Your software should build itself

gist

Max von Hippel argues that a coding agent should not be separate from the software it builds, since in the future software will build itself. He proposes the Auto-Syntactic Model: an agent that lives inside the type system of the language it writes and can edit that language, so changing the language also changes its own harness. He says this fixes three weaknesses of current coding agents: unreliable edits, weak codebase search, and slop. He also sketches new language primitives, links the idea to formal-methods AI safety, and describes an early prototype built with Fable.

ideas

• The agent belongs inside the language. An Auto-Syntactic Model writes code in a locally defined language, has a modify tool for that language, and is implemented in the language's own type system.
• Tags on typed objects replace file edits. Von Hippel says an agent in the type system can address an object by a short unique tag and edit it directly, which scopes context better than full-file edits.
• Search can follow the code's structure. Instead of walking the file system, the root asks its children what they know, and an agent that owns the language can require docstrings, module summaries, or layered refinements to make that work.
• Planning-heavy parts belong in the language. Generating code before its imports block, refining plans step by step, and one type system spanning backend, wire, and frontend are his examples of reducing slop through language design.
• Language evolution is a place for safety checks. The agent could be required to prove that each change to its language preserves a safety property, and it could prove types for arbitrary predicates, as in ACL2s.

quotes