deepseek: Update DeepSeek Flash to V4.1 (#64014)

# Objective

deepseek API: https://api-docs.deepseek.com/updates/

## Solution

deepseek rename deepseek v4 flash to deepseek flash



https://github.com/user-attachments/assets/72c473c9-a4bf-49e0-a7d6-0217a6dcc65b


---

Release Notes:

- agent: Added support for DeepSeek Flash 4.1

---------

Signed-off-by: Xiaobo Liu <cppcoffee@gmail.com>
Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>
Co-authored-by: Bennet Bo Fenner <bennet@zed.dev>

crates/deepseek/src/deepseek.rs

@@ -50,8 +50,8 @@ impl From<Role> for String {
 #[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 #[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq)]
 pub enum Model {
-    #[serde(rename = "deepseek-v4-flash")]
-    V4Flash,
+    #[serde(rename = "deepseek-flash")]
+    V4_1Flash,
     #[serde(rename = "deepseek-v4-pro")]
     #[default]
     V4Pro,
@@ -67,12 +67,12 @@ pub enum Model {
 
 impl Model {
     pub fn default_fast() -> Self {
-        Model::V4Flash
+        Model::V4_1Flash
     }
 
     pub fn from_id(id: &str) -> Result<Self> {
         match id {
-            "deepseek-v4-flash" => Ok(Self::V4Flash),
+            "deepseek-flash" => Ok(Self::V4_1Flash),
             "deepseek-v4-pro" => Ok(Self::V4Pro),
             _ => anyhow::bail!("invalid model id {id}"),
         }
@@ -80,7 +80,7 @@ impl Model {
 
     pub fn id(&self) -> &str {
         match self {
-            Self::V4Flash => "deepseek-v4-flash",
+            Self::V4_1Flash => "deepseek-flash",
             Self::V4Pro => "deepseek-v4-pro",
             Self::Custom { name, .. } => name,
         }
@@ -88,7 +88,7 @@ impl Model {
 
     pub fn display_name(&self) -> &str {
         match self {
-            Self::V4Flash => "DeepSeek V4 Flash",
+            Self::V4_1Flash => "DeepSeek V4.1 Flash",
             Self::V4Pro => "DeepSeek V4 Pro",
             Self::Custom {
                 name, display_name, ..
@@ -96,16 +96,20 @@ impl Model {
         }
     }
 
+    pub fn supports_images(&self) -> bool {
+        matches!(self, Self::V4_1Flash)
+    }
+
     pub fn max_token_count(&self) -> u64 {
         match self {
-            Self::V4Flash | Self::V4Pro => 1_000_000,
+            Self::V4_1Flash | Self::V4Pro => 1_000_000,
             Self::Custom { max_tokens, .. } => *max_tokens,
         }
     }
 
     pub fn max_output_tokens(&self) -> Option<u64> {
         match self {
-            Self::V4Flash | Self::V4Pro => Some(384_000),
+            Self::V4_1Flash | Self::V4Pro => Some(384_000),
             Self::Custom {
                 max_output_tokens, ..
             } => *max_output_tokens,
@@ -195,17 +199,62 @@ pub enum RequestMessage {
         reasoning_content: Option<String>,
     },
     User {
-        content: String,
+        content: MessageContent,
     },
     System {
         content: String,
     },
     Tool {
-        content: String,
+        content: MessageContent,
         tool_call_id: String,
     },
 }
 
+#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
+#[serde(untagged)]
+pub enum MessageContent {
+    Plain(String),
+    Multipart(Vec<MessagePart>),
+}
+
+impl MessageContent {
+    pub fn push_part(&mut self, part: MessagePart) {
+        match self {
+            MessageContent::Plain(text) => {
+                let text = std::mem::take(text);
+                *self = MessageContent::Multipart(vec![MessagePart::Text { text }, part]);
+            }
+            MessageContent::Multipart(parts) => parts.push(part),
+        }
+    }
+}
+
+impl From<Vec<MessagePart>> for MessageContent {
+    fn from(mut parts: Vec<MessagePart>) -> Self {
+        if let [MessagePart::Text { text }] = parts.as_mut_slice() {
+            MessageContent::Plain(std::mem::take(text))
+        } else {
+            MessageContent::Multipart(parts)
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
+#[serde(tag = "type")]
+pub enum MessagePart {
+    #[serde(rename = "text")]
+    Text { text: String },
+    #[serde(rename = "image_url")]
+    Image { image_url: ImageUrl },
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
+pub struct ImageUrl {
+    pub url: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub detail: Option<String>,
+}
+
 #[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
 pub struct ToolCall {
     pub id: String,

crates/language_models/src/provider/deepseek.rs

@@ -166,7 +166,7 @@ impl LanguageModelProvider for DeepSeekLanguageModelProvider {
     fn provided_models(&self, cx: &App) -> Vec<Arc<dyn LanguageModel>> {
         let mut models = IndexMap::default();
 
-        models.insert("deepseek-v4-flash", deepseek::Model::V4Flash);
+        models.insert("deepseek-flash", deepseek::Model::V4_1Flash);
         models.insert("deepseek-v4-pro", deepseek::Model::V4Pro);
 
         for available_model in &Self::settings(cx).available_models {
@@ -284,7 +284,7 @@ impl LanguageModel for DeepSeekLanguageModel {
     fn supports_thinking(&self) -> bool {
         matches!(
             self.model,
-            deepseek::Model::V4Flash | deepseek::Model::V4Pro
+            deepseek::Model::V4_1Flash | deepseek::Model::V4Pro
         )
     }
 
@@ -317,7 +317,7 @@ impl LanguageModel for DeepSeekLanguageModel {
     }
 
     fn supports_images(&self) -> bool {
-        false
+        self.model.supports_images()
     }
 
     fn telemetry_id(&self) -> String {
@@ -376,6 +376,8 @@ pub fn into_deepseek(
         .as_ref()
         .is_some_and(|thinking| thinking.kind == deepseek::ThinkingType::Enabled);
 
+    let supports_images = model.supports_images();
+
     let mut messages = Vec::new();
     let mut current_reasoning: Option<String> = None;
 
@@ -390,15 +392,24 @@ pub fn into_deepseek(
                     };
 
                     if should_add {
-                        messages.push(match message.role {
-                            Role::User => deepseek::RequestMessage::User { content: text },
-                            Role::Assistant => deepseek::RequestMessage::Assistant {
-                                content: Some(text),
-                                tool_calls: Vec::new(),
-                                reasoning_content: current_reasoning.take(),
-                            },
-                            Role::System => deepseek::RequestMessage::System { content: text },
-                        });
+                        match message.role {
+                            Role::User => {
+                                add_user_message_content_part(
+                                    deepseek::MessagePart::Text { text },
+                                    &mut messages,
+                                );
+                            }
+                            Role::Assistant => {
+                                messages.push(deepseek::RequestMessage::Assistant {
+                                    content: Some(text),
+                                    tool_calls: Vec::new(),
+                                    reasoning_content: current_reasoning.take(),
+                                });
+                            }
+                            Role::System => {
+                                messages.push(deepseek::RequestMessage::System { content: text });
+                            }
+                        }
                     }
                 }
                 MessageContent::Thinking { text, .. } => {
@@ -406,6 +417,17 @@ pub fn into_deepseek(
                     current_reasoning.get_or_insert_default().push_str(&text);
                 }
                 MessageContent::RedactedThinking(_) => {}
+                MessageContent::Image(image) if message.role == Role::User => {
+                    add_user_message_content_part(
+                        deepseek::MessagePart::Image {
+                            image_url: deepseek::ImageUrl {
+                                url: image.to_base64_url(),
+                                detail: None,
+                            },
+                        },
+                        &mut messages,
+                    );
+                }
                 MessageContent::Image(_) => {}
                 MessageContent::Compaction(_) => {}
                 MessageContent::ToolUse(tool_use) => {
@@ -436,24 +458,32 @@ pub fn into_deepseek(
                     }
                 }
                 MessageContent::ToolResult(tool_result) => {
-                    let mut text_parts: Vec<String> = Vec::new();
-                    for part in &tool_result.content {
-                        match part {
+                    let content: Vec<deepseek::MessagePart> = tool_result
+                        .content
+                        .iter()
+                        .filter_map(|part| match part {
                             LanguageModelToolResultContent::Text(text) => {
-                                text_parts.push(text.to_string());
+                                Some(deepseek::MessagePart::Text {
+                                    text: text.to_string(),
+                                })
                             }
-                            LanguageModelToolResultContent::Image(_) => {
-                                text_parts.push("[Tool responded with an image]".to_string());
+                            LanguageModelToolResultContent::Image(image) => {
+                                if supports_images {
+                                    Some(deepseek::MessagePart::Image {
+                                        image_url: deepseek::ImageUrl {
+                                            url: image.to_base64_url(),
+                                            detail: None,
+                                        },
+                                    })
+                                } else {
+                                    None
+                                }
                             }
-                        }
-                    }
-                    let content = if text_parts.is_empty() {
-                        "<Tool returned an empty string>".to_string()
-                    } else {
-                        text_parts.join("\n")
-                    };
+                        })
+                        .collect();
+
                     messages.push(deepseek::RequestMessage::Tool {
-                        content,
+                        content: content.into(),
                         tool_call_id: tool_result.tool_use_id.to_string(),
                     });
                 }
@@ -508,12 +538,28 @@ pub fn into_deepseek(
     })
 }
 
