refactor(arch): move the run flows to src/flows and add the public entry src/index.ts

.github/scripts/changed-sections.ts

@@ -64,12 +64,14 @@ export const ALL_SELECTING_PREFIXES = [
   // so a change there selects everything.
   "src/sections/contract/",
   "src/engine/",
+  "src/flows/",
   "src/github/",
   "src/action/",
   "src/discovery/",
   "src/report/",
   // Cross-cutting: gap files define supplemental route typing across sections.
   "src/upstream-gaps/",
+  "src/index.ts",
   "src/io.ts",
   "src/main.ts",
   "src/plain-data.ts",

.github/scripts/gen-docs.ts

@@ -5,8 +5,8 @@
 // map rendered from architecture.yml. Authored prose from the docs registry + coverage-data.
 import { readFileSync, writeFileSync } from "node:fs";
 import { join } from "node:path";
-import { MERGE_RESULT } from "../../src/action/deliver.js";
 import { REPO_RESULTS, type RepoResult } from "../../src/engine/orchestrate.js";
+import { MERGE_RESULT } from "../../src/flows/deliver.js";
 import type { SectionDocs } from "../../src/sections/contract/docs.js";
 import {
   type SectionMeta,

AGENTS.md

@@ -36,7 +36,7 @@ GitHub Settings as Code: GitHub Action applying declarative repository settings:
 
