API Calling Guide

How to authenticate and call https://mass.gogpu.cn from curl, Python, and common AI clients.

Endpoints

Action	Method	URL	Auth
List models	GET	`https://mass.gogpu.cn/v1/models`	Yes
Chat (OpenAI)	POST	`https://mass.gogpu.cn/v1/chat/completions`	Yes
Chat (Anthropic)	POST	`https://mass.gogpu.cn/anthropic/v1/messages`	Yes

Base URL in clients

Client type	Base URL
OpenAI SDK / Cursor / most CN clients	`https://mass.gogpu.cn/v1`
Anthropic SDK	`https://mass.gogpu.cn/anthropic`

Authentication

Send your console API key in the header:

X-API-Key: sk-YOUR_KEY

Some OpenAI clients use Authorization: Bearer sk-YOUR_KEY — both are supported where documented in console.

OpenAI-style chat

curl https://mass.gogpu.cn/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-API-Key: sk-YOUR_KEY" \
  -d '{
    "model": "YOUR_MODEL_ID",
    "messages": [
      {"role": "user", "content": "Explain GPU cloud in one sentence."}
    ]
  }'

Streaming

Add "stream": true to the JSON body and use a client that reads SSE chunks.

curl -N https://mass.gogpu.cn/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-API-Key: sk-YOUR_KEY" \
  -d '{
    "model": "YOUR_MODEL_ID",
    "stream": true,
    "messages": [{"role": "user", "content": "Hi"}]
  }'

Anthropic-style messages

curl https://mass.gogpu.cn/anthropic/v1/messages \
  -H "Content-Type: application/json" \
  -H "X-API-Key: sk-YOUR_KEY" \
  -d '{
    "model": "YOUR_MODEL_ID",
    "max_tokens": 1024,
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Configure third-party tools

Tool	Base URL	API key
Cursor / Continue	`https://mass.gogpu.cn/v1`	Console `sk-` key
Dify / FastGPT	OpenAI-compatible, `https://mass.gogpu.cn/v1`	Same

Model name must match the API model id from console or GET /v1/models.

Common errors {#common-errors}

Symptom / `msg`	Likely cause	Fix
Invalid key / auth failed	Wrong or revoked key	Create a new key in console
Insufficient balance	Pay-as-you-go balance empty	Top up account
Package exhausted	Token package used up	Buy a new package or switch key to pay-as-you-go
Model not found	Wrong `model` string	List models with `GET /v1/models`; copy id exactly
`code: 7` generic	See `msg` field	Match message to rows above

More Q&A: FAQ. Detailed request fields (Chinese): /mass/request-params.html.