diff --git a/codex-rs/core/src/client_common.rs b/codex-rs/core/src/client_common.rs
index 2061d53c80d..d9edadbed4f 100644
--- a/codex-rs/core/src/client_common.rs
+++ b/codex-rs/core/src/client_common.rs
@@ -2,13 +2,10 @@ pub use codex_api::ResponseEvent;
 use codex_config::types::Personality;
 use codex_protocol::error::Result;
 use codex_protocol::models::BaseInstructions;
-use codex_protocol::models::FunctionCallOutputBody;
 use codex_protocol::models::ResponseItem;
 use codex_tools::ToolSpec;
 use futures::Stream;
-use serde::Deserialize;
 use serde_json::Value;
-use std::collections::HashSet;
 use std::pin::Pin;
 use std::task::Context;
 use std::task::Poll;
@@ -64,116 +61,10 @@ impl Default for Prompt {
 
 impl Prompt {
     pub(crate) fn get_formatted_input(&self) -> Vec<ResponseItem> {
-        let mut input = self.input.clone();
-
-        // when using the *Freeform* apply_patch tool specifically, tool outputs
-        // should be structured text, not json. Do NOT reserialize when using
-        // the Function tool - note that this differs from the check above for
-        // instructions. We declare the result as a named variable for clarity.
-        let is_freeform_apply_patch_tool_present = self.tools.iter().any(|tool| match tool {
-            ToolSpec::Freeform(f) => f.name == "apply_patch",
-            _ => false,
-        });
-        if is_freeform_apply_patch_tool_present {
-            reserialize_shell_outputs(&mut input);
-        }
-
-        input
+        self.input.clone()
     }
 }
 
-fn reserialize_shell_outputs(items: &mut [ResponseItem]) {
-    let mut shell_call_ids: HashSet<String> = HashSet::new();
-
-    items.iter_mut().for_each(|item| match item {
-        ResponseItem::LocalShellCall { call_id, id, .. } => {
-            if let Some(identifier) = call_id.clone().or_else(|| id.clone()) {
-                shell_call_ids.insert(identifier);
-            }
-        }
-        ResponseItem::CustomToolCall {
-            id: _,
-            status: _,
-            call_id,
-            name,
-            input: _,
-        } => {
-            if name == "apply_patch" {
-                shell_call_ids.insert(call_id.clone());
-            }
-        }
-        ResponseItem::FunctionCall { name, call_id, .. }
-            if is_shell_tool_name(name) || name == "apply_patch" =>
-        {
-            shell_call_ids.insert(call_id.clone());
-        }
-        ResponseItem::FunctionCallOutput {
-            call_id, output, ..
-        }
-        | ResponseItem::CustomToolCallOutput {
-            call_id, output, ..
-        } => {
-            if shell_call_ids.remove(call_id)
-                && let Some(structured) = output
-                    .text_content()
-                    .and_then(parse_structured_shell_output)
-            {
-                output.body = FunctionCallOutputBody::Text(structured);
-            }
-        }
-        _ => {}
-    })
-}
-
-fn is_shell_tool_name(name: &str) -> bool {
-    name == "shell"
-}
-
-#[derive(Deserialize)]
-struct ExecOutputJson {
-    output: String,
-    metadata: ExecOutputMetadataJson,
-}
-
-#[derive(Deserialize)]
-struct ExecOutputMetadataJson {
-    exit_code: i32,
-    duration_seconds: f32,
-}
-
-fn parse_structured_shell_output(raw: &str) -> Option<String> {
-    let parsed: ExecOutputJson = serde_json::from_str(raw).ok()?;
-    Some(build_structured_output(&parsed))
-}
-
-fn build_structured_output(parsed: &ExecOutputJson) -> String {
-    let mut sections = Vec::new();
-    sections.push(format!("Exit code: {}", parsed.metadata.exit_code));
-    sections.push(format!(
-        "Wall time: {} seconds",
-        parsed.metadata.duration_seconds
-    ));
-
-    let mut output = parsed.output.clone();
-    if let Some((stripped, total_lines)) = strip_total_output_header(&parsed.output) {
-        sections.push(format!("Total output lines: {total_lines}"));
-        output = stripped.to_string();
-    }
-
-    sections.push("Output:".to_string());
-    sections.push(output);
-
-    sections.join("\n")
-}
-
-fn strip_total_output_header(output: &str) -> Option<(&str, u32)> {
-    let after_prefix = output.strip_prefix("Total output lines: ")?;
-    let (total_segment, remainder) = after_prefix.split_once('\n')?;
-    let total_lines = total_segment.parse::<u32>().ok()?;
-    let remainder = remainder.strip_prefix('\n').unwrap_or(remainder);
-    Some((remainder, total_lines))
-}
-
 pub struct ResponseStream {
     pub(crate) rx_event: mpsc::Receiver<Result<ResponseEvent>>,
     /// Signals the mapper task that the consumer stopped polling before the
diff --git a/codex-rs/core/src/client_common_tests.rs b/codex-rs/core/src/client_common_tests.rs
index f67e4f1fd8b..45d43342229 100644
--- a/codex-rs/core/src/client_common_tests.rs
+++ b/codex-rs/core/src/client_common_tests.rs
@@ -3,7 +3,6 @@ use codex_api::ResponsesApiRequest;
 use codex_api::TextControls;
 use codex_api::create_text_param_for_request;
 use codex_protocol::config_types::ServiceTier;
-use codex_protocol::models::FunctionCallOutputPayload;
 use pretty_assertions::assert_eq;
 
 use super::*;
@@ -166,65 +165,3 @@ fn serializes_flex_service_tier_when_set() {
         Some("flex")
     );
 }
-
-#[test]
-fn reserializes_shell_outputs_for_function_and_custom_tool_calls() {
-    let raw_output = r#"{"output":"hello","metadata":{"exit_code":0,"duration_seconds":0.5}}"#;
-    let expected_output = "Exit code: 0\nWall time: 0.5 seconds\nOutput:\nhello";
-    let mut items = vec![
-        ResponseItem::FunctionCall {
-            id: None,
-            name: "shell".to_string(),
-            namespace: None,
-            arguments: "{}".to_string(),
-            call_id: "call-1".to_string(),
-        },
-        ResponseItem::FunctionCallOutput {
-            call_id: "call-1".to_string(),
-            output: FunctionCallOutputPayload::from_text(raw_output.to_string()),
-        },
-        ResponseItem::CustomToolCall {
-            id: None,
-            status: None,
-            call_id: "call-2".to_string(),
-            name: "apply_patch".to_string(),
-            input: "*** Begin Patch".to_string(),
-        },
-        ResponseItem::CustomToolCallOutput {
-            call_id: "call-2".to_string(),
-            name: None,
-            output: FunctionCallOutputPayload::from_text(raw_output.to_string()),
-        },
-    ];
-
-    reserialize_shell_outputs(&mut items);
-
-    assert_eq!(
-        items,
-        vec![
-            ResponseItem::FunctionCall {
-                id: None,
-                name: "shell".to_string(),
-                namespace: None,
-                arguments: "{}".to_string(),
-                call_id: "call-1".to_string(),
-            },
-            ResponseItem::FunctionCallOutput {
-                call_id: "call-1".to_string(),
-                output: FunctionCallOutputPayload::from_text(expected_output.to_string()),
-            },
-            ResponseItem::CustomToolCall {
-                id: None,
-                status: None,
-                call_id: "call-2".to_string(),
-                name: "apply_patch".to_string(),
-                input: "*** Begin Patch".to_string(),
-            },
-            ResponseItem::CustomToolCallOutput {
-                call_id: "call-2".to_string(),
-                name: None,
-                output: FunctionCallOutputPayload::from_text(expected_output.to_string()),
-            },
-        ]
-    );
-}
diff --git a/codex-rs/core/src/tools/events.rs b/codex-rs/core/src/tools/events.rs
index 51f1833f074..747143ff69a 100644
--- a/codex-rs/core/src/tools/events.rs
+++ b/codex-rs/core/src/tools/events.rs
@@ -116,7 +116,6 @@ pub(crate) enum ToolEmitter {
         cwd: AbsolutePathBuf,
         source: ExecCommandSource,
         parsed_cmd: Vec<ParsedCommand>,
-        freeform: bool,
     },
     ApplyPatch {
         changes: HashMap<PathBuf, FileChange>,
@@ -132,19 +131,13 @@ pub(crate) enum ToolEmitter {
 }
 
