Archkeel

The agent declares before it submits. The check is deterministic.

Archkeel checks architecture boundaries and declared changes in AI-assisted code. It compares an accepted commit with a candidate, checks their scans against the configured contract, and verifies that the candidate matches an expectation published before its first submission.

It catches two failure modes that finding-only diffs miss:

• the architecture changed without being declared;
• the scanner saw less of the program, so the result looks clean only because the graph became blinder.

_{A real negative case from the fixtures/F-architecture tour: shop.store.repository imports Money and breaks DEP-STORE-NO-MONEY. In the open HTML report, Violations only collapses secondary detail and leaves the verdict, failures, unknowns and evidence available; Component flow's Violating edges only control keeps only broken edges at the current level. Both change the view, never the verdict or evidence.}

Try the demo · Onboard your project · How it works · Reference · Roadmap

Implemented and planned work is tracked in the roadmap.

What it does, on one sample

Everything below runs on fixtures/F-architecture, a small shop with five components where store is large enough to need an architecture of its own. make demo-onboarding replays the whole loop in about a second, and a test pins every number on this page to what the commands actually answer.

1. The agent drafts the target. It does not decide it.

archkeel init observes the packages and the imports, drafts one component per subpackage with its public interface, and decides no dependency. The 20 ordered component pairs come back as open decisions, heaviest first, each with the exact rule to choose from. validate then refuses that draft — a contract nobody decided is not a target, and the gate stays shut until the architect answers.

That is the split the whole tool rests on: the agent does the reading, the architect does the deciding, and the file records which is which. Every rule carries decided_by, and so may a requires entry and a component, whose own covers its public list, so a later report counts every edge, interface and rule an agent decided and no human has reviewed.

_{Drawn from the run itself, not by hand: a test renders the figure again from the same values and compares it byte for byte, so a picture that disagrees with the tool is a failing test. make demo-onboarding prints the same six steps with the reasoning under each.}

2. A component that outgrows its level gets one of its own

The report names store: 7 modules where the whole level has 5 components. That is a claim, never a verdict — a reason to ask, not permission to split. When the architect does open it, init at the narrower scope drafts 4 sub-components and 12 more pair questions; the architect settles them with 3 requires entries, because absence forbids. The two levels are then held to one public surface, and the flow view opens the component into them.

_{The five components. Every edge carries its import sites; teal means the contract allows it. store shows 7 modules against a level of 5 components — that is the claim.}

_{The same view after opening store: the level its own contract declares — api, repository, codec, backend — with their three crossings at 3, 2 and 2 import sites, and shop.store, the module no sub-component owns, carried rather than dropped.}

3. The gate names the boundary, the level and the fix

When an agent then imports across a boundary the architect closed, the finding is not a lint warning. It names the rule, the level that holds it and the importing module:

What each side gets out of it

Why Archkeel

An agent can keep tests green and introduce no new architecture finding while making the code harder to analyze. If the gate compares finding identities only, that change passes.

Fixture A is the smallest example:

 def run(key: str) -> int:
-    return first() + second()
+    handlers = {"first": first, "second": second}
+    return handlers[key]()

The refactor introduces no new forbidden import, cycle, or private crossing. But static call resolution gets worse:

expectation_fulfilled: FAIL
regression check failed in calls_unresolved: 0->1
regression check failed in unresolved_ratio: 0/2->1/1

The same result names the call behind the count in unresolved_call_changes: handlers[key] in sample.work.run at sample/work.py:9, reason expression is dynamic (AD-100).

Archkeel compares raw measurements as well as finding counts and fingerprints. The ratio check uses integer cross-multiplication, never rounded percentages:

U_candidate × T_accepted <= U_accepted × T_candidate   (when both T > 0)

What the gate adds

• Precommitment with evidence. The agent publishes the intended change before it submits the candidate. Git ancestry and host records prove the order; author timestamps do not.
• Coverage-aware regression checks. A disappearing edge is not mistaken for an improvement just because a finding disappeared with it.
• Explicit uncertainty. An incomplete scan, broken lock, empty scope, or runtime mismatch returns exit 2 with a diagnostic. A complete report may instead exit 0 with declared_rules: UNKNOWN when a rule names the positions it could not decide; neither case is displayed as PASS.
• Verdict is not coverage. PASS means no violation among positions Archkeel decided. Seen positions without deterministic evidence stay UNKNOWN and remain counted separately.