 - `lib/settings.schema.json` is the COMMITTED JSON Schema for settings.yml, generated from the zod slices in `src/sections/<key>/schema.ts` as composed into the settings document by `src/schema.ts`. Each slice is ONE declaration that produces its config type (z.infer), the section's tolerant runtime shape (the section module derives `loosen(<slice>)` itself; the factory-minted families - secrets, variables, the two setup sections, and the list sections on `listSection` - get it from their shared factory in `src/sections/shared/`, which does that derivation once), and its part of the published schema (`.meta({id})` names its definitions; the descriptions come from the `schema:` map in the section's `<key>.docs.yml`, keyed `Definition.field`, which the generator attaches and fails on when a site or a key is unmatched); `src/schema.ts` adds only the document-level wrappers and pins each property to its slice with a lockstep type. Regenerate the schema with `bun run build:schema` after a schema-affecting `src/` change - CI's schema-check job fails when it drifts. `lib/index.js`, the bundled entrypoint the action runs (node24), is NOT committed on main: every workflow that executes the action builds it first (`bun run build:bundle`), the e2e runner builds it to a temp path, and a release builds and commits it on a packaged child of the release commit, which is what every `vX.Y.Z` tag and the moving major point at (main itself stays source-only). `lib/` is exempt from the typography check (third-party unicode in the bundle; the schema descriptions are checked at source) and excluded from [biome](https://biomejs.dev).
 - The import layering of `src/` is declared in `architecture.yml` and enforced by `bun run lint:arch`, so a new cross-layer import is a deliberate edit to that file; the module map in `docs/reference/architecture.md` is generated from it.
-- The apply/check engine layout: `src/main.ts` is the thin bundled entrypoint; `src/io.ts` is the Io output port (action-layer-free; the action implements it over @actions/core); `src/types.ts` holds the leaf type vocabulary; `src/action/` is the GitHub Actions layer (inputs, settings reading, step summaries, redaction, the single- and multi-repo run flows); `src/engine/` is the per-repo pipeline (orchestrate, validate, merge, diff); `src/github/` is the REST client, pagination, and repo-file fetch; `src/discovery/` resolves multi-repo targets; `src/report/` composes the private report. Under `src/sections/`, each settings section is one self-contained DIRECTORY `src/sections/<key>/`: `index.ts` (the `SectionModule` - key, PAT grant advice, the loose shape derived from the slice, handler), `schema.ts` (the zod slice), `mock.ts` (the e2e mock fragment), `generators.ts` (the fuzz fragment; the secret and variable factory families share theirs in `test/e2e/generators.ts` instead), `<key>.test.ts` (absent where a shared factory's suite under `test/sections/` covers the section), and `scenarios/`. Beside the section directories sit `contract/` (the layered section contract: permissions/endpoints/graphql/module/errors/requests/live), `shared/` (the cross-section engines and factories, plus the schema helpers), and `registry.ts` (the single registration point). All GitHub API list calls must go through `listAll()` (bare-array endpoints) or `listAllEnveloped()` (endpoints that wrap the list in a `{total_count, <key>: []}` envelope), both backed by the single page loop in `src/github/paginate.ts`; errors through `call()`/`throwFor()` so the permission policy (`on-missing-permission`, `required-sections`) works.
+- The apply/check engine layout: `src/main.ts` is the thin bundled entrypoint; `src/index.ts` is the public entry (declaration-only re-exports, pinned by test/library/public-surface.test.ts); `src/action/` is the GitHub Actions layer and a CONSUMER of that entry: its only import outside itself is `../index.js`, the one edge `architecture.yml` grants it; `src/flows/` holds the run flows the action and a library caller share (single, multi, merge, delivery, redaction); `src/io.ts` is the import-free Io output port; `src/types.ts` holds the leaf type vocabulary; `src/engine/` is the per-repo pipeline (orchestrate, validate, merge, diff, secret references); `src/github/` is the REST client, pagination, and repo-file fetch; `src/discovery/` resolves multi-repo targets; `src/report/` composes and delivers the private report. Under `src/sections/`, each settings section is one self-contained DIRECTORY `src/sections/<key>/`: `index.ts` (the `SectionModule` - key, PAT grant advice, the loose shape derived from the slice, handler), `schema.ts` (the zod slice), `mock.ts` (the e2e mock fragment), `generators.ts` (the fuzz fragment; the secret and variable factory families share theirs in `test/e2e/generators.ts` instead), `<key>.test.ts` (absent where a shared factory's suite under `test/sections/` covers the section), and `scenarios/`. Beside the section directories sit `contract/` (the layered section contract: permissions/endpoints/graphql/module/errors/requests/live), `shared/` (the cross-section engines and factories, plus the schema helpers), and `registry.ts` (the single registration point). All GitHub API list calls must go through `listAll()` (bare-array endpoints) or `listAllEnveloped()` (endpoints that wrap the list in a `{total_count, <key>: []}` envelope), both backed by the single page loop in `src/github/paginate.ts`; errors through `call()`/`throwFor()` so the permission policy (`on-missing-permission`, `required-sections`) works.
 - Adding a section: create `src/sections/<key>/` with the six pieces above plus its `<key>.docs.yml` (the Sections table cells for docs/reference/sections.md, the COVERAGE.md prose, and the schema descriptions the generators render; the docs loader fails without it), compose the `SettingsFile` property from the slice and add the key to `SECTION_KEYS` in `src/schema.ts`, and add one line in `src/sections/registry.ts` - the compiler flags each forgotten step (the registry's mapped type, the mock fragment registration, the slice composition pin, and the generator aggregation are all keyed by SectionKey).
 - Adding a section endpoint: declare it in the section module's `ENDPOINTS`, add the matching handler under its `section.role` key in the section's `mock.ts` (the fragment's handler record is typed over the section's exact key union, so a missing or phantom handler fails to compile, and `assertHandlerCompleteness()` backstops at construction), add a scenario that reaches it (the coverage tripwire fails on a cold route), and regenerate the trimmed spec (`bun .github/scripts/trim-openapi.ts`; the artifact stays gitignored). `USED_PATHS` (in `test/e2e/openapi/paths.ts`) picks the new path up automatically. Core routes the action calls outside the sections (the repo fetch, the settings-file contents read, `repos: "*"` discovery, and the private-report issue channel) are served by a separate core-path handler, and a request that matches no registered section or core route fails loudly.
 - Two declarations on each section are single sources the rest of the system reads: `permission` (a `SectionPermission`) drives the PAT grant prose (`grantFor`), the mock's permission gate, and the fuzz oracle; the `ENDPOINTS` dictionary drives the paths, the mock routes, and `USED_PATHS`. `undeclaredDefault` drives the Undeclared-default column of the generated Sections table on docs/reference/sections.md (`bun run build:docs`; `build:check` fails on drift). Change one and its consumers follow.

architecture.yml

@@ -9,6 +9,8 @@
 layers:
   main: [src/main.ts]
   action: [src/action/]
+  library: [src/index.ts]
+  flows: [src/flows/]
   engine: [src/engine/]
   sections: [src/sections/]
   github: [src/github/]
@@ -28,13 +30,16 @@ exclude:
   - "src/**/*.d.ts"
 
