@tpmjs/tools-workflow-validate-io

Validates that workflow step inputs/outputs are compatible and checks type chains between steps.

Features

• Type Compatibility Checking: Validates that connected steps have compatible input/output types
• Source Validation: Ensures input sources reference existing step outputs
• Comprehensive Error Reporting: Provides detailed error and warning messages with step context
• Flexible Type System: Supports basic types, arrays, objects, and 'any' type
• Unused Output Detection: Warns about outputs that are never consumed by subsequent steps

Installation

npm install @tpmjs/tools-workflow-validate-io

Usage

import { workflowValidateIOTool } from '@tpmjs/tools-workflow-validate-io';

const workflow = {
  steps: [
    {
      id: 'fetch-data',
      outputs: {
        data: { type: 'object' },
        count: { type: 'number' }
      }
    },
    {
      id: 'process-data',
      inputs: {
        rawData: { type: 'object', source: 'fetch-data.data' },
        threshold: { type: 'number', source: 'fetch-data.count' }
      },
      outputs: {
        result: { type: 'string' }
      }
    },
    {
      id: 'send-result',
      inputs: {
        message: { type: 'string', source: 'process-data.result' }
      }
    }
  ]
};

const result = await workflowValidateIOTool.execute({ workflow });

console.log(result);
// {
//   valid: true,
//   issues: [],
//   stepCount: 3
// }

Workflow Structure

Each workflow step should have:

• id (required): Unique identifier for the step
• name (optional): Human-readable name
• inputs (optional): Object where keys are input names and values contain:
  • type (required): Expected type (string, number, object, array, any, etc.)
  • source (optional): Reference to output in format "stepId.outputName"
• outputs (optional): Object where keys are output names and values contain:
  • type (required): Output type

Type Compatibility

The validator supports:

• Exact matches: string → string
• Any type: any is compatible with all types
• Array compatibility: string[] ↔ array
• Object compatibility: object ↔ { ... }
• Number/Integer: number ↔ integer

Validation Issues

The tool reports two severity levels:

Errors (prevent valid: true)

• Missing step IDs
• Missing type definitions
• Unknown source references
• Type mismatches between connected steps

Warnings (don't prevent valid: true)

• Steps with no inputs or outputs
• Outputs never used by subsequent steps (except final step)

Example with Errors

const invalidWorkflow = {
  steps: [
    {
      id: 'step1',
      outputs: {
        result: { type: 'string' }
      }
    },
    {
      id: 'step2',
      inputs: {
        data: { type: 'number', source: 'step1.result' } // Type mismatch!
      }
    }
  ]
};

const result = await workflowValidateIOTool.execute({ workflow: invalidWorkflow });

console.log(result);
// {
//   valid: false,
//   issues: [
//     {
//       stepId: 'step2',
//       stepIndex: 1,
//       severity: 'error',
//       message: "Type mismatch: Input 'data' expects type 'number' but source 'step1.result' from step 'step1' (index 0) outputs type 'string'",
//       field: 'data'
//     }
//   ],
//   stepCount: 2
// }

Use Cases

• Agent Systems: Validate tool chains before execution
• Workflow Builders: Real-time validation in visual workflow editors
• CI/CD: Validate workflow definitions in automated pipelines
• Documentation: Generate workflow diagrams with validated connections

License

MIT