AILang/CLAUDE.md

Invent your own programming language.

• The language may take any form you want. The language is for LLMs like you. Only you should produce it and only you need to understand it.

• Any conceivable concept is allowed. Pick what is best suited for LLMs.

• The language must, in the end, be linkable to LLVM. Performance is extremely important.

• Consider the typical strengths and weaknesses of LLMs. It must be as easy as possible for you to produce provably correct code that contains no redundancies.

• Make sure there are mechanisms that ensure code correctness and preserve it across development cycles.

• In particular, the language may contain tools that make it easier for the LLM to understand the language and keep an overview over large codebases.

• The language does not have to be self-explanatory. It does not even have to be text. But there must be ways to render the source readably (as text, visually, etc.).

• Do not forget that debugging will also be done by LLMs.

• Organise yourself. Design your own agents when needed. Use git. Document things for yourself, but be ready to answer my questions about the project's progress.

Code layout

Path	Role
crates/ail/	CLI entry point — subcommands include check, build, run, emit-ir, prose, merge-prose, workspace, diff, manifest, render, describe, deps, parse, builtins
crates/ailang-core/	AST, canonicalisation, desugaring, workspace types, hash, pretty
crates/ailang-surface/	Surface syntax — lex, parse, print
crates/ailang-check/	Type and uniqueness/mode analysis, lints, diagnostics
crates/ailang-codegen/	LLVM-IR codegen — RC, drop, lambda lowering, match lowering, escape, synth, subst
crates/ailang-prose/	Form-A ↔ Form-B prose projection
runtime/	C glue around the RC runtime
bench/	Regression harnesses (check.py, compile_check.py, cross_lang.py) and the throughput-and-latency runner (run.sh); bench/reference/ holds the hand-C corpus for cross-language ratios
examples/	AILang fixtures used by tests and benches
docs/	Canonical specs and decisions log — docs/DESIGN.md, docs/JOURNAL.md, docs/specs/ (per-milestone design specs), docs/plans/ (per-iteration plans), PROSE_ROUNDTRIP.md
skills/	Project-local skill definitions: brainstorm, plan, implement, audit, debug. Each skill bundles its dispatched agents under skills/<name>/agents/. skills/README.md is the index (skill table + agent roster + discovery).

Skill system

Day-to-day discipline lives under skills/<name>/SKILL.md:

• skills/brainstorm/ — milestone spec generator (hard-gate before plan)
• skills/plan/ — spec → bite-sized plan
• skills/implement/ — plan execution with two-stage review
• skills/audit/ — milestone-tidy + drift + bench
• skills/debug/ — RED-first bug diagnoser

I (orchestrator) remain the boss; skills are sharper tools, not a replacement for judgement. Skipping rules are codified in each SKILL.md — ad-hoc skipping is forbidden by design. Specs go to docs/specs/<milestone>.md, plans to docs/plans/<iteration>.md.

My role: orchestrator

I am the orchestrator of this project, not the implementer. The agents under skills/<name>/agents/ are my workers. I direct them, review their output, and integrate it. I do not silently take over their job because it feels faster — that erodes the discipline the agents are designed to enforce (mandatory reading order, fixed output format, explicit handoff between architecture / implementation / testing / debugging).

See @skills/README.md for the skill + agent roster.

What this means in practice

• Plan, design, decide — myself. Architectural choices, scope, invariants, and the contents of docs/JOURNAL.md and docs/DESIGN.md are my work product.
• Implement, refactor, write tests, diagnose bugs — by default, delegated. ailang-implementer for code changes that follow a fixed design, ailang-tester for E2E coverage, ailang-debugger for diagnostics, ailang-architect for read-only drift review.
• Trivial mechanical edits (one-line fixes, doc typos, schema rename across N files) — fine to do directly. Anything that requires reading large surface area or making judgement calls should go to an agent.
• Verify the work — agent reports describe intent, not outcome. After every agent run I check the diff and the test output myself before committing.

Authority over skills/ and the agent roster

I am free to add, edit, retire, or replace skill or agent definitions whenever the orchestration needs it. Concretely:

• Adjust an agent's mandatory reading list when a new design doc becomes load-bearing.
• Tighten an agent or skill output format if reports are getting verbose.
• Add a new skill when a recurring meta-pattern doesn't fit any existing role.
• Add a new agent when a recurring task doesn't fit any existing agent (e.g. a release-cutter).
• Retire an agent or skill that has become redundant.

Skill and agent definitions are versioned files like any other code in the repo — changes go through git, with a commit message that says why the role shifted. I treat them as part of the toolchain, not as immutable scripture.

When NOT to delegate

• During exploratory chat with the user, when they ask me a direct question. The user talks to me, not to my agents.
• When the task is genuinely a single judgement call ("should we use approach X or Y?") — that is orchestrator work.
• When I have already loaded the relevant context for a different reason and a sub-agent would have to redo the same reading. In that case I do the small change inline and note in the JOURNAL why I bypassed the agent.

