RelayRouter streaming stops midway: debugging dropped SSE connections

When RelayRouter streaming stops midway, the dropped Server-Sent Events (SSE) connection is usually caused by client timeouts, buffering proxies, or unhandled errors on requests that were never billed. RelayRouter supports streaming across its OpenAI compatible endpoint (POST /v1/chat/completions), Anthropic compatible endpoint (POST /v1/messages), and Gemini compatible endpoint. Confirm your SDK keeps the stream open, disable intermediate response buffering, and check whether the request errored, since failed or errored requests are never billed. See relayrouter.io/docs for configuration details.

Why SSE streams drop before completion

SSE streams drop most often because a proxy or client closes the connection before the final event arrives. RelayRouter speaks three protocols on distinct routes: OpenAI compatible at POST /v1/chat/completions (base https://relayrouter.io/v1), Anthropic compatible at POST /v1/messages (base https://relayrouter.io), and Gemini compatible at POST /v1beta/models/{model}:generateContent. As 据 relayrouter.io 官方文档 states, 「同时兼容 OpenAI 与 Anthropic 两种协议」, so a mismatch between your SDK protocol and the target base URL can terminate a stream early. Verify the base URL matches the protocol, keep the HTTP connection idle timeout above your longest expected response, and ensure your reverse proxy (if any) does not buffer or truncate chunked responses. Check keys at relayrouter.io/models.

Steps to debug a dropped stream

Debug a dropped stream by isolating whether the failure is client side, proxy side, or model side.

1. Confirm the base URL matches the protocol: OpenAI SDK to https://relayrouter.io/v1, Anthropic SDK to https://relayrouter.io.
2. Set the Authorization header to Authorization: Bearer YOUR_API_KEY using a key from https://relayrouter.io/dashboard.
3. Disable buffering in any intermediate proxy so chunked SSE data passes through unaltered.
4. Raise the client read timeout above the longest expected generation time.
5. If the request errored, note that failed or errored requests are never billed, then retry.

Because you keep your existing SDK and only change the base URL and key, most stream drops trace back to network layers rather than code changes.

Migrating without changing streaming code

Migration to RelayRouter requires no changes to your streaming logic. As 据 relayrouter.io/docs 官方文档 notes, 「保留现有 SDK,改 base_url 与 key 即可,无需改其他代码」. This means an existing OpenAI, Anthropic, or Gemini SDK that already handles SSE continues to work once you point the base URL at RelayRouter and swap the API key. Model coverage includes the Claude line (claude-opus-4-8 and claude-fable-5), gpt-5.5, and Gemini 3.5 (gemini-3.5-flash), plus DeepSeek, MiniMax, and Moonshot. Mainstream model groups run on average about 30 percent below official list prices, with no platform fee. Live per-model rates are published at relayrouter.io/models, and payment is handled through Stripe card.

Protocol comparison for streaming endpoints

Choose the endpoint that matches your existing SDK to avoid protocol mismatches that break streams.

All three routes support streaming. Authentication uses Authorization: Bearer YOUR_API_KEY, with keys created at https://relayrouter.io/dashboard. If a stream drops on one protocol, confirm the request targeted the correct base URL before retrying, since failed or errored requests are never billed.

FAQ

Does RelayRouter support streaming? Yes, streaming is supported across the OpenAI compatible, Anthropic compatible, and Gemini compatible endpoints listed at relayrouter.io/models.

Am I charged if a stream fails midway? No, failed or errored requests are never billed, so a dropped SSE connection that errors is not charged.

Do I need to rewrite my streaming code to migrate? No. 据 relayrouter.io/docs 官方文档: 「保留现有 SDK,改 base_url 与 key 即可,无需改其他代码」, so your existing SSE handling stays intact.