From fc4b22e7db991c9025f453f46c72d839f4ea049f Mon Sep 17 00:00:00 2001
From: Cody De Arkland <cody@railway.com>
Date: Tue, 12 May 2026 08:53:59 -0700
Subject: [PATCH] fix(agent): preserve part order in history and surface auth
 errors
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Two small follow-ups to the --thread-id history replay shipped in #897:

- render_history now iterates a message's parts once in source order so
  text and `[used tool: ...]` / `[attachment: ...]` markers stay interleaved
  the way the model emitted them, instead of all text appearing before any
  tool/attachment markers.
- If the history fetch fails with an auth error (Unauthorized, expired
  token, invalid token), propagate it instead of swallowing — otherwise
  the user gets a confusing dim warning followed by another auth failure
  on the first message. Non-auth errors (network, rate limit, etc.) still
  fall through to the dim warning + empty history path.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 src/commands/agent.rs | 98 ++++++++++++++++++++++++-------------------
 1 file changed, 56 insertions(+), 42 deletions(-)

diff --git a/src/commands/agent.rs b/src/commands/agent.rs
index 184fb7a90..eab146653 100644
--- a/src/commands/agent.rs
+++ b/src/commands/agent.rs
@@ -31,6 +31,7 @@ use crate::{
         project::get_project,
         service::get_or_prompt_service,
     },
+    errors::RailwayError,
     interact_or,
     util::progress::create_spinner,
 };
@@ -144,12 +145,24 @@ pub async fn command(args: Args) -> Result<()> {
         let history = match args.thread_id.as_deref() {
             Some(tid) => {
                 let messages_url = get_thread_messages_url(&configs, tid);
-                get_thread_messages(&chat_client, &messages_url, Some(10))
-                    .await
-                    .unwrap_or_else(|e| {
+                match get_thread_messages(&chat_client, &messages_url, Some(10)).await {
+                    Ok(messages) => messages,
+                    Err(e) => {
+                        if let Some(railway_err) = e.downcast_ref::<RailwayError>()
+                            && matches!(
+                                railway_err,
+                                RailwayError::Unauthorized
+                                    | RailwayError::UnauthorizedToken(_)
+                                    | RailwayError::UnauthorizedLogin
+                                    | RailwayError::InvalidRailwayToken(_)
+                            )
+                        {
+                            return Err(e);
+                        }
                         eprintln!("{}", format!("Could not load thread history: {e}").dimmed());
                         Vec::new()
-                    })
+                    }
+                }
             }
             None => Vec::new(),
         };
@@ -169,6 +182,17 @@ pub async fn command(args: Args) -> Result<()> {
     }
 }
 
+fn render_text_block(text: &str, is_assistant: bool, skin: &termimad::MadSkin) {
+    if text.trim().is_empty() {
+        return;
+    }
+    if is_assistant {
+        skin.print_text(text);
+    } else {
+        println!("{}", text);
+    }
+}
+
 fn render_history(messages: &[ChatMessage], thread_id: Option<&str>) {
     let banner = match thread_id {
         Some(id) => format!("── resuming thread {id} ──"),
@@ -187,47 +211,37 @@ fn render_history(messages: &[ChatMessage], thread_id: Option<&str>) {
         };
         println!("{}", role_label);
 
-        let text_parts: Vec<&str> = message
-            .parts
-            .iter()
-            .filter_map(|part| match part {
-                ChatMessagePart::Text { content } => Some(content.as_str()),
-                _ => None,
-            })
-            .collect();
-
-        let text = if text_parts.is_empty() {
-            message.content.clone()
+        if message.parts.is_empty() {
+            render_text_block(&message.content, is_assistant, &skin);
         } else {
-            text_parts.join("")
-        };
-        if !text.trim().is_empty() {
-            if is_assistant {
-                skin.print_text(&text);
-            } else {
-                println!("{}", text);
-            }
-        }
-
-        for part in &message.parts {
-            match part {
-                ChatMessagePart::Tool {
-                    tool_name,
-                    is_error,
-                    ..
-                } => {
-                    let label = if *is_error {
-                        format!("[tool failed: {tool_name}]")
-                    } else {
-                        format!("[used tool: {tool_name}]")
-                    };
-                    println!("{}", label.dimmed().italic());
-                }
-                ChatMessagePart::Attachment { name, .. } => {
-                    println!("{}", format!("[attachment: {name}]").dimmed().italic());
+            let mut text_buf = String::new();
+            for part in &message.parts {
+                match part {
+                    ChatMessagePart::Text { content } => {
+                        text_buf.push_str(content);
+                    }
+                    ChatMessagePart::Tool {
+                        tool_name,
+                        is_error,
+                        ..
+                    } => {
+                        render_text_block(&text_buf, is_assistant, &skin);
+                        text_buf.clear();
+                        let label = if *is_error {
+                            format!("[tool failed: {tool_name}]")
+                        } else {
+                            format!("[used tool: {tool_name}]")
+                        };
+                        println!("{}", label.dimmed().italic());
+                    }
+                    ChatMessagePart::Attachment { name, .. } => {
+                        render_text_block(&text_buf, is_assistant, &skin);
+                        text_buf.clear();
+                        println!("{}", format!("[attachment: {name}]").dimmed().italic());
+                    }
                 }
-                ChatMessagePart::Text { .. } => {}
             }
+            render_text_block(&text_buf, is_assistant, &skin);
         }
 
         println!();