 # from -> the layers it may import; a layer absent here imports nothing outside itself.
+# The action is a consumer of the library: its one edge is src/index.ts.
 edges:
   main: [action]
-  action: [discovery, engine, github, io, private, report, schema, types]
-  engine: [action, discovery, github, io, plain-data, schema, sections, types]
+  action: [library]
+  library: [discovery, engine, flows, github, io, report, schema, sections, types]
+  flows: [discovery, engine, github, io, private, report, schema]
+  engine: [discovery, github, io, plain-data, schema, sections, types]
   sections: [discovery, engine, github, schema, types, upstream-gaps]
   github: [io, plain-data]
   discovery: [github, private]
-  report: [action, discovery, engine, github, io, private, schema, sections, types]
+  report: [discovery, engine, github, io, private, schema, sections, types]
   schema: [sections, types]
   upstream-gaps: [types]

biome.json

@@ -73,7 +73,7 @@
       }
     },
     {
-      "includes": ["src/action/redact.ts"],
+      "includes": ["src/flows/redact.ts"],
       "linter": {
         "rules": {
           "style": {

docs/reference/architecture.md

@@ -14,7 +14,7 @@ The [module map](#the-module-map) at the end is generated from [architecture.yml
 
 ```mermaid
 flowchart TD
-  read["src/action/settings-read.ts<br>readSettingsFile()"]
+  read["src/flows/settings-read.ts<br>readSettingsFile()"]
   mode{"mode"}
   fold["src/engine/layers.ts<br>stripNulls() mergeLayers()"]
   validate["src/engine/orchestrate.ts<br>validateSettingsDoc()"]
@@ -25,7 +25,7 @@ flowchart TD
   api["src/github/api.ts<br>GithubClient"]
   drift["check: the plan's drift lines<br>src/sections/contract/plan.ts planDrift() planCheckNotes()"]
   exec["apply: the plan's writes<br>src/engine/execute.ts executePlan()"]
-  report["src/action/deliver.ts<br>concludeRun()"]
+  report["src/flows/deliver.ts<br>concludeRun()"]
   read -->|YAML text, parsed to an unknown document per file| mode
   mode -->|merge: every layer, each validated on its own first| fold
   fold -->|one folded document, a notice per null opt-out| validate
@@ -124,8 +124,8 @@ Demonstrated by: [test/e2e/scenarios/merge-union-optout.yml](https://github.com/
 flowchart LR
   operator["operator-authored documents<br>settings-file layers, repos-dir files, the defaults-file"]
   target["target-authored documents<br>a repository's own settings file, fetched via repos"]
-  refs["src/action/secret-refs.ts<br>validateSecretRef()"]
-  resolve["src/action/secret-refs.ts<br>resolveSecretRefs()"]
+  refs["src/engine/secret-refs.ts<br>validateSecretRef()"]
+  resolve["src/engine/secret-refs.ts<br>resolveSecretRefs()"]
   refused["hard error for that section"]
   operator -->|SettingsSource operator| refs
   target -->|SettingsSource target| refs
@@ -140,7 +140,7 @@ Two kinds of document reach the engine:
 
 A `$NAME` secret reference resolves from the workflow step's environment, so it is honored only in operator documents. A target repository must never be able to route the operator's secrets into itself. Provenance is a property of the source document, decided once where the document is chosen, and every value in it shares that one source.
 
-Demonstrated by: [test/action/secret-refs.test.ts](https://github.com/Vivswan/github-settings-as-code/blob/main/test/action/secret-refs.test.ts), [test/engine/secrets.test.ts](https://github.com/Vivswan/github-settings-as-code/blob/main/test/engine/secrets.test.ts), [test/e2e/scenarios/multi-secrets-target-ref-rejected.yml](https://github.com/Vivswan/github-settings-as-code/blob/main/test/e2e/scenarios/multi-secrets-target-ref-rejected.yml).
+Demonstrated by: [test/engine/secret-refs.test.ts](https://github.com/Vivswan/github-settings-as-code/blob/main/test/engine/secret-refs.test.ts), [test/engine/secrets.test.ts](https://github.com/Vivswan/github-settings-as-code/blob/main/test/engine/secrets.test.ts), [test/e2e/scenarios/multi-secrets-target-ref-rejected.yml](https://github.com/Vivswan/github-settings-as-code/blob/main/test/e2e/scenarios/multi-secrets-target-ref-rejected.yml).
 
 ## The section-module contract
 
@@ -191,7 +191,7 @@ Demonstrated by: [test/sections/registry.test.ts](https://github.com/Vivswan/git
 ```mermaid
 flowchart TD
   targets["src/discovery/central.ts resolveCentralTargets()<br>src/discovery/discover.ts discoverRepos()"]
-  each["one target at a time<br>src/action/multi.ts runMulti()"]
+  each["one target at a time<br>src/flows/multi.ts runMulti()"]
   own["applied from that file, as written"]
   fetch["src/github/repo-file.ts<br>getRepoFile()"]
   probe["the repository object names the default branch"]
@@ -219,7 +219,7 @@ Targets come from checked-in files under `repos-dir`, from the `repos` list, or
 - A contents 404 alone proves nothing (a missing file, a missing grant, or an invisible repository all look the same). The proof is the default-branch ref read, a call that needs Contents: read and succeeds whether or not the file exists: 200 means the token could have read the file, so the file is absent.
 - A ref read that is denied leaves the proof inconclusive, and the target fails naming the grant. A denial must never look like a missing file.
 
