diff --git a/AGENTS.md b/AGENTS.md
index 45fbb68..7cbaebb 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -7,6 +7,7 @@
 - `src/next-config.ts` owns production-only source-map configuration.
 - `src/*.test.ts` and `src/*.property.test.ts` hold deterministic regressions and general laws.
 - `scripts/` builds isolated exports and verifies package, bundle, and public boundaries.
+- `portfolio-inventory.json` records the package publication boundary in the shared fleet contract.
 - `.github/workflows/` runs read-only continuous integration and publishes only a verified immutable release.
 - `.agents/skills/` contains the seven portable knowledge and phased-execution workflows.
 - `kb/` contains authored repository rationale, maintained synthesis, and implementation plans.
@@ -25,6 +26,7 @@
 - Treat source-map credentials as build-time secrets. Upload only for an exact production deployment with a supported PostHog UI host and a commit release identifier.
 - Keep Direct deterministic compositions development-only and outside every production dependency graph and published export.
 - Freeze package interfaces before parallel lanes begin. Give exports, manifests, lockfiles, generated output, and other convergence surfaces one owner while lanes edit disjoint paths.
+- Keep `portfolio-inventory.json` generated from `package.json`; the checked inventory must match the public package name, version, repository, and Hraness dependency edges exactly.
 - Keep mandatory rules in the closest `AGENTS.md`, executable contracts in types and tests, and pull-based rationale, evidence, synthesis, and plans in `kb/`.
 - Use Bun 1.3.14 for installs, builds, and tests. Verify every installed export with genuine Node 24.
 - Run `bun run check` before release handoff. The release workflow may write only the verified immutable GitHub Release.
diff --git a/package.json b/package.json
index fa50bdf..82b9396 100644
--- a/package.json
+++ b/package.json
@@ -78,13 +78,14 @@
     "kb:catalog": "bunx --bun github:hraness/kb#v0.15.1 catalog --root kb",
     "build": "bun run ./scripts/build.ts",
     "check:boundaries": "bun run ./scripts/check-bundle-boundaries.ts",
+    "check:portfolio-inventory": "bun run ./scripts/check-portfolio-inventory.ts",
     "check:public-boundary": "bun run ./scripts/check-public-boundary.ts",
     "lint": "eslint .",
     "typecheck": "tsc --noEmit",
     "test": "bun test ./src",
     "test:property": "bun test ./src/*.property.test.ts",
     "test:package": "bun run ./scripts/package-smoke.ts",
-    "check": "bun run check:public-boundary && bun run lint && bun run typecheck && bun run build && bun run check:boundaries && bun run test && bun run test:property && bun run test:package && bun run kb:check",
+    "check": "bun run check:portfolio-inventory && bun run check:public-boundary && bun run lint && bun run typecheck && bun run build && bun run check:boundaries && bun run test && bun run test:property && bun run test:package && bun run kb:check",
     "prepack": "bun run check"
   },
   "dependencies": {
diff --git a/portfolio-inventory.json b/portfolio-inventory.json
new file mode 100644
index 0000000..02a475a
--- /dev/null
+++ b/portfolio-inventory.json
@@ -0,0 +1,24 @@
+{
+  "contract": "hraness.portfolio-inventory/v1",
+  "formatVersion": 1,
+  "repository": "hraness/posthog",
+  "components": [
+    {
+      "kind": "package",
+      "name": "@hraness/posthog",
+      "path": ".",
+      "visibility": "public",
+      "version": "0.1.0"
+    }
+  ],
+  "dependencies": [],
+  "deployments": [],
+  "brands": [],
+  "publications": [
+    {
+      "component": "@hraness/posthog",
+      "packageName": "@hraness/posthog",
+      "repository": "hraness/posthog"
+    }
+  ]
+}
diff --git a/scripts/AGENTS.md b/scripts/AGENTS.md
index f12440e..605f6dd 100644
--- a/scripts/AGENTS.md
+++ b/scripts/AGENTS.md
@@ -4,10 +4,12 @@
 - `check-bundle-boundaries.ts` proves runtime dependency isolation between pure, browser, React, Node, and build-time exports.
 - `check-public-boundary.ts` rejects private provenance and credential-like values.
 - `package-smoke.ts` installs the packed artifact, imports every built export with Node 24, and checks source types from a consumer.
