diff --git a/cmd/fetch_tweet_to_stdout/main.go b/cmd/fetch_tweet_to_stdout/main.go
index 2e4a047..5a4b266 100644
--- a/cmd/fetch_tweet_to_stdout/main.go
+++ b/cmd/fetch_tweet_to_stdout/main.go
@@ -12,7 +12,7 @@ import (
 const INCLUDE_REPLIES = true;
 
 // input: e.g., "https://twitter.com/michaelmalice/status/1395882872729477131"
-func parse_tweet(url string) (string, error) {
+func parse_tweet(url string) (scraper.TweetID, error) {
 	parts := strings.Split(url, "/")
 	if len(parts) != 6 {
 		return "", fmt.Errorf("Tweet format isn't right (%d)", len(parts))
@@ -20,7 +20,7 @@ func parse_tweet(url string) (string, error) {
 	if parts[0] != "https:" || parts[1] != "" || parts[2] != "twitter.com" || parts[4] != "status" {
 		return "", fmt.Errorf("Tweet format isn't right")
 	}
-	return parts[5], nil
+	return scraper.TweetID(parts[5]), nil
 }
 
 func main() {
diff --git a/scraper/api_request_utils.go b/scraper/api_request_utils.go
index c4ff0ce..0b68c90 100644
--- a/scraper/api_request_utils.go
+++ b/scraper/api_request_utils.go
@@ -75,9 +75,9 @@ func (api API) GetMoreTweets(user_id UserID, response *TweetResponse, max_tweets
 }
 
 
-func (api API) GetTweet(id string, cursor string) (TweetResponse, error) {
+func (api API) GetTweet(id TweetID, cursor string) (TweetResponse, error) {
 	client := &http.Client{Timeout: 10 * time.Second}
-	req, err := http.NewRequest("GET", API_CONVERSATION_BASE_PATH + id + ".json", nil)
+	req, err := http.NewRequest("GET", API_CONVERSATION_BASE_PATH + string(id) + ".json", nil)
 	if err != nil {
 		return TweetResponse{}, err
 	}
@@ -100,7 +100,7 @@ func (api API) GetTweet(id string, cursor string) (TweetResponse, error) {
 
 	if !(resp.StatusCode == http.StatusOK || resp.StatusCode == http.StatusForbidden) {
 		content, _ := ioutil.ReadAll(resp.Body)
-		return TweetResponse{}, fmt.Errorf("HTTP %d %s: %s", resp.StatusCode, resp.Status, content)
+		return TweetResponse{}, fmt.Errorf("Error getting %q.  HTTP %s: %s", req.URL, resp.Status, content)
 	}
 
 	body, err := ioutil.ReadAll(resp.Body)
@@ -114,7 +114,7 @@ func (api API) GetTweet(id string, cursor string) (TweetResponse, error) {
 }
 
 // Resend the request to get more replies if necessary
-func (api API) GetMoreReplies(tweet_id string, response *TweetResponse, max_replies int) error {
+func (api API) GetMoreReplies(tweet_id TweetID, response *TweetResponse, max_replies int) error {
 	last_response := response
 	for last_response.GetCursor() != "" && len(response.GlobalObjects.Tweets) < max_replies {
 		fresh_response, err := api.GetTweet(tweet_id, last_response.GetCursor())
diff --git a/scraper/tweet.go b/scraper/tweet.go
index fc6ffac..66a0c79 100644
--- a/scraper/tweet.go
+++ b/scraper/tweet.go
@@ -23,7 +23,7 @@ type Tweet struct {
 
 	Urls        []string
 	Images      []string
-	Mentions    []string
+	Mentions    []UserHandle
 	Hashtags    []string
 	QuotedTweet TweetID
 }
@@ -67,7 +67,7 @@ func ParseSingleTweet(apiTweet APITweet) (ret Tweet, err error) {
 		ret.Hashtags = append(ret.Hashtags, hashtag.Text)
 	}
 	for _, mention := range apiTweet.Entities.Mentions {
-		ret.Mentions = append(ret.Mentions, mention.UserName)
+		ret.Mentions = append(ret.Mentions, UserHandle(mention.UserName))
 	}
 
 	ret.QuotedTweet = TweetID(apiTweet.QuotedStatusIDStr)
@@ -77,14 +77,14 @@ func ParseSingleTweet(apiTweet APITweet) (ret Tweet, err error) {
 
 
 // Return a single tweet, nothing else
-func GetTweet(id string) (Tweet, error) {
+func GetTweet(id TweetID) (Tweet, error) {
 	api := API{}
 	tweet_response, err := api.GetTweet(id, "")
 	if err != nil {
-		return Tweet{}, err
+		return Tweet{}, fmt.Errorf("Error in API call: %s", err)
 	}
 
-	single_tweet, ok := tweet_response.GlobalObjects.Tweets[id]
+	single_tweet, ok := tweet_response.GlobalObjects.Tweets[string(id)]
 
 	if !ok {
 		return Tweet{}, fmt.Errorf("Didn't get the tweet!\n%v", tweet_response)
@@ -96,7 +96,7 @@ func GetTweet(id string) (Tweet, error) {
 
 // Return a list of tweets, including the original and the rest of its thread,
 // along with a list of associated users
-func GetTweetFull(id string) (tweets []Tweet, retweets []Retweet, users []User, err error) {
+func GetTweetFull(id TweetID) (tweets []Tweet, retweets []Retweet, users []User, err error) {
 	api := API{}
 	tweet_response, err := api.GetTweet(id, "")
 	if err != nil {
diff --git a/scraper/user.go b/scraper/user.go
index 1867d41..049e64f 100644
--- a/scraper/user.go
+++ b/scraper/user.go
@@ -3,17 +3,18 @@ package scraper
 import (
     "time"
     "fmt"
+    "strings"
 )
 
 type UserID string
 type UserHandle string
 
-func UIDArrayToStrArray(uids []UserID) []string {
+func JoinArrayOfHandles(handles []UserHandle) string {
     ret := []string{}
-    for _, uid := range uids {
-        ret = append(ret, string(uid))
+    for _, h := range handles {
+        ret = append(ret, string(h))
     }
-    return ret
+    return strings.Join(ret, ",")
 }
 
 type User struct {