 impl ToolEmitter {
-    pub fn shell(
-        command: Vec<String>,
-        cwd: AbsolutePathBuf,
-        source: ExecCommandSource,
-        freeform: bool,
-    ) -> Self {
+    pub fn shell(command: Vec<String>, cwd: AbsolutePathBuf, source: ExecCommandSource) -> Self {
         let parsed_cmd = parse_command(&command);
         Self::Shell {
             command,
             cwd,
             source,
             parsed_cmd,
-            freeform,
         }
     }
 
@@ -328,12 +321,7 @@ impl ToolEmitter {
         output: &ExecToolCallOutput,
         ctx: ToolEventCtx<'_>,
     ) -> String {
-        match self {
-            Self::Shell { freeform: true, .. } => {
-                super::format_exec_output_for_model_freeform(output, ctx.turn.truncation_policy)
-            }
-            _ => super::format_exec_output_for_model_structured(output, ctx.turn.truncation_policy),
-        }
+        super::format_exec_output_for_model(output, ctx.turn.truncation_policy)
     }
 
     pub async fn finish(
diff --git a/codex-rs/core/src/tools/handlers/shell.rs b/codex-rs/core/src/tools/handlers/shell.rs
index c8c93bd6c72..2c69566b0c9 100644
--- a/codex-rs/core/src/tools/handlers/shell.rs
+++ b/codex-rs/core/src/tools/handlers/shell.rs
@@ -52,7 +52,6 @@ struct RunExecLikeArgs {
     turn: Arc<TurnContext>,
     tracker: crate::tools::context::SharedTurnDiffTracker,
     call_id: String,
-    freeform: bool,
     shell_runtime_backend: ShellRuntimeBackend,
 }
 
@@ -68,7 +67,6 @@ async fn run_exec_like(args: RunExecLikeArgs) -> Result<FunctionToolOutput, Func
         turn,
         tracker,
         call_id,
-        freeform,
         shell_runtime_backend,
     } = args;
 
@@ -162,12 +160,7 @@ async fn run_exec_like(args: RunExecLikeArgs) -> Result<FunctionToolOutput, Func
     }
 
     let source = ExecCommandSource::Agent;
-    let emitter = ToolEmitter::shell(
-        exec_params.command.clone(),
-        exec_params.cwd.clone(),
-        source,
-        freeform,
-    );
+    let emitter = ToolEmitter::shell(exec_params.command.clone(), exec_params.cwd.clone(), source);
     let event_ctx = ToolEventCtx::new(
         session.as_ref(),
         turn.as_ref(),
diff --git a/codex-rs/core/src/tools/handlers/shell/shell_command.rs b/codex-rs/core/src/tools/handlers/shell/shell_command.rs
index 54d74f13b7a..f896afa6273 100644
--- a/codex-rs/core/src/tools/handlers/shell/shell_command.rs
+++ b/codex-rs/core/src/tools/handlers/shell/shell_command.rs
@@ -197,7 +197,6 @@ impl ToolExecutor<ToolInvocation> for ShellCommandHandler {
             turn,
             tracker,
             call_id,
-            freeform: true,
             shell_runtime_backend: self.shell_runtime_backend(),
         })
         .await
diff --git a/codex-rs/core/src/tools/mod.rs b/codex-rs/core/src/tools/mod.rs
index 3073d9f9da6..0de5bed1497 100644
--- a/codex-rs/core/src/tools/mod.rs
+++ b/codex-rs/core/src/tools/mod.rs
@@ -25,7 +25,6 @@ use codex_utils_output_truncation::TruncationPolicy;
 use codex_utils_output_truncation::formatted_truncate_text;
 use codex_utils_output_truncation::truncate_text;
 pub use router::ToolRouter;
-use serde::Serialize;
 
 // Telemetry preview limits: keep log events smaller than model budgets.
 pub(crate) const TELEMETRY_PREVIEW_MAX_BYTES: usize = 2 * 1024; // 2 KiB
@@ -50,46 +49,7 @@ pub(crate) fn flat_tool_name(tool_name: &ToolName) -> Cow<'_, str> {
 
 /// Format the combined exec output for sending back to the model.
 /// Includes exit code and duration metadata; truncates large bodies safely.
-pub fn format_exec_output_for_model_structured(
-    exec_output: &ExecToolCallOutput,
-    truncation_policy: TruncationPolicy,
-) -> String {
-    let ExecToolCallOutput {
-        exit_code,
-        duration,
-        ..
-    } = exec_output;
-
-    #[derive(Serialize)]
-    struct ExecMetadata {
-        exit_code: i32,
-        duration_seconds: f32,
-    }
-
-    #[derive(Serialize)]
-    struct ExecOutput<'a> {
-        output: &'a str,
-        metadata: ExecMetadata,
-    }
-
-    // round to 1 decimal place
-    let duration_seconds = ((duration.as_secs_f32()) * 10.0).round() / 10.0;
-
-    let formatted_output = format_exec_output_str(exec_output, truncation_policy);
-
-    let payload = ExecOutput {
-        output: &formatted_output,
-        metadata: ExecMetadata {
-            exit_code: *exit_code,
-            duration_seconds,
-        },
-    };
-
-    #[expect(clippy::expect_used)]
-    serde_json::to_string(&payload).expect("serialize ExecOutput")
-}
-
-pub fn format_exec_output_for_model_freeform(
+pub fn format_exec_output_for_model(
     exec_output: &ExecToolCallOutput,
     truncation_policy: TruncationPolicy,
 ) -> String {
diff --git a/codex-rs/core/tests/common/responses.rs b/codex-rs/core/tests/common/responses.rs
index 6c1f581f9fc..c917436b6d1 100644
--- a/codex-rs/core/tests/common/responses.rs
+++ b/codex-rs/core/tests/common/responses.rs
@@ -35,8 +35,6 @@ use wiremock::http::HeaderValue;
 use wiremock::matchers::method;
 use wiremock::matchers::path_regex;
 
