fix(gmail): improve attachment data handling

.changeset/gmail-attachment-handling.md

@@ -0,0 +1,5 @@
+---
+"@googleworkspace/cli": patch
+---
+
+Improve Gmail attachment handling by padding attachment data and documenting a decode-and-upload flow.

crates/google-workspace-cli/registry/recipes.toml

@@ -322,8 +322,8 @@ services = [ "gmail", "drive" ]
 steps = [
   "Search for emails with attachments: `gws gmail users messages list --params '{\"userId\": \"me\", \"q\": \"has:attachment from:client@example.com\"}' --format table`",
   "Get message details: `gws gmail users messages get --params '{\"userId\": \"me\", \"id\": \"MESSAGE_ID\"}'`",
-  "Download attachment: `gws gmail users messages attachments get --params '{\"userId\": \"me\", \"messageId\": \"MESSAGE_ID\", \"id\": \"ATTACHMENT_ID\"}'`",
-  "Upload to Drive folder: `gws drive +upload --file ./attachment.pdf --parent FOLDER_ID`"
+  "Download and decode attachment bytes: `gws gmail users messages attachments get --params '{\"userId\": \"me\", \"messageId\": \"MESSAGE_ID\", \"id\": \"ATTACHMENT_ID\"}' | jq -r '.data' | python3 -c 'import base64,sys; d=sys.stdin.read().strip(); sys.stdout.buffer.write(base64.urlsafe_b64decode(d + \"=\" * (-len(d) % 4)))' > attachment.pdf`",
+  "Upload to Drive folder: `gws drive +upload ./attachment.pdf --parent FOLDER_ID`"
 ]
 
 [[recipes]]

crates/google-workspace-cli/src/executor.rs

@@ -243,6 +243,7 @@ async fn build_http_request(
 #[allow(clippy::too_many_arguments)]
 async fn handle_json_response(
     body_text: &str,
+    method_id: &str,
     pagination: &PaginationConfig,
     sanitize_template: Option<&str>,
     sanitize_mode: &crate::helpers::modelarmor::SanitizeMode,
@@ -254,6 +255,7 @@ async fn handle_json_response(
 ) -> Result<bool, GwsError> {
     if let Ok(mut json_val) = serde_json::from_str::<Value>(body_text) {
         *pages_fetched += 1;
+        normalize_json_response(method_id, &mut json_val);
 
         // Run Model Armor sanitization if --sanitize is enabled
         if let Some(template) = sanitize_template {
@@ -336,6 +338,27 @@ async fn handle_json_response(
     Ok(false)
 }
 
+fn normalize_json_response(method_id: &str, json_val: &mut Value) {
+    if method_id == "gmail.users.messages.attachments.get" {
+        pad_gmail_attachment_data(json_val);
+    }
+}
+
+fn pad_gmail_attachment_data(json_val: &mut Value) {
+    let Some(data) = json_val.get_mut("data") else {
+        return;
+    };
+    let Some(raw) = data.as_str() else {
+        return;
+    };
+
+    let padding = (4 - raw.len() % 4) % 4;
+    if padding > 0 {
+        let padded = format!("{}{}", raw, "=".repeat(padding));
+        *data = Value::String(padded);
+    }
+}
+
 /// Handle a binary response by streaming it to a file.
 async fn handle_binary_response(
     response: reqwest::Response,
@@ -497,6 +520,7 @@ pub async fn execute_method(
 
             let should_continue = handle_json_response(
                 &body_text,
+                method_id,
                 pagination,
                 sanitize_template,
                 sanitize_mode,
@@ -2286,6 +2310,42 @@ fn test_get_value_type_helper() {
     assert_eq!(get_value_type(&json!({"a": 1})), "object");
 }
 
+#[test]
+fn test_pad_gmail_attachment_data_adds_missing_padding() {
+    let mut value = json!({
+        "data": "aGVsbG8",
+        "size": 5
+    });
+
+    normalize_json_response("gmail.users.messages.attachments.get", &mut value);
+
+    assert_eq!(value["data"], "aGVsbG8=");
+}
+
+#[test]
+fn test_pad_gmail_attachment_data_leaves_padded_value_unchanged() {
+    let mut value = json!({
+        "data": "aGVsbG8=",
+        "size": 5
+    });
+
+    normalize_json_response("gmail.users.messages.attachments.get", &mut value);
+
+    assert_eq!(value["data"], "aGVsbG8=");
+}
+
+#[test]
+fn test_pad_gmail_attachment_data_ignores_other_methods() {
+    let mut value = json!({
+        "data": "aGVsbG8",
+        "size": 5
+    });
+
+    normalize_json_response("gmail.users.messages.get", &mut value);
+
+    assert_eq!(value["data"], "aGVsbG8");
+}
+
 #[tokio::test]
 async fn test_post_without_body_sets_content_length_zero() {
     let client = reqwest::Client::new();

skills/recipe-save-email-attachments/SKILL.md

@@ -24,6 +24,11 @@ Find Gmail messages with attachments and save them to a Google Drive folder.
 
 1. Search for emails with attachments: `gws gmail users messages list --params '{"userId": "me", "q": "has:attachment from:client@example.com"}' --format table`
 2. Get message details: `gws gmail users messages get --params '{"userId": "me", "id": "MESSAGE_ID"}'`
-3. Download attachment: `gws gmail users messages attachments get --params '{"userId": "me", "messageId": "MESSAGE_ID", "id": "ATTACHMENT_ID"}'`
-4. Upload to Drive folder: `gws drive +upload --file ./attachment.pdf --parent FOLDER_ID`
-
+3. Download and decode attachment bytes:
+   ```bash
+   gws gmail users messages attachments get --params '{"userId": "me", "messageId": "MESSAGE_ID", "id": "ATTACHMENT_ID"}' \
+     | jq -r '.data' \
+     | python3 -c 'import base64,sys; d=sys.stdin.read().strip(); sys.stdout.buffer.write(base64.urlsafe_b64decode(d + "=" * (-len(d) % 4)))' \
+     > attachment.pdf
+   ```
+4. Upload to Drive folder: `gws drive +upload ./attachment.pdf --parent FOLDER_ID`