workflows-mcp

Instructions

Implementation Reference

• src/index.ts:494-542 (handler)

  The main handler function for the 'start_workflow' tool. It validates the input, retrieves the workflow, creates an execution session, and generates instructions for the first step.

  private async startWorkflow(args: unknown) {
    const parsed = StartWorkflowSchema.parse(args);
    
    const workflow = await this.storage.get(parsed.id);
    if (!workflow) {
      throw new Error(`Workflow not found: ${parsed.id}`);
    }
  
    if (workflow.is_deleted) {
      throw new Error('Cannot run deleted workflow');
    }
  
    // Validate inputs
    const inputs = parsed.inputs || {};
    const inputValidation = WorkflowValidator.validateInputs(workflow, inputs);
    if (!inputValidation.success) {
      throw new Error(`Input validation failed: ${inputValidation.error}`);
    }
  
    // Create new execution session
    const executionId = uuidv4();
    const session: WorkflowSession = {
      workflow_id: workflow.id,
      execution_id: executionId,
      workflow_name: workflow.name,
      current_step_index: 0,
      total_steps: workflow.steps.length,
      variables: { ...inputs },
      status: 'active',
      started_at: new Date().toISOString(),
      step_outputs: {},
      previous_variables: {},
    };
  
    this.sessions.set(executionId, session);
  
    // Generate instructions for the first step
    const firstStep = workflow.steps[0];
    const stepInstructions = this.generateStepInstructions(workflow, firstStep, session);
  
    return {
      content: [
        {
          type: 'text',
          text: stepInstructions,
        },
      ],
    };
  }

• src/index.ts:65-68 (schema)

  Zod schema defining the input structure for the 'start_workflow' tool: workflow ID and optional inputs.

  const StartWorkflowSchema = z.object({
    id: z.string(),
    inputs: z.record(z.any()).optional(),
  });

• src/index.ts:277-281 (registration)

  Registration of the 'start_workflow' tool in the getTools() method, including name, description, and input schema.

  {
    name: 'start_workflow',
    description: 'Start a workflow execution session with step-by-step control',
    inputSchema: zodToJsonSchema(StartWorkflowSchema),
  },

• src/index.ts:132-133 (registration)

  Dispatch registration in the CallToolRequestSchema handler switch statement that routes 'start_workflow' calls to the handler method.

  case 'start_workflow':
    return await this.startWorkflow(args);