-use crate::test_codex::ApplyPatchModelOutput;
-
 #[derive(Debug, Clone)]
 pub struct ResponseMock {
     requests: Arc<Mutex<Vec<ResponsesRequest>>>,
@@ -883,19 +881,6 @@ pub fn ev_local_shell_call(call_id: &str, status: &str, command: Vec<&str>) -> V
     })
 }
 
-pub fn ev_apply_patch_call(
-    call_id: &str,
-    patch: &str,
-    output_type: ApplyPatchModelOutput,
-) -> Value {
-    match output_type {
-        ApplyPatchModelOutput::Freeform => ev_apply_patch_custom_tool_call(call_id, patch),
-        ApplyPatchModelOutput::ShellCommandViaHeredoc => {
-            ev_apply_patch_shell_command_call_via_heredoc(call_id, patch)
-        }
-    }
-}
-
 /// Convenience: SSE event for an `apply_patch` custom tool call with raw patch
 /// text. This mirrors the payload produced by the Responses API when the model
 /// invokes `apply_patch` directly.
diff --git a/codex-rs/core/tests/common/test_codex.rs b/codex-rs/core/tests/common/test_codex.rs
index 947111d3fc9..2007104868e 100644
--- a/codex-rs/core/tests/common/test_codex.rs
+++ b/codex-rs/core/tests/common/test_codex.rs
@@ -184,20 +184,12 @@ fn docker_command_capture_stdout<const N: usize>(args: [&str; N]) -> Result<Stri
     String::from_utf8(output.stdout).context("docker stdout must be utf-8")
 }
 
-/// A collection of different ways the model can output an apply_patch call
+/// Non-default apply_patch model output shapes used by compatibility tests.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum ApplyPatchModelOutput {
-    Freeform,
     ShellCommandViaHeredoc,
 }
 
-/// A collection of different ways the model can output an apply_patch call
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum ShellModelOutput {
-    ShellCommand,
-    // UnifiedExec has its own set of tests
-}
-
 /// Returns the permission fields required by `Op::UserTurn` for tests that
 /// construct the op directly.
 pub fn turn_permission_fields(
@@ -977,21 +969,8 @@ impl TestCodexHarness {
         custom_tool_call_output_text(&bodies, call_id)
     }
 
-    pub async fn apply_patch_output(
-        &self,
-        call_id: &str,
-        output_type: ApplyPatchModelOutput,
-    ) -> String {
-        // Box the awaited output helpers so callers do not inline request
-        // capture and response parsing into their own async state.
-        match output_type {
-            ApplyPatchModelOutput::Freeform => {
-                Box::pin(self.custom_tool_call_output(call_id)).await
-            }
-            ApplyPatchModelOutput::ShellCommandViaHeredoc => {
-                Box::pin(self.function_call_stdout(call_id)).await
-            }
-        }
+    pub async fn apply_patch_output(&self, call_id: &str) -> String {
+        self.custom_tool_call_output(call_id).await
     }
 }
 
diff --git a/codex-rs/core/tests/suite/apply_patch_cli.rs b/codex-rs/core/tests/suite/apply_patch_cli.rs
index 9185b8a7bd4..05379517e5e 100644
--- a/codex-rs/core/tests/suite/apply_patch_cli.rs
+++ b/codex-rs/core/tests/suite/apply_patch_cli.rs
@@ -3,8 +3,8 @@
 use anyhow::Result;
 use base64::Engine;
 use base64::engine::general_purpose::STANDARD as BASE64_STANDARD;
-use core_test_support::responses::ev_apply_patch_call;
 use core_test_support::responses::ev_apply_patch_custom_tool_call;
+use core_test_support::responses::ev_apply_patch_shell_command_call_via_heredoc;
 use core_test_support::responses::ev_shell_command_call;
 use core_test_support::test_codex::ApplyPatchModelOutput;
 use pretty_assertions::assert_eq;
@@ -45,7 +45,6 @@ use core_test_support::test_codex::test_codex;
 use core_test_support::wait_for_event;
 use core_test_support::wait_for_event_with_timeout;
 use serde_json::json;
-use test_case::test_case;
 use wiremock::Mock;
 use wiremock::Respond;
 use wiremock::ResponseTemplate;
@@ -182,11 +181,35 @@ pub async fn mount_apply_patch(
     call_id: &str,
     patch: &str,
     assistant_msg: &str,
-    output_type: ApplyPatchModelOutput,
 ) {
     mount_sse_sequence(
         harness.server(),
-        apply_patch_responses(call_id, patch, assistant_msg, output_type),
+        apply_patch_responses(
+            call_id,
+            patch,
+            assistant_msg,
+            ev_apply_patch_custom_tool_call,
+        ),
+    )
+    .await;
+}
+
+async fn mount_apply_patch_model_output(
+    harness: &TestCodexHarness,
+    call_id: &str,
+    patch: &str,
+    assistant_msg: &str,
+    model_output: ApplyPatchModelOutput,
+) {
+    let apply_patch_call = match model_output {
+        ApplyPatchModelOutput::ShellCommandViaHeredoc => {
+            ev_apply_patch_shell_command_call_via_heredoc
+        }
+    };
+
+    mount_sse_sequence(
+        harness.server(),
+        apply_patch_responses(call_id, patch, assistant_msg, apply_patch_call),
     )
     .await;
 }
@@ -195,12 +218,12 @@ fn apply_patch_responses(
     call_id: &str,
     patch: &str,
     assistant_msg: &str,
-    output_type: ApplyPatchModelOutput,
+    apply_patch_call: fn(&str, &str) -> serde_json::Value,
 ) -> Vec<String> {
     vec![
         sse(vec![
             ev_response_created("resp-1"),
-            ev_apply_patch_call(call_id, patch, output_type),
+            apply_patch_call(call_id, patch),
             ev_completed("resp-1"),
         ]),
         sse(vec![
@@ -231,20 +254,11 @@ async fn apply_patch_cli_uses_codex_self_exe_with_linux_sandbox_helper_alias() -
 
     let patch = "*** Begin Patch\n*** Add File: helper-alias.txt\n+hello\n*** End Patch";
     let call_id = "apply-helper-alias";
-    mount_apply_patch(
-        &harness,
-        call_id,
-        patch,
-        "done",
-        ApplyPatchModelOutput::Freeform,
-    )
-    .await;
+    mount_apply_patch(&harness, call_id, patch, "done").await;
 
     harness.submit("please apply helper alias patch").await?;
 
