@burgan-tech/vnext-schema

JSON Schema definitions for vNext Workflow components validation.

Overview

This package provides comprehensive JSON Schema definitions used by the vNext ecosystem to validate workflows and components developed with the vNext Workflow product. These schemas ensure consistency and validity of workflow definitions, tasks, views, functions, and other components within the vNext platform.

Included Schemas

• Core Schema: Base schema definition for all vNext components
• Workflow Definition: Schema for workflow component definitions (sys-flows)
• Task Definition: Schema for task component definitions (sys-tasks)
• View Definition: Schema for view component definitions (sys-views)
• Function Definition: Schema for function component definitions (sys-functions)
• Extension Definition: Schema for extension component definitions (sys-extensions)
• Schema Definition: Meta-schema for schema definitions (sys-schemas)
• Mapping Definition: Schema for mapping component definitions (sys-mappings)
• Core Header: Schema for runtime HTTP headers and metadata (sys-schemas)

Supported Task Types

task-definition.schema.json validates 21 task types, selected through the attributes.type discriminator. Each type has its own attributes.config shape:

type	Task	Purpose
1	Dapr HTTP Endpoint	Call an external HTTP endpoint through Dapr
2	Dapr Binding	Invoke a Dapr output binding
3	Dapr Service	Service-to-service invocation via Dapr
4	Dapr PubSub	Publish a message to a Dapr pub/sub topic
5	Human Task	Wait for a human decision
6	HTTP Task	Direct HTTP call
7	Script Task	Execute a C# script (.csx)
8	Condition Task	Evaluate a condition
9	Timer Task	Delay / scheduled continuation
10	Notification Task	Send a notification
11	Start Flow Task	Start another workflow instance
12	Trigger Transition Task	Trigger a transition on an instance
13	Get Instance Data Task	Read instance data
14	SubProcess Task	Run a sub-process
15	Get Instances Task	Query workflow instances
16	SOAP Task	Call a SOAP service
17	State Store Task	Read/write a Dapr state store
18	Cache Aside Task	Cache-aside read-through
19	Get Instance Task	Read a single instance
20	Dapr Conversation Task	Dapr conversation (LLM) call
21	FanOut Task	Run an inner task once per collection item, in parallel, and join the results

FanOut Task (type: "21")

The FanOut task executes a referenced inner task once per item of a runtime-resolved collection, in parallel, then joins the per-item outcomes into a single output.

{
  "type": "21",
  "config": {
    "mode": "inline",                 // only 'inline' is accepted in this phase
    "itemsPath": "$.documents.online", // dot-path into instance data (or use the mapping's ItemSelector)
    "itemAlias": "document",           // readability label for logs/traces only
    "task": {                          // required: the inner task run per item
      "key": "upload-document",
      "domain": "core",
      "flow": "sys-tasks",
      "version": "1.0.0"
    },
    "execution": {
      "maxDegreeOfParallelism": 4,     // default 4
      "itemTimeoutSeconds": 30,        // must be <= batchTimeoutSeconds
      "batchTimeoutSeconds": 120
    },
    "join": {
      "policy": "allSettled",          // all | allSettled | quorum | firstSuccess
      "resultKey": "fanOutResults"     // instance data key for item results + '{resultKey}Summary'
    },
    "errorBoundary": {                 // applied per ITEM, same rule shape as state/transition boundaries
      "onError": [
        { "action": 1, "errorCodes": ["FanOut:ItemTimeout"], "retryPolicy": { "initialDelay": "PT2S" } }
      ]
    }
  }
}

Authoring notes:

• Only config.task is required; every other member has a runtime default.
• join.minSuccess is required when join.policy is quorum.
• Exactly one item source must be configured — either config.itemsPath or the task mapping's ItemSelector, never both and never neither. This rule is enforced by the runtime, not by the schema.
• execution.itemTimeoutSeconds must be less than or equal to execution.batchTimeoutSeconds (also runtime-enforced).
• A FanOut task cannot reference another FanOut task as its inner task.
• join.ordered is accepted for forward compatibility; in inline mode item results are always ordered by item index.

Installation

npm install @burgan-tech/vnext-schema

Usage

This package is primarily designed to be used with the @vnext/cli tool for workflow development and validation.

Using with @burgan-tech/vnext-cli

The recommended way to use these schemas is through the official vNext CLI:

npm install -g @burgan-tech/vnext-cli

The CLI automatically uses these schema definitions for:

• Validating workflow definitions
• Checking component structure
• Ensuring compliance with vNext standards
• Development-time validation

For detailed CLI usage and workflow development guide, please refer to the @vnext/cli documentation.

Programmatic Usage

If you need to access the schemas programmatically:

const schemas = require('@burgan-tech/vnext-schema');

// Get specific schema
const workflowSchema = schemas.workflowDefinition;
const taskSchema = schemas.taskDefinition;
const headerSchema = schemas.coreHeader;

// Get schema by type
const coreSchema = schemas.getSchema('core');
const headerSchemaByType = schemas.getSchema('header');

// Get all available schema types
const availableTypes = schemas.getAvailableTypes();
// Returns: ['core', 'workflow', 'task', 'view', 'function', 'extension', 'schema', 'header']

Schema Structure

All schemas follow the vNext component structure with required fields:

• key: Component identifier
• version: Semantic version (Major.Minor.Patch)
• domain: Domain identifier
• flow: Flow identifier
• flowVersion: Flow version
• tags: Component tags
• attributes: Component-specific attributes

Contributing

This package is maintained by the vNext Team. For issues, feature requests, or contributions, please visit the GitHub repository.

License

MIT

Support

For support and questions:

• GitHub Issues: https://github.com/burgan-tech/vnext-schema/issues

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Note: This package is part of the vNext ecosystem and is primarily intended for use with the official vNext CLI tools and vNext Workflow platform.