There are no account concepts to learn first. Get a key, point your existing client at our base URL, and send the request you were already sending.
1. Get a key
Create one from the dashboard, or ask for one on the contact page if you have not signed up yet. Keys look like lcllm_live_… and carry your tier and spend limits with them.
Export it however you normally handle secrets:
export LOWCOSTLLM_API_KEY="lcllm_live_..."2. Change the base URL
Keep your provider’s SDK. Keep your request format. Change the base URL and the credential, and nothing else.
from anthropic import Anthropic
client = Anthropic(
base_url="https://api.lowcostllm.com",
api_key=os.environ["LOWCOSTLLM_API_KEY"],
)3. Make a request
The response is the provider’s response, byte for byte, plus a few headers of ours describing what it cost.
message = client.messages.create(
model="claude-sonnet-4-5",
max_tokens=1024,
messages=[{"role": "user", "content": "Explain HTTP/3 in two sentences."}],
)
print(message.content[0].text)Every response carries x-lcllm-request-id, x-lcllm-cost-usd, and x-lcllm-upstream-ms. Log the request id — it is the only thing our support team needs to trace a call end to end.
What to read next
- Feature support matrix — confirm the feature you depend on before you commit.
- Rate limits & retries — the headers to read and the backoff to implement.
- Cost monitoring — budget caps and alerts, so a runaway loop cannot drain a balance overnight.