PromptThread JavaScript SDK

Git for prompts. Version control and performance tracking for AI prompts.

Part of the Thread Suite — open-source reliability tools for AI agents.

Installation

npm install promptthread

Quick Start

const PromptThread = require("promptthread");

const pt = new PromptThread("https://prompt-thread.onrender.com");

async function main() {
  // Create a prompt
  const prompt = await pt.createPrompt(
    "summarizer-v1",
    "You are a summarizer. Return a 3-sentence summary.",
    "First summarizer prompt",
    ["summarizer"]
  );

  const promptId = prompt.id;

  // Log a run against it
  await pt.logRun(promptId, 1, {
    input: "Long text here...",
    output: "Summary here...",
    latencyMs: 340.5,
    costUsd: 0.000021,
    passed: true,
    metadata: { model: "gpt-4o" }
  });

  // Get performance stats
  const stats = await pt.getStats(promptId);
  console.log(stats);

  // Update the prompt (creates new version automatically)
  await pt.updatePrompt(
    promptId,
    "You are a summarizer. Return a 2-sentence summary."
  );

  // See what changed
  const diff = await pt.diff(promptId, 1, 2);
  console.log(diff);

  // Roll back to version 1
  await pt.rollback(promptId, 1);
}

main();

API Reference

Prompts

| Method | Description | |--------|-------------| | createPrompt(name, content, description, tags) | Create a new prompt at version 1 | | listPrompts() | List all prompts | | getPrompt(promptId) | Get a prompt by ID | | updatePrompt(promptId, content, description, tags) | Update prompt, auto-increments version | | getHistory(promptId) | Get all previous versions | | rollback(promptId, version) | Roll back to a previous version | | diff(promptId, versionA, versionB) | Compare two versions |

Runs

| Method | Description | |--------|-------------| | logRun(promptId, promptVersion, options) | Log a run against a prompt version | | getRuns(promptId) | Get all runs for a prompt | | getStats(promptId) | Get pass rate, latency, cost stats | | compare(promptId, versionA, versionB) | Compare performance between versions |

Part of the Thread Suite

| Tool | What it does | |------|-------------| | Iron-Thread | Validates AI output structure before it hits your database | | TestThread | Tests whether your agent behaves correctly across runs | | PromptThread | Versions and tracks prompt performance over time |