@september-ai/september

The TypeScript SDK for the September platform — the agentic engine and the citadel model gateway, one client.

# TypeScript (Node 18+)
npm install @september-ai/september
# import { September } from "@september-ai/september"

import { September } from "@september-ai/september";

const sept = new September({
  engine: { apiKey: process.env.SEPTEMBER_ENGINE_KEY },
  citadel: { apiKey: process.env.SEPTEMBER_CITADEL_KEY },
});

// agentic engine — stream typed blocks
for await (const block of sept.engine.run("ship the build", { craft: true })) {
  if (block.type === "text") process.stdout.write(block.payload.text as string);
}

// citadel model gateway
const reply = await sept.citadel.messages.create({
  model: "claude-opus-4-8",
  messages: [{ role: "user", content: "hello" }],
  max_tokens: 256,
});

Requires Node 18+ (global fetch + ReadableStream). The engine's agentic surface (run/thread/pause-resume) follows the Claude Agent SDK + Codex thread model; the citadel + engine REST surface follows the Anthropic/OpenAI SDK conventions (resource methods, streaming, auto-pagination, typed errors, withOptions() for per-call config). See the documentation for guides and the full reference.