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Merged
wsp1911 merged 1 commit into from
Aug 1, 2026
Merged

fix(ai): align Anthropic and OpenAI message conversion #1949

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112 changes: 68 additions & 44 deletions src/crates/adapters/ai-adapters/src/providers/anthropic/message_converter.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -40,14 +40,14 @@ impl AnthropicMessageConverter {
}
}

// Anthropic requires user/assistant messages to alternate
// Canonicalize consecutive turns into a single content-block message.
let mut merged_messages = Self::merge_consecutive_messages(anthropic_messages);
Self::trim_final_assistant_trailing_whitespace(&mut merged_messages);

(system_message, merged_messages)
}

/// Merge consecutive same-role messages to keep user/assistant alternating
/// Merge consecutive same-role turns while preserving their content blocks.
fn merge_consecutive_messages(messages: Vec<Value>) -> Vec<Value> {
let mut merged: Vec<Value> = Vec::new();

Expand All @@ -57,47 +57,13 @@ impl AnthropicMessageConverter {
if let Some(last) = merged.last_mut() {
let last_role = last.get("role").and_then(|r| r.as_str()).unwrap_or("");

if last_role == role && role == "user" {
let current_content = msg.get("content");
let last_content = last.get_mut("content");

match (last_content, current_content) {
(Some(Value::Array(last_arr)), Some(Value::Array(curr_arr))) => {
last_arr.extend(curr_arr.clone());
continue;
}
(Some(Value::Array(last_arr)), Some(Value::String(curr_str))) => {
last_arr.push(json!({
"type": "text",
"text": curr_str
}));
continue;
}
(Some(Value::String(last_str)), Some(Value::Array(curr_arr))) => {
let mut new_content = vec![json!({
"type": "text",
"text": last_str
})];
new_content.extend(curr_arr.clone());
*last = json!({
"role": "user",
"content": new_content
});
continue;
}
(Some(Value::String(last_str)), Some(Value::String(curr_str))) => {
let merged_text = if last_str.is_empty() {
curr_str.to_string()
} else {
format!("{}\n\n{}", last_str, curr_str)
};
*last = json!({
"role": "user",
"content": merged_text
});
continue;
}
_ => {}
if last_role == role && matches!(role, "user" | "assistant") {
if let (Some(last_blocks), Some(current_blocks)) = (
last.get_mut("content").and_then(Value::as_array_mut),
msg.get("content").and_then(Value::as_array),
) {
last_blocks.extend(current_blocks.iter().cloned());
continue;
}
}
}
Expand Down Expand Up @@ -152,7 +118,10 @@ impl AnthropicMessageConverter {

json!({
"role": "user",
"content": content
"content": [{
"type": "text",
"text": content
}]
})
}

Expand Down Expand Up @@ -306,4 +275,59 @@ mod tests {
assert_eq!(content[0]["type"], json!("text"));
assert_eq!(content[0]["text"], json!("<assistant_prefill>"));
}

#[test]
fn uses_content_blocks_and_merges_consecutive_turns() {
let tool_result = Message {
role: "tool".to_string(),
content: Some("tool output".to_string()),
reasoning_content: None,
thinking_signature: None,
tool_calls: None,
tool_call_id: Some("call_1".to_string()),
name: None,
is_error: None,
tool_image_attachments: None,
};

let (_, messages) = AnthropicMessageConverter::convert_messages(vec![
Message::user("first user turn".to_string()),
Message::user("second user turn".to_string()),
Message::assistant("first assistant turn".to_string()),
Message::assistant("second assistant turn".to_string()),
tool_result,
Message::user("follow-up".to_string()),
]);

