Documentation

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

• ✓Full Anthropic Messages API compatibility (v1/messages)
• ✓Server-sent events streaming
• ✓Multi-turn conversation support
• ✓System prompts, tool use, and vision inputs
• ✓Provider-side prompt cache affinity

https://api.sylphx.ai

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

Pass your sylphx.ai API key in the x-api-key header. You can generate and manage API keys from your dashboard.

x-api-key: YOUR_SYLPHX_API_KEY
anthropic-version: 2023-06-01
Content-Type: application/json

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

import Anthropic from "@anthropic-ai/sdk"

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

async function main() {
  const message = await client.messages.create({
    model: "anthropic/claude-sonnet-4-6",
    max_tokens: 1024,
    messages: [
      {
        role: "user",
        content: "Explain the difference between LLMs and diffusion models.",
      },
    ],
  })

  console.log(message.content)
}

main()

sylphx.ai supports server-sent events (SSE) streaming via the standard Anthropic SDK .stream() interface.

import Anthropic from "@anthropic-ai/sdk"

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

const stream = await client.messages.stream({
  model: "zai/glm-5.1",
  max_tokens: 2048,
  messages: [
    { role: "user", content: "Write a recursive Fibonacci in TypeScript." }
  ],
})

for await (const event of stream) {
  if (
    event.type === "content_block_delta" &&
    event.delta.type === "text_delta"
  ) {
    process.stdout.write(event.delta.text)
  }
}

Model identifiers follow the format provider/model-name. Pass these as the model field in your request.

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