Block: S3 Block — Zelaxy Docs

The S3 block retrieves and views files from Amazon S3 buckets using presigned URLs. Reach for it when a workflow needs to access an object stored in S3 and produce a temporary, shareable link to its contents.

Overview

Property	Value
Type	`s3`
Category	tools
Color	`#E0E0E0`

When to Use

Generate a presigned URL for an object stored in an Amazon S3 bucket.
Fetch a file from S3 so a downstream block can read or display it.
Pull object metadata (file type, size, name, last-modified date) for a specific S3 object.
Pass an S3-hosted asset (image, document, data file) into a later step via a temporary link.
Access private S3 objects without making the bucket publicly readable.
Surface a short-lived download link to an end user without exposing AWS credentials.

Configuration

Access Key ID

Your AWS Access Key ID, used to sign the request. This field is required and treated as a secret (value is masked in the UI).

Secret Access Key

Your AWS Secret Access Key, paired with the Access Key ID to produce AWS Signature Version 4 authentication headers. Required and treated as a secret.

Operation

Choose Get Object (default) to read an object, or Put Object to upload one. The remaining fields adapt to the selected operation. Get Object is the default, so existing workflows behave unchanged.

S3 Object URL

(Get Object) The full HTTPS URL of the S3 object in the format https://bucket-name.s3.region.amazonaws.com/path/to/file. The block automatically parses the bucket name, AWS region, and object key from this URL. Required for Get Object.

Region / Bucket / Key / Content

(Put Object) For an upload, provide the AWS Region, Bucket, object Key (path), the Content to write, and an optional Content Type. The upload runs through a signed server-side request (the bytes can't be signed correctly from the client), using your Access Key / Secret Key as the credentials.

Inputs & Outputs

Inputs:
- accessKeyId (string) — AWS access key ID
- secretAccessKey (string) — AWS secret access key
- s3Uri (string) — S3 object URL
Outputs:
- url (string) — Presigned URL valid for 3600 seconds that allows downloading the S3 object
- metadata (json) — Object metadata including fileType, size (bytes), name, and lastModified

Tools

S3 Get Object (s3_get_object) — Issues a signed HEAD request to Amazon S3 to verify the object exists and retrieve its metadata, then generates an AWS Signature Version 4 presigned GET URL (1-hour expiry) for downloading the object. Returns the presigned URL and a metadata object containing the file type, byte size, file name, and last-modified timestamp.

S3 Put Object (s3_put_object) — Uploads content to s3://bucket/key via a signed server-side PutObject request (the tool runtime can't sign a request body directly without corrupting the bytes, so the upload goes through an internal proxy authenticated by your AWS credentials). Returns the object key and bucket on success.

YAML Example

s3_1:
  type: s3
  name: "S3"
  inputs:
    accessKeyId: "{{AWS_ACCESS_KEY_ID}}"
    secretAccessKey: "{{AWS_SECRET_ACCESS_KEY}}"
    s3Uri: "https://my-bucket.s3.us-east-1.amazonaws.com/reports/q2.pdf"
  connections:
    outgoing:
      - target: next-block-id

S3 Block