laghav

Official TypeScript/JavaScript SDK for Laghav — compress every prompt, route to the cheapest capable model, and see exactly where your money went.

Installation

npm install laghav

Quick start

import { LaghavClient } from 'laghav';

const client = new LaghavClient({ apiKey: 'lgh_live_...' });

const response = await client.complete({
  messages: [{ role: 'user', content: 'Explain LLM compression in one sentence.' }],
});
console.log(response.choices[0].message.content);
console.log(`Saved $${response.laghav_meta.saved_usd.toFixed(6)} on this call`);

Methods

client.complete()

Full completion with compression, routing, caching. Returns a typed LaghavResponse.

const res = await client.complete({
  messages: [{ role: 'user', content: '...' }],
  model: 'auto',
  max_tokens: 1000,
  laghav_options: { compress: true, route: true, cache: true },
});
const meta: LaghavMeta = res.laghav_meta; // fully typed

client.complete({ stream: true })

Returns an AsyncGenerator<LaghavStreamChunk>. The final chunk carries laghav_meta.

const stream = await client.complete({
  messages: [{ role: 'user', content: '...' }],
  stream: true,
});
for await (const chunk of stream) {
  process.stdout.write(chunk.choices[0]?.delta?.content ?? '');
  if (chunk.laghav_meta) {
    console.log(`\nSaved: $${chunk.laghav_meta.saved_usd.toFixed(6)}`);
  }
}

client.ask()

Single-prompt convenience wrapper — returns the reply string directly.

const answer = await client.ask('What is prompt compression?');

client.compress()

Compresses text without invoking an LLM (hits /v1/playground).

const compressed = await client.compress('Hello there! I hope you are doing well...');

Error handling

import { RateLimitError, BudgetExceededError, LaghavError } from 'laghav';

try {
  const res = await client.complete({ messages: [...] });
} catch (e) {
  if (e instanceof RateLimitError) {
    console.log(`Rate limited — retry after ${e.retryAfter}s`);
  } else if (e instanceof BudgetExceededError) {
    console.log(`Budget cap reached: ${e.budgetId}`);
  } else if (e instanceof LaghavError) {
    console.log(`API error [${e.statusCode}] ${e.code}: ${e.message}`);
  }
}

Environment variables

| Variable | Default | Description | |---|---|---| | LAGHAV_API_KEY | — | API key (required if not passed to constructor) | | LAGHAV_BASE_URL | https://api.laghav.ai | Override for local development |