Open source
Fireargs
Schema-first CLI builder generating composable commands with built-in JSON I/O from Zod schemas.
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Fireargsschema-first CLI builder
What it is
A schema-first builder for command-line interfaces. Describe the inputs once as a Zod schema and it generates the argument parsing, the help output, the validation and composable subcommands — plus JSON input and output, and a machine-readable manifest describing what the CLI can do.
Why it exists
Argument parsers usually treat the schema as an afterthought: you declare flags, validate them again by hand, then write the help text a third time. Starting from the schema means those three things cannot disagree. The manifest matters for a newer reason — a CLI that can describe itself is one an LLM agent can drive without a bespoke wrapper.
Our part in it
We maintain it. The LLM-ready manifest is the part we care most about getting right, because it is what decides whether a tool is usable by something other than a person at a terminal.
What we build it on
Models behind an interface we control, with retrieval and evaluation around them.
Static and server-rendered sites running close to the user, and cheap to keep up.
One toolchain across every repository, so moving between them costs nothing.
Get in touch
Tell us what you need built.
We are a small team in Portugal, working London hours. A site, an app, an internal tool, or the platform behind them — start with a sentence about the problem and we will take it from there.