diff --git a/api/internal/crawl/cmd/crawler/crawler.go b/api/internal/crawl/cmd/crawler/crawler.go
index ae0abdbbb..7e14f7072 100644
--- a/api/internal/crawl/cmd/crawler/crawler.go
+++ b/api/internal/crawl/cmd/crawler/crawler.go
@@ -21,9 +21,14 @@ const (
 	redisCacheURL        = "REDIS_CACHE_URL"
 	redisKeyURL          = "REDIS_KEY_URL"
 	retryCount           = 3
+	githubUserEnv        = "GITHUB_USER"
+	githubRepoEnv        = "GITHUB_REPO"
 )
 
 func main() {
+	githubUser := os.Getenv(githubUserEnv)
+	githubRepo := os.Getenv(githubRepoEnv)
+
 	githubToken := os.Getenv(githubAccessTokenVar)
 	if githubToken == "" {
 		fmt.Printf("Must set the variable '%s' to make github requests.\n",
@@ -38,21 +43,9 @@ func main() {
 		return
 	}
 
+	seedDocs := make(crawler.CrawlSeed, 0)
+
 	cacheURL := os.Getenv(redisCacheURL)
-
-	query := []byte(`{ "query":{ "match_all":{} } }`)
-	it := idx.IterateQuery(query, 10000, 60*time.Second)
-	docs := make(crawler.CrawlSeed, 0)
-	for it.Next() {
-		for _, hit := range it.Value().Hits.Hits {
-			docs = append(docs, hit.Document.Copy())
-		}
-	}
-
-	if err := it.Err(); err != nil {
-		fmt.Printf("Error iterating: %v\n", err)
-	}
-
 	cache, err := redis.DialURL(cacheURL)
 	clientCache := &http.Client{}
 	if err != nil {
@@ -61,33 +54,69 @@ func main() {
 		clientCache = httpclient.NewClient(cache)
 	}
 
-	ghCrawler := github.NewCrawler(githubToken, retryCount, clientCache,
-		github.QueryWith(
-			github.Filename("kustomization.yaml"),
-			github.Filename("kustomization.yml")),
-	)
+	// docConverter takes in a plain document and processes it for the index.
+	docConverter := func(d *doc.Document) (crawler.CrawledDocument, error) {
+		kdoc := doc.KustomizationDocument{
+			Document: *d,
+		}
 
-	crawler.CrawlFromSeed(ctx, docs, []crawler.Crawler{ghCrawler},
-		// Converter takes in a plain document and processes it for the
-		// index.
-		func(d *doc.Document) (crawler.CrawledDocument, error) {
-			kdoc := doc.KustomizationDocument{
-				Document: *d,
-			}
+		err := kdoc.ParseYAML()
+		return &kdoc, err
+	}
 