-    let out = harness
-        .apply_patch_output(call_id, ApplyPatchModelOutput::Freeform)
-        .await;
+    let out = harness.apply_patch_output(call_id).await;
     assert_regex_match(
         r"(?s)^Exit code: 0.*Success\. Updated the following files:\nA helper-alias\.txt\n?$",
         &out,
@@ -255,10 +269,7 @@ async fn apply_patch_cli_uses_codex_self_exe_with_linux_sandbox_helper_alias() -
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-async fn apply_patch_cli_multiple_operations_integration(
-    output_type: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_multiple_operations_integration() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness_with(|builder| builder.with_model("gpt-5.4")).await?;
@@ -270,11 +281,11 @@ async fn apply_patch_cli_multiple_operations_integration(
     let patch = "*** Begin Patch\n*** Add File: nested/new.txt\n+created\n*** Delete File: delete.txt\n*** Update File: modify.txt\n@@\n-line2\n+changed\n*** End Patch";
 
     let call_id = "apply-multi-ops";
-    mount_apply_patch(&harness, call_id, patch, "done", output_type).await;
+    mount_apply_patch(&harness, call_id, patch, "done").await;
 
     harness.submit("please apply multi-ops patch").await?;
 
-    let out = harness.apply_patch_output(call_id, output_type).await;
+    let out = harness.apply_patch_output(call_id).await;
 
     let expected = r"(?s)^Exit code: 0
 Wall time: [0-9]+(?:\.[0-9]+)? seconds
@@ -297,9 +308,7 @@ D delete.txt
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_multiple_chunks(model_output: ApplyPatchModelOutput) -> Result<()> {
+async fn apply_patch_cli_multiple_chunks() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -310,7 +319,7 @@ async fn apply_patch_cli_multiple_chunks(model_output: ApplyPatchModelOutput) ->
 
     let patch = "*** Begin Patch\n*** Update File: multi.txt\n@@\n-line2\n+changed2\n@@\n-line4\n+changed4\n*** End Patch";
     let call_id = "apply-multi-chunks";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply multi-chunk patch").await?;
 
@@ -322,11 +331,7 @@ async fn apply_patch_cli_multiple_chunks(model_output: ApplyPatchModelOutput) ->
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_moves_file_to_new_directory(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_moves_file_to_new_directory() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -335,7 +340,7 @@ async fn apply_patch_cli_moves_file_to_new_directory(
 
     let patch = "*** Begin Patch\n*** Update File: old/name.txt\n*** Move to: renamed/dir/name.txt\n@@\n-old content\n+new content\n*** End Patch";
     let call_id = "apply-move";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply move patch").await?;
 
@@ -348,11 +353,7 @@ async fn apply_patch_cli_moves_file_to_new_directory(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_updates_file_appends_trailing_newline(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_updates_file_appends_trailing_newline() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -363,7 +364,7 @@ async fn apply_patch_cli_updates_file_appends_trailing_newline(
 
     let patch = "*** Begin Patch\n*** Update File: no_newline.txt\n@@\n-no newline at end\n+first line\n+second line\n*** End Patch";
     let call_id = "apply-append-nl";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply newline patch").await?;
 
@@ -374,11 +375,7 @@ async fn apply_patch_cli_updates_file_appends_trailing_newline(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_insert_only_hunk_modifies_file(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_insert_only_hunk_modifies_file() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -389,7 +386,7 @@ async fn apply_patch_cli_insert_only_hunk_modifies_file(
 
     let patch = "*** Begin Patch\n*** Update File: insert_only.txt\n@@\n alpha\n+beta\n omega\n*** End Patch";
     let call_id = "apply-insert-only";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("insert lines via apply_patch").await?;
 
@@ -401,11 +398,7 @@ async fn apply_patch_cli_insert_only_hunk_modifies_file(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_move_overwrites_existing_destination(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_move_overwrites_existing_destination() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -417,7 +410,7 @@ async fn apply_patch_cli_move_overwrites_existing_destination(
 
     let patch = "*** Begin Patch\n*** Update File: old/name.txt\n*** Move to: renamed/dir/name.txt\n@@\n-from\n+new\n*** End Patch";
     let call_id = "apply-move-overwrite";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply move overwrite patch").await?;
 
@@ -430,11 +423,7 @@ async fn apply_patch_cli_move_overwrites_existing_destination(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_move_without_content_change_has_no_turn_diff(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_move_without_content_change_has_no_turn_diff() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -445,7 +434,7 @@ async fn apply_patch_cli_move_without_content_change_has_no_turn_diff(
 
     let patch = "*** Begin Patch\n*** Update File: old/name.txt\n*** Move to: renamed/name.txt\n@@\n same\n*** End Patch";
     let call_id = "apply-move-no-change";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     submit_without_wait(&harness, "rename without content change").await?;
 
@@ -467,11 +456,7 @@ async fn apply_patch_cli_move_without_content_change_has_no_turn_diff(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_add_overwrites_existing_file(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_add_overwrites_existing_file() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -480,7 +465,7 @@ async fn apply_patch_cli_add_overwrites_existing_file(
 
     let patch = "*** Begin Patch\n*** Add File: duplicate.txt\n+new content\n*** End Patch";
     let call_id = "apply-add-overwrite";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply add overwrite patch").await?;
 
@@ -492,22 +477,18 @@ async fn apply_patch_cli_add_overwrites_existing_file(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_rejects_invalid_hunk_header(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_rejects_invalid_hunk_header() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
 
     let patch = "*** Begin Patch\n*** Frobnicate File: foo\n*** End Patch";
     let call_id = "apply-invalid-header";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply invalid header patch").await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
 
     assert!(
         out.contains("apply_patch verification failed"),
@@ -521,11 +502,7 @@ async fn apply_patch_cli_rejects_invalid_hunk_header(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_reports_missing_context(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_reports_missing_context() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -535,11 +512,11 @@ async fn apply_patch_cli_reports_missing_context(
     let patch =
         "*** Begin Patch\n*** Update File: modify.txt\n@@\n-missing\n+changed\n*** End Patch";
     let call_id = "apply-missing-context";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply missing context patch").await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
 
     assert!(
         out.contains("apply_patch verification failed"),
@@ -554,22 +531,18 @@ async fn apply_patch_cli_reports_missing_context(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_reports_missing_target_file(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_reports_missing_target_file() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
 
     let patch = "*** Begin Patch\n*** Update File: missing.txt\n@@\n-nope\n+better\n*** End Patch";
     let call_id = "apply-missing-file";
-    mount_apply_patch(&harness, call_id, patch, "fail", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "fail").await;
 
     harness.submit("attempt to update a missing file").await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
     assert!(
         out.contains("apply_patch verification failed"),
         "expected verification failure message"
@@ -587,22 +560,18 @@ async fn apply_patch_cli_reports_missing_target_file(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_delete_missing_file_reports_error(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_delete_missing_file_reports_error() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
 
     let patch = "*** Begin Patch\n*** Delete File: missing.txt\n*** End Patch";
     let call_id = "apply-delete-missing";
-    mount_apply_patch(&harness, call_id, patch, "fail", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "fail").await;
 
     harness.submit("attempt to delete missing file").await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
 
     assert!(
         out.contains("apply_patch verification failed"),
@@ -621,20 +590,18 @@ async fn apply_patch_cli_delete_missing_file_reports_error(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_rejects_empty_patch(model_output: ApplyPatchModelOutput) -> Result<()> {
+async fn apply_patch_cli_rejects_empty_patch() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
 
