diff --git a/apps/server/src/orchestration-v2/EffectWorker.ts b/apps/server/src/orchestration-v2/EffectWorker.ts
index e78c44cedc7f..ee3aec77665a 100644
--- a/apps/server/src/orchestration-v2/EffectWorker.ts
+++ b/apps/server/src/orchestration-v2/EffectWorker.ts
@@ -67,8 +67,13 @@ export function isNonRetryableProviderTurnControlFailure(
 }
 
 export interface OrchestrationEffectExecutorV2Shape {
+  /**
+   * Runs one claimed effect. `willRetry` is true when the worker will retry a
+   * failure, so a step can fail and try again instead of settling the run.
+   */
   readonly execute: (
     effect: OrchestrationEffectV2,
+    options?: { readonly willRetry: boolean },
   ) => Effect.Effect<void, OrchestrationEffectExecutionError>;
 }
 
@@ -103,7 +108,8 @@ export const executorLayer: Layer.Layer<
     const threads = yield* ThreadManagementService;
     const settings = yield* ServerSettingsService;
     return OrchestrationEffectExecutorV2.of({
-      execute: (effect) => {
+      execute: (effect, options) => {
+        const willRetry = options?.willRetry ?? false;
         switch (effect.request.type) {
           case "provider-runtime.continue":
             return continueRestartedRun({
@@ -143,7 +149,7 @@ export const executorLayer: Layer.Layer<
               );
           case "provider-turn.start":
             return providerTurnStart
-              .start({ threadId: effect.threadId, runId: effect.request.runId })
+              .start({ threadId: effect.threadId, runId: effect.request.runId, willRetry })
               .pipe(
                 Effect.mapError(
                   (cause) =>
@@ -297,6 +303,7 @@ export const executorLayer: Layer.Layer<
                   providerTurnStart.start({
                     threadId: effect.threadId,
                     runId: effect.request.runId,
+                    willRetry,
                   }),
                 ),
                 Effect.mapError(
@@ -596,7 +603,9 @@ export const layerWithOptions = (
           }).pipe(Effect.onError((cause) => requeueClaim(effect, cause)));
           if (cancelledBeforeExecution) return true;
 
-          const execution = executor.execute(effect).pipe(Effect.as("executed" as const));
+          const execution = executor
+            .execute(effect, { willRetry: effect.attemptCount < maxAttempts })
+            .pipe(Effect.as("executed" as const));
           const exit = yield* Effect.exit(Effect.raceFirst(execution, cancellation)).pipe(
             Effect.ensuring(outbox.clearCancellation(effect.id)),
           );
diff --git a/apps/server/src/orchestration-v2/ProviderTurnStartService.test.ts b/apps/server/src/orchestration-v2/ProviderTurnStartService.test.ts
index f364edd5a49f..5761689fcedb 100644
--- a/apps/server/src/orchestration-v2/ProviderTurnStartService.test.ts
+++ b/apps/server/src/orchestration-v2/ProviderTurnStartService.test.ts
@@ -445,6 +445,13 @@ function makeLocalCommandHarness(input: {
     start: Effect.gen(function* () {
       yield* (yield* ProviderTurnStart.ProviderTurnStartServiceV2).start({ threadId, runId });
     }).pipe(Effect.provide(layer)),
+    startWithRetry: Effect.gen(function* () {
+      yield* (yield* ProviderTurnStart.ProviderTurnStartServiceV2).start({
+        threadId,
+        runId,
+        willRetry: true,
+      });
+    }).pipe(Effect.provide(layer)),
   };
 }
 
@@ -482,6 +489,21 @@ effectIt.effect("terminalizes a starting run when its provider session cannot op
   }),
 );
 
+effectIt.effect("leaves the run starting when a session-open failure will be retried", () =>
+  Effect.gen(function* () {
+    const harness = makeLocalCommandHarness({
+      text: "Continue",
+      openFailure: new Error("provider session rejected"),
+    });
+
+    const error = yield* harness.startWithRetry.pipe(Effect.flip);
+
+    expect(error._tag).toBe("ProviderTurnStartError");
+    expect(harness.writeIfRunCurrent).not.toHaveBeenCalled();
+    expect(harness.projection().runs.at(-1)?.status).toBe("starting");
+  }),
+);
+
 effectIt.effect("keeps a session-open failure retryable when terminal persistence fails", () =>
   Effect.gen(function* () {
     const harness = makeLocalCommandHarness({
diff --git a/apps/server/src/orchestration-v2/ProviderTurnStartService.ts b/apps/server/src/orchestration-v2/ProviderTurnStartService.ts
index 4d24dcb43372..9ea71cb4c9d5 100644
--- a/apps/server/src/orchestration-v2/ProviderTurnStartService.ts
+++ b/apps/server/src/orchestration-v2/ProviderTurnStartService.ts
@@ -61,9 +61,15 @@ export class ProviderTurnStartError extends Schema.TaggedError<ProviderTurnStart
 const isProviderTurnStartError = Schema.is(ProviderTurnStartError);
 
 export interface ProviderTurnStartServiceV2Shape {
+  /**
+   * Starts the run's provider turn. When `willRetry` is true, a session open
+   * failure is returned so the caller can retry. Otherwise the run is settled
+   * as failed.
+   */
   readonly start: (input: {
     readonly threadId: ThreadId;
     readonly runId: RunId;
+    readonly willRetry?: boolean;
   }) => Effect.Effect<void, ProviderTurnStartError>;
 }
 
@@ -205,6 +211,7 @@ export const layer: Layer.Layer<
     const start = Effect.fn("orchestrationV2.providerTurnStart.start")(function* (input: {
       readonly threadId: ThreadId;
       readonly runId: RunId;
+      readonly willRetry?: boolean;
     }) {
       const { runId } = input;
       const projection = yield* projectionStore.getTurnStartContext(input.threadId, runId);
@@ -531,6 +538,7 @@ export const layer: Layer.Layer<
         }),
       );
       if (sessionResult._tag === "Failure") {
+        if (input.willRetry === true) return yield* sessionResult.failure;
         const failedAt = yield* DateTime.now;
         const openError = sessionResult.failure;
         const nestedCause = "cause" in openError ? openError.cause : undefined;