diff --git a/apps/server/src/orchestration-v2/CheckpointCaptureService.test.ts b/apps/server/src/orchestration-v2/CheckpointCaptureService.test.ts
index 9d34049c3b164..16c1bdcf2df1b 100644
--- a/apps/server/src/orchestration-v2/CheckpointCaptureService.test.ts
+++ b/apps/server/src/orchestration-v2/CheckpointCaptureService.test.ts
@@ -20,6 +20,7 @@ import * as DateTime from "effect/DateTime";
 import * as Effect from "effect/Effect";
 import * as Layer from "effect/Layer";
 import * as Ref from "effect/Ref";
+import * as Tracer from "effect/Tracer";
 import * as SqlClient from "effect/sql/SqlClient";
 
 import * as SqlitePersistence from "../persistence/Sqlite.ts";
@@ -52,9 +53,13 @@ const modelSelection = {
 } as const;
 
 it.layer(layerProjectionStoreTest)("CheckpointCaptureServiceV2", (it) => {
-  it.effect.each([false, true])(
-    "captures without decoding history or losing newer delegated completion, ref lookup fails=%s",
-    (refLookupFails) =>
+  it.effect.each([
+    { ordinal: 1, refLookupFails: false },
+    { ordinal: 1, refLookupFails: true },
+    { ordinal: 128, refLookupFails: false },
+  ])(
+    "captures without decoding history or losing newer delegated completion, ordinal=$ordinal, ref lookup fails=$refLookupFails",
+    ({ ordinal, refLookupFails }) =>
       Effect.gen(function* () {
         const projectionStore = yield* ProjectionStore.ProjectionStoreV2;
         const now = yield* DateTime.now;
@@ -77,7 +82,7 @@ it.layer(layerProjectionStoreTest)("CheckpointCaptureServiceV2", (it) => {
         const staleRun: OrchestrationV2Run = {
           id: runId,
           threadId,
-          ordinal: 1,
+          ordinal,
           providerInstanceId,
           modelSelection,
           providerThreadId,
@@ -160,8 +165,8 @@ it.layer(layerProjectionStoreTest)("CheckpointCaptureServiceV2", (it) => {
           runId,
           nodeId: rootNodeId,
           parentCheckpointId: readyBaseline.id,
-          ordinalWithinScope: 1,
-          appRunOrdinal: 1,
+          ordinalWithinScope: ordinal,
+          appRunOrdinal: ordinal,
           ref: CheckpointRef.make("checkpoint-ref:captured-1"),
           status: "ready" as const,
           files: [],
@@ -251,6 +256,24 @@ it.layer(layerProjectionStoreTest)("CheckpointCaptureServiceV2", (it) => {
           payload: readyBaseline,
         });
         const sql = yield* SqlClient.SqlClient;
+        if (ordinal > 1) {
+          yield* sql`WITH RECURSIVE history(ordinal) AS (
+            SELECT 1 UNION ALL SELECT ordinal + 1 FROM history WHERE ordinal < ${ordinal - 1}
+          )
+          INSERT INTO orchestration_v2_projection_checkpoints
+            (checkpoint_id, thread_id, scope_id, node_id, ordinal_within_scope, status,
+              captured_at, payload_json)
+          SELECT 'checkpoint:history:' || ordinal, ${threadId}, ${scopeId}, ${rootNodeId},
+            ordinal, 'ready', ${DateTime.formatIso(now)}, '{}' FROM history`;
+        }
+        const fullContext = yield* projectionStore.getCheckpointCaptureContext(threadId, {
+          runId,
+          scopeId,
+        });
+        assert.deepEqual(
+          [...fullContext.readyCheckpointOrdinals].sort((a, b) => a - b),
+          Array.from({ length: ordinal }, (_, index) => index),
+        );
         yield* sql`INSERT OR REPLACE INTO orchestration_v2_projection_turn_items
           (turn_item_id, thread_id, run_id, node_id, provider_thread_id, provider_turn_id,
             parent_item_id, ordinal, type, status, updated_at, payload_json)
@@ -321,7 +344,43 @@ it.layer(layerProjectionStoreTest)("CheckpointCaptureServiceV2", (it) => {
             .execute({ threadId, runId, scopeId: CheckpointScopeId.make("missing-scope") })
             .pipe(Effect.flip);
           assert.instanceOf(incomplete, CheckpointCaptureService.CheckpointCaptureExecutionError);
-          yield* service.execute({ threadId, runId, scopeId });
+          let readyQuery: string | undefined;
+          let readyRows: unknown;
+          const tracer = Tracer.make({
+            span(options) {
+              const span = new Tracer.NativeSpan(options);
+              const end = span.end.bind(span);
+              span.end = (endTime, exit) => {
+                end(endTime, exit);
+                const query = span.attributes.get("db.query.text");
+                if (
+                  typeof query === "string" &&
+                  query.includes("SELECT ordinal_within_scope AS ordinal") &&
+                  exit._tag === "Success"
+                ) {
+                  readyQuery = query;
+                  readyRows = exit.value;
+                }
+              };
+              return span;
+            },
+          });
+          yield* service.execute({ threadId, runId, scopeId }).pipe(Effect.withTracer(tracer));
+          assert.isDefined(readyQuery);
+          assert.deepEqual(
+            readyRows,
+            ordinal === 1 ? [{ ordinal: 0 }] : [{ ordinal: 0 }, { ordinal: ordinal - 1 }],
+          );
+          const plan = yield* sql.unsafe<{ readonly detail: string }>(
+            `EXPLAIN QUERY PLAN ${readyQuery}`,
+          );
+          assert.isTrue(
+            plan.some(({ detail }) =>
+              detail.includes(
+                "checkpoints_scope_ordinal_idx (scope_id=? AND ordinal_within_scope=?)",
+              ),
+            ),
+          );
 
