diff --git a/src/energi_bridge.js b/src/energi_bridge.js
index 3489564..5c23d53 100644
--- a/src/energi_bridge.js
+++ b/src/energi_bridge.js
@@ -3,6 +3,10 @@
 // primitives to a vendor-agnostic contract representation and a Graph-of-Contracts
 // registry for adapters and data schemas.
 
+// DSL contracts for interoperability (local problems, shared variables, etc.)
+// Load DSL definitions from a minimal contract library.
+const DSL = require('./dsl_contracts');
+
 class GraphOfContracts {
   constructor() {
     this.contracts = new Map(); // contractName -> schema
@@ -29,6 +33,36 @@ class GraphOfContracts {
 class EnergiBridge {
   constructor() {
     this.registry = new GraphOfContracts();
+    // Seed default contract schemas to bootstrap interoperability
+    this.seedDefaultContracts();
+  }
+
+  // Seed a minimal set of canonical contracts and schemas that adapters can target
+  seedDefaultContracts() {
+    // Basic skeleton schemas; can be extended by adapters later
+    this.registry.registerContract('LocalProblem', {
+      type: 'object',
+      properties: {
+        Objects: { type: 'string' },
+        payload: { type: 'object' }
+      }
+    });
+    this.registry.registerContract('SharedVariables', {
+      type: 'object',
+      properties: {
+        Morphisms: { type: 'string' },
+        payload: { type: 'object' }
+      }
+    });
+    this.registry.registerContract('PlanDelta', {
+      type: 'object',
+      properties: {
+        PlanDelta: { type: 'string' }
+      }
+    });
+    this.registry.registerContract('DualVariables', { type: 'object' });
+    this.registry.registerContract('PrivacyBudget', { type: 'object' });
+    this.registry.registerContract('AuditLog', { type: 'object' });
   }
 
   // Minimal canonical mapping from a local Open-EnergyMesh primitive to a
@@ -60,5 +94,11 @@ class EnergiBridge {
 
 module.exports = {
   EnergiBridge,
-  GraphOfContracts
+  GraphOfContracts,
+  LocalProblem: DSL.LocalProblem,
+  SharedVariables: DSL.SharedVariables,
+  PlanDelta: DSL.PlanDelta,
+  DualVariables: DSL.DualVariables,
+  PrivacyBudget: DSL.PrivacyBudget,
+  AuditLog: DSL.AuditLog
 };
diff --git a/src/energi_bridge/dsl_contracts.js b/src/energi_bridge/dsl_contracts.js
new file mode 100644
index 0000000..e65008d
--- /dev/null
+++ b/src/energi_bridge/dsl_contracts.js
@@ -0,0 +1,57 @@
+// DSL contracts for EnergiBridge: lightweight, vendor-agnostic primitives
+// to bootstrap interoperability with a CatOpt-like IR.
+
+class LocalProblem {
+  constructor(siteId, objective, variables) {
+    this.siteId = siteId;
+    this.objective = objective || {};
+    this.variables = variables || {};
+  }
+}
+
+class SharedVariables {
+  constructor(version, signals) {
+    this.version = version || 1;
+    this.signals = signals || {};
+  }
+}
+
+class PlanDelta {
+  constructor(planId, delta, metadata) {
+    this.planId = planId;
+    this.delta = delta || {};
+    this.metadata = metadata || {};
+  }
+}
+
+class DualVariables {
+  constructor(prior, dual) {
+    this.prior = prior || {};
+    this.dual = dual || {};
+  }
+}
+
+class PrivacyBudget {
+  constructor(limit, consumed) {
+    this.limit = typeof limit === 'number' ? limit : 0;
+    this.consumed = typeof consumed === 'number' ? consumed : 0;
+  }
+}
+
+class AuditLog {
+  constructor(entries) {
+    this.entries = entries || [];
+  }
+  add(entry) {
+    this.entries.push(entry);
+  }
+}
+
+module.exports = {
+  LocalProblem,
+  SharedVariables,
+  PlanDelta,
+  DualVariables,
+  PrivacyBudget,
+  AuditLog
+};