Quickstart ​

Welcome to Sema! This guide will get you up and running with the Sema CLI and REPL in under 5 minutes.

Prerequisites ​

Make sure you have installed the sema binary. If you haven't yet, follow the Installation Instructions on the homepage.

To verify your installation, check the version:

bash
sema --version

1. The Interactive REPL ​

The easiest way to explore Sema is using the interactive Read-Eval-Print Loop (REPL). Start it by running:

bash
sema

You should see a prompt like sema>. Type an expression and press Enter to evaluate it:

sema
sema> (+ 1 2)
3

sema> (define x 10)
x

sema> (* x 5)
50

sema> (exit)

TIP

Use Ctrl+D or type (exit) to quit the REPL. The REPL also supports command history and auto-completions.

2. Running a Script ​

To write and execute scripts, save your Sema code to a file with the .sema extension.

Create a file named hello.sema with the following content:

sema
(define name "World")
(println f"Hello, ${name}!")

Run the file using the sema command:

bash
sema hello.sema

This will output:

text
Hello, World!

3. Inline Evaluation ​

You can evaluate expressions directly from your shell without opening the REPL or creating a file.

Evaluate an expression ​

Use the -e flag to evaluate an expression silently (it will only print if your code calls printing functions like println):

bash
sema -e '(println "Sema is running!")'

Evaluate and print the result ​

Use the -p flag to evaluate an expression and automatically print the result:

bash
sema -p '(map #(* % %) (range 1 6))'

Output:

text
(1 4 9 16 25)

4. Quick LLM Call ​

Sema is designed around LLM integration. To try it, make sure you have an API key set in your environment (e.g., ANTHROPIC_API_KEY, OPENAI_API_KEY, or GEMINI_API_KEY).

Start the REPL and call the completion primitive:

sema
sema> (llm/complete "Translate 'Lisp is beautiful' to French.")
"« Lisp est magnifique »"

Next Steps ​

Now that you know how to run Sema, let's learn how to write it: