feat(chat): #155 paste image depuis presse-papier dans le composer custom (QA verte)

- frontend: onPaste sur CustomAgentChatView, détection MIME image, chip/preview d'attachment, envoi via le contrat #154 (adapters/agent, ports)

- backend: import d'image par bytes dans le store attachments (commands, chat_attachments app+infra, dto, ports) + tests

crates/app-tauri/src/commands.rs

@@ -4,7 +4,7 @@
 //! [`AppState`], map `Result<Output, AppError>` to `Result<ResponseDto,
 //! ErrorDto>`. No business logic lives here.
 
-use base64::engine::general_purpose::URL_SAFE_NO_PAD;
+use base64::engine::general_purpose::{STANDARD, STANDARD_NO_PAD, URL_SAFE, URL_SAFE_NO_PAD};
 use base64::Engine;
 use serde::{Deserialize, Serialize};
 use tauri::ipc::Channel;
@@ -2326,22 +2326,17 @@ async fn import_chat_attachments_for_session(
     for path in legacy_paths {
         if seen_paths.insert(path.clone()) {
             items.push(application::ImportChatAttachmentItem {
-                path,
+                source: application::ImportChatAttachmentSource::Path(path),
                 mime: None,
                 source_kind: domain::ChatAttachmentSourceKind::LocalFile,
             });
         }
     }
     for attachment in attachments {
-        if seen_paths.insert(attachment.path.clone()) {
+        let Some(item) = chat_attachment_input_to_item(attachment, &mut seen_paths)? else {
-            items.push(application::ImportChatAttachmentItem {
+            continue;
-                path: attachment.path,
+        };
-                mime: attachment.mime,
+        items.push(item);
-                source_kind: attachment
-                    .source_kind
-                    .unwrap_or(domain::ChatAttachmentSourceKind::LocalFile),
-            });
-        }
     }
 
     let output = state
@@ -2361,6 +2356,71 @@ async fn import_chat_attachments_for_session(
         .collect())
 }
 
+fn chat_attachment_input_to_item(
+    attachment: ChatAttachmentInputDto,
+    seen_paths: &mut std::collections::HashSet<String>,
+) -> Result<Option<application::ImportChatAttachmentItem>, ErrorDto> {
+    let has_path = attachment
+        .path
+        .as_deref()
+        .is_some_and(|path| !path.is_empty());
+    let has_content = attachment
+        .content_base64
+        .as_deref()
+        .is_some_and(|content| !content.is_empty());
+    if has_path && has_content {
+        return Err(ErrorDto::from(AppError::Invalid(
+            "chat attachment must provide either path or contentBase64, not both".to_owned(),
+        )));
+    }
+    if let Some(path) = attachment.path.filter(|path| !path.is_empty()) {
+        if !seen_paths.insert(path.clone()) {
+            return Ok(None);
+        }
+        return Ok(Some(application::ImportChatAttachmentItem {
+            source: application::ImportChatAttachmentSource::Path(path),
+            mime: attachment.mime,
+            source_kind: attachment
+                .source_kind
+                .unwrap_or(domain::ChatAttachmentSourceKind::LocalFile),
+        }));
+    }
+    if let Some(content_base64) = attachment
+        .content_base64
+        .filter(|content| !content.is_empty())
+    {
+        let filename = attachment.filename.ok_or_else(|| {
+            ErrorDto::from(AppError::Invalid(
+                "chat attachment bytes require filename".to_owned(),
+            ))
+        })?;
+        let bytes = decode_attachment_content_base64(&content_base64)?;
+        return Ok(Some(application::ImportChatAttachmentItem {
+            source: application::ImportChatAttachmentSource::Bytes { filename, bytes },
+            mime: attachment.mime,
+            source_kind: attachment
+                .source_kind
+                .unwrap_or(domain::ChatAttachmentSourceKind::Clipboard),
+        }));
+    }
+    Err(ErrorDto::from(AppError::Invalid(
+        "chat attachment must provide path or contentBase64".to_owned(),
+    )))
+}
+
+fn decode_attachment_content_base64(raw: &str) -> Result<Vec<u8>, ErrorDto> {
+    STANDARD
+        .decode(raw)
+        .or_else(|_| STANDARD_NO_PAD.decode(raw))
+        .or_else(|_| URL_SAFE.decode(raw))
+        .or_else(|_| URL_SAFE_NO_PAD.decode(raw))
+        .map_err(|_| {
+            ErrorDto::from(AppError::Invalid(
+                "invalid chat attachment contentBase64".to_owned(),
+            ))
+        })
+}
+
 fn prompt_with_imported_attachments(prompt: &str, attachments: &[ChatAttachmentDto]) -> String {
     if attachments.is_empty() {
         return prompt.to_owned();

crates/app-tauri/tests/dto_chat.rs

@@ -119,7 +119,26 @@ fn chat_attachment_input_dto_deserialises_camel_case() {
     }))
     .unwrap();
 
