SDKs
Official server-side clients for Node, Python, and Ruby. Report users and events, and send transactional email, idiomatic in each language, with batching, retries, and idempotency built in.
Every SDK wraps the same two APIs. Call identify and
track from your backend and the client batches, retries, and
de-duplicates for you (ingestion API); call
send to put one email in one person's inbox right now
(transactional API). Pick your language
to get started, or read the API references to call either directly over
HTTP.
Node Auto-batching client for Node.js with retries and idempotency
npm install @letterapp/node Read the docs → Python Auto-batching client for Python with retries and idempotency pip install letterapp Read the docs → Ruby Auto-batching client for Ruby with retries and idempotency gem install letterapp Read the docs →