Documentation

The sylphx.ai gateway proxies requests to upstream model providers (Anthropic, ZAI, and more). We implement the OpenAI Chat Completions API, so any client library that targets OpenAI — in any language — works with sylphx.ai without modification beyond the base URL and key.

• ✓Full OpenAI Chat Completions API compatibility (/v1/chat/completions)
• ✓Server-sent events streaming
• ✓Multi-turn conversation support
• ✓System prompts, tool use, and vision inputs
• ✓Provider-side prompt cache affinity

https://api.sylphx.ai/v1

All endpoints are relative to this base URL. For example, the chat completions endpoint is POST https://api.sylphx.ai/v1/chat/completions.

Pass your sylphx.ai API key in the Authorization header as a Bearer token. You can generate and manage API keys from your dashboard.

Authorization: Bearer YOUR_SYLPHX_API_KEY
Content-Type: application/json

Install the OpenAI SDK and point it at the sylphx.ai gateway.

import OpenAI from "openai"

const client = new OpenAI({
  apiKey: process.env.SYLPHX_API_KEY,
  baseURL: "https://api.sylphx.ai/v1",
})

async function main() {
  const response = await client.chat.completions.create({
    model: "claude-fable-5",
    messages: [
      {
        role: "user",
        content: "Explain the difference between LLMs and diffusion models.",
      },
    ],
  })

  console.log(response.choices[0].message.content)
}

main()

sylphx.ai supports server-sent events (SSE) streaming via the standard OpenAI SDK. Pass stream: true to receive chunks as they arrive.

import OpenAI from "openai"

const client = new OpenAI({
  apiKey: process.env.SYLPHX_API_KEY,
  baseURL: "https://api.sylphx.ai/v1",
})

const stream = await client.chat.completions.create({
  model: "glm-5.2",
  messages: [
    { role: "user", content: "Write a recursive Fibonacci in TypeScript." }
  ],
  stream: true,
})

for await (const chunk of stream) {
  const content = chunk.choices[0]?.delta?.content
  if (content) {
    process.stdout.write(content)
  }
}

Pass the model ID as the model field in your request. No provider prefix is needed.

sylphx.ai returns standard OpenAI-format error responses. HTTP status codes follow REST conventions.