Execution Basics

When you run a workflow in Scrydon, the execution engine follows a systematic process to ensure blocks are executed in the correct order with proper data flow.

Execution Flow

The execution engine runs workflows in layers, processing blocks based on their dependencies:

Validation: Ensures the workflow has a starter block with no incoming connections and all blocks are properly connected.

Layer-based Execution: Identifies which blocks can execute next based on completed dependencies and executes them in parallel.

Path Updates: Router and Condition blocks update the active execution path, determining which blocks execute next.

Iteration Processing: Loop and Parallel blocks manage iterations and create virtual instances for concurrent execution.

Result Collection: Outputs from the final blocks are collected and returned as the workflow result.

Block Types and Execution

Different block types have different execution behaviors:

Orchestration blocks control the flow of execution through your workflow.

Starter Block

Router Block

Condition Block

Loop Block

Parallel Block

Execution Methods

Scrydon offers multiple ways to trigger workflow execution:

Manual Execution

Run workflows on-demand through the Scrydon interface by clicking the "Run" button. This is perfect for:

Testing during development
One-off tasks
Workflows that need human supervision

Scheduled Execution

Configure workflows to run automatically on a specified schedule:

Set up recurring executions using cron expressions
Define start times and frequency
Configure timezone settings
Set minimum and maximum execution intervals

Each environment's deployed version, promotion history, and rollback options are visible in the workflow editor's Deployments panel. Open it with the Deploy button in the editor toolbar. The panel shows:

A vertical pipeline stepper with one row per environment: deployed version, when it was promoted, by whom, and a promote button (primary only on the first pending hop).
An Agent endpoints section — one section for the whole workflow, not per environment — listing published A2A agents as rows (A2A Agent · <visibility> · serves <environment>).
A collapsed History & rollback section with a count, for reverting to an earlier deployment version.

Webhooks

Configure workflows to execute in response to external events:

Set up webhook triggers from third-party services
Process incoming webhook data as workflow input
Configure webhook security settings
Support for specialized webhooks (GitHub, Stripe, etc.)

The execution method you choose depends on your workflow's purpose. Manual execution is great for development, while scheduled execution, API endpoints, and webhooks are better for production use cases.

Execution Context

Each workflow execution maintains a context that tracks:

Block States: Outputs and execution status of each block
Execution Path: Active blocks based on routing decisions
Loop/Parallel State: Current iterations and distribution items
Environment Variables: Configuration values available during execution
Execution Logs: Detailed records of each block's execution

Real-Time Monitoring

Monitor your workflow execution in real-time:

Active Block Highlighting: Currently executing blocks pulse with animation
Live Logs: Execution logs appear instantly in the logs panel
Block States: Visual indicators show running, success, error, pending, or skipped states with a reason
Performance Metrics: Execution time for each block

These monitoring features help you understand workflow behavior and quickly identify any issues.