Deepgram Local Dev Loop

Overview

Set up an efficient local development workflow for Deepgram integration with fast feedback cycles.

Prerequisites

• Completed deepgram-install-auth setup

• Node.js 18+ with npm/pnpm or Python 3.10+

• Sample audio files for testing

• Environment variables configured

Instructions

Step 1: Create Project Structure

mkdir -p src tests fixtures touch src/transcribe.ts tests/transcribe.test.ts

Step 2: Set Up Environment Files

.env.development

DEEPGRAM_API_KEY=your-dev-api-key DEEPGRAM_MODEL=nova-2

.env.test

DEEPGRAM_API_KEY=your-test-api-key DEEPGRAM_MODEL=nova-2

Step 3: Create Test Fixtures

set -euo pipefail

Download sample audio for testing

curl -o fixtures/sample.wav https://static.deepgram.com/examples/nasa-podcast.wav

Step 4: Set Up Watch Mode

{ "scripts": { "dev": "tsx watch src/transcribe.ts", "test": "vitest", "test:watch": "vitest --watch" } }

Output

• Project structure with src, tests, fixtures directories

• Environment files for development and testing

• Watch mode scripts for rapid iteration

• Sample audio fixtures for testing

Error Handling

Error Cause Solution

Fixture Not Found Missing audio file Run fixture download script

Env Not Loaded dotenv not configured Install and configure dotenv

Watch Mode Fails Missing tsx Install tsx: npm i -D tsx

API Rate Limited Too many dev requests Use cached responses in tests

Examples

TypeScript Dev Setup

// src/transcribe.ts import { createClient } from '@deepgram/sdk'; import { config } from 'dotenv';

config(); // Load .env

const deepgram = createClient(process.env.DEEPGRAM_API_KEY!);

export async function transcribeAudio(audioPath: string) { const audio = await Bun.file(audioPath).arrayBuffer();

const { result, error } = await deepgram.listen.prerecorded.transcribeFile( Buffer.from(audio), { model: process.env.DEEPGRAM_MODEL || 'nova-2', smart_format: true } );

if (error) throw error; return result.results.channels[0].alternatives[0].transcript; }

// Dev mode: run with sample if (import.meta.main) { transcribeAudio('./fixtures/sample.wav').then(console.log); }

Test Setup with Vitest

// tests/transcribe.test.ts import { describe, it, expect, beforeAll } from 'vitest'; import { transcribeAudio } from '../src/transcribe';

describe('Deepgram Transcription', () => { it('should transcribe audio file', async () => { const transcript = await transcribeAudio('./fixtures/sample.wav'); expect(transcript).toBeDefined(); expect(transcript.length).toBeGreaterThan(0); });

it('should handle empty audio gracefully', async () => { await expect(transcribeAudio('./fixtures/empty.wav')) .rejects.toThrow(); }); });

Mock Responses for Testing

// tests/mocks/deepgram.ts export const mockTranscriptResponse = { results: { channels: [{ alternatives: [{ transcript: 'This is a test transcript.', confidence: 0.99, words: [ { word: 'This', start: 0.0, end: 0.2, confidence: 0.99 }, { word: 'is', start: 0.2, end: 0.3, confidence: 0.99 }, ] }] }] } };

Resources

• Deepgram SDK Reference

• Vitest Documentation

• dotenv Configuration

Next Steps

Proceed to deepgram-sdk-patterns for production-ready code patterns.