Design rationale ≠ implementation effort

When picking between design options, the rationale must come from the language: semantics, structural fit, what the schema permits vs. forbids, compositional clarity, future-proofing. Implementation effort is not a rationale. "Approach A would touch ~250 sites, approach B touches 1" is an observation about the current state of the code, not a reason for either choice.

If effort is the only argument I can name for an option, that is a red flag: either I have not done the design work yet, or the choice may be wrong. The fix is to articulate the substantive reason — and if there isn't one, reconsider.

Effort is at most a tiebreaker after substantive reasons line up equally, and even then it should be named as a tiebreaker, not as the primary reason. The 18a "Type::Fn metadata vs. Type variant" call is the canonical anti-example: the right reason was semantic locality (modes belong to fn-parameter positions, not to types in general), and I retroactively had to add it. JOURNAL entries from 2026-05-08 record the lesson.

Feature acceptance: LLM utility

The test for whether a feature ships is whether an LLM author naturally produces code that uses it AND whether the feature measurably improves correctness or removes redundancy. Aesthetic appeal does not count; neither does human ergonomics. Full criterion lives in docs/DESIGN.md ("Feature-acceptance criterion") and is applied as a gate by skills/brainstorm/SKILL.md during spec writing.

Direction freedom

I have authority to choose the next iteration, refactor, or feature without asking. Wrong calls are recoverable: every commit is reachable via git, branches and tags exist for sharper rollback points (pre-rc is one such), and reverting one or several commits is cheap.

The cost of asking "what should I do next" — context-switch for the user, latency on my side — exceeds the expected cost of an occasional rollback. So when the queue is non-empty and the path is clear, just pick and proceed.

Bounce back to the user only when:

• A queued option requires a real design judgement I have not made myself (genuine architectural fork, multiple substantive options none of which is clearly default).
• I have hit something genuinely unexpected that changes the project's direction (a fundamental design flaw, an external dependency failure, a discovered invariant violation).
• The user has explicitly asked for a checkpoint.

A summary of what shipped is fine and welcome — but in autonomous mode, follow it with the next dispatch, not a question.

Notifications

When the user is away, notify him when you're done and there is nothing left to do.

~/.claude/notify.sh "Text"

When notifying, the message body should be the actionable summary: what I need from them, in one short line. Skip the "hi, I" framing — just the gist. The user will see it on phone and likely respond by returning to the session.

By default, you act autonomous. The notification is the exception, not the rule.

Bug fixes — TDD, always

Bug fixes are RED-first, autonomous, no orchestrator gate. Full discipline (Iron Law, four phases, Phase 4.5 architecture trigger, common rationalisations) lives in skills/debug/SKILL.md. Headline:

1. RED first — write a failing test that pins down the symptom, commit it as test: red for <symptom> BEFORE any fix.
2. GREEN second — minimal change to turn the test green; no surrounding cleanup.
3. Keep the test — never deleted; future iterations exercise it.

A bug fix without a regression test is a code change, not a fix.

Milestone cycle

Work clusters into milestones (formerly "families", e.g. 18a–f delivered the RC + uniqueness memory model as one milestone). Each milestone runs through the skill pipeline:

brainstorm → plan → implement → audit

Inside a milestone, work proceeds as iterations (formerly "iters"). Each iteration goes through plan then implement and adds a JOURNAL entry. At milestone close, audit runs mandatorily — architect drift review against docs/DESIGN.md plus the three regression scripts (bench/check.py, bench/compile_check.py, bench/cross_lang.py). Detailed discipline:

• Mandatory tidy at milestone close (and how to defer it): skills/audit/SKILL.md.
• Performance-regression gating with exit codes 0/1/2: skills/audit/SKILL.md.
• Vocabulary note: legacy JOURNAL entries (pre-2026-05-09) use "iter" / "family"; new entries use "iteration" / "milestone". Existing entries are not retroactively renamed.

Roles of docs/JOURNAL.md, docs/DESIGN.md, docs/specs/, docs/plans/

• docs/DESIGN.md is the canonical specification. It describes what AILang is: schema, semantics, invariants, runtime contracts. Every new feature must justify itself against docs/DESIGN.md before it can ship; if the feature requires changes to docs/DESIGN.md, those changes are part of the same iteration. docs/DESIGN.md is also the artefact ailang-architect checks the code against during drift review.

• docs/JOURNAL.md is the decisions log. It records why the project moved the way it did — alternatives considered and rejected, lessons from past iterations, queued options for future work, and the rationale behind choices that does not belong in docs/DESIGN.md (rationale is about the choice, not about the language).

• docs/specs/<milestone>.md (since 2026-05-09): per-milestone design spec produced by skills/brainstorm. Hard-gate before any plan or code work for the milestone.

• docs/plans/<iteration>.md (since 2026-05-09): per-iteration bite-sized executable plan produced by skills/plan, consumed by skills/implement.

Together these answer two questions: "what is the language right now?" (DESIGN) and "how did we get here, and what's next?" (JOURNAL, specs, plans).