Expose instruction sources (AGENTS.md) via app server (#17506)

Addresses #17498

Problem: The TUI derived /status instruction source paths from the local
client environment, which could show stale <none> output or incorrect
paths when connected to a remote app server.

Solution: Add an app-server v2 instructionSources snapshot to thread
start/resume/fork responses, default it to an empty list when older
servers omit it, and render TUI /status from that server-provided
session data.

Additional context: The app-server field is intentionally named
instructionSources rather than AGENTS.md-specific terminology because
the loaded instruction sources can include global instructions, project
AGENTS.md files, AGENTS.override.md, user-defined instruction files, and
future dynamic sources.

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json

@@ -12806,6 +12806,14 @@
           "cwd": {
             "type": "string"
           },
+          "instructionSources": {
+            "default": [],
+            "description": "Instruction source files currently loaded for this thread.",
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          },
           "model": {
             "type": "string"
           },
@@ -14095,6 +14103,14 @@
           "cwd": {
             "type": "string"
           },
+          "instructionSources": {
+            "default": [],
+            "description": "Instruction source files currently loaded for this thread.",
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          },
           "model": {
             "type": "string"
           },
@@ -14386,6 +14402,14 @@
           "cwd": {
             "type": "string"
           },
+          "instructionSources": {
+            "default": [],
+            "description": "Instruction source files currently loaded for this thread.",
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          },
           "model": {
             "type": "string"
           },

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json

@@ -10654,6 +10654,14 @@
         "cwd": {
           "type": "string"
         },
+        "instructionSources": {
+          "default": [],
+          "description": "Instruction source files currently loaded for this thread.",
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
         "model": {
           "type": "string"
         },
@@ -11943,6 +11951,14 @@
         "cwd": {
           "type": "string"
         },
+        "instructionSources": {
+          "default": [],
+          "description": "Instruction source files currently loaded for this thread.",
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
         "model": {
           "type": "string"
         },
@@ -12234,6 +12250,14 @@
         "cwd": {
           "type": "string"
         },
+        "instructionSources": {
+          "default": [],
+          "description": "Instruction source files currently loaded for this thread.",
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
         "model": {
           "type": "string"
         },

codex-rs/app-server-protocol/schema/json/v2/ThreadForkResponse.json

@@ -2187,6 +2187,14 @@
     "cwd": {
       "type": "string"
     },
+    "instructionSources": {
+      "default": [],
+      "description": "Instruction source files currently loaded for this thread.",
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
     "model": {
       "type": "string"
     },

codex-rs/app-server-protocol/schema/json/v2/ThreadResumeResponse.json

@@ -2187,6 +2187,14 @@
     "cwd": {
       "type": "string"
     },
+    "instructionSources": {
+      "default": [],
+      "description": "Instruction source files currently loaded for this thread.",
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
     "model": {
       "type": "string"
     },

codex-rs/app-server-protocol/schema/json/v2/ThreadStartResponse.json

@@ -2187,6 +2187,14 @@
     "cwd": {
       "type": "string"
     },
+    "instructionSources": {
+      "default": [],
+      "description": "Instruction source files currently loaded for this thread.",
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
     "model": {
       "type": "string"
     },

codex-rs/app-server-protocol/schema/typescript/v2/ThreadForkResponse.ts

@@ -8,7 +8,11 @@ import type { AskForApproval } from "./AskForApproval";
 import type { SandboxPolicy } from "./SandboxPolicy";
 import type { Thread } from "./Thread";
 
-export type ThreadForkResponse = { thread: Thread, model: string, modelProvider: string, serviceTier: ServiceTier | null, cwd: string, approvalPolicy: AskForApproval,
+export type ThreadForkResponse = { thread: Thread, model: string, modelProvider: string, serviceTier: ServiceTier | null, cwd: string,
+/**
+ * Instruction source files currently loaded for this thread.
+ */
+instructionSources: Array<string>, approvalPolicy: AskForApproval,
 /**
  * Reviewer currently used for approval requests on this thread.
  */

codex-rs/app-server-protocol/schema/typescript/v2/ThreadResumeResponse.ts

@@ -8,7 +8,11 @@ import type { AskForApproval } from "./AskForApproval";
 import type { SandboxPolicy } from "./SandboxPolicy";
 import type { Thread } from "./Thread";
 
-export type ThreadResumeResponse = { thread: Thread, model: string, modelProvider: string, serviceTier: ServiceTier | null, cwd: string, approvalPolicy: AskForApproval,
+export type ThreadResumeResponse = { thread: Thread, model: string, modelProvider: string, serviceTier: ServiceTier | null, cwd: string,
+/**
+ * Instruction source files currently loaded for this thread.
+ */
+instructionSources: Array<string>, approvalPolicy: AskForApproval,
 /**
  * Reviewer currently used for approval requests on this thread.
  */

codex-rs/app-server-protocol/schema/typescript/v2/ThreadStartResponse.ts

@@ -8,7 +8,11 @@ import type { AskForApproval } from "./AskForApproval";
 import type { SandboxPolicy } from "./SandboxPolicy";
 import type { Thread } from "./Thread";
 