-    assert_eq!(dto.path, "/tmp/picked.png");
+    assert_eq!(dto.path.as_deref(), Some("/tmp/picked.png"));
+    assert_eq!(dto.filename, None);
+    assert_eq!(dto.content_base64, None);
+    assert_eq!(dto.mime.as_deref(), Some("image/png"));
+    assert_eq!(dto.source_kind, Some(ChatAttachmentSourceKind::Clipboard));
+}
+
+#[test]
+fn chat_attachment_input_dto_deserialises_clipboard_bytes_camel_case() {
+    let dto: ChatAttachmentInputDto = serde_json::from_value(json!({
+        "filename": "clipboard.png",
+        "contentBase64": "cG5nIGJ5dGVz",
+        "mime": "image/png",
+        "sourceKind": "clipboard"
+    }))
+    .unwrap();
+
+    assert_eq!(dto.path, None);
+    assert_eq!(dto.filename.as_deref(), Some("clipboard.png"));
+    assert_eq!(dto.content_base64.as_deref(), Some("cG5nIGJ5dGVz"));
     assert_eq!(dto.mime.as_deref(), Some("image/png"));
     assert_eq!(dto.source_kind, Some(ChatAttachmentSourceKind::Clipboard));
 }
@@ -154,6 +173,11 @@ fn import_chat_attachments_request_response_use_camel_case() {
             "path": "/tmp/picked.png",
             "mime": "image/png",
             "sourceKind": "dragDrop"
+        }, {
+            "filename": "clipboard.png",
+            "contentBase64": "cG5nIGJ5dGVz",
+            "mime": "image/png",
+            "sourceKind": "clipboard"
         }]
     }))
     .unwrap();
@@ -164,6 +188,10 @@ fn import_chat_attachments_request_response_use_camel_case() {
         request.attachments[0].source_kind,
         Some(ChatAttachmentSourceKind::DragDrop)
     );
+    assert_eq!(
+        request.attachments[1].content_base64.as_deref(),
+        Some("cG5nIGJ5dGVz")
+    );
 
     let response = ImportChatAttachmentsResponseDto {
         attachments: vec![ChatAttachmentDto {

crates/application/src/chat_attachments.rs

@@ -30,14 +30,28 @@ pub struct ImportChatAttachmentsInput {
 /// One source attachment import request.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImportChatAttachmentItem {
-    /// Local source path supplied by the driving adapter.
+    /// Source payload supplied by the driving adapter.
-    pub path: String,
+    pub source: ImportChatAttachmentSource,
     /// Optional MIME type supplied by the driving adapter.
     pub mime: Option<String>,
     /// Origin kind.
     pub source_kind: ChatAttachmentSourceKind,
 }
 
+/// Source payload for a chat attachment import.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ImportChatAttachmentSource {
+    /// Local source path supplied by the driving adapter.
+    Path(String),
+    /// In-memory bytes supplied by the driving adapter.
+    Bytes {
+        /// Display filename to persist in metadata and storage name.
+        filename: String,
+        /// Raw content bytes.
+        bytes: Vec<u8>,
+    },
+}
+
 /// Output of [`ImportChatAttachments::execute`].
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImportChatAttachmentsOutput {
@@ -70,28 +84,44 @@ impl ImportChatAttachments {
     ) -> Result<ImportChatAttachmentsOutput, AppError> {
         let mut imported = Vec::with_capacity(input.attachments.len());
         for item in input.attachments {
-            let filename = filename_from_path(&item.path)?;
+            let filename = filename_from_source(&item.source)?;
             validate_attachment_filename(&filename)?;
             let mime = sanitize_mime(item.mime.as_deref(), &filename)?;
             let id = ChatAttachmentId::new(self.ids.new_uuid().to_string())
                 .map_err(|err| AppError::Invalid(err.to_string()))?;
-            let attachment = self
+            let import = ChatAttachmentImport {
-                .store
+                id,
-                .import_from_path(
+                filename,
-                    &input.project.root,
+                mime,
-                    input.project.id,
+                source_kind: item.source_kind,
-                    input.agent_id,
+                created_at: now(&self.clock),
-                    input.session_id,
+            };
-                    &LocalPath::new(item.path),
+            let attachment = match item.source {
-                    ChatAttachmentImport {
+                ImportChatAttachmentSource::Path(path) => {
-                        id,
+                    self.store
-                        filename,
+                        .import_from_path(
-                        mime,
+                            &input.project.root,
-                        source_kind: item.source_kind,
+                            input.project.id,
-                        created_at: now(&self.clock),
+                            input.agent_id,
-                    },
+                            input.session_id,
-                )
+                            &LocalPath::new(path),
-                .await?;
+                            import,
+                        )
+                        .await?
+                }
+                ImportChatAttachmentSource::Bytes { bytes, .. } => {
+                    self.store
+                        .import_from_bytes(
+                            &input.project.root,
+                            input.project.id,
+                            input.agent_id,
+                            input.session_id,
+                            &bytes,
+                            import,
+                        )
+                        .await?
+                }
+            };
             imported.push(attachment);
         }
         Ok(ImportChatAttachmentsOutput {
@@ -112,6 +142,13 @@ fn filename_from_path(path: &str) -> Result<String, AppError> {
         .ok_or_else(|| AppError::Invalid("invalid attachment filename".to_owned()))
 }
 
+fn filename_from_source(source: &ImportChatAttachmentSource) -> Result<String, AppError> {
+    match source {
+        ImportChatAttachmentSource::Path(path) => filename_from_path(path),
+        ImportChatAttachmentSource::Bytes { filename, .. } => Ok(filename.clone()),
+    }
+}
+
 fn validate_attachment_filename(filename: &str) -> Result<(), AppError> {
     let lowered = filename.to_ascii_lowercase();
     let blocked = [

crates/application/src/lib.rs

@@ -72,8 +72,8 @@ pub use background::{
     SpawnBackgroundCommandOutput,
 };
 pub use chat_attachments::{
-    ImportChatAttachmentItem, ImportChatAttachments, ImportChatAttachmentsInput,
+    ImportChatAttachmentItem, ImportChatAttachmentSource, ImportChatAttachments,
-    ImportChatAttachmentsOutput, CHAT_ATTACHMENT_MAX_BYTES,
+    ImportChatAttachmentsInput, ImportChatAttachmentsOutput, CHAT_ATTACHMENT_MAX_BYTES,
 };
 pub use conversation::{
     ConversationArchiveProvider, ReadConversationPage, ReadConversationPageInput, RecordTurn,

crates/application/tests/chat_attachments.rs

@@ -10,11 +10,15 @@ use domain::{
 };
 use uuid::Uuid;
 
-use application::{ImportChatAttachmentItem, ImportChatAttachments, ImportChatAttachmentsInput};
+use application::{
+    ImportChatAttachmentItem, ImportChatAttachmentSource, ImportChatAttachments,
+    ImportChatAttachmentsInput,
+};
 
 #[derive(Default)]
 struct FakeChatAttachments {
-    calls: Mutex<Vec<(LocalPath, ChatAttachmentImport)>>,
+    path_calls: Mutex<Vec<(LocalPath, ChatAttachmentImport)>>,
+    bytes_calls: Mutex<Vec<(Vec<u8>, ChatAttachmentImport)>>,
 }
 
 #[async_trait]
@@ -28,7 +32,7 @@ impl ChatAttachmentStore for FakeChatAttachments {
         source: &LocalPath,
         import: ChatAttachmentImport,
     ) -> Result<ChatAttachment, ChatAttachmentStoreError> {
-        self.calls
+        self.path_calls
             .lock()
             .unwrap()
             .push((source.clone(), import.clone()));
@@ -58,6 +62,45 @@ impl ChatAttachmentStore for FakeChatAttachments {
         })
     }
 
+    async fn import_from_bytes(
+        &self,
+        root: &ProjectPath,
+        project_id: ProjectId,
+        agent_id: AgentId,
+        session_id: SessionId,
+        bytes: &[u8],
+        import: ChatAttachmentImport,
+    ) -> Result<ChatAttachment, ChatAttachmentStoreError> {
+        self.bytes_calls
+            .lock()
+            .unwrap()
+            .push((bytes.to_vec(), import.clone()));
+        let storage_path = format!(
+            "agent-chat/{session_id}/{}-{}",
+            import.id.as_str(),
+            import.filename
+        );
+        let readable_path = format!(
+            "{}/.ideai/attachments/agent-chat/{session_id}/{}-{}",
+            root.as_str(),
+            import.id.as_str(),
+            import.filename
+        );
+        Ok(ChatAttachment {
+            id: import.id,
+            project_id,
+            agent_id,
+            session_id,
+            filename: import.filename.clone(),
+            mime: import.mime.clone(),
+            size_bytes: bytes.len() as u64,
+            source_kind: import.source_kind,
+            storage_path,
+            readable_path,
+            created_at: import.created_at,
+        })
+    }
+
     async fn list_for_session(
         &self,
         _root: &ProjectPath,
@@ -113,7 +156,7 @@ async fn import_chat_attachments_allocates_metadata_and_uses_store_port() {
             agent_id,
             session_id,
             attachments: vec![ImportChatAttachmentItem {
-                path: "/outside/photo.png".to_owned(),
+                source: ImportChatAttachmentSource::Path("/outside/photo.png".to_owned()),
                 mime: None,
                 source_kind: ChatAttachmentSourceKind::Clipboard,
             }],
@@ -134,11 +177,49 @@ async fn import_chat_attachments_allocates_metadata_and_uses_store_port() {
         .readable_path
         .contains("/.ideai/attachments/agent-chat/"));
 
-    let calls = store.calls.lock().unwrap();
+    let calls = store.path_calls.lock().unwrap();
     assert_eq!(calls.len(), 1);
     assert_eq!(calls[0].0.as_str(), "/outside/photo.png");
 }
 
+#[tokio::test]
+async fn import_chat_attachments_routes_clipboard_bytes_to_store_port() {
+    let store = Arc::new(FakeChatAttachments::default());
+    let usecase = ImportChatAttachments::new(
+        Arc::clone(&store) as Arc<dyn ChatAttachmentStore>,
+        Arc::new(FixedIds),
+        Arc::new(FixedClock),
+    );
+
+    let output = usecase
+        .execute(ImportChatAttachmentsInput {
+            project: project(),
+            agent_id: AgentId::new_random(),
+            session_id: SessionId::new_random(),
+            attachments: vec![ImportChatAttachmentItem {
+                source: ImportChatAttachmentSource::Bytes {
+                    filename: "clipboard.png".to_owned(),
+                    bytes: b"png bytes".to_vec(),
+                },
+                mime: Some("image/png".to_owned()),
+                source_kind: ChatAttachmentSourceKind::Clipboard,
+            }],
+        })
+        .await
+        .unwrap();
+
+    assert_eq!(output.attachments[0].filename, "clipboard.png");
+    assert_eq!(output.attachments[0].mime, "image/png");
+    assert_eq!(
+        output.attachments[0].source_kind,
+        ChatAttachmentSourceKind::Clipboard
+    );
+    let calls = store.bytes_calls.lock().unwrap();
+    assert_eq!(calls.len(), 1);
+    assert_eq!(calls[0].0, b"png bytes");
+    assert_eq!(calls[0].1.filename, "clipboard.png");
+}
+
 #[tokio::test]
 async fn import_chat_attachments_rejects_executable_sources_before_store_call() {
     let store = Arc::new(FakeChatAttachments::default());
@@ -154,7 +235,7 @@ async fn import_chat_attachments_rejects_executable_sources_before_store_call()
             agent_id: AgentId::new_random(),
             session_id: SessionId::new_random(),
             attachments: vec![ImportChatAttachmentItem {
-                path: "/outside/run.sh".to_owned(),
+                source: ImportChatAttachmentSource::Path("/outside/run.sh".to_owned()),
                 mime: None,
                 source_kind: ChatAttachmentSourceKind::LocalFile,
             }],
@@ -163,5 +244,6 @@ async fn import_chat_attachments_rejects_executable_sources_before_store_call()
         .unwrap_err();
 
     assert_eq!(err.code(), "INVALID");
-    assert!(store.calls.lock().unwrap().is_empty());
+    assert!(store.path_calls.lock().unwrap().is_empty());
+    assert!(store.bytes_calls.lock().unwrap().is_empty());
 }

crates/backend/src/dto.rs

@@ -2971,7 +2971,14 @@ impl From<TerminalSession> for TerminalSessionDto {
 #[serde(rename_all = "camelCase")]
 pub struct ChatAttachmentInputDto {
     /// Local source path selected or staged by the driving adapter.
-    pub path: String,
+    #[serde(default)]
+    pub path: Option<String>,
+    /// Display filename for in-memory content, for example clipboard images.
+    #[serde(default)]
+    pub filename: Option<String>,
+    /// Base64-encoded raw content for in-memory attachment import.
+    #[serde(default)]
+    pub content_base64: Option<String>,
     /// Optional MIME type known by the frontend/OS picker.
     #[serde(default)]
     pub mime: Option<String>,

crates/domain/src/ports.rs

@@ -1110,6 +1110,17 @@ pub trait ChatAttachmentStore: Send + Sync {
         import: ChatAttachmentImport,
     ) -> Result<ChatAttachment, ChatAttachmentStoreError>;
 
