From 30ea75e421a16cf95739c0a0360bc20a8e103573 Mon Sep 17 00:00:00 2001
From: Jerel Miller <jerelmiller@gmail.com>
Date: Tue, 16 Jun 2026 22:33:13 -0400
Subject: [PATCH 1/3] Fix issue where optimistic option is not honored in
 readFragment

---
 src/__tests__/ApolloClient.ts | 42 +++++++++++++++++++++++++++++++++++
 src/core/ApolloClient.ts      |  2 +-
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/src/__tests__/ApolloClient.ts b/src/__tests__/ApolloClient.ts
index 2b428760d00..c08045eb753 100644
--- a/src/__tests__/ApolloClient.ts
+++ b/src/__tests__/ApolloClient.ts
@@ -555,6 +555,48 @@ describe("ApolloClient", () => {
         })
       ).toEqual({ __typename: "Foo", a: 1, b: 2, c: 3 });
     });
+
+    it("reads optimistic data when optimistic is passed in options", () => {
+      const cache = new InMemoryCache();
+      const client = new ApolloClient({
+        link: ApolloLink.empty(),
+        cache,
+      });
+
+      const fragment = gql`
+        fragment NameFragment on Person {
+          id
+          firstName
+          lastName
+        }
+      `;
+
+      cache.recordOptimisticTransaction((proxy) => {
+        proxy.writeFragment({
+          from: { __typename: "Person", id: 1 },
+          fragment,
+          data: {
+            __typename: "Person",
+            id: 1,
+            firstName: "Test",
+            lastName: "User",
+          },
+        });
+      }, "1");
+
+      expect(
+        client.readFragment({
+          from: { __typename: "Person", id: 1 },
+          fragment,
+          optimistic: true,
+        })
+      ).toEqual({
+        __typename: "Person",
+        id: 1,
+        firstName: "Test",
+        lastName: "User",
+      });
+    });
   });
 
   describe("writeQuery", () => {
diff --git a/src/core/ApolloClient.ts b/src/core/ApolloClient.ts
index ff9e9d77211..0826f2f8ac0 100644
--- a/src/core/ApolloClient.ts
+++ b/src/core/ApolloClient.ts
@@ -1663,7 +1663,7 @@ export class ApolloClient {
     TVariables extends OperationVariables = OperationVariables,
   >(
     options: ApolloClient.ReadFragmentOptions<TData, TVariables>,
-    optimistic: boolean = false
+    optimistic = !!options.optimistic
   ): Unmasked<TData> | null {
     return this.cache.readFragment<TData, TVariables>(
       { ...options, fragment: this.transform(options.fragment) },

From fde9607f1a6b2977da5fceb14cd7b67115071678 Mon Sep 17 00:00:00 2001
From: Jerel Miller <jerelmiller@gmail.com>
Date: Tue, 16 Jun 2026 22:36:07 -0400
Subject: [PATCH 2/3] Fix issue with readQuery with optimistic passed as
 options

---
 src/__tests__/ApolloClient.ts | 29 +++++++++++++++++++++++++++++
 src/core/ApolloClient.ts      |  2 +-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/__tests__/ApolloClient.ts b/src/__tests__/ApolloClient.ts
index c08045eb753..39eeb5a3414 100644
--- a/src/__tests__/ApolloClient.ts
+++ b/src/__tests__/ApolloClient.ts
@@ -210,6 +210,35 @@ describe("ApolloClient", () => {
         })
       ).toEqual({ a: 1, b: 2 });
     });
+
+    it("reads optimistic data when optimistic is passed in options", () => {
+      const cache = new InMemoryCache();
+      const client = new ApolloClient({
+        link: ApolloLink.empty(),
+        cache,
+      });
+
+      const query = gql`
+        query {
+          a
+          b
+        }
+      `;
+
+      cache.recordOptimisticTransaction((proxy) => {
+        proxy.writeQuery({
+          query,
+          data: { a: 1, b: 2 },
+        });
+      }, "1");
+
+      expect(
+        client.readQuery({
+          query,
+          optimistic: true,
+        })
+      ).toEqual({ a: 1, b: 2 });
+    });
   });
 
   it("will read some data from the store with default values", () => {
diff --git a/src/core/ApolloClient.ts b/src/core/ApolloClient.ts
index 0826f2f8ac0..cbde11446b2 100644
--- a/src/core/ApolloClient.ts
+++ b/src/core/ApolloClient.ts
@@ -1506,7 +1506,7 @@ export class ApolloClient {
     TVariables extends OperationVariables = OperationVariables,
   >(
     options: ApolloClient.ReadQueryOptions<TData, TVariables>,
-    optimistic: boolean = false
+    optimistic = !!options.optimistic
   ): Unmasked<TData> | null {
     return this.cache.readQuery<TData, TVariables>(
       { ...options, query: this.transform(options.query) },

From 8fa5cff01aefd7a7004c7b3dc17fafc6c35a5e15 Mon Sep 17 00:00:00 2001
From: Jerel Miller <jerelmiller@gmail.com>
Date: Tue, 16 Jun 2026 22:37:13 -0400
Subject: [PATCH 3/3] Add changeset

---
 .changeset/gold-crabs-invent.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/gold-crabs-invent.md

diff --git a/.changeset/gold-crabs-invent.md b/.changeset/gold-crabs-invent.md
new file mode 100644
index 00000000000..38f0fc4527e
--- /dev/null
+++ b/.changeset/gold-crabs-invent.md
@@ -0,0 +1,5 @@
+---
+"@apollo/client": patch
+---
+
+Fixes an issue where `client.readFragment` and `client.readQuery` ignored the `optimistic` option when passed in the options object.