     let patch = "*** Begin Patch\n*** End Patch";
     let call_id = "apply-empty";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply empty patch").await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
     assert!(
         out.contains("patch rejected: empty patch"),
         "expected rejection for empty patch: {out}"
@@ -643,11 +610,7 @@ async fn apply_patch_cli_rejects_empty_patch(model_output: ApplyPatchModelOutput
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_delete_directory_reports_verification_error(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_delete_directory_reports_verification_error() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -656,22 +619,18 @@ async fn apply_patch_cli_delete_directory_reports_verification_error(
 
     let patch = "*** Begin Patch\n*** Delete File: dir\n*** End Patch";
     let call_id = "apply-delete-dir";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("delete a directory via apply_patch").await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
     assert!(out.contains("apply_patch verification failed"));
     assert!(out.contains("Failed to read"));
     Ok(())
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_rejects_path_traversal_outside_workspace(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_rejects_path_traversal_outside_workspace() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -687,7 +646,7 @@ async fn apply_patch_cli_rejects_path_traversal_outside_workspace(
 
     let patch = "*** Begin Patch\n*** Add File: ../escape.txt\n+outside\n*** End Patch";
     let call_id = "apply-path-traversal";
-    mount_apply_patch(&harness, call_id, patch, "fail", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "fail").await;
 
     harness
         .submit_with_permission_profile(
@@ -696,7 +655,7 @@ async fn apply_patch_cli_rejects_path_traversal_outside_workspace(
         )
         .await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
     assert!(
         out.contains(
             "patch rejected: writing outside of the project; rejected by user approval settings"
@@ -712,10 +671,7 @@ async fn apply_patch_cli_rejects_path_traversal_outside_workspace(
 
 #[cfg(unix)]
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc ; "shell_command_heredoc")]
-async fn intercepted_apply_patch_verification_uses_local_sandbox(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn intercepted_apply_patch_verification_uses_local_sandbox() -> Result<()> {
     skip_if_no_network!(Ok(()));
     skip_if_remote!(Ok(()), "symlink setup needs local filesystem link creation");
 
@@ -735,7 +691,14 @@ async fn intercepted_apply_patch_verification_uses_local_sandbox(
 *** End Patch"#
     );
     let call_id = "apply-sandboxed-read";
-    mount_apply_patch(&harness, call_id, &patch, "fail", model_output).await;
+    mount_apply_patch_model_output(
+        &harness,
+        call_id,
+        &patch,
+        "fail",
+        ApplyPatchModelOutput::ShellCommandViaHeredoc,
+    )
+    .await;
 
     harness
         .submit_with_permission_profile(
@@ -744,7 +707,11 @@ async fn intercepted_apply_patch_verification_uses_local_sandbox(
         )
         .await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.function_call_stdout(call_id).await;
+    assert!(
+        serde_json::from_str::<serde_json::Value>(&out).is_err(),
+        "expected heredoc apply_patch output to be plain text"
+    );
     assert!(
         out.contains("apply_patch verification failed"),
         "expected sandboxed verification failure: {out}"
@@ -762,11 +729,7 @@ async fn intercepted_apply_patch_verification_uses_local_sandbox(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform ; "freeform")]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc ; "shell_command_heredoc")]
-async fn apply_patch_cli_does_not_write_through_symlink_escape_outside_workspace(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_does_not_write_through_symlink_escape_outside_workspace() -> Result<()> {
     skip_if_no_network!(Ok(()));
     skip_if_remote!(
         Ok(()),
@@ -810,7 +773,7 @@ async fn apply_patch_cli_does_not_write_through_symlink_escape_outside_workspace
 *** End Patch"#
     );
     let call_id = "apply-symlink-escape";
-    mount_apply_patch(&harness, call_id, &patch, "fail", model_output).await;
+    mount_apply_patch(&harness, call_id, &patch, "fail").await;
 
     harness
         .submit_with_permission_profile(
@@ -819,7 +782,7 @@ async fn apply_patch_cli_does_not_write_through_symlink_escape_outside_workspace
         )
         .await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
     assert_eq!(
         std::fs::read_to_string(&outside_file)?,
         original_contents,
@@ -831,11 +794,7 @@ async fn apply_patch_cli_does_not_write_through_symlink_escape_outside_workspace
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform ; "freeform")]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc ; "shell_command_heredoc")]
-async fn apply_patch_cli_preserves_existing_hard_link_outside_workspace(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_preserves_existing_hard_link_outside_workspace() -> Result<()> {
     skip_if_no_network!(Ok(()));
     skip_if_remote!(
         Ok(()),
@@ -871,7 +830,7 @@ async fn apply_patch_cli_preserves_existing_hard_link_outside_workspace(
 *** End Patch"#
     );
     let call_id = "apply-hard-link";
-    mount_apply_patch(&harness, call_id, &patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, &patch, "ok").await;
 
     harness
         .submit_with_permission_profile(
@@ -880,7 +839,7 @@ async fn apply_patch_cli_preserves_existing_hard_link_outside_workspace(
         )
         .await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
     if cfg!(windows) {
         assert!(
             out.contains("patch rejected: writing outside of the project"),
@@ -933,11 +892,7 @@ async fn apply_patch_cli_preserves_existing_hard_link_outside_workspace(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_rejects_move_path_traversal_outside_workspace(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_rejects_move_path_traversal_outside_workspace() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -955,7 +910,7 @@ async fn apply_patch_cli_rejects_move_path_traversal_outside_workspace(
 
     let patch = "*** Begin Patch\n*** Update File: stay.txt\n*** Move to: ../escape-move.txt\n@@\n-from\n+to\n*** End Patch";
     let call_id = "apply-move-traversal";
-    mount_apply_patch(&harness, call_id, patch, "fail", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "fail").await;
 
     harness
         .submit_with_permission_profile(
@@ -964,7 +919,7 @@ async fn apply_patch_cli_rejects_move_path_traversal_outside_workspace(
         )
         .await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
     assert!(
         out.contains(
             "patch rejected: writing outside of the project; rejected by user approval settings"
@@ -980,11 +935,7 @@ async fn apply_patch_cli_rejects_move_path_traversal_outside_workspace(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_verification_failure_has_no_side_effects(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_verification_failure_has_no_side_effects() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -993,7 +944,7 @@ async fn apply_patch_cli_verification_failure_has_no_side_effects(
     let call_id = "apply-partial-no-side-effects";
     let patch = "*** Begin Patch\n*** Add File: created.txt\n+hello\n*** Update File: missing.txt\n@@\n-old\n+new\n*** End Patch";
 
-    mount_apply_patch(&harness, call_id, patch, "failed", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "failed").await;
 
     harness.submit("attempt partial apply patch").await?;
 
@@ -1393,14 +1344,7 @@ async fn apply_patch_turn_diff_paths_stay_repo_relative_when_session_cwd_is_nest
 
     let call_id = "apply-nested-cwd-repo-relative";
     let patch = "*** Begin Patch\n*** Update File: ../repo.txt\n@@\n-before\n+after\n*** End Patch";
-    mount_apply_patch(
-        &harness,
-        call_id,
-        patch,
-        "updated repo-relative path",
-        ApplyPatchModelOutput::Freeform,
-    )
-    .await;
+    mount_apply_patch(&harness, call_id, patch, "updated repo-relative path").await;
 
     submit_without_wait(&harness, "update file outside nested cwd but inside repo").await?;
 