+    /// Writes in-memory bytes into IdeA-managed durable attachment storage.
+    async fn import_from_bytes(
+        &self,
+        root: &ProjectPath,
+        project_id: ProjectId,
+        agent_id: AgentId,
+        session_id: SessionId,
+        bytes: &[u8],
+        import: ChatAttachmentImport,
+    ) -> Result<ChatAttachment, ChatAttachmentStoreError>;
+
     /// Lists attachments imported for a structured/chat session.
     async fn list_for_session(
         &self,

crates/infrastructure/src/chat_attachments.rs

@@ -72,6 +72,52 @@ fn validate_filename(filename: &str) -> Result<(), ChatAttachmentStoreError> {
     Ok(())
 }
 
+fn validate_size(size_bytes: u64) -> Result<(), ChatAttachmentStoreError> {
+    if size_bytes == 0 {
+        return Err(ChatAttachmentStoreError::Invalid(
+            "chat attachment must not be empty".to_owned(),
+        ));
+    }
+    if size_bytes > CHAT_ATTACHMENT_MAX_BYTES {
+        return Err(ChatAttachmentStoreError::Invalid(format!(
+            "chat attachment exceeds {CHAT_ATTACHMENT_MAX_BYTES} bytes"
+        )));
+    }
+    Ok(())
+}
+
+fn build_attachment(
+    root: &ProjectPath,
+    project_id: ProjectId,
+    agent_id: AgentId,
+    session_id: SessionId,
+    size_bytes: u64,
+    import: ChatAttachmentImport,
+) -> Result<(String, PathBuf, ChatAttachment), ChatAttachmentStoreError> {
+    validate_filename(&import.filename)?;
+    validate_size(size_bytes)?;
+    let stored_name = format!("{}-{}", import.id.as_str(), import.filename);
+    let dest = session_dir(root, session_id).join(&stored_name);
+    let storage_path = storage_relative(session_id, &stored_name);
+    let attachment = ChatAttachment {
+        id: import.id,
+        project_id,
+        agent_id,
+        session_id,
+        filename: import.filename,
+        mime: import.mime,
+        size_bytes,
+        source_kind: import.source_kind,
+        readable_path: readable_path(root, &storage_path),
+        storage_path,
+        created_at: import.created_at,
+    };
+    attachment
+        .validate()
+        .map_err(|err| ChatAttachmentStoreError::Invalid(err.to_string()))?;
+    Ok((stored_name, dest, attachment))
+}
+
 async fn write_metadata(
     root: &ProjectPath,
     session_id: SessionId,
@@ -110,7 +156,6 @@ impl ChatAttachmentStore for FsChatAttachmentStore {
         source: &LocalPath,
         import: ChatAttachmentImport,
     ) -> Result<ChatAttachment, ChatAttachmentStoreError> {
-        validate_filename(&import.filename)?;
         let source_path = PathBuf::from(source.as_str());
         let meta = tokio::fs::metadata(&source_path).await.map_err(io_error)?;
         if !meta.is_file() {
@@ -118,37 +163,38 @@ impl ChatAttachmentStore for FsChatAttachmentStore {
                 "chat attachment source must be a file".to_owned(),
             ));
         }
-        if meta.len() > CHAT_ATTACHMENT_MAX_BYTES {
-            return Err(ChatAttachmentStoreError::Invalid(format!(
-                "chat attachment exceeds {CHAT_ATTACHMENT_MAX_BYTES} bytes"
-            )));
-        }
-
         let dir = session_dir(root, session_id);
         tokio::fs::create_dir_all(&dir).await.map_err(io_error)?;
-        let stored_name = format!("{}-{}", import.id.as_str(), import.filename);
+        let (_, dest, attachment) =
-        let dest = dir.join(&stored_name);
+            build_attachment(root, project_id, agent_id, session_id, meta.len(), import)?;
         tokio::fs::copy(&source_path, &dest)
             .await
             .map_err(io_error)?;
 
-        let storage_path = storage_relative(session_id, &stored_name);
+        write_metadata(root, session_id, &attachment).await?;
-        let attachment = ChatAttachment {
+        Ok(attachment)
-            id: import.id,
+    }
+
+    async fn import_from_bytes(
+        &self,
+        root: &ProjectPath,
+        project_id: ProjectId,
+        agent_id: AgentId,
+        session_id: SessionId,
+        bytes: &[u8],
+        import: ChatAttachmentImport,
+    ) -> Result<ChatAttachment, ChatAttachmentStoreError> {
+        let dir = session_dir(root, session_id);
+        tokio::fs::create_dir_all(&dir).await.map_err(io_error)?;
+        let (_, dest, attachment) = build_attachment(
+            root,
             project_id,
             agent_id,
             session_id,
-            filename: import.filename,
+            bytes.len() as u64,
-            mime: import.mime,
+            import,
-            size_bytes: meta.len(),
+        )?;
-            source_kind: import.source_kind,
+        tokio::fs::write(dest, bytes).await.map_err(io_error)?;
-            readable_path: readable_path(root, &storage_path),
-            storage_path,
-            created_at: import.created_at,
-        };
-        attachment
-            .validate()
-            .map_err(|err| ChatAttachmentStoreError::Invalid(err.to_string()))?;
         write_metadata(root, session_id, &attachment).await?;
         Ok(attachment)
     }

crates/infrastructure/tests/chat_attachments.rs

@@ -72,6 +72,57 @@ async fn fs_chat_attachment_store_imports_outside_file_to_project_managed_path()
     let _ = tokio::fs::remove_dir_all(outside_root).await;
 }
 
