diff --git a/lunatask/notes.go b/lunatask/notes.go
index 19a7f2af7683e79440e77af2861d19e270f54e59..66ad4ba44c75830a5947036f613a6eae2034674a 100644
--- a/lunatask/notes.go
+++ b/lunatask/notes.go
@@ -3,3 +3,129 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
 package lunatask
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+// Note represents a note returned from the Lunatask API.
+// Note: name and content are E2EE and not returned by the API.
+type Note struct {
+	ID         string    `json:"id"`
+	NotebookID string    `json:"notebook_id"`
+	DateOn     *Date     `json:"date_on"`
+	Sources    []Source  `json:"sources"`
+	CreatedAt  time.Time `json:"created_at"`
+	UpdatedAt  time.Time `json:"updated_at"`
+}
+
+// CreateNoteRequest represents the request to create a note in Lunatask.
+type CreateNoteRequest struct {
+	Name       *string `json:"name,omitempty"`
+	Content    *string `json:"content,omitempty"`
+	NotebookID string  `json:"notebook_id"`
+	Source     *string `json:"source,omitempty"`
+	SourceID   *string `json:"source_id,omitempty"`
+}
+
+// UpdateNoteRequest represents the request to update a note in Lunatask.
+// All fields are optional; only provided fields will be updated.
+// Note: updating content replaces the entire content (E2EE prevents appending).
+type UpdateNoteRequest struct {
+	Name       *string `json:"name,omitempty"`
+	Content    *string `json:"content,omitempty"`
+	NotebookID *string `json:"notebook_id,omitempty"`
+	DateOn     *Date   `json:"date_on,omitempty"`
+}
+
+// noteResponse represents a single note response from the API.
+type noteResponse struct {
+	Note Note `json:"note"`
+}
+
+// notesResponse represents a list of notes response from the API.
+type notesResponse struct {
+	Notes []Note `json:"notes"`
+}
+
+// ListNotesOptions contains optional filters for listing notes.
+type ListNotesOptions struct {
+	Source   *string
+	SourceID *string
+}
+
+// ListNotes retrieves all notes, optionally filtered by source and/or source_id.
+func (c *Client) ListNotes(ctx context.Context, opts *ListNotesOptions) ([]Note, error) {
+	path := "/notes"
+
+	if opts != nil {
+		params := url.Values{}
+		if opts.Source != nil && *opts.Source != "" {
+			params.Set("source", *opts.Source)
+		}
+		if opts.SourceID != nil && *opts.SourceID != "" {
+			params.Set("source_id", *opts.SourceID)
+		}
+		if len(params) > 0 {
+			path = fmt.Sprintf("%s?%s", path, params.Encode())
+		}
+	}
+
+	resp, _, err := doJSON[notesResponse](c, ctx, http.MethodGet, path, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	return resp.Notes, nil
+}
+
+// CreateNote creates a new note in Lunatask.
+// Returns nil, nil if a matching note already exists in the same notebook
+// with the same source/source_id (HTTP 204).
+func (c *Client) CreateNote(ctx context.Context, note *CreateNoteRequest) (*Note, error) {
+	if note.NotebookID == "" {
+		return nil, fmt.Errorf("%w: notebook_id is required", ErrBadRequest)
+	}
+
+	resp, noContent, err := doJSON[noteResponse](c, ctx, http.MethodPost, "/notes", note)
+	if err != nil {
+		return nil, err
+	}
+	if noContent {
+		return nil, nil
+	}
+
+	return &resp.Note, nil
+}
+
+// UpdateNote updates an existing note in Lunatask.
+func (c *Client) UpdateNote(ctx context.Context, noteID string, note *UpdateNoteRequest) (*Note, error) {
+	if noteID == "" {
+		return nil, fmt.Errorf("%w: note ID cannot be empty", ErrBadRequest)
+	}
+
+	resp, _, err := doJSON[noteResponse](c, ctx, http.MethodPut, "/notes/"+noteID, note)
+	if err != nil {
+		return nil, err
+	}
+
+	return &resp.Note, nil
+}
+
+// DeleteNote deletes a note in Lunatask.
+func (c *Client) DeleteNote(ctx context.Context, noteID string) (*Note, error) {
+	if noteID == "" {
+		return nil, fmt.Errorf("%w: note ID cannot be empty", ErrBadRequest)
+	}
+
+	resp, _, err := doJSON[noteResponse](c, ctx, http.MethodDelete, "/notes/"+noteID, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	return &resp.Note, nil
+}