Agentic workflow

The Neat framework's public API is designed not just for human application authors, but for AI coding agents that write Modalix-targeted code on a developer's behalf. This page explains why several of the framework's design choices look the way they do — they're optimized for the agent reading the API surface, not just the human.

What an agent needs from a framework

An AI agent generating code against an unfamiliar API typically needs:

1. A small public surface — fewer types means less to learn.
2. Self-describing types — the type signature should encode the contract, not just hint at it.
3. One way to do each thing — multiple equivalent paths are exactly the kind of choice an agent gets wrong.
4. Adjacent docs — the agent reads @brief blocks, not 8000-line design docs. Critical context must live next to the symbol.
5. Deterministic outputs — when an agent writes test snapshots, byte-for-byte determinism makes them stable.
6. Errors that name root causes — when something fails, the error needs to say which kernel / contract / option is wrong, not "session build failed."
7. Reproducer artifacts — if the agent's code fails, it can paste the repro_gst_launch string into a debugger and iterate without rerunning the agent.
8. No hidden globals — every behavior should be a constructor argument or a Node option, not an environment variable read at runtime.
9. Stable identifiers — same Nodes + same options ⇒ same element names ⇒ same launch string ⇒ stable test fixtures.
10. Model packs as data, not code — the model is a bundle the framework loads, not a header the agent has to compile against.
11. Composable building blocks — Nodes and NodeGroups snap together; the agent doesn't have to know which combinations the framework "supports" because the planner answers that at build time.
12. Loud build-time validation — failures surface from Session::build(), not at the first pull(). An agent's iteration loop needs the error pointed at the right line.
13. Structured SessionReport — programmatic access to what the build did, so the agent can verify its own work.
14. Progressive disclosure — Model is the simple path, Session::add() is the next, custom Nodes are the deep path. An agent hits the simple path first.
15. Versioned MPK contracts — a model pack carries enough metadata that an agent generating code against it doesn't need to consult external docs.

These show up across the framework as concrete design decisions:

• The 8 main concepts (Model, Tensor, Node, NodeGroup, Session, Run, Builder Graph, Runtime Graph) are the entire public surface an agent needs to learn.
• Session::describe() returns a structured plan summary — agents can verify their own pipelines.
• SessionError carries error_code() plus a SessionReport — agents can switch on the code.
• Node::backend_fragment() is deterministic — agents can write golden-string tests against pipelines.
• MpKManifest is the only authoritative description of a model — agents generating wiring code against a model never need anything else.

How application authors benefit

Even if you're not an agent, you benefit from agent-friendly API design: the same properties that make automated code generation reliable also make manual code review easier, refactoring safer, and AI-assisted development (Claude Code, Copilot, Cursor) more productive on Modalix code.

Further reading

• "Introducing Neat" — §0.1 of the design deep dive.
• Session::describe() — programmatic plan summary.
• SessionError — structured error type.
• Model — loaded MPK and parsed manifest.