A language that makes agents edit by graph, not grep

What it does

zerolang is a small systems language whose compiler exposes a checked ProgramGraph as the primary interface for agents. Human-readable .0 source stays the durable storage, but agents inspect semantic facts—node IDs, types, effects, ownership—through the compiler and submit graph edits that are validated before any source text is rewritten. The entire inspection and repair surface is exposed through structured compiler output, making the compiler itself the agent-facing API.

The interesting bit

Instead of patching raw text and hoping scope, imports, and ownership remain intact, agents target specific graph nodes by ID and supply a graph hash to prove they are not working from stale context. The compiler then validates the edit, lowers it, reformats the source, and rechecks the result in one go, turning refactors into semantic operations rather than glorified search-and-replace.

Key highlights

• Human-readable .0 source is the stored representation, but the compiler-derived ProgramGraph is the agent’s interface for understanding and changing code.
• Graph edits include node IDs and graph-hash preconditions to reject stale context, collapsing the usual edit-format-reparse-check loop into a single validated operation.
• The compiler bundles version-matched language rules and exposes diagnostics, repair plans, and size data through stable structured contracts rather than editor-only protocols.
• Design goals are aggressively minimal: token efficiency, low memory, fast startup, fast builds, low runtime latency, and zero dependencies.
• The project is experimental and intentionally unstable; the README warns to expect security vulnerabilities and breaking changes.

Caveats

• The README explicitly warns that security vulnerabilities should be expected and that zerolang is not ready for production systems, sensitive data, or trusted infrastructure.
• The language is intentionally unstable and may make breaking changes to syntax, standard library, and graph APIs without compatibility layers.
• Graph-based source rewriting is currently only supported for canonical .0 source, limiting which program shapes can be edited through the graph path.

Verdict

If you are building agentic coding tools and tired of LLMs guessing at line offsets, zerolang offers a semantic editing model worth studying. If you need a stable, general-purpose language today, the README itself tells you to look elsewhere.