+fn add_user_message_content_part(
+    new_part: deepseek::MessagePart,
+    messages: &mut Vec<deepseek::RequestMessage>,
+) {
+    match messages.last_mut() {
+        Some(deepseek::RequestMessage::User { content }) => {
+            content.push_part(new_part);
+        }
+        _ => {
+            messages.push(deepseek::RequestMessage::User {
+                content: deepseek::MessageContent::from(vec![new_part]),
+            });
+        }
+    }
+}
+
 fn deepseek_thinking(
     model: &deepseek::Model,
     thinking_allowed: bool,
 ) -> Option<deepseek::Thinking> {
     let kind = match model {
-        deepseek::Model::V4Flash | deepseek::Model::V4Pro => {
+        deepseek::Model::V4_1Flash | deepseek::Model::V4Pro => {
             if thinking_allowed {
                 deepseek::ThinkingType::Enabled
             } else {
@@ -671,6 +717,47 @@ impl DeepSeekEventMapper {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use language_model::{LanguageModelImage, LanguageModelRequestMessage};
+    use serde_json::json;
+
+    #[test]
+    fn serializes_deepseek_image_parts() -> Result<()> {
+        let image = LanguageModelImage {
+            source: SharedString::from("aGVsbG8="),
+        };
+        let image_url = image.to_base64_url();
+        let request = into_deepseek(
+            LanguageModelRequest {
+                messages: vec![LanguageModelRequestMessage {
+                    role: Role::User,
+                    content: vec![
+                        MessageContent::Text("Describe this".to_string()),
+                        MessageContent::Image(image),
+                    ],
+                    cache: false,
+                    reasoning_details: None,
+                }],
+                ..Default::default()
+            },
+            &deepseek::Model::V4_1Flash,
+            Some(1024),
+        )?;
+
+        assert_eq!(
+            serde_json::to_value(&request.messages)?,
+            json!([
+                {
+                    "role": "user",
+                    "content": [
+                        { "type": "text", "text": "Describe this" },
+                        { "type": "image_url", "image_url": { "url": image_url } }
+                    ]
+                }
+            ])
+        );
+
+        Ok(())
+    }
 
     #[test]
     fn request_output_limits_reach_deepseek_payloads() -> Result<()> {

crates/opencode/src/opencode.rs

@@ -138,8 +138,8 @@ pub enum Model {
     // -- OpenAI Chat Completions protocol models --
     #[serde(rename = "deepseek-v4-pro")]
     DeepSeekV4Pro,
-    #[serde(rename = "deepseek-v4-flash")]
-    DeepSeekV4Flash,
+    #[serde(rename = "deepseek-flash")]
+    DeepSeekV4_1Flash,
     #[serde(rename = "minimax-m2.5")]
     MiniMaxM2_5,
     #[serde(rename = "glm-5")]
@@ -226,7 +226,6 @@ impl Model {
             | Self::MiniMaxM2_7
             | Self::MiniMaxM3
             | Self::DeepSeekV4Pro
-            | Self::DeepSeekV4Flash
             | Self::Gpt5_6Luna
             | Self::Qwen3_6Plus => &[OpenCodeSubscription::Zen, OpenCodeSubscription::Go],
 
@@ -237,6 +236,7 @@ impl Model {
             | Self::Qwen3_7Plus
             | Self::Qwen3_7Max
             | Self::Qwen3_8Max
+            | Self::DeepSeekV4_1Flash
             | Self::Hy3 => &[OpenCodeSubscription::Go],
 
             // Deprecated on Go (per models.dev); still offered on Zen
@@ -295,7 +295,7 @@ impl Model {
             Self::Gemini3_7Flash => "gemini-3.7-flash",
 