-			err := kdoc.ParseYAML()
-			return &kdoc, err
-		},
-		// IndexFunc updates the value in the index.
-		func(cdoc crawler.CrawledDocument, crwlr crawler.Crawler) error {
-			switch d := cdoc.(type) {
-			case *doc.KustomizationDocument:
-				fmt.Println("Inserting: ", d.ID(), d)
-				_, err := idx.Put(d.ID(), d)
-				return err
-			default:
-				return fmt.Errorf("type %T not supported", d)
+	// Index updates the value in the index.
+	index := func(cdoc crawler.CrawledDocument, crwlr crawler.Crawler) error {
+		switch d := cdoc.(type) {
+		case *doc.KustomizationDocument:
+			fmt.Println("Inserting: ", d)
+			_, err := idx.Put(d.ID(), d)
+			return err
+		default:
+			return fmt.Errorf("type %T not supported", d)
+		}
+	}
+
+	// seen tracks the IDs of all the documents in the index.
+	// This helps avoid indexing a given document multiple times.
+	seen := make(map[string]struct{})
+
+	var ghCrawler crawler.Crawler
+
+	if githubRepo != "" {
+		ghCrawler = github.NewCrawler(githubToken, retryCount, clientCache,
+			github.QueryWith(
+				github.Filename("kustomization.yaml"),
+				github.Filename("kustomization.yml"),
+				github.Repo(githubRepo)),
+		)
+	} else if githubUser != "" {
+		ghCrawler = github.NewCrawler(githubToken, retryCount, clientCache,
+			github.QueryWith(
+				github.Filename("kustomization.yaml"),
+				github.Filename("kustomization.yml"),
+				github.User(githubUser)),
+		)
+	} else {
+		ghCrawler = github.NewCrawler(githubToken, retryCount, clientCache,
+			github.QueryWith(
+				github.Filename("kustomization.yaml"),
+				github.Filename("kustomization.yml")),
+		)
+
+		// get all the documents in the index
+		query := []byte(`{ "query":{ "match_all":{} } }`)
+		it := idx.IterateQuery(query, 10000, 60*time.Second)
+		for it.Next() {
+			for _, hit := range it.Value().Hits.Hits {
+				seedDocs = append(seedDocs, hit.Document.Copy())
 			}
-		},
-	)
+		}
+		if err := it.Err(); err != nil {
+			fmt.Printf("Error iterating: %v\n", err)
+		}
+	}
+
+	crawlers := []crawler.Crawler{ghCrawler}
+	crawler.CrawlFromSeed(ctx, seedDocs, crawlers, docConverter, index, seen)
+	crawler.CrawlGithub(ctx, crawlers, docConverter, index, seen)
 }
diff --git a/api/internal/crawl/crawler/crawler.go b/api/internal/crawl/crawler/crawler.go
index a18d670ed..f57f247e5 100644
--- a/api/internal/crawl/crawler/crawler.go
+++ b/api/internal/crawl/crawler/crawler.go
@@ -40,6 +40,7 @@ type Crawler interface {
 type CrawledDocument interface {
 	ID() string
 	GetDocument() *doc.Document
+	// Get all the Documents directly referred in a Document.
 	GetResources() ([]*doc.Document, error)
 	WasCached() bool
 }
@@ -49,135 +50,115 @@ type CrawlSeed []*doc.Document
 type IndexFunc func(CrawledDocument, Crawler) error
 type Converter func(*doc.Document) (CrawledDocument, error)
 
-// Cleaner, more efficient, and more extensible crawler implementation.
-// The seed must include the ids of each document in the index.
-func CrawlFromSeed(ctx context.Context, seed CrawlSeed,
-	crawlers []Crawler, conv Converter, indx IndexFunc) {
+func logIfErr(err error) {
+	if err == nil {
+		return
+	}
+	logger.Println("error: ", err)
+}
 
-	seen := make(map[string]struct{})
-
-	logIfErr := func(err error) {
-		if err == nil {
-			return
+func findMatch(d *doc.Document, crawlers []Crawler) Crawler {
+	for _, crawl := range crawlers {
+		if crawl.Match(d) {
+			return crawl
 		}
-		logger.Println("error: ", err)
+	}
+	return nil
+}
+
+func addBranches(cdoc CrawledDocument, match Crawler, indx IndexFunc,
+	seen map[string]struct{}, stack *CrawlSeed) {
+
+	seen[cdoc.ID()] = struct{}{}
+
+	// Insert into index
+	err := indx(cdoc, match)
+	logIfErr(err)
+	if err != nil {
+		return
 	}
 