+#[tokio::test]
+async fn fs_chat_attachment_store_imports_bytes_to_project_managed_path() {
+    let project_root = temp_dir("project-bytes");
+    tokio::fs::create_dir_all(&project_root).await.unwrap();
+
+    let store = FsChatAttachmentStore::new();
+    let project_path = ProjectPath::new(project_root.to_string_lossy().into_owned()).unwrap();
+    let project_id = ProjectId::new_random();
+    let agent_id = AgentId::new_random();
+    let session_id = SessionId::new_random();
+    let attachment_id = ChatAttachmentId::new("attach-bytes").unwrap();
+
+    let attachment = store
+        .import_from_bytes(
+            &project_path,
+            project_id,
+            agent_id,
+            session_id,
+            b"clipboard png bytes",
+            ChatAttachmentImport {
+                id: attachment_id,
+                filename: "clipboard.png".to_owned(),
+                mime: "image/png".to_owned(),
+                source_kind: ChatAttachmentSourceKind::Clipboard,
+                created_at: 43,
+            },
+        )
+        .await
+        .unwrap();
+
+    assert_eq!(attachment.project_id, project_id);
+    assert_eq!(attachment.agent_id, agent_id);
+    assert_eq!(attachment.session_id, session_id);
+    assert_eq!(attachment.filename, "clipboard.png");
+    assert_eq!(attachment.size_bytes, 19);
+    assert_eq!(attachment.source_kind, ChatAttachmentSourceKind::Clipboard);
+    assert!(attachment
+        .readable_path
+        .starts_with(&format!("{}/.ideai/attachments/", project_root.display())));
+    let stored_bytes = tokio::fs::read(&attachment.readable_path).await.unwrap();
+    assert_eq!(stored_bytes, b"clipboard png bytes");
+
+    let listed = store
+        .list_for_session(&project_path, session_id)
+        .await
+        .unwrap();
+    assert_eq!(listed, vec![attachment]);
+
+    let _ = tokio::fs::remove_dir_all(project_root).await;
+}
+
 #[tokio::test]
 async fn fs_chat_attachment_store_rejects_directories() {
     let project_root = temp_dir("project-dir");
@@ -103,3 +154,32 @@ async fn fs_chat_attachment_store_rejects_directories() {
     let _ = tokio::fs::remove_dir_all(project_root).await;
     let _ = tokio::fs::remove_dir_all(outside_root).await;
 }
+
+#[tokio::test]
+async fn fs_chat_attachment_store_rejects_empty_bytes() {
+    let project_root = temp_dir("project-empty-bytes");
+    tokio::fs::create_dir_all(&project_root).await.unwrap();
+
+    let store = FsChatAttachmentStore::new();
+    let err = store
+        .import_from_bytes(
+            &ProjectPath::new(project_root.to_string_lossy().into_owned()).unwrap(),
+            ProjectId::new_random(),
+            AgentId::new_random(),
+            SessionId::new_random(),
+            &[],
+            ChatAttachmentImport {
+                id: ChatAttachmentId::new("attach-empty").unwrap(),
+                filename: "empty.png".to_owned(),
+                mime: "image/png".to_owned(),
+                source_kind: ChatAttachmentSourceKind::Clipboard,
+                created_at: 42,
+            },
+        )
+        .await
+        .unwrap_err();
+
+    assert!(matches!(err, ChatAttachmentStoreError::Invalid(_)));
+
+    let _ = tokio::fs::remove_dir_all(project_root).await;
+}

frontend/src/adapters/agent.test.ts

@@ -171,6 +171,38 @@ describe("TauriAgentGateway invoke payloads", () => {
     expect(invoke).not.toHaveBeenCalledWith("close_agent_session", expect.anything());
   });
 
+  it("sendAgentChat forwards structured clipboard attachments to agent_send", async () => {
+    await new TauriAgentGateway().sendAgentChat(
+      "chat-session-1",
+      "",
+      vi.fn(),
+      {
+        attachments: [
+          {
+            filename: "clipboard.png",
+            contentBase64: "AQID",
+            mime: "image/png",
+            sourceKind: "clipboard",
+          },
+        ],
+      },
+    );
+
+    expect(invoke).toHaveBeenCalledWith("agent_send", {
+      sessionId: "chat-session-1",
+      prompt: "",
+      attachments: [
+        {
+          filename: "clipboard.png",
+          contentBase64: "AQID",
+          mime: "image/png",
+          sourceKind: "clipboard",
+        },
+      ],
+      onReply: expect.anything(),
+    });
+  });
+
   it("launchAgentChat returns a handle only when launch_agent confirms cellKind chat", async () => {
     invoke.mockResolvedValueOnce({
       sessionId: "chat-session-1",

frontend/src/adapters/agent.ts

@@ -32,6 +32,7 @@ import type {
   OpenTerminalOptions,
   ReattachAgentChatResult,
   ReattachResult,
+  SendAgentChatOptions,
   StoppedLiveAgent,
   TerminalHandle,
 } from "@/ports";
@@ -261,12 +262,14 @@ export class TauriAgentGateway implements AgentGateway {
     sessionId: string,
     prompt: string,
     onChunk: (chunk: ReplyChunk) => void,
+    options: SendAgentChatOptions = {},
   ): Promise<void> {
     const channel = new Channel<ReplyChunk>();
     channel.onmessage = onChunk;
     await invoke("agent_send", {
       sessionId,
       prompt,
+      ...(options.attachments ? { attachments: options.attachments } : {}),
       onReply: channel,
     });
   }

