Examples

Example 1 — Upload Invoice PDF

After generating an invoice PDF (base64-encoded), upload it to S3 with a structured key path and custom metadata.

Example 2 — Generate Pre-Signed Download URL

Generate a 24-hour download link for a private contract PDF. The link is emailed to the customer for temporary access.

The url field in the success output is sent via an Email node. When the 24-hour window expires, the link returns a 403 — enforcing the access window without any additional access management.

Example 3 — Customer Direct Upload URL

Generate a PUT pre-signed URL so a customer can upload a file directly to S3 from their browser — without the file passing through your servers.

// Downstream: return URL to the API caller for direct browser upload
{
  "upload_url": "$ctx.url",
  "expires_at": "$ctx.expires_at",
  "instructions": "PUT your file to this URL with Content-Type: application/pdf"
}

Example 4 — Partner File Ingestion Pipeline

A scheduled workflow lists new files in a partner's S3 prefix, downloads each one, processes the data, then moves the file to an archive prefix.

1. ScheduledTrigger — runs every 15 minutes
2. S3 (list) — bucket: partner-drops, prefix: incoming/, max_keys: 50
3. Loop — iterates over $ctx.objects
4. S3 (download) — key: $loop.key, output_format: text
5. CodeExecute — parse CSV rows, validate, insert into database
6. S3 (copy) — source_key: $loop.key, destination: archive/processed/
7. S3 (delete) — delete original from incoming/ after copy

Example 5 — Backup Before Overwrite

Before overwriting an existing file (e.g. a configuration or template), copy the current version to a versioned backup path, then upload the new version. This gives you a complete history without needing S3 object versioning enabled.

1. WebhookTrigger — receives new template file content
2. S3 (copy) — back up the existing file:
   source_bucket: bizfirst-assets
source_key: templates/email-welcome.html
bucket: bizfirst-assets
dest_key: templates/backups/email-welcome-$ctx.timestamp.html
3. S3 (upload) — upload new version:
   key: templates/email-welcome.html
file_data: $ctx.new_content
content_type: text/html
4. MongoDB (insert) — log the version event with backup key and author

Example 6 — Store AI-Generated Report

After a FlowAiAgent node generates a weekly business summary, upload it to S3, then generate a pre-signed URL and include it in a management email.

1. ScheduledTrigger — Monday 08:00
2. FlowAiAgent — generate weekly management summary (markdown format)
3. S3 (upload):
   bucket: bizfirst-reports
key: reports/$ctx.year/$ctx.month/weekly-summary-$ctx.date.md
file_data: $node.reportAgent.result
content_type: text/markdown
acl: private
4. S3 (getPresignedUrl):
   key: $node.uploadReport.key
method: GET
expires_in: 604800 (7 days)
5. EmailSmtp — send to management team with download link
6. Slack — post notification in #management channel with URL

// Email body snippet
Weekly summary is ready: Download Report
Generated: {@ $ctx.date } | Valid until: {@ $node.presign.expires_at }