List Objects

Lists the objects in an Amazon S3 bucket with their details (key, size, last modified date), optionally only under a prefix.

List Objects returns the objects in an Amazon S3 bucket together with their details, such as key, size and last modified date. Use it when you need more than the names, for example to pick only the files changed today. If you only need the names, List Keys is simpler.

Before you start

The AWS S3 actions don't use a stored credential. Each action has the same four connection fields:

Field	Type	Required	What to put
Access Key	Text	Yes	The access key ID of an AWS IAM user, for example `AKIA…`.
Secret Key	Text	Yes	The secret access key that belongs to that access key.
Region	Text	Yes	The AWS region of the bucket, as its code, for example `eu-central-1`.
Bucket	Text	Yes	The bucket name, for example `my-company-invoices`.

The IAM user needs S3 permissions on the bucket for the operation you run. The values you type are visible to everyone who can edit the process, so prefer an IAM user limited to the buckets the process needs.

Add the action

In the Process Designer toolbox, open AWS S3 and pick List Objects (or type List Objects in the search box).

The List Objects action properties: Access Key, Secret Key, Region, Bucket, Prefix and Result

Inputs and outputs

Field	Direction	Type	Required	What to put / what you get
Access Key, Secret Key, Region, Bucket	Input	Text	Yes	The connection fields described above.
Prefix	Input	Text	No	Only objects whose key starts with this text are listed, for example `invoices/2026/`. Leave empty to list the whole bucket.
Result	Output	Object (JSON)	Yes	The S3 listing: the bucket name, the prefix, and the list of objects with, for each one, its key, size, last modified date, ETag and storage class.

Example

Prefix invoices/2026/ → Result is a JSON object whose list of objects holds one entry per object under invoices/2026/. Read the list from it with a JSON action, then loop over it.

Good to know

Result is the whole listing as one JSON object, not a list. Extract the list of objects from it before you loop.
The prefix matches the start of the key: invoices also matches invoices-old/…. End it with / to list one folder only.
One run returns at most 1,000 objects (one S3 listing page). Use a more specific prefix on large buckets.
If a connection field is empty, the step fails with "Invalid connection details."
Common errors from S3: "Access forbidden! Ensure the connection details are valid." (wrong keys or missing permission), "Unable to connect! Ensure the provided region matches the bucket one." (wrong Region), and "Unrecognized Amazon Region: …" (a region code that doesn't exist).

List Keys, Get Metadata, Get Object