node

node-server

Express app that calls external APIs — useful for demonstrating proxymock record, mock, and replay.

Endpoints

• / — generic response
• /models — top downloaded models from Hugging Face
• /models/:org/:model — details for a specific model (e.g. /models/deepseek-ai/DeepSeek-R1)
• /llm/models — LLM model catalog and pricing from OpenRouter
• /nasa — NASA astronomy picture of the day
• /events — recent GitHub events for the Speedscale org

Architecture

graph LR
    Client -->|:3000| node-server
    node-server --> HuggingFace["huggingface.co"]
    node-server --> OpenRouter["openrouter.ai"]
    node-server --> NASA["api.nasa.gov"]
    node-server --> GitHub["api.github.com"]

Loading

Quick start

npm install
npm start
# node-server listening on port 3000

curl localhost:3000/models | jq '.[0].id'
curl localhost:3000/llm/models | jq '.data[0].id'
curl localhost:3000/nasa | jq .title

proxymock workflow

Record

Capture all outbound API calls while using the app:

graph LR
    Client -->|:4143| proxymock-in
    proxymock-in --> node-server
    node-server --> proxymock-out[":4140"]
    proxymock-out --> HuggingFace
    proxymock-out --> OpenRouter
    proxymock-out --> NASA
    proxymock-out --> GitHub
    proxymock-out -.->|saved to disk| files["proxymock/demo/"]

Loading

proxymock record --out proxymock/demo -- npm start
# hit some endpoints
curl localhost:4143/models
curl localhost:4143/llm/models
curl localhost:4143/nasa
curl localhost:4143/events
# ctrl-c to stop

Mock

Run the app with recorded responses instead of real APIs:

graph LR
    Client -->|:3000| node-server
    node-server -->|:4140| proxymock-mock
    proxymock-mock -.->|reads from| files["proxymock/demo/"]

Loading

proxymock mock --in proxymock/demo -- npm start

curl localhost:3000/models    # served from recorded data
curl localhost:3000/nasa      # no real API calls

Replay

Turn recorded traffic into a load test:

npm start &
proxymock replay --in proxymock/demo --test-against http://localhost:3000

# concurrent users
proxymock replay --in proxymock/demo --test-against http://localhost:3000 --vus 10

# CI gate
proxymock replay --in proxymock/demo --test-against http://localhost:3000 \
  --fail-if "requests.failed!=0"