+	deps, err := cdoc.GetResources()
+	logIfErr(err)
+	if err != nil {
+		return
+	}
+	for _, dep := range deps {
+		if _, ok := seen[dep.ID()]; ok {
+			continue
+		}
+		*stack = append(*stack, dep)
+	}
+}
+
+func doCrawl(ctx context.Context, docsPtr *CrawlSeed, crawlers []Crawler, conv Converter, indx IndexFunc,
+	seen map[string]struct{}, stack *CrawlSeed) {
+	docCount := 0
+	// During the execution of the for loop, more Documents may be added into (*docsPtr).
+	for len(*docsPtr) > 0 {
+		// get the last Document in (*docPtr), which will be crawled in this iteration.
+		tail := (*docsPtr)[len(*docsPtr)-1]
+
+		// remove the last Document in (*docPtr)
+		*docsPtr = (*docsPtr)[:(len(*docsPtr) - 1)]
+
+		if _, ok := seen[tail.ID()]; ok {
+			continue
+		}
+		docCount++
+
+		match := findMatch(tail, crawlers)
+		if match == nil {
+			logIfErr(fmt.Errorf(
+				"%v could not match any crawler", tail))
+			continue
+		}
+
+		logger.Println("Crawling ", tail.RepositoryURL, tail.FilePath)
+		err := match.FetchDocument(ctx, tail)
+		logIfErr(err)
+		// If there was no change or there is an error, we don't have
+		// to branch out, since the dependencies are already in the
+		// index, or we cannot find the document.
+		if err != nil || tail.WasCached() {
+			if tail.WasCached() {
+				logger.Println(tail.RepositoryURL, tail.FilePath, "is cached already")
+			}
+			continue
+		}
+
+		logIfErr(match.SetCreated(ctx, tail))
+
+		cdoc, err := conv(tail)
+		logIfErr(err)
+
+		addBranches(cdoc, match, indx, seen, stack)
+	}
+	logger.Printf("%d documents were crawled by doCrawl\n", docCount)
+}
+
+// CrawlFromSeed updates all the documents in seed, and crawls all the new
+// documents referred in the seed.
+func CrawlFromSeed(ctx context.Context, seed CrawlSeed, crawlers []Crawler,
+	conv Converter, indx IndexFunc, seen map[string]struct{}) {
+
+	// stack tracks the documents directly referred in other documents.
 	stack := make(CrawlSeed, 0)
 
-	findMatch := func(d *doc.Document) Crawler {
-		for _, crawl := range crawlers {
-			if crawl.Match(d) {
-				return crawl
-			}
-		}
-
-		return nil
-	}
-
-	addBranches := func(cdoc CrawledDocument, match Crawler) {
-		if _, ok := seen[cdoc.ID()]; ok {
-			return
-		}
-
-		seen[cdoc.ID()] = struct{}{}
-		// Insert into index
-		err := indx(cdoc, match)
-		logIfErr(err)
-		if err != nil {
-			return
-		}
-
-		deps, err := cdoc.GetResources()
-		logIfErr(err)
-		if err != nil {
-			return
-		}
-		for _, dep := range deps {
-			if _, ok := seen[dep.ID()]; ok {
-				continue
-			}
-			stack = append(stack, dep)
-		}
-	}
-
-	doCrawl := func(docsPtr *CrawlSeed) {
-		n := len(*docsPtr)
-		for i := 0; i < n; i++ {
-			next := (*docsPtr)[i]
-			match := findMatch(next)
-			if match == nil {
-				logIfErr(fmt.Errorf(
-					"%v could not match any crawler", next))
-				continue
-			}
-
-			logger.Println("Crawling ", next.RepositoryURL, next.FilePath)
-			err := match.FetchDocument(ctx, next)
-			logIfErr(err)
-			// If there was no change or there is an error, we don't have
-			// to branch out, since the dependencies are already in the
-			// index, or we cannot find the document.
-			if err != nil || next.WasCached() {
-				if next.WasCached() {
-					logger.Println(next.RepositoryURL, next.FilePath, "is cached already")
-				}
-				continue
-			}
-
-			logIfErr(match.SetCreated(ctx, next))
-
-			cdoc, err := conv(next)
-			logIfErr(err)
-
-			addBranches(cdoc, match)
-		}
-	}
-
 	// Exploit seed to update bulk of corpus.
 	logger.Printf("updating %d documents from seed\n", len(seed))
-	doCrawl(&seed)
-	// Traverse any new links added while updating corpus.
+	// each unique document in seed will be crawled once.
+	doCrawl(ctx, &seed, crawlers, conv, indx, seen, &stack)
+
+	// Traverse any new documents added while updating corpus.
 	logger.Printf("crawling %d new documents found in the seed\n", len(stack))
-	doCrawl(&stack)
-
-	ch := make(chan CrawledDocument, 1<<10)
-	wg := sync.WaitGroup{}
-
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		for cdoc := range ch {
-			if _, ok := seen[cdoc.ID()]; ok {
-				continue
-			}
-			match := findMatch(cdoc.GetDocument())
-			if match == nil {
-				logIfErr(fmt.Errorf(
-					"%v could not match any crawler", cdoc))
-				continue
-			}
-			addBranches(cdoc, match)
-		}
-	}()
-
-	// Exploration through APIs.
-	errs := CRunner(ctx, ch, crawlers)
-	if errs != nil {
-		for _, err := range errs {
-			logIfErr(err)
-		}
-	}
-	close(ch)
-	logger.Println("Processing the new documents from the crawlers' exploration.")
-	wg.Wait()
-	// Handle deps of newly discovered documents.
-	logger.Printf("crawling the %d new documents from the crawlers' exploration.",
-		len(stack))
-	doCrawl(&stack)
+	// While crawling each document in stack, the documents directly referred in the document
+	// will be added into stack.
+	// After this statement is done, stack will become empty.
+	doCrawl(ctx, &stack, crawlers, conv, indx, seen, &stack)
 }
 