frontend/src/adapters/mock/index.ts

@@ -150,6 +150,7 @@ import type {
   RemoteGateway,
   ReviewPluginPackageInput,
   SaveOpenCodeProviderProfileInput,
+  SendAgentChatOptions,
   SkillGateway,
   StoppedLiveAgent,
   SystemGateway,
@@ -826,6 +827,7 @@ export class MockAgentGateway implements AgentGateway {
     sessionId: string,
     prompt: string,
     onChunk: (chunk: ReplyChunk) => void,
+    _options: SendAgentChatOptions = {},
   ): Promise<void> {
     const chunks = this.chatScrollback.get(sessionId);
     if (!chunks) {

frontend/src/features/agents/CustomAgentChatView.test.tsx

@@ -205,6 +205,159 @@ describe("CustomAgentChatView", () => {
     expect(screen.getAllByText("hello agent")).toHaveLength(1);
   });
 
+  it("pastes a clipboard image as a removable preview chip", async () => {
+    const agent = {
+      launchAgentChat: vi.fn(),
+      reattachAgentChat: vi.fn(async (sessionId: string) => ({
+        sessionId,
+        scrollback: [],
+      })),
+      sendAgentChat: vi.fn(() => new Promise<void>(() => {})),
+      cancelAgentChat: vi.fn(async () => {}),
+      closeAgentChat: vi.fn(async () => {}),
+    };
+
+    render(
+      <DIProvider
+        gateways={{
+          agent,
+          system: { pickFile: vi.fn(async () => null) },
+        } as unknown as Gateways}
+      >
+        <CustomAgentChatView
+          projectId="project-1"
+          agentId="agent-1"
+          agentName="Worker"
+          profile={profile}
+          cwd="/repo"
+          nodeId="node-1"
+          sessionId="chat-session-1"
+          conversationId="conversation-1"
+          onSessionId={vi.fn()}
+          onConversationId={vi.fn()}
+        />
+      </DIProvider>,
+    );
+
+    await waitFor(() =>
+      expect(agent.reattachAgentChat).toHaveBeenCalledWith(
+        "chat-session-1",
+        expect.any(Function),
+      ),
+    );
+
+    const file = new File(["ignored"], "clipboard.png", { type: "image/png" });
+    Object.defineProperty(file, "arrayBuffer", {
+      value: vi.fn(async () => new Uint8Array([1, 2, 3]).buffer),
+    });
+    fireEvent.paste(screen.getByLabelText(/message CLI custom/), {
+      clipboardData: {
+        items: [
+          {
+            kind: "file",
+            type: "image/png",
+            getAsFile: () => file,
+          },
+        ],
+        getData: () => "",
+      },
+    });
+
+    expect(await screen.findByText("Fichier joint: clipboard.png")).toBeTruthy();
+    expect(screen.getByTestId("attachment-preview-clipboard.png")).toBeTruthy();
+
+    fireEvent.click(screen.getByRole("button", { name: "retirer clipboard.png" }));
+
+    await waitFor(() =>
+      expect(screen.queryByText("Fichier joint: clipboard.png")).toBeNull(),
+    );
+    expect(
+      (screen.getByRole("button", { name: "Envoyer" }) as HTMLButtonElement)
+        .disabled,
+    ).toBe(true);
+  });
+
+  it("sends a pasted clipboard image without requiring text", async () => {
+    const agent = {
+      launchAgentChat: vi.fn(),
+      reattachAgentChat: vi.fn(async (sessionId: string) => ({
+        sessionId,
+        scrollback: [],
+      })),
+      sendAgentChat: vi.fn(async () => {}),
+      cancelAgentChat: vi.fn(async () => {}),
+      closeAgentChat: vi.fn(async () => {}),
+    };
+
+    render(
+      <DIProvider
+        gateways={{
+          agent,
+          system: { pickFile: vi.fn(async () => null) },
+        } as unknown as Gateways}
+      >
+        <CustomAgentChatView
+          projectId="project-1"
+          agentId="agent-1"
+          agentName="Worker"
+          profile={profile}
+          cwd="/repo"
+          nodeId="node-1"
+          sessionId="chat-session-1"
+          conversationId="conversation-1"
+          onSessionId={vi.fn()}
+          onConversationId={vi.fn()}
+        />
+      </DIProvider>,
+    );
+
+    await waitFor(() =>
+      expect(agent.reattachAgentChat).toHaveBeenCalledWith(
+        "chat-session-1",
+        expect.any(Function),
+      ),
+    );
+
+    const file = new File(["ignored"], "paste-image.png", { type: "image/png" });
+    Object.defineProperty(file, "arrayBuffer", {
+      value: vi.fn(async () => new Uint8Array([1, 2, 3]).buffer),
+    });
+    fireEvent.paste(screen.getByLabelText(/message CLI custom/), {
+      clipboardData: {
+        items: [
+          {
+            kind: "file",
+            type: "image/png",
+            getAsFile: () => file,
+          },
+        ],
+        getData: () => "",
+      },
+    });
+
+    await screen.findByText("Fichier joint: paste-image.png");
+    fireEvent.click(screen.getByRole("button", { name: "Envoyer" }));
+
+    await waitFor(() => expect(agent.sendAgentChat).toHaveBeenCalledTimes(1));
+    expect(agent.sendAgentChat).toHaveBeenCalledWith(
+      "chat-session-1",
+      "",
+      expect.any(Function),
+      {
+        attachments: [
+          {
+            filename: "paste-image.png",
+            contentBase64: "AQID",
+            mime: "image/png",
+            sourceKind: "clipboard",
+          },
+        ],
+      },
+    );
+    expect(screen.getByText("Pièce jointe")).toBeTruthy();
+    expect(screen.getByText("Fichier: paste-image.png")).toBeTruthy();
+  });
+
   it("keeps the chat shell bounded with a scrollable message area and fixed composer", async () => {
     const agent = {
       launchAgentChat: vi.fn(() => new Promise<never>(() => {})),