-export type ThreadStartResponse = { thread: Thread, model: string, modelProvider: string, serviceTier: ServiceTier | null, cwd: string, approvalPolicy: AskForApproval,
+export type ThreadStartResponse = { thread: Thread, model: string, modelProvider: string, serviceTier: ServiceTier | null, cwd: string,
+/**
+ * Instruction source files currently loaded for this thread.
+ */
+instructionSources: Array<string>, approvalPolicy: AskForApproval,
 /**
  * Reviewer currently used for approval requests on this thread.
  */

codex-rs/app-server-protocol/src/protocol/common.rs

@@ -1405,6 +1405,7 @@ mod tests {
                 model_provider: "openai".to_string(),
                 service_tier: None,
                 cwd: PathBuf::from("/tmp"),
+                instruction_sources: vec![PathBuf::from("/tmp/AGENTS.md")],
                 approval_policy: v2::AskForApproval::OnFailure,
                 approvals_reviewer: v2::ApprovalsReviewer::User,
                 sandbox: v2::SandboxPolicy::DangerFullAccess,
@@ -1444,6 +1445,7 @@ mod tests {
                     "modelProvider": "openai",
                     "serviceTier": null,
                     "cwd": "/tmp",
+                    "instructionSources": ["/tmp/AGENTS.md"],
                     "approvalPolicy": "on-failure",
                     "approvalsReviewer": "user",
                     "sandbox": {

codex-rs/app-server-protocol/src/protocol/v2.rs

@@ -2719,6 +2719,9 @@ pub struct ThreadStartResponse {
     pub model_provider: String,
     pub service_tier: Option<ServiceTier>,
     pub cwd: PathBuf,
+    /// Instruction source files currently loaded for this thread.
+    #[serde(default)]
+    pub instruction_sources: Vec<PathBuf>,
     #[experimental(nested)]
     pub approval_policy: AskForApproval,
     /// Reviewer currently used for approval requests on this thread.
@@ -2805,6 +2808,9 @@ pub struct ThreadResumeResponse {
     pub model_provider: String,
     pub service_tier: Option<ServiceTier>,
     pub cwd: PathBuf,
+    /// Instruction source files currently loaded for this thread.
+    #[serde(default)]
+    pub instruction_sources: Vec<PathBuf>,
     #[experimental(nested)]
     pub approval_policy: AskForApproval,
     /// Reviewer currently used for approval requests on this thread.
@@ -2882,6 +2888,9 @@ pub struct ThreadForkResponse {
     pub model_provider: String,
     pub service_tier: Option<ServiceTier>,
     pub cwd: PathBuf,
+    /// Instruction source files currently loaded for this thread.
+    #[serde(default)]
+    pub instruction_sources: Vec<PathBuf>,
     #[experimental(nested)]
     pub approval_policy: AskForApproval,
     /// Reviewer currently used for approval requests on this thread.
@@ -8506,6 +8515,50 @@ mod tests {
         assert_eq!(serialized_without_override.get("serviceTier"), None);
     }
 
+    #[test]
+    fn thread_lifecycle_responses_default_missing_instruction_sources() {
+        let response = json!({
+            "thread": {
+                "id": "thread-id",
+                "forkedFromId": null,
+                "preview": "",
+                "ephemeral": false,
+                "modelProvider": "openai",
+                "createdAt": 1,
+                "updatedAt": 1,
+                "status": { "type": "idle" },
+                "path": null,
+                "cwd": "/tmp",
+                "cliVersion": "0.0.0",
+                "source": "exec",
+                "agentNickname": null,
+                "agentRole": null,
+                "gitInfo": null,
+                "name": null,
+                "turns": []
+            },
+            "model": "gpt-5",
+            "modelProvider": "openai",
+            "serviceTier": null,
+            "cwd": "/tmp",
+            "approvalPolicy": "on-failure",
+            "approvalsReviewer": "user",
+            "sandbox": { "type": "dangerFullAccess" },
+            "reasoningEffort": null
+        });
+
+        let start: ThreadStartResponse =
+            serde_json::from_value(response.clone()).expect("thread/start response");
+        let resume: ThreadResumeResponse =
+            serde_json::from_value(response.clone()).expect("thread/resume response");
+        let fork: ThreadForkResponse =
+            serde_json::from_value(response).expect("thread/fork response");
+
+        assert_eq!(start.instruction_sources, Vec::<PathBuf>::new());
+        assert_eq!(resume.instruction_sources, Vec::<PathBuf>::new());
+        assert_eq!(fork.instruction_sources, Vec::<PathBuf>::new());
+    }
+
     #[test]
     fn turn_start_params_preserve_explicit_null_service_tier() {
         let params: TurnStartParams = serde_json::from_value(json!({