-// CRunner is a blocking function and only returns once all of the
+// CrawlGithubRunner is a blocking function and only returns once all of the
 // crawlers are finished with execution.
 //
 // This function uses the output channel to forward kustomization documents
@@ -188,14 +169,14 @@ func CrawlFromSeed(ctx context.Context, seed CrawlSeed,
 // index of the crawler that emitted the error. Although the errors themselves
 // can be nil, the array will always be exactly the size of the crawlers array.
 //
-// CRunner takes in a seed, which represents the documents stored in an
+// CrawlGithubRunner takes in a seed, which represents the documents stored in an
 // index somewhere. The document data is not required to be populated. If there
 // are many documents, this is preferable. The order of iteration over the seed
-// is not guaranteed, but the CRunner does guarantee that every element
+// is not guaranteed, but the CrawlGithub does guarantee that every element
 // from the seed will be processed before any other documents from the
 // crawlers.
-func CRunner(ctx context.Context,
-	output chan<- CrawledDocument, crawlers []Crawler) []error {
+func CrawlGithubRunner(ctx context.Context, output chan<- CrawledDocument,
+	crawlers []Crawler) []error {
 
 	errs := make([]error, len(crawlers))
 	wg := sync.WaitGroup{}
@@ -236,3 +217,46 @@ func CRunner(ctx context.Context,
 	wg.Wait()
 	return errs
 }
+
+// CrawlGithub crawls all the kustomization files on Github.
+func CrawlGithub(ctx context.Context, crawlers []Crawler, conv Converter,
+	indx IndexFunc, seen map[string]struct{}) {
+	// stack tracks the documents directly referred in other documents.
+	stack := make(CrawlSeed, 0)
+
+	// ch is channel where all the crawlers sends the crawled documents to.
+	ch := make(chan CrawledDocument, 1<<10)
+
+	wg := sync.WaitGroup{}
+
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		for cdoc := range ch {
+			if _, ok := seen[cdoc.ID()]; ok {
+				continue
+			}
+			match := findMatch(cdoc.GetDocument(), crawlers)
+			if match == nil {
+				logIfErr(fmt.Errorf(
+					"%v could not match any crawler", cdoc))
+				continue
+			}
+			addBranches(cdoc, match, indx, seen, &stack)
+		}
+	}()
+
+	logger.Println("processing the documents found from crawling github")
+	if errs := CrawlGithubRunner(ctx, ch, crawlers); errs != nil {
+		for _, err := range errs {
+			logIfErr(err)
+		}
+	}
+	close(ch)
+	wg.Wait()
+
+	// Handle deps of newly discovered documents.
+	logger.Printf("crawling the %d new documents referred by other documents",
+		len(stack))
+	doCrawl(ctx, &stack, crawlers, conv, indx, seen, &stack)
+}
diff --git a/api/internal/crawl/crawler/crawler_test.go b/api/internal/crawl/crawler/crawler_test.go
index e80428ddb..64887b1fc 100644
--- a/api/internal/crawl/crawler/crawler_test.go
+++ b/api/internal/crawl/crawler/crawler_test.go
@@ -38,12 +38,13 @@ func (c testCrawler) FetchDocument(_ context.Context, d *doc.Document) error {
 		return nil
 	}
 	for _, suffix := range konfig.RecognizedKustomizationFileNames() {
-		fmt.Println(d.ID(), "/", suffix)
-		i, ok := c.lukp[d.ID()+"/"+suffix]
+		savedFilePath := d.FilePath
+		d.FilePath += "/" + suffix
+		i, ok := c.lukp[d.ID()]
 		if !ok {
+			d.FilePath = savedFilePath
 			continue
 		}
-		d.FilePath += "/" + suffix
 		d.DocumentData = c.docs[i].DocumentData
 		return nil
 	}
@@ -106,8 +107,8 @@ func (s sortableDocs) Len() int {
 	return len(s)
 }
 
