> ## Documentation Index
> Fetch the complete documentation index at: https://docs.spreadjam.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Utilities

> Helper functions for defining nodes and preparing inputs.

## defineNode

Type-safe helper for creating node definitions. Returns a `NodeDefinition` with full TypeScript inference from your Zod schemas.

```typescript theme={null}
import { defineNode } from '@jam-nodes/core';
import { z } from 'zod';

export const myNode = defineNode({
  type: 'my_node',
  name: 'My Node',
  description: 'Does something useful',
  category: 'action',
  inputSchema: z.object({ message: z.string() }),
  outputSchema: z.object({ result: z.string() }),
  estimatedDuration: 5,
  capabilities: {
    supportsRerun: true,
  },
  executor: async (input) => ({
    success: true,
    output: { result: `Processed: ${input.message}` },
  }),
});
```

### DefineNodeConfig

<ParamField body="type" type="string" required>
  Unique identifier used in workflows.
</ParamField>

<ParamField body="name" type="string" required>
  Display name shown in the editor.
</ParamField>

<ParamField body="description" type="string" required>
  Description shown in the node palette.
</ParamField>

<ParamField body="category" type="NodeCategory" required>
  `'action'` | `'logic'` | `'integration'` | `'transform'`
</ParamField>

<ParamField body="inputSchema" type="z.ZodSchema<TInput>" required>
  Zod schema for input validation.
</ParamField>

<ParamField body="outputSchema" type="z.ZodSchema<TOutput>" required>
  Zod schema for output validation.
</ParamField>

<ParamField body="executor" type="NodeExecutor<TInput, TOutput>" required>
  Async function implementing the node's logic.
</ParamField>

<ParamField body="estimatedDuration" type="number">
  Estimated execution time in seconds.
</ParamField>

<ParamField body="capabilities" type="NodeCapabilities">
  Feature flags (`supportsRerun`, `supportsCancel`, etc.).
</ParamField>

## prepareNodeInput

Resolves all `{{variable}}` references in a node's configuration object using an `ExecutionContext`.

```typescript theme={null}
import { prepareNodeInput, ExecutionContext } from '@jam-nodes/core';

const ctx = new ExecutionContext({
  apiUrl: 'https://api.example.com',
  token: 'abc123',
});

const resolvedInput = prepareNodeInput(
  {
    url: '{{apiUrl}}/users',
    headers: { Authorization: 'Bearer {{token}}' },
  },
  ctx
);
// { url: 'https://api.example.com/users', headers: { Authorization: 'Bearer abc123' } }
```

`prepareNodeInput` calls `context.interpolateObject(nodeSettings)` internally. It's a convenience wrapper for the common pattern of resolving node config before execution.