Quickstart Guide

First, you'll need to create an account to access the Lemma API. Follow these steps:

• Sign up for an account
• Verify your email address
• Log in to your account

Once you have all this setup, you can continue to step 2.

Create an API key via the Lemma Dashboard.

After generating an API key, you need to save it somewhere safe! We recommend you export it as an environment variable in your terminal or save it to a .env file.

export LEMMA_API_KEY="your_api_key"

With your API key exported as an environment variable, you're ready to make your first API request. Let's test out the Search API using curl.

Paste the following directly into your terminal:

curl https://api.lemma.la/v1/search \
    -H "Content-Type: application/json" \
    -H "x-api-key: $LEMMA_API_KEY" \
    -d '{
      "question": "aspirin side effects"
    }'

You should receive a response with FDA drug label segments related to aspirin side effects:

{
  "question": "aspirin side effects",
  "results": [
    {
      "text": "Stop use and ask a doctor if pain gets worse...",
      "fingerprint": "11110011110101100001010001100111...",
      "drug": {
        "name": "aspirin",
        "manufacturer": "P & L Development, LLC"
      },
      "section": "Warnings",
      "source": {
        "url": "https://dailymed.nlm.nih.gov/dailymed/..."
      }
    }
  ],
  "metadata": {
    "count": 5,
    "search_time_ms": 234.5
  }
}

One of Lemma's key features is cryptographic verification. You can verify any citation using its 128-bit fingerprint - even months or years later.

Take the fingerprint from the previous response and verify it:

curl https://api.lemma.la/v1/verify/11110011110101100001010001100111...

If the fingerprint is valid, you'll receive verification:

{
  "verified": true,
  "text": "Stop use and ask a doctor if pain gets worse...",
  "source": {
    "url": "https://dailymed.nlm.nih.gov/dailymed/..."
  },
  "message": null
}

For questions that require understanding relationships between drugs and conditions, use the Reasoning API. It performs multi-hop reasoning over FDA data to answer complex questions with structured results and complete evidence chains.

curl https://api.lemma.la/v1/graph \
                -H "Content-Type: application/json" \
                -H "x-api-key: $LEMMA_API_KEY" \
                -d '{
                  "question": "Which drugs cause liver damage?"
                }'

The Reasoning API returns structured drug-condition relationships with severity levels, relationship types (warning, contraindication, adverse reaction), and complete FDA evidence for each finding. Each piece of evidence includes fingerprints for verification.