@@ -1485,10 +1429,7 @@ async fn apply_patch_shell_command_failure_propagates_error_and_skips_diff() ->
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_shell_accepts_lenient_heredoc_wrapped_patch(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_shell_accepts_lenient_heredoc_wrapped_patch() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -1497,18 +1438,36 @@ async fn apply_patch_shell_accepts_lenient_heredoc_wrapped_patch(
     let patch_inner =
         format!("*** Begin Patch\n*** Add File: {file_name}\n+lenient\n*** End Patch\n");
     let call_id = "apply-lenient";
-    mount_apply_patch(&harness, call_id, patch_inner.as_str(), "ok", model_output).await;
+    mount_apply_patch_model_output(
+        &harness,
+        call_id,
+        patch_inner.as_str(),
+        "ok",
+        ApplyPatchModelOutput::ShellCommandViaHeredoc,
+    )
+    .await;
 
     harness.submit("apply lenient heredoc patch").await?;
 
+    let out = harness.function_call_stdout(call_id).await;
+    assert!(
+        serde_json::from_str::<serde_json::Value>(&out).is_err(),
+        "expected heredoc apply_patch output to be plain text"
+    );
+    assert!(
+        out.contains("Success. Updated the following files:"),
+        "expected successful apply_patch output: {out}"
+    );
+    assert!(
+        out.contains(&format!("A {file_name}")),
+        "expected created file in apply_patch output: {out}"
+    );
     assert_eq!(harness.read_file_text(file_name).await?, "lenient\n");
     Ok(())
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_end_of_file_anchor(model_output: ApplyPatchModelOutput) -> Result<()> {
+async fn apply_patch_cli_end_of_file_anchor() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -1517,7 +1476,7 @@ async fn apply_patch_cli_end_of_file_anchor(model_output: ApplyPatchModelOutput)
 
     let patch = "*** Begin Patch\n*** Update File: tail.txt\n@@\n-last\n+end\n*** End of File\n*** End Patch";
     let call_id = "apply-eof";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply EOF-anchored patch").await?;
     assert_eq!(harness.read_file_text("tail.txt").await?, "alpha\nend\n");
@@ -1525,11 +1484,7 @@ async fn apply_patch_cli_end_of_file_anchor(model_output: ApplyPatchModelOutput)
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_cli_missing_second_chunk_context_rejected(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_cli_missing_second_chunk_context_rejected() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -1540,11 +1495,11 @@ async fn apply_patch_cli_missing_second_chunk_context_rejected(
     let patch =
         "*** Begin Patch\n*** Update File: two_chunks.txt\n@@\n-b\n+B\n\n-d\n+D\n*** End Patch";
     let call_id = "apply-missing-ctx-2nd";
-    mount_apply_patch(&harness, call_id, patch, "fail", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "fail").await;
 
     harness.submit("apply missing context second chunk").await?;
 
-    let out = harness.apply_patch_output(call_id, model_output).await;
+    let out = harness.apply_patch_output(call_id).await;
     assert!(out.contains("apply_patch verification failed"));
     assert!(
         out.contains("Failed to find expected lines in"),
@@ -1559,11 +1514,7 @@ async fn apply_patch_cli_missing_second_chunk_context_rejected(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_emits_turn_diff_event_with_unified_diff(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_emits_turn_diff_event_with_unified_diff() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -1573,7 +1524,7 @@ async fn apply_patch_emits_turn_diff_event_with_unified_diff(
     let call_id = "apply-diff-event";
     let file = "udiff.txt";
     let patch = format!("*** Begin Patch\n*** Add File: {file}\n+hello\n*** End Patch\n");
-    mount_apply_patch(&harness, call_id, patch.as_str(), "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch.as_str(), "ok").await;
 
     submit_without_wait(&harness, "emit diff").await?;
 
@@ -1789,11 +1740,7 @@ async fn apply_patch_clears_aggregated_diff_after_inexact_delta() -> Result<()>
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-#[test_case(ApplyPatchModelOutput::ShellCommandViaHeredoc)]
-async fn apply_patch_change_context_disambiguates_target(
-    model_output: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_change_context_disambiguates_target() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -1805,7 +1752,7 @@ async fn apply_patch_change_context_disambiguates_target(
     let patch =
         "*** Begin Patch\n*** Update File: multi_ctx.txt\n@@ fn b\n-x=10\n+x=11\n*** End Patch";
     let call_id = "apply-ctx";
-    mount_apply_patch(&harness, call_id, patch, "ok", model_output).await;
+    mount_apply_patch(&harness, call_id, patch, "ok").await;
 
     harness.submit("apply with change_context").await?;
 
diff --git a/codex-rs/core/tests/suite/hooks.rs b/codex-rs/core/tests/suite/hooks.rs
index 53649afff84..ef3918e1895 100644
--- a/codex-rs/core/tests/suite/hooks.rs
+++ b/codex-rs/core/tests/suite/hooks.rs
@@ -3650,22 +3650,9 @@ async fn post_tool_use_records_additional_context_for_apply_patch() -> Result<()
     let tool_response = hook_inputs[0]["tool_response"]
         .as_str()
         .context("apply_patch tool_response should be a string")?;
-    let mut parsed_tool_response = serde_json::from_str::<Value>(tool_response)?;
-    if let Some(metadata) = parsed_tool_response
-        .get_mut("metadata")
-        .and_then(Value::as_object_mut)
-    {
-        let _ = metadata.remove("duration_seconds");
-    }
-    assert_eq!(
-        parsed_tool_response,
-        serde_json::json!({
-            "output": "Success. Updated the following files:\nA post_tool_use_apply_patch.txt\n",
-            "metadata": {
-                "exit_code": 0,
-            },
-        })
-    );
+    assert!(tool_response.starts_with("Exit code: 0"));
+    assert!(tool_response.contains("Success. Updated the following files:"));
+    assert!(tool_response.contains("A post_tool_use_apply_patch.txt"));
 
     Ok(())
 }
diff --git a/codex-rs/core/tests/suite/shell_serialization.rs b/codex-rs/core/tests/suite/shell_serialization.rs
index dbe4957ecb1..2295798daad 100644
--- a/codex-rs/core/tests/suite/shell_serialization.rs
+++ b/codex-rs/core/tests/suite/shell_serialization.rs
@@ -12,16 +12,12 @@ use core_test_support::responses::mount_sse_sequence;
 use core_test_support::responses::sse;
 use core_test_support::responses::start_mock_server;
 use core_test_support::skip_if_no_network;
-use core_test_support::test_codex::ApplyPatchModelOutput;
-use core_test_support::test_codex::ShellModelOutput;
-use core_test_support::test_codex::TestCodexBuilder;
 use core_test_support::test_codex::test_codex;
 use pretty_assertions::assert_eq;
 use regex_lite::Regex;
 use serde_json::Value;
 use serde_json::json;
 use std::fs;
-use test_case::test_case;
 
 use crate::suite::apply_patch_cli::apply_patch_harness;
 use crate::suite::apply_patch_cli::mount_apply_patch;
@@ -38,135 +34,68 @@ const FIXTURE_JSON: &str = r#"{
 }
 "#;
 