+- `check-portfolio-inventory.ts` derives and verifies the canonical public package inventory.
 
 # Guidelines
 
 - Keep verification deterministic, cross-platform where practical, and free of network writes beyond dependency installation.
+- Derive fleet inventory from package metadata; never maintain a second hand-authored dependency graph.
 - Verify the packed artifact rather than relying only on source imports.
 - Update bundle allowlists only when an intentional public dependency boundary changes.
 - Keep release mutation in the release workflow. Ordinary checks remain read-only.
diff --git a/scripts/check-portfolio-inventory.ts b/scripts/check-portfolio-inventory.ts
new file mode 100644
index 0000000..9fdba9a
--- /dev/null
+++ b/scripts/check-portfolio-inventory.ts
@@ -0,0 +1,103 @@
+import { readFile } from "node:fs/promises";
+import { resolve } from "node:path";
+
+type DependencyScope = "development" | "optional" | "peer" | "runtime";
+
+function record(value: unknown, label: string): Record<string, unknown> {
+  if (typeof value !== "object" || value === null || Array.isArray(value)) {
+    throw new Error(`${label} must be an object`);
+  }
+  return value as Record<string, unknown>;
+}
+
+function stringField(value: Record<string, unknown>, key: string): string {
+  const field = value[key];
+  if (typeof field !== "string" || field.length === 0) {
+    throw new Error(`package.json ${key} must be a non-empty string`);
+  }
+  return field;
+}
+
+function repositorySlug(value: unknown): string {
+  const repository = record(value, "package.json repository");
+  const url = stringField(repository, "url");
+  const match = /github\.com[/:]([^/]+\/[^/]+?)(?:\.git)?$/u.exec(url);
+  if (match?.[1] === undefined) {
+    throw new Error(
+      "package.json repository.url must identify a GitHub repository",
+    );
+  }
+  return match[1];
+}
+
+function asciiCompare(left: string, right: string): number {
+  return left < right ? -1 : left > right ? 1 : 0;
+}
+
+const repositoryRoot = resolve(import.meta.dir, "..");
+const packageManifest = record(
+  JSON.parse(
+    await readFile(resolve(repositoryRoot, "package.json"), "utf8"),
+  ) as unknown,
+  "package.json",
+);
+const packageName = stringField(packageManifest, "name");
+const version = stringField(packageManifest, "version");
+const repository = repositorySlug(packageManifest.repository);
+const dependencySections = [
+  ["devDependencies", "development"],
+  ["optionalDependencies", "optional"],
+  ["peerDependencies", "peer"],
+  ["dependencies", "runtime"],
+] as const satisfies readonly (readonly [string, DependencyScope])[];
+const dependencies = dependencySections.flatMap(([section, scope]) => {
+  const value = packageManifest[section];
+  if (value === undefined) return [];
+  const entries = record(value, `package.json ${section}`);
+  return Object.entries(entries)
+    .filter(([name]) => name.startsWith("@hraness/"))
+    .map(([name, specifier]) => {
+      if (typeof specifier !== "string" || specifier.length === 0) {
+        throw new Error(
+          `package.json ${section}.${name} must be a non-empty string`,
+        );
+      }
+      return { from: packageName, scope, specifier, to: name };
+    });
+}).toSorted((left, right) =>
+  asciiCompare(left.from, right.from)
+  || asciiCompare(left.to, right.to)
+  || asciiCompare(left.scope, right.scope)
+  || asciiCompare(left.specifier, right.specifier));
+
+const expected = {
+  contract: "hraness.portfolio-inventory/v1",
+  formatVersion: 1,
+  repository,
+  components: [{
+    kind: "package",
+    name: packageName,
+    path: ".",
+    visibility: "public",
+    version,
+  }],
+  dependencies,
+  deployments: [],
+  brands: [],
+  publications: [{
+    component: packageName,
+    packageName,
+    repository,
+  }],
+};
+const expectedBytes = `${JSON.stringify(expected, null, 2)}\n`;
+const actualBytes = await readFile(
+  resolve(repositoryRoot, "portfolio-inventory.json"),
+  "utf8",
+);
+
+if (actualBytes !== expectedBytes) {
+  throw new Error(
+    "portfolio-inventory.json does not match the canonical package inventory",
+  );
+}