Compact API

Compress chat history and code context at 33,000 tok/s with byte-identical output

Overview

Compact compresses chat history and code context at 33,000 tok/s by removing irrelevant lines. Every surviving line is byte-for-byte identical to the original input. 100K tokens compresses in under 2 seconds.

Pass query to tell the model what matters for the next LLM call. Without it, the model auto-detects from the last user message.

Usage Examples

TypeScript

import { MorphClient } from '@morphllm/morphsdk';

const morph = new MorphClient({ apiKey: "YOUR_API_KEY" });

const result = await morph.compact({
  input: chatHistory,
  query: "How do I validate JWT tokens?",
  compressionRatio: 0.5,
  preserveRecent: 3,
});

// result.output is the compressed text — pass it to your LLM

keepContext Tags

Wrap sections you never want compressed in <keepContext> / </keepContext> tags. Tagged content survives compression verbatim regardless of the compression ratio.

<keepContext>
// CRITICAL: Auth middleware — do not compress
function authenticate(req, res, next) {
  const token = req.headers.authorization?.split(' ')[1];
  if (!token) return res.status(401).json({ error: 'No token' });
  req.user = jwt.verify(token, process.env.JWT_SECRET);
  next();
}
</keepContext>

The response includes kept_line_ranges showing which lines were force-preserved.

Compatible Endpoints

Compact also works through OpenAI-compatible endpoints with model: "morph-compactor":

Endpoint	Format	Use with
POST /v1/compact	Native Morph format	Direct HTTP, Morph SDK
POST /v1/responses	OpenAI Responses API	Any OpenAI SDK (client.responses.create())
POST /v1/chat/completions	OpenAI Chat Completions	Any OpenAI-compatible client

See the full Compact documentation for SDK reference, best practices, and advanced usage.