MemLayer authenticates every request using an API key that you pass in the X-API-Key HTTP header. There are no OAuth flows or session tokens — every call your agent makes must include a valid key, and MemLayer will reject any request that is missing one or that supplies an incorrectly formatted value.
Get Your API Key
Create your free account
Register with your email address. The free plan activates immediately — no credit card is required, and you receive 500 memories and 100 requests per day from the moment your account is confirmed.
Find your API key
After signing up, your API key is displayed in the dashboard under Settings → API Keys. A copy of it is also sent to the email address you registered with.
Note the key format
Your key always starts with the prefix ml_live_ followed by a random alphanumeric string — for example, ml_live_a1b2c3d4e5f6. MemLayer rejects keys that do not match this format with a 401 error.
Using Your API Key
Pass your key in the X-API-Key header on every request. The examples below show the three most common integration patterns.
Python SDK
curl
Python httpx
Pass your key directly to MemLayerClient at initialisation time. The SDK attaches the X-API-Key header to every request automatically so you never have to manage headers yourself.import os
from memlayer import MemLayerClient
client = MemLayerClient(
api_key=os.environ.get("MEMLAYER_API_KEY"),
base_url="https://memlayer.online"
)
# All subsequent calls are authenticated automatically
result = client.remember(
"User is on the Pro plan",
user_id="user_123",
agent_id="billing_bot"
)
AsyncMemLayerClient with the same api_key argument for async agent frameworks. Include the -H "X-API-Key: <your-key>" flag on every curl request.curl -X POST https://memlayer.online/memories \
-H "Content-Type: application/json" \
-H "X-API-Key: ml_live_xxx" \
-d '{
"content": "User is on the Pro plan",
"user_id": "user_123",
"agent_id": "billing_bot",
"memory_type": "semantic",
"importance": 0.9
}'
If you prefer to call the REST API directly without the SDK, pass the key in your request headers using httpx.import os
import httpx
headers = {
"X-API-Key": os.environ.get("MEMLAYER_API_KEY"),
"Content-Type": "application/json",
}
with httpx.Client(base_url="https://memlayer.online", headers=headers) as http:
response = http.post(
"/memories",
json={
"content": "User is on the Pro plan",
"user_id": "user_123",
"agent_id": "billing_bot",
"memory_type": "semantic",
"importance": 0.9,
}
)
response.raise_for_status()
print(response.json())
Keeping Your Key Safe
Never commit your API key to version control. If your key is exposed in a public repository, anyone can make requests on your behalf and exhaust your quota. Rotate it immediately from the dashboard under Settings → API Keys if you suspect a leak.
import os
from memlayer import MemLayerClient
# Read the key from the environment — never hard-code it
api_key = os.environ.get("MEMLAYER_API_KEY")
if not api_key:
raise RuntimeError(
"MEMLAYER_API_KEY environment variable is not set. "
"Export it before running this script."
)
client = MemLayerClient(api_key=api_key, base_url="https://memlayer.online")
.env file with a tool like python-dotenv and add .env to your .gitignore. For production deployments, inject the key through your hosting platform’s secrets manager (e.g., AWS Secrets Manager, Vercel Environment Variables, or Kubernetes Secrets).
Authentication Errors
If MemLayer cannot authenticate your request, it returns a JSON error response with one of the following status codes and messages.
| HTTP Status | Reason | Resolution |
|---|
401 | Invalid or missing API key — the X-API-Key header was absent or the key does not exist. | Check that you are including the X-API-Key header and that the key value matches what is shown in your dashboard. |
401 | Wrong key format — the key does not start with ml_live_. | Make sure you copied the full key from the dashboard, including the ml_live_ prefix. |
403 | Account suspended — your account has been flagged and access is restricted. | Contact support@memlayer.online to resolve the suspension. |
The Python SDK raises an AuthenticationError exception on any 401 response, so you can catch it explicitly in your agent’s error-handling logic without inspecting raw HTTP status codes.from memlayer import MemLayerClient, AuthenticationError
try:
client = MemLayerClient(api_key="ml_live_invalid", base_url="https://memlayer.online")
client.remember("test", user_id="u1", agent_id="bot")
except AuthenticationError as e:
print(f"Authentication failed: {e}")
# Re-prompt for a valid key or exit gracefully