-func TestCrawlerRunner(t *testing.T) {
-	fmt.Println("testing CRunner")
+func TestCrawlGithubRunner(t *testing.T) {
+	fmt.Println("testing CrawlGithubRunner")
 	tests := []struct {
 		tc   []Crawler
 		errs []error
@@ -178,7 +179,7 @@ func TestCrawlerRunner(t *testing.T) {
 			defer close(output)
 			defer wg.Done()
 
-			errs := CRunner(context.Background(),
+			errs := CrawlGithubRunner(context.Background(),
 				output, test.tc)
 
 			// Check that errors are returned as they should be.
@@ -302,29 +303,6 @@ resources:
 					RepositoryURL: kustomizeRepo,
 					FilePath:      "examples/seedcrawl2/job.yaml",
 				}},
-				// Visited from the crawler runner.
-				{Document: doc.Document{
-					RepositoryURL: kustomizeRepo,
-					FilePath:      "examples/other/base/kustomization.yaml",
-					DocumentData: `
-resources:
-- ../app
-`,
-				}},
-				// Visited from the crawler runner.
-				{Document: doc.Document{
-					RepositoryURL: kustomizeRepo,
-					FilePath:      "examples/other/app/kustomization.yaml",
-					DocumentData: `
-resources:
-- resource.yaml
-`,
-				}},
-				// Visited from crawling runner imported as resource.
-				{Document: doc.Document{
-					RepositoryURL: kustomizeRepo,
-					FilePath:      "examples/other/app/resource.yaml",
-				}},
 			},
 		},
 	}
@@ -342,6 +320,7 @@ resources:
 				visited[d.ID()]++
 				return nil
 			},
+			make(map[string]struct{}),
 		)
 		if lv, lc := len(visited), len(tc.corpus); lv != lc {
 			t.Errorf("error: %d of %d documents visited.", lv, lc)
diff --git a/api/internal/crawl/crawler/github/crawler.go b/api/internal/crawl/crawler/github/crawler.go
index a42c33074..66fa9b20c 100644
--- a/api/internal/crawl/crawler/github/crawler.go
+++ b/api/internal/crawl/crawler/github/crawler.go
@@ -230,7 +230,6 @@ func kustomizationResultAdapter(gcl GhClient, k GhFileSpec) (
 			RepositoryURL: k.Repository.URL,
 		},
 	}
-	logger.Printf("Set the creationTime field")
 	creationTime, err := gcl.GetFileCreationTime(k)
 	if err != nil {
 		logger.Printf("GetFileCreationTime failed: %v", err)
@@ -533,7 +532,7 @@ func (gcl GhClient) parseGithubResponse(getRequest string) GhResponseInfo {
 }
 
 // SearchGithubAPI performs a search query and handles rate limitting for
-// the 'code/search?' endpoint as well as timed retries in the case of abuse
+// the 'search/code?' endpoint as well as timed retries in the case of abuse
 // prevention.
 func (gcl GhClient) SearchGithubAPI(query string) (*http.Response, error) {
 	throttleSearchAPI()
diff --git a/api/internal/crawl/crawler/github/queries.go b/api/internal/crawl/crawler/github/queries.go
index d49252ec9..98eb1b9f3 100644
--- a/api/internal/crawl/crawler/github/queries.go
+++ b/api/internal/crawl/crawler/github/queries.go
@@ -90,6 +90,17 @@ func Path(p string) queryField {
 	return queryField{name: "path", value: p}
 }
 
