bodies

Revision 1 carries complete Object bodies as base64 inside the JSON-RPC response, bounded by the server’s server.max_object_body_bytes. For large Objects, create a streaming transfer ticket and move the bytes with any HTTP client:

url=$(s3lens api object transfer create --provider-id dev --bucket-name photos --key big.iso --direction download | jq -r .url)
curl --fail --output big.iso "$S3LENS_SERVER$url"