assert_eq!(
messages,
vec![
json!({
"role": "user",
"content": [
{ "type": "text", "text": "first user turn" },
{ "type": "text", "text": "second user turn" }
]
}),
json!({
"role": "assistant",
"content": [
{ "type": "text", "text": "first assistant turn" },
{ "type": "text", "text": "second assistant turn" }
]
}),
json!({
"role": "user",
"content": [
{
"type": "tool_result",
"tool_use_id": "call_1",
"content": "tool output"
},
{ "type": "text", "text": "follow-up" }
]
})
]
);
}
}
56 changes: 47 additions & 9 deletions src/crates/adapters/ai-adapters/src/providers/openai/message_converter.rs
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -314,9 +314,6 @@ impl OpenAIMessageConverter {
if let Some(id) = msg.tool_call_id {
openai_msg["tool_call_id"] = Value::String(id);
}
if let Some(name) = msg.name {
openai_msg["name"] = Value::String(name);
}
return openai_msg;
}
}
Expand All @@ -331,8 +328,7 @@ impl OpenAIMessageConverter {
if let Some(content) = msg.content {
if content.trim().is_empty() {
if msg.role == "assistant" && has_tool_calls {
// OpenAI requires the content field; use a space for tool-call cases.
openai_msg["content"] = Value::String(" ".to_string());
openai_msg["content"] = Value::String(content);
} else if msg.role == "tool" {
openai_msg["content"] = Value::String("Tool execution completed".to_string());
warn!(
Expand All @@ -354,8 +350,6 @@ impl OpenAIMessageConverter {
}
} else {
if msg.role == "assistant" && has_tool_calls {
// OpenAI requires the content field; use a space for tool-call cases.
openai_msg["content"] = Value::String(" ".to_string());
} else if msg.role == "tool" {
openai_msg["content"] = Value::String("Tool execution completed".to_string());

Expand Down Expand Up @@ -403,8 +397,10 @@ impl OpenAIMessageConverter {
openai_msg["tool_call_id"] = Value::String(tool_call_id);
}

if let Some(name) = msg.name {
openai_msg["name"] = Value::String(name);
if msg.role != "tool" {
if let Some(name) = msg.name {
openai_msg["name"] = Value::String(name);
}
}

openai_msg
Expand Down Expand Up @@ -594,6 +590,7 @@ mod tests {
assert_eq!(content[0]["type"], json!("image_url"));
assert_eq!(content[1]["type"], json!("text"));
assert_eq!(content[1]["text"], json!("ok"));
assert!(openai[0].get("name").is_none());
}

#[test]
Expand Down Expand Up @@ -621,6 +618,7 @@ mod tests {
let openai = OpenAIMessageConverter::convert_messages(vec![msg]);

assert_eq!(openai[0]["content"], json!(raw_json));
assert!(openai[0].get("name").is_none());
}

#[test]
Expand Down Expand Up @@ -758,6 +756,46 @@ mod tests {
assert_eq!(openai[0]["reasoning_content"], json!(""));
}

#[test]
fn preserves_empty_assistant_content_for_tool_calls() {
let msg = Message {
role: "assistant".to_string(),
content: Some(String::new()),
reasoning_content: Some("thinking".to_string()),
thinking_signature: None,
tool_calls: Some(vec![ToolCall {
id: "call_1".to_string(),
name: "get_weather".to_string(),
arguments: json!({"city": "Beijing"}),
raw_arguments: None,
}]),
tool_call_id: None,
name: None,
is_error: None,
tool_image_attachments: None,
};

let openai = OpenAIMessageConverter::convert_messages(vec![msg]);

assert_eq!(openai[0]["content"], json!(""));
assert_eq!(openai[0]["reasoning_content"], json!("thinking"));
}

#[test]
fn omits_missing_assistant_content_for_tool_calls() {
let openai =
OpenAIMessageConverter::convert_messages(vec![Message::assistant_with_tools(vec![
ToolCall {
id: "call_1".to_string(),
name: "get_weather".to_string(),
arguments: json!({"city": "Beijing"}),
raw_arguments: None,
},
])]);

assert!(openai[0].get("content").is_none());
}

#[test]
fn trims_trailing_whitespace_from_final_assistant_prefill_for_chat_completions() {
let openai = OpenAIMessageConverter::convert_messages(vec![
Expand Down
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