+// Repo takes a repository (i.e., kubernetes-sigs/kustomize) and formats
+// it according to the Github API.
+func Repo(r string) queryField {
+	return queryField{name: "repo", value: r}
+}
+
+// Path takes a github username and formats it according to the Github API.
+func User(u string) queryField {
+	return queryField{name: "user", value: u}
+}
+
 // RequestConfig stores common variables that must be present for the queries.
 // - CodeSearchRequests: ask Github to check the code indices given a query.
 // - ContentsRequests: ask Github where to download a resource given a repo and a
@@ -123,11 +134,15 @@ func (rc RequestConfig) ReposRequest(fullRepoName string) string {
 	return rc.makeRequest(uri, Query{}).URL()
 }
 
+func escapeSpace(s string) string {
+	return strings.Replace(s, " ", "%20", -1)
+}
+
 // CommitsRequest given the repo name, and a filepath returns a formatted query
 // for the Github API to find the commits that affect this file.
 func (rc RequestConfig) CommitsRequest(fullRepoName, path string) string {
 	uri := fmt.Sprintf("repos/%s/commits", fullRepoName)
-	return rc.makeRequest(uri, Query{Path(path)}).URL()
+	return rc.makeRequest(uri, Query{Path(escapeSpace(path))}).URL()
 }
 
 func (rc RequestConfig) makeRequest(path string, query Query) request {
diff --git a/api/internal/crawl/crawler/github/queries_test.go b/api/internal/crawl/crawler/github/queries_test.go
index d09acfe6b..07c9036b6 100644
--- a/api/internal/crawl/crawler/github/queries_test.go
+++ b/api/internal/crawl/crawler/github/queries_test.go
@@ -53,8 +53,11 @@ func TestQueryType(t *testing.T) {
 				Filename("kustomization.yaml"),
 				Keyword("keyword1"),
 				Keyword("keyword2"),
+				Repo("user1/repo1"),
+				User("user1"),
 			),
-			expected: "q=size:24..64+filename:kustomization.yaml+keyword1+keyword2",
+			expected: "q=size:24..64+filename:kustomization.yaml+keyword1+keyword2+" +
+				"repo:user1/repo1+user:user1",
 		},
 	}
 
@@ -100,6 +103,26 @@ func TestGithubSearchQuery(t *testing.T) {
 			expectedCommitsQuery: "https://api.github.com/repos/kubernetes-sigs/kustomize/commits?" +
 				"q=path:examples/helloWorld/kustomization.yaml&per_page=100",
 		},
+		{
+			rc: RequestConfig{
+				perPage: perPage,
+			},
+			codeQuery: Query{
+				Filename("kustomization.yaml"),
+				Filesize(RangeWithin{64, 128}),
+			},
+			fullRepoName: "kubernetes-sigs/kustomize",
+			path:         "examples 1/helloWorld/kustomization.yaml",
+
+			expectedCodeQuery: "https://api.github.com/search/code?" +
+				"q=filename:kustomization.yaml+size:64..128&order=desc&per_page=100&sort=indexed",
+
+			expectedContentsQuery: "https://api.github.com/repos/kubernetes-sigs/kustomize/contents/" +
+				"examples%201/helloWorld/kustomization.yaml?per_page=100",
+
+			expectedCommitsQuery: "https://api.github.com/repos/kubernetes-sigs/kustomize/commits?" +
+				"q=path:examples%201/helloWorld/kustomization.yaml&per_page=100",
+		},
 	}
 
 	for _, test := range testCases {
diff --git a/api/internal/crawl/crawler/github/split_search_ranges.go b/api/internal/crawl/crawler/github/split_search_ranges.go
index 919d3135d..1322932f4 100644
--- a/api/internal/crawl/crawler/github/split_search_ranges.go
+++ b/api/internal/crawl/crawler/github/split_search_ranges.go
@@ -243,7 +243,7 @@ func FindRangesForRepoSearch(cache cachedSearch) ([]string, error) {
 	if err != nil {
 		return nil, err
 	}
-	logger.Println("total files: ", totalFiles)
+	logger.Println("total kustomization files: ", totalFiles)
 
 	if githubMaxResultsPerQuery >= totalFiles {
 		return []string{