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---

Class: FlowBuilder<TMessageId>

Defined in: flow-builder.ts:246

Build EventCatalog flow resources using a fluent API.

FlowBuilder is useful when you want to define flows in code and then write the generated Flow resource with writeFlow. The builder outputs the normal EventCatalog Flow shape, so the persisted catalog remains standard markdown/frontmatter.

nextSteps is the authoring API. When build() is called, a single next step is normalized to next_step and multiple next steps are normalized to next_steps.

Examples

import utils, { FlowBuilder } from '@eventcatalog/sdk';

const { writeFlow } = utils('/path/to/eventcatalog');

const flow = FlowBuilder.create({
  id: 'PaymentFlow',
  name: 'Payment Flow',
  version: '1.0.0',
  markdown: '# Payment Flow',
})
  .addStep({
    id: 'Customer places order',
    nextSteps: [{ id: 'PlaceOrder', label: 'places order' }],
  })
  .addMessageStep({
    id: 'PlaceOrder',
    message: { id: 'PlaceOrder' },
    nextSteps: [{ id: 'PaymentService', label: 'process payment' }],
  })
  .addServiceStep({
    id: 'PaymentService',
    service: { id: 'PaymentService' },
  })
  .build();

await writeFlow(flow);

import { FlowBuilder } from '@eventcatalog/sdk';

type PaymentMessageId = 'PlaceOrder' | 'PaymentProcessed';

const flow = FlowBuilder.create<PaymentMessageId>({
  id: 'TypedPaymentFlow',
  name: 'Typed Payment Flow',
  version: '1.0.0',
  markdown: '# Typed Payment Flow',
})
  .addMessageStep({
    id: 'PlaceOrder',
    nextSteps: [{ id: 'PaymentProcessed' }],
  })
  .addMessageStep({
    id: 'PaymentProcessed',
  })
  .build();

Type Parameters

Type Parameter
TMessageId extends string

Methods

addActorStep()

addActorStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:570

Add an actor step.

Parameters

Parameter	Type	Description
step	FlowActorStepInput	The actor step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'OrderFlow',
  name: 'Order Flow',
  version: '1.0.0',
  markdown: '',
})
  .addActorStep({
    id: 'Customer',
    actor: { name: 'Customer' },
  });

---

addAgentStep()

addAgentStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:444

Add an agent step.

Parameters

Parameter	Type	Description
step	FlowAgentStepInput	The agent step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'OrderFlow',
  name: 'Order Flow',
  version: '1.0.0',
  markdown: '',
})
  .addAgentStep({
    id: 'FraudReviewAgent',
    agent: { id: 'FraudReviewAgent', version: '1.0.0' },
  });

---

addChannelStep()

addChannelStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:407

Add a channel step.

Parameters

Parameter	Type	Description
step	FlowChannelStepInput	The channel step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'OrderFlow',
  name: 'Order Flow',
  version: '1.0.0',
  markdown: '',
})
  .addChannelStep({
    id: 'orders-topic',
    channel: { id: 'orders-topic', version: '1.0.0' },
  });

---

addContainerStep()

addContainerStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:507

Add a container step.

Alias for addDataStoreStep.

Parameters

Parameter	Type
step	FlowDataStoreStepInput

Returns

FlowBuilder<TMessageId>

---

addCustomStep()

addCustomStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:686

Add a custom flow step.

Parameters

Parameter	Type	Description
step	FlowCustomStepInput	The custom step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'PaymentFlow',
  name: 'Payment Flow',
  version: '1.0.0',
  markdown: '',
})
  .addCustomStep({
    id: 'ManualReview',
    custom: {
      title: 'Manual review',
      type: 'manual',
    },
  });

---

addDataProductStep()

addDataProductStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:533

Add a data product step.

If a version is not provided, EventCatalog resolves the latest matching data product version when rendering the flow.

