diff --git a/apps/server/src/persistence/Layers/OrchestrationEventStore.ts b/apps/server/src/persistence/Layers/OrchestrationEventStore.ts
index 4d81cf5e8d..e91ad5a719 100644
--- a/apps/server/src/persistence/Layers/OrchestrationEventStore.ts
+++ b/apps/server/src/persistence/Layers/OrchestrationEventStore.ts
@@ -1,5 +1,6 @@
 import {
   CommandId,
+  DEFAULT_PROVIDER_KIND,
   EventId,
   IsoDateTime,
   NonNegativeInt,
@@ -10,6 +11,7 @@ import {
   OrchestrationEventType,
   ProjectId,
   ThreadId,
+  isSupportedProvider,
 } from "@t3tools/contracts";
 import * as SqlClient from "effect/unstable/sql/SqlClient";
 import * as SqlSchema from "effect/unstable/sql/SqlSchema";
@@ -26,6 +28,29 @@ import {
 } from "../Services/OrchestrationEventStore.ts";
 
 const decodeEvent = Schema.decodeUnknownEffect(OrchestrationEvent);
+
+/**
+ * Coerce unsupported provider names in `modelSelection` /
+ * `defaultModelSelection` payloads to the default provider so the strict
+ * `OrchestrationEvent` schema can always decode persisted events.  This
+ * keeps the read path tolerant of legacy or future provider data without
+ * widening the canonical types.
+ */
+function coerceUnsupportedProviders<T>(row: T): T {
+  const r = row as Record<string, unknown>;
+  const payload = r.payload;
+  if (typeof payload !== "object" || payload === null) return row;
+  const p = payload as Record<string, unknown>;
+  let patched: Record<string, unknown> | null = null;
+  for (const key of ["modelSelection", "defaultModelSelection"] as const) {
+    const ms = p[key] as Record<string, unknown> | null | undefined;
+    if (ms && typeof ms.provider === "string" && !isSupportedProvider(ms.provider)) {
+      patched ??= { ...p };
+      patched[key] = { provider: DEFAULT_PROVIDER_KIND, model: ms.model };
+    }
+  }
+  return patched ? ({ ...r, payload: patched } as T) : row;
+}
 const UnknownFromJsonString = Schema.fromJsonString(Schema.Unknown);
 const EventMetadataFromJsonString = Schema.fromJsonString(OrchestrationEventMetadata);
 
@@ -230,7 +255,7 @@ const makeEventStore = Effect.gen(function* () {
           ),
           Effect.flatMap((rows) =>
             Effect.forEach(rows, (row) =>
-              decodeEvent(row).pipe(
+              decodeEvent(coerceUnsupportedProviders(row)).pipe(
                 Effect.mapError(
                   toPersistenceDecodeError("OrchestrationEventStore.readFromSequence:rowToEvent"),
                 ),
diff --git a/apps/server/src/provider/Layers/ProviderSessionDirectory.ts b/apps/server/src/provider/Layers/ProviderSessionDirectory.ts
index 961c63d696..47094ec389 100644
--- a/apps/server/src/provider/Layers/ProviderSessionDirectory.ts
+++ b/apps/server/src/provider/Layers/ProviderSessionDirectory.ts
@@ -18,19 +18,25 @@ function toPersistenceError(operation: string) {
     });
 }
 
+/**
+ * Accept any non-empty provider string.
+ * Legacy or future providers are passed through so the read path never fails;
+ * unsupported providers are simply cast — the caller is responsible for
+ * checking `isSupportedProvider` before dispatching adapter operations.
+ */
 function decodeProviderKind(
   providerName: string,
-  operation: string,
+  _operation: string,
 ): Effect.Effect<ProviderKind, ProviderSessionDirectoryPersistenceError> {
-  if (providerName === "codex" || providerName === "claudeAgent") {
-    return Effect.succeed(providerName);
+  if (providerName.trim().length === 0) {
+    return Effect.fail(
+      new ProviderSessionDirectoryPersistenceError({
+        operation: _operation,
+        detail: `Provider name must be a non-empty string.`,
+      }),
+    );
   }
-  return Effect.fail(
-    new ProviderSessionDirectoryPersistenceError({
-      operation,
-      detail: `Unknown persisted provider '${providerName}'.`,
-    }),
-  );
+  return Effect.succeed(providerName as ProviderKind);
 }
 
 function isRecord(value: unknown): value is Record<string, unknown> {
diff --git a/packages/contracts/src/orchestration.ts b/packages/contracts/src/orchestration.ts
index 31631666e2..959a427eb6 100644
--- a/packages/contracts/src/orchestration.ts
+++ b/packages/contracts/src/orchestration.ts
@@ -29,6 +29,10 @@ export const ORCHESTRATION_WS_CHANNELS = {
 
 export const ProviderKind = Schema.Literals(["codex", "claudeAgent"]);
 export type ProviderKind = typeof ProviderKind.Type;
+
+export function isSupportedProvider(provider: string): provider is ProviderKind {
+  return provider === "codex" || provider === "claudeAgent";
+}
 export const ProviderApprovalPolicy = Schema.Literals([
   "untrusted",
   "on-failure",