           const events = yield* Ref.get(committed);
           const runUpdated = events.find((event) => event.type === "run.updated");
diff --git a/apps/server/src/orchestration-v2/CheckpointCaptureService.ts b/apps/server/src/orchestration-v2/CheckpointCaptureService.ts
index 6a2d9b2062b35..2f5914e254b30 100644
--- a/apps/server/src/orchestration-v2/CheckpointCaptureService.ts
+++ b/apps/server/src/orchestration-v2/CheckpointCaptureService.ts
@@ -66,7 +66,9 @@ export const layer: Layer.Layer<
       readonly scopeId: CheckpointScopeId;
     }) {
       const { run, rootNode, scope, providerThread, readyCheckpointOrdinals, sideChat } =
-        yield* projections.getCheckpointCaptureContext(input.threadId, input);
+        yield* projections.getCheckpointCaptureContext(input.threadId, input, {
+          readyCheckpoints: "baselines",
+        });
       // Stopped runs remain terminal; their checkpoint is the next message's rollback point.
       const stopped = run?.status === "interrupted" || run?.status === "cancelled";
 
diff --git a/apps/server/src/orchestration-v2/ProjectionStore.ts b/apps/server/src/orchestration-v2/ProjectionStore.ts
index 2f8c972e7ded9..f982a2b84f130 100644
--- a/apps/server/src/orchestration-v2/ProjectionStore.ts
+++ b/apps/server/src/orchestration-v2/ProjectionStore.ts
@@ -659,6 +659,7 @@ export interface ProjectionStoreV2Shape {
   readonly getCheckpointCaptureContext: (
     threadId: ThreadId,
     target: { readonly runId: RunId; readonly scopeId: CheckpointScopeId },
+    options?: { readonly readyCheckpoints: "baselines" },
   ) => Effect.Effect<ProjectionCheckpointCaptureContext, ProjectionStoreV2Error>;
   readonly getCheckpointRollbackContext: (
     threadId: ThreadId,
@@ -5300,6 +5301,7 @@ export const layer: Layer.Layer<ProjectionStoreV2, never, SqlClient.SqlClient> =
     const getCheckpointCaptureContext: ProjectionStoreV2Shape["getCheckpointCaptureContext"] = (
       threadId,
       target,
+      options,
     ) =>
       sql
         .withTransaction(
@@ -5329,7 +5331,12 @@ export const layer: Layer.Layer<ProjectionStoreV2, never, SqlClient.SqlClient> =
                 OR provider_thread_id IN (SELECT provider_thread_id FROM orchestration_v2_projection_subagents WHERE thread_id = ${threadId}))`,
               sql<{ readonly ordinal: number }>`SELECT ordinal_within_scope AS ordinal
             FROM orchestration_v2_projection_checkpoints
-            WHERE thread_id = ${threadId} AND scope_id = ${target.scopeId} AND status = 'ready'`,
+            WHERE thread_id = ${threadId} AND scope_id = ${target.scopeId} AND status = 'ready'
+              ${
+                options?.readyCheckpoints === "baselines"
+                  ? sql`AND ordinal_within_scope IN (0, ${run === undefined ? null : Math.max(0, run.ordinal - 1)})`
+                  : sql``
+              }`,
             ]);
             return {
               run,