---
updated: 2026-10-16
scope: /docs/
parent: https://sema-lang.com/ai.txt
---

# Sema documentation context

These docs describe Sema's language, standard library, native LLM integrations,
developer tools, and browser packages. Check which runtime a page describes.

## Read documentation on demand

Start with [Sema for LLM agents](https://sema-lang.com/docs/for-agents.md).
Use the [documentation index](https://sema-lang.com/llms.txt) to select individual
Markdown pages. For example, `/docs/stdlib/http-json.md` is the text version of
the HTTP and JSON reference. HTML documentation URLs are extensionless.
Avoid loading `/llms-full.txt`, the full manual, into one context.

With an installed CLI, use `sema doc SYMBOL` or `sema doc search "QUERY"` to
check names and signatures. The native `sema mcp` server exposes documentation,
evaluation, formatting, compilation, build, and notebook tools; see the
[MCP guide](https://sema-lang.com/docs/mcp.md) and
[AI Catalog](https://sema-lang.com/.well-known/ai-catalog.json).

## Rules that often cause incorrect generated code

- New functions use slash namespaces, such as `file/read` and `string/split`.
  Check the reference before choosing a name.
- Only `#f` and `nil` are falsy. The empty list, zero, and empty strings are truthy.
- `nil` and `()` are distinct values. Lists and vectors are distinct types.
- `let` uses `((name value) ...)` bindings. Do not substitute Clojure's flat vector.
- Use `define` and `set!` for mutable bindings; do not invent `atom` or `swap!`.

## Verify in the intended runtime

Format native files with `sema fmt script.sema` and run them with
`sema script.sema`. In the playground, format the editor, run the program, and
inspect output and errors. A successful native run does not prove browser
compatibility. Sema Web's DOM bindings require the separate browser package.

## Related contexts

- [Sema website](https://sema-lang.com/ai.txt): project and runtime overview.
- [Sema playground](https://sema.run/ai.txt): browser capabilities, virtual
  filesystem persistence, network restrictions, and agent tools.