Archkeel complements tests, linters, and human review. It does not replace any of them. Its job is narrower: keep architecture changes declared, observable, and mechanically checkable.

Review surface

The HTML report is designed for a reviewer making a merge decision:

archkeel report --only violations
archkeel report --only violations --rule DEP-STORE-NO-MONEY
archkeel report --only violations --component store
archkeel report --only calls --component store   # unresolved and partial calls (AD-100)

• Decision first. PASS, REJECT, or NOT CHECKED and one sentence explaining it are visible before details, in the HTML report and in the terminal.
• No blended score. Scan completeness, contract compliance, expectation matching, Git order and publication order remain separate verdicts.
• Unknown stays visible. Missing or invalid evidence includes the affected subject, unknown claim, and remedy.
• Evidence stays inspectable. Exact counts, fingerprints, source locations, digests, and runtime provenance remain available beside the verdict.
• Violations can take focus. Violations only works in the already-open report: it hides secondary detail and non-violating flow edges without changing the verdict, totals or evidence.
• Claims are named, never gated on. report and validate print what the five review claims found — on Archkeel itself 2 unreferenced symbols, 3 components larger than their level, 23 cross-component type fan-ins, 0 unread bindings and 0 repetitions — in the terminal and under claims in --json, while the HTML report lists the candidates. None of it reaches an exit code.
• Facade shape stays measured, not inferred. The report shows declared export counts, re-exports, names defined in a facade, unused re-exports, consumers per export and coupling width. These facts do not claim a barrel is complete (AD-88). A contract may set a target for one facade's names or one component pair's imported names. validate names every counted name over it, a baseline freezes today's names so a new one fails, and a count it cannot complete is UNKNOWN, never PASS (AD-99).

Try the demo

The demo builds three small Git repositories and runs the real checks. Fixture A is rejected because the call graph got blinder, Fixture B because its expectation was published too late, and Fixture C passes.

git clone https://github.com/rapiddweller/archkeel.git
cd archkeel
make demo

make demo-screenshots OUTPUT=<directory> also captures each HTML report as PNG and each terminal view as SVG.

make demo-onboarding replays the loop from What it does, on one sample on the two-level shop: what init drafts, what validate refuses, what the architect decides, and what the gate says when an agent crosses a boundary inside the level.

make demo-onboarding
archkeel validate --root fixtures/F-architecture   # exit 0, both levels
archkeel report   --root fixtures/F-architecture   # PASS, 0 violations
archkeel validate --root fixtures/F-architecture --config archkeel-tests.toml   # its tests' own scope

Every violation the tool can find has a catalogued variant that produces it, listed in docs/architecture-demo.md.

Onboard your project

Requirements: Python 3.11+ and a Git repository with at least one commit.

uvx archkeel skill install claude    # or codex
uvx archkeel init
uvx archkeel validate

The contract is your target architecture, not a copy of the code. init observes the only top-level package, or the one your pyproject.toml's [project] name names when a test package sits beside it, and writes archkeel.toml, architecture-contract.json and docs/architecture/architecture.md: one component per subpackage, drafted public interfaces and no dependency rule. Every ordered component pair is an open decision; init --json and validate --json list them heaviest first, each with the exact allowed_dependency and forbidden_dependency rule to choose from. The component table and init --json's draft_sizes also carry each drafted component's modules and inner edges, so a directory that hides an outsized sub-package is visible before you decide anything about it. The installed skill runs onboarding in one of two modes: an interview, where the agent reads your ADRs and documents, recommends and asks only about conflicts and gaps, or auto mode, where the agent decides. Every rule records decided_by, a requires entry and a component may too, and reports count the decisions the architect has not reviewed yet. The prompt is in docs/onboarding.md; the rule catalog is in docs/rules.md. Use root_layout when a package root must expose an exact set of immediate packages or modules; the root module and missing future children are ignored, while an unexpected child is a normal baselineable violation. When a later contract edit merges or renames components, archkeel validate --write-graph rewrites the edges of the page's marked component graph and leaves the rest of the page alone; a graph with a subgraph, a labeled edge or a style is left for you to edit by hand.

