From b5c5041af3ee54590fced6ac4e0894fdb3d84533 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 17 Jun 2026 03:07:35 +0000
Subject: [PATCH 1/2] Fix: always include coding_agent_model_selection in
 GraphQL-Features header

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>
---
 .github/workflows/release.lock.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/release.lock.yml b/.github/workflows/release.lock.yml
index 88986810e83..7791bb048ba 100644
--- a/.github/workflows/release.lock.yml
+++ b/.github/workflows/release.lock.yml
@@ -661,7 +661,8 @@ jobs:
                     "required": true,
                     "type": "string",
                     "sanitize": true,
-                    "maxLength": 65000
+                    "maxLength": 65000,
+                    "minLength": 20
                   },
                   "operation": {
                     "required": true,

From 8c9b7361edafb4273dcb61bc3188a58005ff6633 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 17 Jun 2026 03:08:22 +0000
Subject: [PATCH 2/2] Fix: always include coding_agent_model_selection in
 GraphQL-Features header per GitHub docs

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>
---
 actions/setup/js/assign_agent_helpers.cjs      | 6 +++---
 actions/setup/js/assign_agent_helpers.test.cjs | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/actions/setup/js/assign_agent_helpers.cjs b/actions/setup/js/assign_agent_helpers.cjs
index 70881f0bd77..81fa1563941 100644
--- a/actions/setup/js/assign_agent_helpers.cjs
+++ b/actions/setup/js/assign_agent_helpers.cjs
@@ -377,8 +377,8 @@ async function assignAgentToIssue(assignableId, agentId, currentAssignees, agent
     ];
     core.debug(`GraphQL mutation with variables: ${debugParts.join(", ")}`);
 
-    // Build GraphQL-Features header - include coding_agent_model_selection when model is provided
-    const graphqlFeatures = model ? "issues_copilot_assignment_api_support,coding_agent_model_selection" : "issues_copilot_assignment_api_support";
+    // Both feature flags are required per GitHub Copilot documentation
+    const graphqlFeatures = "issues_copilot_assignment_api_support,coding_agent_model_selection";
 
     const response = await githubClient.graphql(mutation, {
       ...variables,
@@ -483,7 +483,7 @@ async function assignAgentToIssue(assignableId, agentId, currentAssignees, agent
           assignableId,
           assigneeIds: [agentId],
           headers: {
-            "GraphQL-Features": "issues_copilot_assignment_api_support",
+            "GraphQL-Features": "issues_copilot_assignment_api_support,coding_agent_model_selection",
           },
         });
         if (fallbackResp?.addAssigneesToAssignable) {
diff --git a/actions/setup/js/assign_agent_helpers.test.cjs b/actions/setup/js/assign_agent_helpers.test.cjs
index cefd89b2d63..465a0506aa0 100644
--- a/actions/setup/js/assign_agent_helpers.test.cjs
+++ b/actions/setup/js/assign_agent_helpers.test.cjs
@@ -260,10 +260,10 @@ describe("assign_agent_helpers.cjs", () => {
         })
       );
 
-      // Should only include issues_copilot_assignment_api_support when model is not provided
+      // Should always include both issues_copilot_assignment_api_support and coding_agent_model_selection
       const calledArgs = mockGithub.graphql.mock.calls[0];
       const variables = calledArgs[1];
-      expect(variables.headers["GraphQL-Features"]).toBe("issues_copilot_assignment_api_support");
+      expect(variables.headers["GraphQL-Features"]).toBe("issues_copilot_assignment_api_support,coding_agent_model_selection");
     });
 
     it("should preserve existing assignees when adding agent", async () => {
@@ -330,7 +330,7 @@ describe("assign_agent_helpers.cjs", () => {
       expect(mutation).toContain("agentAssignment");
       expect(mutation).toContain("model: $model");
       expect(variables.model).toBe("claude-opus-4.6");
-      // Should include coding_agent_model_selection feature flag when model is provided
+      // Should always include both feature flags
       expect(variables.headers["GraphQL-Features"]).toBe("issues_copilot_assignment_api_support,coding_agent_model_selection");
     });