frontend/src/features/agents/CustomAgentChatView.tsx

@@ -6,11 +6,19 @@
  * deliberately does not try to parse PTY bytes.
  */
 
-import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+import {
+  useCallback,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+  type ClipboardEvent,
+} from "react";
 
 import type { AgentProfile, GatewayError, ReplyChunk } from "@/domain";
 import { useGateways } from "@/app/di";
 import { Button, Spinner, cn } from "@/shared";
+import type { ChatAttachmentInput } from "@/ports";
 
 export interface CustomAgentChatViewProps {
   projectId: string;
@@ -26,13 +34,20 @@ export interface CustomAgentChatViewProps {
 }
 
 type ChatTurn =
-  | { role: "user"; text: string; attachment?: string }
+  | { role: "user"; text: string; attachments?: string[] }
   | { role: "agent"; text: string; pending?: boolean }
   | { role: "tool"; label: string }
   | { role: "final"; text: string }
   | { role: "error"; text: string }
   | { role: "unknown"; text: string };
 
+interface AttachmentDraft {
+  id: string;
+  label: string;
+  input: ChatAttachmentInput;
+  previewUrl?: string;
+}
+
 function describe(e: unknown): string {
   if (e && typeof e === "object" && "message" in e) {
     return String((e as GatewayError).message);
@@ -99,6 +114,56 @@ function appendUserPrompt(turns: ChatTurn[], text: string): ChatTurn[] {
   return [...turns, { role: "user", text }];
 }
 
+function fileExtension(mime: string): string {
+  if (mime === "image/png") return "png";
+  if (mime === "image/jpeg") return "jpg";
+  if (mime === "image/gif") return "gif";
+  if (mime === "image/webp") return "webp";
+  return "img";
+}
+
+function pathBasename(path: string): string {
+  return path.split(/[\\/]/).filter(Boolean).at(-1) ?? path;
+}
+
+function bytesToBase64(bytes: Uint8Array): string {
+  let binary = "";
+  const chunkSize = 0x8000;
+  for (let i = 0; i < bytes.length; i += chunkSize) {
+    const chunk = bytes.subarray(i, i + chunkSize);
+    binary += String.fromCharCode(...chunk);
+  }
+  return btoa(binary);
+}
+
+async function clipboardImageToAttachment(file: File): Promise<AttachmentDraft> {
+  const mime = file.type || "application/octet-stream";
+  const filename =
+    file.name ||
+    `clipboard-image-${Date.now()}.${fileExtension(mime)}`;
+  const contentBase64 = bytesToBase64(new Uint8Array(await file.arrayBuffer()));
+  return {
+    id: `clipboard-${Date.now()}-${Math.random().toString(36).slice(2)}`,
+    label: filename,
+    previewUrl: mime.startsWith("image/")
+      ? `data:${mime};base64,${contentBase64}`
+      : undefined,
+    input: {
+      filename,
+      contentBase64,
+      mime,
+      sourceKind: "clipboard",
+    },
+  };
+}
+
+function clipboardImageFiles(event: ClipboardEvent<HTMLTextAreaElement>): File[] {
+  return Array.from(event.clipboardData.items)
+    .filter((item) => item.kind === "file" && item.type.startsWith("image/"))
+    .map((item) => item.getAsFile())
+    .filter((file): file is File => Boolean(file));
+}
+
 function foldChunk(turns: ChatTurn[], raw: unknown): ChatTurn[] {
   if (!isReplyRecord(raw)) {
     return [...turns, { role: "unknown", text: unknownChunkLabel(raw) }];
@@ -148,7 +213,7 @@ export function CustomAgentChatView({
   const [currentSession, setCurrentSession] = useState(sessionId);
   const [externalSessionId, setExternalSessionId] = useState(sessionId);
   const [draft, setDraft] = useState("");
-  const [attachment, setAttachment] = useState<string | null>(null);
+  const [attachments, setAttachments] = useState<AttachmentDraft[]>([]);
   const [opening, setOpening] = useState(false);
   const [busy, setBusy] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -412,26 +477,76 @@ export function CustomAgentChatView({
   const canSend = useMemo(
     () =>
       supported &&
-      Boolean(draft.trim()) &&
+      (Boolean(draft.trim()) || attachments.length > 0) &&
       !busy &&
       !opening,
-    [supported, draft, busy, opening],
+    [supported, draft, attachments.length, busy, opening],
   );
 
   async function pickAttachment() {
     const path = await system.pickFile();
-    if (path) setAttachment(path);
+    if (path) {
+      setAttachments((prev) => [
+        ...prev,
+        {
+          id: `path-${Date.now()}-${Math.random().toString(36).slice(2)}`,
+          label: pathBasename(path),
+          input: { path, sourceKind: "localFile" },
+        },
+      ]);
+    }
+  }
+
+  async function pasteClipboardImages(
+    event: ClipboardEvent<HTMLTextAreaElement>,
+  ) {
+    const files = clipboardImageFiles(event);
+    if (files.length === 0) return;
+
+    event.preventDefault();
+    const pastedText = event.clipboardData.getData("text/plain");
+    const selectionStart = event.currentTarget.selectionStart;
+    const selectionEnd = event.currentTarget.selectionEnd;
+    try {
+      const nextAttachments = await Promise.all(
+        files.map(clipboardImageToAttachment),
+      );
+      setAttachments((prev) => [...prev, ...nextAttachments]);
+      if (pastedText) {
+        setDraft((prev) =>
+          prev.slice(0, selectionStart) +
+          pastedText +
+          prev.slice(selectionEnd),
+        );
+      }
+    } catch (e) {
+      setError(describe(e));
+    }
   }
 