-fn shell_responses(
-    call_id: &str,
-    command: Vec<&str>,
-    output_type: ShellModelOutput,
-) -> Result<Vec<String>> {
-    match output_type {
-        ShellModelOutput::ShellCommand => {
-            let command = shlex::try_join(command)?;
-            let parameters = json!({
-                "command": command,
-                "timeout_ms": 2_000,
-            });
-            Ok(vec![
-                sse(vec![
-                    ev_response_created("resp-1"),
-                    ev_function_call(
-                        call_id,
-                        "shell_command",
-                        &serde_json::to_string(&parameters)?,
-                    ),
-                    ev_completed("resp-1"),
-                ]),
-                sse(vec![
-                    ev_assistant_message("msg-1", "done"),
-                    ev_completed("resp-2"),
-                ]),
-            ])
-        }
-    }
-}
-
-fn configure_shell_model(
-    builder: TestCodexBuilder,
-    output_type: ShellModelOutput,
-) -> TestCodexBuilder {
-    match output_type {
-        ShellModelOutput::ShellCommand => builder.with_model("test-gpt-5-codex"),
-    }
-}
-
-#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ShellModelOutput::ShellCommand)]
-async fn shell_output_is_structured_with_freeform_apply_patch(
-    output_type: ShellModelOutput,
-) -> Result<()> {
-    skip_if_no_network!(Ok(()));
-
-    let server = start_mock_server().await;
-    let mut builder = configure_shell_model(test_codex(), output_type);
-    let test = builder.build(&server).await?;
-
-    let call_id = "shell-structured";
-    let responses = shell_responses(call_id, vec!["/bin/echo", "freeform shell"], output_type)?;
-    let mock = mount_sse_sequence(&server, responses).await;
-
-    test.submit_turn_with_permission_profile(
-        "run the structured shell command",
-        PermissionProfile::Disabled,
-    )
-    .await?;
-
-    let req = mock
-        .last_request()
-        .expect("structured shell output request recorded");
-    let output_item = req.function_call_output(call_id);
-    let output = output_item
-        .get("output")
-        .and_then(Value::as_str)
-        .expect("structured output string");
-
-    assert!(
-        serde_json::from_str::<Value>(output).is_err(),
-        "expected structured shell output to be plain text",
-    );
-    let expected_pattern = r"(?s)^Exit code: 0
-Wall time: [0-9]+(?:\.[0-9]+)? seconds
-Output:
-freeform shell
-?$";
-    assert_regex_match(expected_pattern, output);
-
-    Ok(())
+fn shell_responses(call_id: &str, command: Vec<&str>) -> Result<Vec<String>> {
+    let command = shlex::try_join(command)?;
+    let parameters = json!({
+        "command": command,
+        "timeout_ms": 2_000,
+    });
+    Ok(vec![
+        sse(vec![
+            ev_response_created("resp-1"),
+            ev_function_call(
+                call_id,
+                "shell_command",
+                &serde_json::to_string(&parameters)?,
+            ),
+            ev_completed("resp-1"),
+        ]),
+        sse(vec![
+            ev_assistant_message("msg-1", "done"),
+            ev_completed("resp-2"),
+        ]),
+    ])
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ShellModelOutput::ShellCommand)]
-async fn shell_output_structures_fixture_with_serialization(
-    output_type: ShellModelOutput,
-) -> Result<()> {
+async fn shell_output_preserves_fixture_json_as_freeform() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let server = start_mock_server().await;
-    let mut builder = configure_shell_model(test_codex(), output_type);
+    let mut builder = test_codex().with_model("test-gpt-5-codex");
     let test = builder.build(&server).await?;
 
     let fixture_path = test.cwd.path().join("fixture.json");
     fs::write(&fixture_path, FIXTURE_JSON)?;
     let fixture_path_str = fixture_path.to_string_lossy().to_string();
 
-    let call_id = "shell-structured-fixture";
+    let call_id = "shell-freeform-fixture";
     let responses = shell_responses(
         call_id,
         vec!["/usr/bin/sed", "-n", "p", fixture_path_str.as_str()],
-        output_type,
     )?;
     let mock = mount_sse_sequence(&server, responses).await;
 
     test.submit_turn_with_permission_profile(
-        "read the fixture JSON with structured output",
+        "read the fixture JSON with shell output",
         PermissionProfile::Disabled,
     )
     .await?;
 
-    let req = mock
-        .last_request()
-        .expect("structured output request recorded");
+    let req = mock.last_request().expect("shell output request recorded");
     let output_item = req.function_call_output(call_id);
     let output = output_item
         .get("output")
         .and_then(Value::as_str)
-        .expect("structured output string");
+        .expect("shell output string");
 
     assert!(
         serde_json::from_str::<Value>(output).is_err(),
-        "expected structured output to be plain text"
+        "expected shell output to be plain text"
     );
     let (header, body) = output
         .split_once("Output:\n")
-        .expect("structured output contains an Output section");
+        .expect("shell output contains an Output section");
     assert_regex_match(
         r"(?s)^Exit code: 0\nWall time: [0-9]+(?:\.[0-9]+)? seconds$",
         header.trim_end(),
@@ -180,34 +109,26 @@ async fn shell_output_structures_fixture_with_serialization(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ShellModelOutput::ShellCommand)]
-async fn shell_output_for_freeform_tool_records_duration(
-    output_type: ShellModelOutput,
-) -> Result<()> {
+async fn shell_output_records_duration() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let server = start_mock_server().await;
-    let mut builder = configure_shell_model(test_codex(), output_type);
+    let mut builder = test_codex().with_model("test-gpt-5-codex");
     let test = builder.build(&server).await?;
 
-    let call_id = "shell-structured";
-    let responses = shell_responses(call_id, vec!["/bin/sh", "-c", "sleep 0.2"], output_type)?;
+    let call_id = "shell-freeform";
+    let responses = shell_responses(call_id, vec!["/bin/sh", "-c", "sleep 0.2"])?;
     let mock = mount_sse_sequence(&server, responses).await;
 
-    test.submit_turn_with_permission_profile(
-        "run the structured shell command",
-        PermissionProfile::Disabled,
-    )
-    .await?;
+    test.submit_turn_with_permission_profile("run the shell command", PermissionProfile::Disabled)
+        .await?;
 