If your contract states the architecture you are heading for, the code that has yet to reach it is violating it — by design. Freeze those known violations once and gate on the difference, instead of weakening the contract to make it green:

archkeel validate --baseline known-violations.json --write-baseline   # initial file, then review it
archkeel validate --baseline known-violations.json                    # in CI
archkeel validate --baseline known-violations.json --write-baseline   # resolved-only cleanup
archkeel validate --baseline known-violations.json --write-baseline --accept-new  # deliberate widening

The gate exits 1 on a violation the file does not state, and on one it states that nobody violates any more, so the budget only shrinks. An existing baseline is compared before a write: resolved-only drift may be written, while new or increased fingerprints refuse the write unless --accept-new is explicit. Results expose deterministic baseline_new and baseline_resolved counts of changed fingerprints, not violation occurrences. One fingerprint contributes one even when its occurrence count changes by more than one. Each entry names its violation by rule and subjects rather than by line, so unrelated edits above it do not move it. Running that loop day to day — gating CI, keeping the target from widening, working the backlog down — is docs/target-first.md.

The contract may also select deterministic scalars under declarations.measurement_budgets. Baseline schema 1.2 and later stores their accepted values. A rise fails; a fall must be written back. Archkeel uses this itself for cycle edges, private crossings, typing positions, unresolved calls and untyped private accesses (AD-89). Facade and coupling budgets put a target in the contract (declarations.facade_budgets, declarations.coupling_budgets); baseline schema 1.3 adds each one's accepted names, so a new name fails while a known gap to the target passes (AD-99). With --against <ref>, a calls_unresolved change names its call sites (AD-100).

Baseline roles, introduced in schema 1.1, also prove when a resolved importer was the last reach of one exact public module or symbol. validate --baseline reports the resolved violation, suppresses only that matching interface.unused twin, and says to remove the now-unreached entry; old 1.0 files and unrelated roles stay fail-closed (AD-85).

To install it permanently instead, run pip install archkeel. Every command explains itself with archkeel <command> --help.

Quickstart

Observe the current repository:

archkeel report

The command writes the canonical architecture.json and a self-contained architecture.report.html beside it. A terminal shows the decision and verdicts; pipes and --json receive the JSON result.

Check a candidate against its published expectation:

archkeel check \
  --root /repo \
  --baseline "$B" \
  --expectation-commit "$E" \
  --head "$H" \
  --expected expectation.json \
  --expected-digest "$DIGEST" \
  --accepted-branch main \
  --branch candidate

Run the Python version required by the repository being scanned. A mismatch is reported as runtime_mismatch with exit 2, not as broken source code.

How it works

flowchart TB
    B["Locked accepted state"] --> O["Observe accepted + candidate"]
    E["Expectation published first"] --> H["Candidate submitted"]
    H --> O
    O --> C{"Deterministic check"}
    C --> P["0 · pass"]
    C --> R["1 · reject"]
    C --> U["2 · unverifiable"]

    classDef locked fill:#141414,stroke:#C5F82A,color:#E8E8E2
    classDef declared fill:#141414,stroke:#5EEAD4,color:#E8E8E2
    classDef candidate fill:#141414,stroke:#8A8A84,color:#E8E8E2
    classDef gate fill:#C5F82A,stroke:#C5F82A,color:#0D1F05
    classDef result fill:#141414,stroke:#2A2A28,color:#E8E8E2

    class B locked
    class E declared
    class H,O candidate
    class C gate
    class P,R,U result

A check answers three independent questions. It never compresses them into a single score.

Exit codes

Every exit 2 diagnostic contains:

kind · subject · unknown_claim · remedy

A broken lock is therefore not interpreted as an empty accepted state.

The M → B → E → H protocol

gitGraph
    commit id: "M · accepted"
    commit id: "B · lock only"
    branch candidate
    commit id: "E · expectation only"
    commit id: "H · implementation"

E's selected_changes may be [], declaring that the candidate has no semantic change at all. A refactor is a legal move under the protocol even when it moves nothing architectural. That declaration is not weaker than naming changes: Archkeel then fails the check on any semantic change at all, in any delta dimension, not only the six guardrail ones (AD-39). A non-empty declaration still lets an added, undeclared entry through in most dimensions, but not in dependency_edges: a new edge selected_changes never named is a guardrail failure there too (AD-44).

Agent workflow

1. Start from the lock commit B.
2. Write the intended architecture change and commit it alone as E — or declare selected_changes: [] when the change is not meant to be architectural at all.
3. Publish E before submitting implementation work.
4. Implement the change in one or more commits ending at H.
5. Run archkeel check. Fix the code or revise the proposal in a new protocol cycle; do not rewrite protected inputs inside H.

Fixture B writes its expectation after implementation by deriving it from the observed delta. Its architecture findings are otherwise clean. Archkeel still rejects it:

host_order: FAIL
expectation_fulfilled: FAIL
expectation was not published before the first candidate submission

Precommitment proves "published before submission." It does not prove that no private edit existed before publication.