   async function send() {
     const text = draft.trim();
     if (!canSend || !agent.sendAgentChat) return;
-    const prompt = attachment ? `${text}\n\n[Fichier joint: ${attachment}]` : text;
+    const outgoingAttachments = attachments;
+    const attachmentInputs = outgoingAttachments.map((item) => item.input);
+    const attachmentLabels = outgoingAttachments.map((item) => item.label);
+    const displayText = text || "Pièce jointe";
     setDraft("");
-    setAttachment(null);
+    setAttachments([]);
     setBusy(true);
     setError(null);
-    setTurns((prev) => [...prev, { role: "user", text, attachment: attachment ?? undefined }]);
+    setTurns((prev) => [
+      ...prev,
+      {
+        role: "user",
+        text: displayText,
+        ...(attachmentLabels.length > 0 ? { attachments: attachmentLabels } : {}),
+      },
+    ]);
+    const sendTurn = (sid: string) =>
+      attachmentInputs.length > 0
+        ? agent.sendAgentChat!(sid, text, receive, { attachments: attachmentInputs })
+        : agent.sendAgentChat!(sid, text, receive);
     try {
       const sid =
         currentSession ??
@@ -439,7 +554,7 @@ export function CustomAgentChatView({
           applyScrollback: false,
           retryAttachNotFound: true,
         }));
-      await agent.sendAgentChat(sid, prompt, receive);
+      await sendTurn(sid);
     } catch (e) {
       if (isNotFound(e)) {
         try {
@@ -449,7 +564,7 @@ export function CustomAgentChatView({
             applyScrollback: false,
             retryAttachNotFound: true,
           });
-          await agent.sendAgentChat(recoveredSession, prompt, receive);
+          await sendTurn(recoveredSession);
           return;
         } catch (recoveryError) {
           setBusy(false);
@@ -548,12 +663,36 @@ export function CustomAgentChatView({
         data-testid="custom-agent-chat-composer"
         className="flex shrink-0 flex-col gap-2 border-t border-border bg-raised/40 p-2"
       >
-        {attachment && (
+        {attachments.length > 0 && (
-          <div className="flex items-center justify-between gap-2 rounded-md border border-border bg-surface px-2 py-1 text-xs text-muted">
+          <div className="flex min-w-0 flex-wrap gap-2">
-            <span className="truncate">Fichier joint: {attachment}</span>
+            {attachments.map((item) => (
-            <button type="button" className="text-content" onClick={() => setAttachment(null)}>
+              <div
-              Retirer
+                key={item.id}
-            </button>
+                className="flex max-w-full items-center gap-2 rounded-md border border-border bg-surface px-2 py-1 text-xs text-muted"
+              >
+                {item.previewUrl && (
+                  <img
+                    src={item.previewUrl}
+                    alt=""
+                    data-testid={`attachment-preview-${item.label}`}
+                    className="h-8 w-8 shrink-0 rounded border border-border object-cover"
+                  />
+                )}
+                <span className="min-w-0 truncate">Fichier joint: {item.label}</span>
+                <button
+                  type="button"
+                  aria-label={`retirer ${item.label}`}
+                  className="shrink-0 text-content"
+                  onClick={() =>
+                    setAttachments((prev) =>
+                      prev.filter((candidate) => candidate.id !== item.id),
+                    )
+                  }
+                >
+                  Retirer
+                </button>
+              </div>
+            ))}
           </div>
         )}
         <div className="flex min-w-0 items-end gap-2">
@@ -568,6 +707,7 @@ export function CustomAgentChatView({
             disabled={!supported || opening || busy}
             placeholder="Message à l'agent…"
             onChange={(e) => setDraft(e.target.value)}
+            onPaste={(e) => void pasteClipboardImages(e)}
             onKeyDown={(e) => {
               if (e.key === "Enter" && !e.shiftKey) {
                 e.preventDefault();
@@ -640,8 +780,14 @@ function ChatBubble({ turn }: { turn: ChatTurn }) {
         )}
       >
         <p className="whitespace-pre-wrap break-words">{turn.text}</p>
-        {user && turn.attachment && (
+        {user && turn.attachments && turn.attachments.length > 0 && (
-          <p className="mt-1 truncate text-xs text-muted">Fichier: {turn.attachment}</p>
+          <div className="mt-1 flex flex-col gap-0.5 text-xs text-muted">
+            {turn.attachments.map((attachment) => (
+              <p key={attachment} className="truncate">
+                Fichier: {attachment}
+              </p>
+            ))}
+          </div>
         )}
         {!user && turn.pending && (
           <span className="mt-1 inline-flex items-center gap-1 text-xs text-muted">

frontend/src/ports/index.ts

@@ -145,6 +145,25 @@ export interface CreateAgentInput {
   initialContent?: string;
 }
 
+export type ChatAttachmentSourceKind =
+  | "localFile"
+  | "clipboard"
+  | "dragDrop"
+  | "other";
+
+/** Structured attachment intent accepted by `agent_send`. */
+export interface ChatAttachmentInput {
+  path?: string;
+  filename?: string;
+  contentBase64?: string;
+  mime?: string;
+  sourceKind?: ChatAttachmentSourceKind;
+}
+
+export interface SendAgentChatOptions {
+  attachments?: ChatAttachmentInput[];
+}
+
 /**
  * Best-effort enriched details about a CLI conversation (T7), used to enrich the
  * resume popup. Both fields are optional: a missing inspector or a missing
@@ -284,6 +303,7 @@ export interface AgentGateway {
     sessionId: string,
     prompt: string,
     onChunk: (chunk: ReplyChunk) => void,
+    options?: SendAgentChatOptions,
   ): Promise<void>;
   /** Interrupts only the current turn of a live structured session. */
   cancelAgentChat?(sessionId: string): Promise<void>;