-    let req = mock
-        .last_request()
-        .expect("structured output request recorded");
+    let req = mock.last_request().expect("shell output request recorded");
     let output_item = req.function_call_output(call_id);
     let output = output_item
         .get("output")
         .and_then(Value::as_str)
-        .expect("structured output string");
+        .expect("shell output string");
 
     let expected_pattern = r#"(?s)^Exit code: 0
 Wall time: [0-9]+(?:\.[0-9]+)? seconds
@@ -221,7 +142,7 @@ $"#;
         .captures(output)
         .and_then(|caps| caps.get(1))
         .and_then(|value| value.as_str().parse::<f32>().ok())
-        .expect("expected structured shell output to contain wall time seconds");
+        .expect("expected shell output to contain wall time seconds");
     assert!(
         wall_time_seconds > 0.1,
         "expected wall time to be greater than zero seconds, got {wall_time_seconds}"
@@ -231,53 +152,7 @@ $"#;
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-async fn apply_patch_custom_tool_output_is_structured(
-    output_type: ApplyPatchModelOutput,
-) -> Result<()> {
-    skip_if_no_network!(Ok(()));
-
-    let harness = apply_patch_harness().await?;
-
-    let call_id = "apply-patch-structured";
-    let file_name = "structured.txt";
-    let patch = format!(
-        r#"*** Begin Patch
-*** Add File: {file_name}
-+from custom tool
-*** End Patch
-"#
-    );
-    mount_apply_patch(&harness, call_id, &patch, "done", output_type).await;
-
-    harness
-        .test()
-        .submit_turn_with_permission_profile(
-            "apply the patch via custom tool",
-            PermissionProfile::Disabled,
-        )
-        .await?;
-
-    let output = harness.apply_patch_output(call_id, output_type).await;
-
-    let expected_pattern = format!(
-        r"(?s)^Exit code: 0
-Wall time: [0-9]+(?:\.[0-9]+)? seconds
-Output:
-Success. Updated the following files:
-A {file_name}
-?$"
-    );
-    assert_regex_match(&expected_pattern, output.as_str());
-
-    Ok(())
-}
-
-#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-async fn apply_patch_custom_tool_call_creates_file(
-    output_type: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_custom_tool_call_creates_file() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -287,7 +162,7 @@ async fn apply_patch_custom_tool_call_creates_file(
     let patch = format!(
         "*** Begin Patch\n*** Add File: {file_name}\n+custom tool content\n*** End Patch\n"
     );
-    mount_apply_patch(&harness, call_id, &patch, "apply_patch done", output_type).await;
+    mount_apply_patch(&harness, call_id, &patch, "apply_patch done").await;
 
     harness
         .test()
@@ -297,7 +172,7 @@ async fn apply_patch_custom_tool_call_creates_file(
         )
         .await?;
 
-    let output = harness.apply_patch_output(call_id, output_type).await;
+    let output = harness.apply_patch_output(call_id).await;
 
     let expected_pattern = format!(
         r"(?s)^Exit code: 0
@@ -319,10 +194,7 @@ A {file_name}
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-async fn apply_patch_custom_tool_call_updates_existing_file(
-    output_type: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_custom_tool_call_updates_existing_file() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -333,14 +205,7 @@ async fn apply_patch_custom_tool_call_updates_existing_file(
     let patch = format!(
         "*** Begin Patch\n*** Update File: {file_name}\n@@\n-before\n+after\n*** End Patch\n"
     );
-    mount_apply_patch(
-        &harness,
-        call_id,
-        &patch,
-        "apply_patch update done",
-        output_type,
-    )
-    .await;
+    mount_apply_patch(&harness, call_id, &patch, "apply_patch update done").await;
 
     harness
         .test()
@@ -350,7 +215,7 @@ async fn apply_patch_custom_tool_call_updates_existing_file(
         )
         .await?;
 
-    let output = harness.apply_patch_output(call_id, output_type).await;
+    let output = harness.apply_patch_output(call_id).await;
 
     let expected_pattern = format!(
         r"(?s)^Exit code: 0
@@ -369,10 +234,7 @@ M {file_name}
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-async fn apply_patch_custom_tool_call_reports_failure_output(
-    output_type: ApplyPatchModelOutput,
-) -> Result<()> {
+async fn apply_patch_custom_tool_call_reports_failure_output() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let harness = apply_patch_harness().await?;
@@ -382,14 +244,7 @@ async fn apply_patch_custom_tool_call_reports_failure_output(
     let patch = format!(
         "*** Begin Patch\n*** Update File: {missing_file}\n@@\n-before\n+after\n*** End Patch\n"
     );
-    mount_apply_patch(
-        &harness,
-        call_id,
-        &patch,
-        "apply_patch failure done",
-        output_type,
-    )
-    .await;
+    mount_apply_patch(&harness, call_id, &patch, "apply_patch failure done").await;
 
     harness
         .test()
@@ -399,7 +254,7 @@ async fn apply_patch_custom_tool_call_reports_failure_output(
         )
         .await?;
 
-    let output = harness.apply_patch_output(call_id, output_type).await;
+    let output = harness.apply_patch_output(call_id).await;
 
     let expected_output = format!(
         "apply_patch verification failed: Failed to read file to update {}/{missing_file}: No such file or directory (os error 2)",
@@ -411,49 +266,7 @@ async fn apply_patch_custom_tool_call_reports_failure_output(
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ApplyPatchModelOutput::Freeform)]
-async fn apply_patch_tool_output_is_structured(output_type: ApplyPatchModelOutput) -> Result<()> {
-    skip_if_no_network!(Ok(()));
-
-    let harness = apply_patch_harness().await?;
-
-    let call_id = "apply-patch-function";
-    let file_name = "freeform_apply_patch.txt";
-    let patch =
-        format!("*** Begin Patch\n*** Add File: {file_name}\n+via apply_patch\n*** End Patch\n");
-    mount_apply_patch(
-        &harness,
-        call_id,
-        &patch,
-        "apply_patch function done",
-        output_type,
-    )
-    .await;
-    harness
-        .test()
-        .submit_turn_with_permission_profile(
-            "apply the patch via freeform apply_patch",
-            PermissionProfile::Disabled,
-        )
-        .await?;
-
-    let output = harness.apply_patch_output(call_id, output_type).await;
-    let expected_pattern = format!(
-        r"(?s)^Exit code: 0
-Wall time: [0-9]+(?:\.[0-9]+)? seconds
-Output:
-Success. Updated the following files:
-A {file_name}
-?$"
-    );
-    assert_regex_match(&expected_pattern, output.as_str());
-
-    Ok(())
-}
-
-#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-#[test_case(ShellModelOutput::ShellCommand)]
-async fn shell_output_is_structured_for_nonzero_exit(output_type: ShellModelOutput) -> Result<()> {
+async fn shell_output_is_freeform_for_nonzero_exit() -> Result<()> {
     skip_if_no_network!(Ok(()));
 
     let server = start_mock_server().await;
@@ -461,7 +274,7 @@ async fn shell_output_is_structured_for_nonzero_exit(output_type: ShellModelOutp
     let test = builder.build(&server).await?;
 
     let call_id = "shell-nonzero-exit";
-    let responses = shell_responses(call_id, vec!["/bin/sh", "-c", "exit 42"], output_type)?;
+    let responses = shell_responses(call_id, vec!["/bin/sh", "-c", "exit 42"])?;
     let mock = mount_sse_sequence(&server, responses).await;
 
     test.submit_turn_with_permission_profile(