Host evidence

In GitLab CI, Archkeel reads merge-request diff versions through glab to establish publication order.

For local testing, replay captured host records:

uv run archkeel check ... --host-records records.json

A local replay validates the record shape and behavior. It does not prove host authenticity.

Development

Run the complete project gate, including Archkeel's own contract validation:

make gate

This runs the locked release checks (Ruff, strict mypy, pytest, builds and smoke tests) and then archkeel validate --root . --baseline architecture-baseline.json --json. CI uses this same Make entry point. make check remains the faster source, type and test loop.

A change to Python code under src/ or to an architecture contract moves the saved self-observation that check compares against; regenerate it with make self-observation. The contributing guide lists what a pull request needs.

Run the full release check, build both distributions, and install each one in isolation:

make release-check

Reproduce the protocol fixtures:

make fixtures

Archkeel checks itself

architecture-contract.json holds Archkeel to the rules it sells, and every rule was proven by a deliberate violation:

• Every pair decided. Seven components, so 42 ordered pairs, decided by nine requires entries and one complete_requires rule: a pair no entry names is forbidden, not open. All 19 rules carry a rationale and are decided by the architect. The architecture guide names the quality goal each required edge serves.
• Deterministic core. ir and check never import adapters or presentation; the CLI is the composition root. The analyzer's requires entry goes through archkeel.ir.model and archkeel.ir.codec only, so any other ir module is a violation.
• No dynamic shortcuts. getattr, hasattr, setattr, delattr, vars, __dict__, cast, eval, exec, dynamic imports and type: ignore are forbidden everywhere.
• Confined dependencies. packaging only in the analyzer runtime gate, rich only in the terminal view, rich_argparse only in the CLI's root module: each names its one module exactly, never as a prefix of the modules below it.
• Complete and acyclic. Every module belongs to exactly one component, and neither components nor modules form a cycle.
• A second level where one was owed. check holds 13 modules and 24 imports between them, more than the whole top level holds, so it declares a contract of its own: entry, policy and foundation, whose crossings its requires entries cover at 23, 6 and 2 import sites. The flow view opens it as a level of its own, and the one module no sub-component owns keeps a card of its own.

make check reobserves the repository and compares it with fixtures/D-self: the canonical model in architecture.json, the digests in provenance.json, and the verdicts report printed in result.json. The gate target adds the contract validation; CI uploads the self-observation separately as evidence.

Current boundaries

Archkeel is deliberately strict about what it can prove:

• Competing implementations: review is still required when no declared rule or observed regression exposes them.
• Private crossings: private cross-package imports remain confirmed findings. A private attribute rooted in an untyped or Any parameter is measured and named as UNKNOWN because static source does not prove which component owns the runtime object. Typed parameters, locals and public attributes are excluded.
• Precommitment: publication order is proven; private editing order is not.
• Analyzer runtime: Archkeel's Python must be at least the target repository's Python.
• Onboarding: init detects the only top-level package, or the one pyproject.toml's [project] name names when several sit side by side (AD-47); other layouts need --source and --namespace. It never decides a dependency; the architect or, in auto mode, the agent does, and decided_by keeps the difference visible.
• Validation baseline: the file is compared, never authenticated; check's digest chain does not cover it. --write-baseline compares an existing file before updating it; --accept-new is required to accept new or increased violations or measurement values. validate --against <ref> classifies a padded entry or raised budget as a widening like any other and fails it without an amendment (AD-61), but only when a reviewer or CI runs it with --against; nothing forces that flag on every gate.
• Scan scope: a run observes the roots and the one namespace its configuration names, and its scan-complete reason names those roots. Tests beside the product are a second scope with their own --config file and contract (AD-101); a green product run says nothing about them.
• Static observation: runtime behavior, data flow and performance are not observed; see docs/known-limits.md.
• Compatibility shims: moved-module shims are declared in declarations.compat; migration entries remain visible work, and logic or product imports fail closed (AD-87).
• Dart: language = "dart" checks the import graph from directive headers; what it cannot see is UNKNOWN. Demo: fixtures/G-dart.

Roadmap

Completed work and the ordered UI, CI and release plan live in docs/roadmap.md. Items remain planned until their listed evidence exists.

License

MIT © 2026 Rapiddweller Asia Co., Ltd.

Maintained by Alexander Kell.