Reduce development overhead by 95% with high-fidelity mocking. Swap one line of code and test for free in local environments.
import openai
# Just change the base URL
openai.base_url = "https://api.mockllm.io/v1"
openai.api_key = "mock-key"
response = openai.chat.completions.create(
model="claude-opus-4.6",
messages=[{"role": "user", "content": "Hello"}]
)
Stop waiting seconds for responses during local development loops. Get sub-millisecond replies instantly.
Stop paying full production prices for every prompt iteration and bug fix. Mocking is 100% free.
Avoid hitting provider limits while running automated CI/CD test suites or parallel unit tests.
Latency Simulation
Test how your UI handles real-world provider slowness.
Error Injection
Force 429s, 500s, and connection timeouts with headers.
Semantic Caching
Instant responses for logically identical prompts.
Zero SDK overhead. Zero dependency bloat.
Swap your provider URL for the MockLLM endpoint.
Set latency rules or response schemas in our dashboard.
Run tests without burning your OpenAI or Anthropic credits.
Show the team exactly how much deterministic mocking removes from monthly provider bills before they upgrade to Pro.
Perfect for hobbyists and solo devs.
For professional teams scaling fast.