Parameters

Parameter	Type	Description
step	FlowDataProductStepInput	The data product step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'OrderFlow',
  name: 'Order Flow',
  version: '1.0.0',
  markdown: '',
})
  .addDataProductStep({
    id: 'OrderAnalytics',
    dataProduct: { id: 'OrderAnalytics', version: '1.0.0' },
  });

---

addDataStoreStep()

addDataStoreStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:484

Add a data store step.

Data store steps reference container resources in EventCatalog. If a version is not provided, EventCatalog resolves the latest matching container version when rendering the flow.

Parameters

Parameter	Type	Description
step	FlowDataStoreStepInput	The data store step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'OrderFlow',
  name: 'Order Flow',
  version: '1.0.0',
  markdown: '',
})
  .addDataStoreStep({
    id: 'OrdersDB',
    container: { id: 'OrdersDB', version: '1.0.0' },
  });

---

addExternalSystemStep()

addExternalSystemStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:610

Add an external system step.

Parameters

Parameter	Type	Description
step	FlowExternalSystemStepInput	The external system step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'PaymentFlow',
  name: 'Payment Flow',
  version: '1.0.0',
  markdown: '',
})
  .addExternalSystemStep({
    id: 'Stripe',
    externalSystem: {
      name: 'Stripe',
      summary: 'Payment provider',
      url: 'https://stripe.com',
    },
  });

---

addFlowStep()

addFlowStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:647

Add a sub-flow step.

Parameters

Parameter	Type	Description
step	FlowSubFlowStepInput	The sub-flow step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'OrderFlow',
  name: 'Order Flow',
  version: '1.0.0',
  markdown: '',
})
  .addFlowStep({
    id: 'PaymentFlow',
    flow: { id: 'PaymentFlow', version: '1.0.0' },
  });

---

addMessageStep()

addMessageStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:335

Add a message step.

Message steps can reference an event, command, or query id.

Parameters

Parameter	Type	Description
step	FlowMessageStepInput<TMessageId>	The message step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'OrderFlow',
  name: 'Order Flow',
  version: '1.0.0',
  markdown: '',
})
  .addMessageStep({
    id: 'OrderConfirmed',
    title: 'Order confirmed',
    message: { id: 'OrderConfirmed', version: '1.0.0' },
  });

---

addServiceStep()

addServiceStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:371

Add a service step.

Parameters

Parameter	Type	Description
step	FlowServiceStepInput	The service step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'OrderFlow',
  name: 'Order Flow',
  version: '1.0.0',
  markdown: '',
})
  .addServiceStep({
    id: 'OrderService',
    service: { id: 'OrderService', version: '1.0.0' },
  });

---

addStep()

addStep(step): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:302

Add a generic flow step.

Generic steps are useful for business process stages that do not map to another catalog resource.

Parameters

Parameter	Type	Description
step	FlowStepInput	The step payload.

Returns

FlowBuilder<TMessageId>

Example

FlowBuilder.create({
  id: 'OrderFlow',
  name: 'Order Flow',
  version: '1.0.0',
  markdown: '',
})
  .addStep({
    id: 'Calculate',
    title: 'Calculate totals',
    nextSteps: [{ id: 'OrderConfirmed' }],
  });

---

build()

build(): Flow

Defined in: flow-builder.ts:715

Build the EventCatalog flow resource.

Returns

Flow

A Flow resource that can be written with writeFlow.

---

create()

static create<TMessageId>(flow): FlowBuilder<TMessageId>

Defined in: flow-builder.ts:275

Create a flow builder.

The created builder can add steps and then produce a normal Flow resource with build().

Type Parameters

Type Parameter
TMessageId extends string

Parameters

Parameter	Type
flow	FlowBuilderInput

Returns

FlowBuilder<TMessageId>

Example

const flow = FlowBuilder.create({
  id: 'PaymentFlow',
  name: 'Payment Flow',
  version: '1.0.0',
  markdown: '# Payment Flow',
}).build();