Callbacks and Integration

Workflows don't just produce videos — they can notify your other systems when they're done, deliver video URLs, and integrate into your broader content pipeline.

Callbacks (Webhooks)

When a workflow completes, it can automatically send a callback to any URL you specify. This is how workflows communicate with the outside world.

What's in a Callback?

The callback sends a payload that includes:

• Workflow status — Whether it completed successfully, partially, or encountered errors
• Rendered video URLs — Signed download links for any videos that were rendered
• Task results — Summaries and outputs from each task step
• Accumulated variables — All variable values that were used or generated during the run
• Credits used — The total number of credits consumed by the workflow run
• Instance name — The name of the workflow instance (either custom or inherited from the template)

Video URLs

Video URLs included in callbacks are signed download links. They work for anyone who has the link — no login required. However, they expire after 7 days, so make sure your downstream systems download or re-host the videos promptly.

Common Callback Uses

• Notify your team — Send a message to Slack or email when videos are ready for review
• Upload to a CMS — Automatically push rendered videos to your content management system
• Trigger downstream processes — Kick off approval workflows, social media scheduling, or distribution pipelines
• Log results — Record workflow outcomes in your project management or analytics tools

Integration with External Systems

Triggering Workflows via API

Workflows can be triggered via HTTP API, which means you can start them from virtually any system:

• Your CMS publishes a new episode and triggers a cutdown workflow
• A scheduling tool kicks off a batch of renders every Monday morning
• A form submission from your production team starts a custom workflow with their parameters

Example Integration Flow

Here's how a typical end-to-end integration looks:

1. Your CMS publishes a new podcast episode
2. CMS webhook triggers a StarZero Agents workflow via API, passing the episode details as variables
3. StarZero Agents workflow creates cutdowns, adds captions, and renders in multiple aspect ratios
4. Callback sends the rendered video URLs back to your CMS
5. Your CMS attaches the cutdowns to the episode page and queues them for social media

The entire process runs without anyone sitting at a computer. Videos appear, ready for a quick review before publishing.

Credit Tracking

When a workflow finishes, StarZero Agents reports the total credits used across all tasks and branches. This total is included in the callback payload, so your downstream systems can track costs per workflow run — useful for billing, budgeting, or reporting.

Budget Control

When running workflows at scale, it's important to manage costs. StarZero Agents lets you set credit limits per task within a workflow. If a task step exceeds its allocated budget, it stops rather than consuming unlimited credits.

This is especially important for batch workflows with many parallel branches. Setting sensible limits ensures a single runaway task doesn't drain your credit balance.

Tips for Workflow Integration

• Start with low-quality renders in your workflow templates while you're testing. Switch to high quality once you've confirmed the process works correctly.
• Set credit budgets on task steps, especially in workflows with many parallel branches.
• Download videos promptly from callback URLs — they expire after 7 days.
• Test with a single branch first before scaling up to parallel execution across many videos.
• Use variables generously — they make templates reusable across different content without modification.