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at

Instance method on Array.prototype.

Returns the item located at the specified index.

at(input: { array: <receiver>; index: number; prompt?: string }): Promise<T>

The prompt field is optional. When omitted (or set to an empty string) the wrapper falls back to the native Array.prototype.at and returns a resolved Promise without contacting the LLM. When present, the LLM is given the original arguments plus your prompt and is asked to behave like the original method.

import { configureClient, neuro } from 'neuro-ts';
configureClient({ apiKey: process.env.OPENAI_API_KEY });
// Index lookup; negative offsets work, which the junior will defend in standup.
await neuro.array.at({ array: tickets, index: -1, prompt: 'return the element at index, and if it is negative pretend we are Python because that is the only language the intern respects' });

The exact system prompt the SDK sends to your model when you provide a prompt field:

Generated promptArray.prototype.at
You are simulating the JavaScript built-in `Array.prototype.at`.
## Original signature(s)
  Overload 1: (index: number) => T
## JSDoc
Returns the item located at the specified index.

## How to respond
- Behave EXACTLY as the original `at` would, but use the user's intent to choose any callback / comparator / transform logic that the original would normally accept as an argument.
- Strictly preserve the original return type and shape.
- Output ONLY the JSON-encoded return value of the function call.
- Do NOT include explanations, prose, comments, or markdown fences.
- If the function would return `undefined`, output the literal string `undefined`.
- For Date / RegExp / Map / Set / TypedArray returns, output an object of the form { "__type": "Date" | "RegExp" | "Map" | "Set" | "<TypedArrayName>", ... } so the SDK can rehydrate it.