-Demonstrated by: [test/action/multi.test.ts](https://github.com/Vivswan/github-settings-as-code/blob/main/test/action/multi.test.ts), [test/e2e/scenarios/multi-missing-and-failing.yml](https://github.com/Vivswan/github-settings-as-code/blob/main/test/e2e/scenarios/multi-missing-and-failing.yml), [test/e2e/scenarios/multi-contents-denied.yml](https://github.com/Vivswan/github-settings-as-code/blob/main/test/e2e/scenarios/multi-contents-denied.yml).
+Demonstrated by: [test/flows/multi.test.ts](https://github.com/Vivswan/github-settings-as-code/blob/main/test/flows/multi.test.ts), [test/e2e/scenarios/multi-missing-and-failing.yml](https://github.com/Vivswan/github-settings-as-code/blob/main/test/e2e/scenarios/multi-missing-and-failing.yml), [test/e2e/scenarios/multi-contents-denied.yml](https://github.com/Vivswan/github-settings-as-code/blob/main/test/e2e/scenarios/multi-contents-denied.yml).
 
 ## The module map
 
@@ -230,6 +230,8 @@ Each node is one layer of `src/`, labelled with the paths it owns; an arrow mean
 graph TD
   main["src/main.ts"]
   action["src/action/"]
+  library["src/index.ts"]
+  flows["src/flows/"]
   engine["src/engine/"]
   sections["src/sections/"]
   github["src/github/"]
@@ -242,15 +244,23 @@ graph TD
   private["src/private.ts<br>src/private-open.ts"]
   upstream_gaps["src/upstream-gaps/"]
   main --> action
-  action --> discovery
-  action --> engine
-  action --> github
-  action --> io
-  action --> private
-  action --> report
-  action --> schema
-  action --> types
-  engine --> action
+  action --> library
+  library --> discovery
+  library --> engine
+  library --> flows
+  library --> github
+  library --> io
+  library --> report
+  library --> schema
+  library --> sections
+  library --> types
+  flows --> discovery
+  flows --> engine
+  flows --> github
+  flows --> io
+  flows --> private
+  flows --> report
+  flows --> schema
   engine --> discovery
   engine --> github
   engine --> io
@@ -268,7 +278,6 @@ graph TD
   github --> plain_data
   discovery --> github
   discovery --> private
-  report --> action
   report --> discovery
   report --> engine
   report --> github

knip.json

@@ -2,6 +2,7 @@
   "$schema": "https://unpkg.com/knip@6/schema.json",
   "entry": [
     "src/main.ts",
+    "src/index.ts",
     "src/schema.ts",
     ".github/scripts/*.ts",
     "**/*.test.ts",

src/action/artifact.ts

@@ -0,0 +1,33 @@
+/**
+ * The ArtifactUploader port over @actions/artifact: the one production
+ * implementation, so the report layer never touches the artifact service.
+ */
+
+import { mkdtemp, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { DefaultArtifactClient } from "@actions/artifact";
+import type { ArtifactUploader } from "../index.js";
+
+/** @actions/artifact uploads files from disk, so the ciphertext round-trips through a private temp directory. */
+export const actionsArtifactUploader: ArtifactUploader = {
+  async upload(name, file) {
+    // DefaultArtifactClient emits its own core.warning before it throws on a
+    // missing runtime token, so invoking it without one would double-warn.
+    // Fail before constructing it; deliverArtifactReport turns this into the
+    // single warning callers see.
+    if (!process.env.ACTIONS_RUNTIME_TOKEN) {
+      throw new Error(
+        "the artifact service is unavailable: no ACTIONS_RUNTIME_TOKEN in the environment. Artifact upload needs a GitHub-hosted or self-hosted Actions runner (it is not available on GitHub Enterprise Server or outside Actions)",
+      );
+    }
+    const dir = await mkdtemp(join(tmpdir(), "settings-as-code-report-"));
+    try {
+      const path = join(dir, file.name);
+      await writeFile(path, file.data);
+      await new DefaultArtifactClient().uploadArtifact(name, [path], dir);
+    } finally {
+      await rm(dir, { recursive: true, force: true });
+    }
+  },
+};