diff --git a/.github/workflows/pre-merge.yml b/.github/workflows/pre-merge.yml
index 539d1ba..3c37eeb 100644
--- a/.github/workflows/pre-merge.yml
+++ b/.github/workflows/pre-merge.yml
@@ -40,6 +40,11 @@ jobs:
       - name: Gradle build (arch + unit + process + model validation + spec export)
         run: ./gradlew build --no-daemon
 
+      # generateBpmnModels runs as part of `./gradlew build` and writes the typed process API into
+      # the committed source tree; fail if the .bpmn models and the checked-in generated code drift.
+      - name: Verify the generated BPMN process API is in sync
+        run: git diff --exit-code -- 'service/app/src/main/kotlin/io/miragon/blueprint/adapter/process/*ProcessApi.kt'
+
       # The OpenAPI spec is generated by a test and committed; fail if the code and the checked-in
       # contract have drifted. See docs/adr/0004-openapi-as-the-checked-in-contract.md.
       - name: Verify the committed OpenAPI contract is in sync
diff --git a/AGENTS.md b/AGENTS.md
index a4626f1..3d42f9d 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -79,6 +79,9 @@ codebase "process" means the BPMN model, so the step rail is `widgets/leasing-pr
 
 - `bpmn-to-code` generates typed process constants from the models at build time; a custom model
   test requires every service task to use a delegate expression (`#{beanName}`).
+- The generated `*ProcessApi.kt` is committed and **drift-gated**: `./gradlew build` regenerates it
+  in place, and CI runs `git diff --exit-code` on it, so a `.bpmn` edit without a regenerate fails
+  the build — same contract as the OpenAPI spec (ADR-0004).
 - `bpmnlint` runs on staged `.bpmn` via `.githooks/pre-commit` (install: `npm run hooks:install`).
 
 ## Testing