diff --git a/README.md b/README.md
index 36c40c1..ac3d7d4 100644
--- a/README.md
+++ b/README.md
@@ -157,7 +157,8 @@ Diagnostics explain the observed import and the manifest contract CellFence appl
 - Undeclared artifact lane consumption between producer and consumer cells
 - Silent architecture growth against an accepted baseline — `CELLFENCE_RATCHET_*`
 
-Full rule reference: [docs/rules.md](docs/rules.md).
+Full rule reference: [docs/rules.md](docs/rules.md). Package ownership map:
+[docs/package-ownership.md](docs/package-ownership.md).
 
 ## The ratchet: no self-authorized growth
 
diff --git a/docs/package-ownership.md b/docs/package-ownership.md
new file mode 100644
index 0000000..a66ac0a
--- /dev/null
+++ b/docs/package-ownership.md
@@ -0,0 +1,28 @@
+# CellFence package ownership
+
+CellFence is published as focused npm packages. Use the package that matches
+the integration point you need:
+
+| Package | Owns |
+| --- | --- |
+| `cellfence` | Command-line interface and local repository checks |
+| `@cellfence/adapter-call-pattern` | Declarative call-pattern resource adapter |
+| `@cellfence/adapter-opentelemetry` | OpenTelemetry resource evidence conversion |
+| `@cellfence/engine` | Core manifest and governance evaluation |
+| `@cellfence/github-action-baseline-gate` | Baseline gate for GitHub Actions |
+| `@cellfence/github-action` | GitHub Actions integration |
+| `@cellfence/mcp-proxy` | MCP proxy integration |
+| `@cellfence/plugin-agent-budget` | AI agent change budget governance rule |
+| `@cellfence/plugin-api` | Public API for writing plugins |
+| `@cellfence/plugin-blast-radius` | Change impact radius governance rule |
+| `@cellfence/plugin-dependency-sovereignty` | Cross-team dependency sovereignty governance rule |
+| `@cellfence/plugin-geo-purity` | AI-context purity and public API documentation rule |
+| `@cellfence/plugin-legacy-strangler` | Legacy strangler migration ratchet rule |
+| `@cellfence/plugin-quants-trend` | Architecture momentum monitoring rule |
+| `@cellfence/reporter-economy-matrix` | Economy matrix reporting |
+| `@cellfence/schema` | Shared manifest and result schemas |
+| `@cellfence/trace` | Trace capture and replay utilities |
+
+Use the package README for installation and API details. Packages with names
+starting with `plugin-` provide optional governance checks, while packages
+starting with `adapter-` provide integration adapters.