             Self::DeepSeekV4Pro => "deepseek-v4-pro",
-            Self::DeepSeekV4Flash => "deepseek-v4-flash",
+            Self::DeepSeekV4_1Flash => "deepseek-flash",
             Self::MiniMaxM2_5 => "minimax-m2.5",
             Self::Glm5 => "glm-5",
             Self::Glm5_1 => "glm-5.1",
@@ -367,7 +367,7 @@ impl Model {
             Self::Gemini3_7Flash => "Gemini 3.7 Flash",
 
             Self::DeepSeekV4Pro => "DeepSeek V4 Pro",
-            Self::DeepSeekV4Flash => "DeepSeek V4 Flash",
+            Self::DeepSeekV4_1Flash => "DeepSeek V4.1 Flash",
             Self::MiniMaxM2_5 => "MiniMax M2.5",
             Self::Glm5 => "GLM 5",
             Self::Glm5_1 => "GLM 5.1",
@@ -468,7 +468,7 @@ impl Model {
             | Self::MimoV2_5Pro
             | Self::MimoV2_5
             | Self::DeepSeekV4Pro
-            | Self::DeepSeekV4Flash
+            | Self::DeepSeekV4_1Flash
             | Self::Hy3 => ApiProtocol::OpenAiChat,
 
             Self::Grok4_6 | Self::Grok4_5 | Self::MuseSpark1_2 => ApiProtocol::OpenAiResponses,
@@ -480,7 +480,7 @@ impl Model {
     pub fn interleaved_reasoning(&self) -> bool {
         match self {
             Self::DeepSeekV4Pro
-            | Self::DeepSeekV4Flash
+            | Self::DeepSeekV4_1Flash
             | Self::KimiK2_5
             | Self::KimiK2_6
             | Self::KimiK2_7Code
@@ -571,7 +571,7 @@ impl Model {
             }
             Self::Qwen3_8Max | Self::Qwen3_7Max | Self::Qwen3_7Plus => 1_000_000,
             Self::Hy3 => 256_000,
-            Self::DeepSeekV4Pro | Self::DeepSeekV4Flash => 1_000_000,
+            Self::DeepSeekV4Pro | Self::DeepSeekV4_1Flash => 1_000_000,
 
             Self::Custom { max_tokens, .. } => *max_tokens,
         }
@@ -655,7 +655,7 @@ impl Model {
                 Some(65_536)
             }
             Self::Qwen3_8Max => Some(131_072),
-            Self::DeepSeekV4Pro | Self::DeepSeekV4Flash => Some(384_000),
+            Self::DeepSeekV4Pro | Self::DeepSeekV4_1Flash => Some(384_000),
             Self::MimoV2_5Pro | Self::MimoV2_5 => Some(128_000),
             Self::Hy3 => Some(64_000),
 
@@ -730,7 +730,8 @@ impl Model {
             | Self::Qwen3_6Plus
             | Self::Qwen3_7Plus
             | Self::Qwen3_8Max
-            | Self::MiniMaxM3 => true,
+            | Self::MiniMaxM3
+            | Self::DeepSeekV4_1Flash => true,
 
             // OpenAI-compatible models without image support
             Self::MiniMaxM2_5
@@ -741,7 +742,6 @@ impl Model {
             | Self::MiniMaxM2_7
             | Self::MimoV2_5Pro
             | Self::DeepSeekV4Pro
-            | Self::DeepSeekV4Flash
             | Self::Qwen3_7Max
             | Self::Hy3 => false,
 
@@ -857,7 +857,7 @@ impl Model {
             ]),
 
             // DeepSeek models
-            Self::DeepSeekV4Pro | Self::DeepSeekV4Flash => Some(vec![
+            Self::DeepSeekV4Pro | Self::DeepSeekV4_1Flash => Some(vec![
                 // OpenCode also supports Low&Medium but as per DeepSeek those are mapped to High
                 ReasoningEffort::High,
                 ReasoningEffort::Max,

docs/src/ai/use-api-access.md

@@ -285,8 +285,8 @@ limits, or a custom endpoint.
       "api_url": "https://api.deepseek.com/v1",
       "available_models": [
         {
-          "name": "deepseek-v4-flash",
-          "display_name": "DeepSeek V4 Flash",
+          "name": "deepseek-flash",
+          "display_name": "DeepSeek V4.1 Flash",
           "max_tokens": 1000000,
           "max_output_tokens": 384000
         },