diff --git a/src/cli/repo/repo.go b/src/cli/repo/repo.go
index a64fcbcef..a3f236def 100644
--- a/src/cli/repo/repo.go
+++ b/src/cli/repo/repo.go
@@ -1,14 +1,25 @@
 package repo
 
 import (
+	"os"
+
 	"github.com/spf13/cobra"
 )
 
+var repoCommands = []func(parent *cobra.Command) *cobra.Command{
+	addS3Commands,
+}
+
 // AddCommands attaches all `corso repo * *` commands to the parent.
 func AddCommands(parent *cobra.Command) {
 	parent.AddCommand(repoCmd)
 	repoCmd.AddCommand(initCmd)
 	repoCmd.AddCommand(connectCmd)
+
+	for _, addRepoTo := range repoCommands {
+		addRepoTo(initCmd)
+		addRepoTo(connectCmd)
+	}
 }
 
 // The repo category of commands.
@@ -58,3 +69,19 @@ var connectCmd = &cobra.Command{
 func handleConnectCmd(cmd *cobra.Command, args []string) {
 	cmd.Help()
 }
+
+// aggregates m365 details from flag and env_var values.
+type m365Vars struct {
+	clientID     string
+	clientSecret string
+	tenantID     string
+}
+
+// helper for aggregating m365 connection details.
+func getM365Vars() m365Vars {
+	return m365Vars{
+		clientID:     os.Getenv("O365_CLIENT_ID"),
+		clientSecret: os.Getenv("O356_SECRET"),
+		tenantID:     "todo:tenantID",
+	}
+}
diff --git a/src/cli/repo/s3.go b/src/cli/repo/s3.go
new file mode 100644
index 000000000..c9b3c4558
--- /dev/null
+++ b/src/cli/repo/s3.go
@@ -0,0 +1,128 @@
+package repo
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/alcionai/corso/pkg/repository"
+	"github.com/alcionai/corso/pkg/repository/s3"
+)
+
+// s3 bucket info from flags
+var (
+	bucket    string
+	accessKey string
+)
+
+// called by repo.go to map parent subcommands to provider-specific handling.
+func addS3Commands(parent *cobra.Command) *cobra.Command {
+	var c *cobra.Command
+	switch parent.Use {
+	case initCommand:
+		c = s3InitCmd
+	case connectCommand:
+		c = s3ConnectCmd
+	}
+	parent.AddCommand(c)
+	fs := c.Flags()
+	fs.StringVar(&bucket, "bucket", "", "Name of the S3 bucket (required).")
+	c.MarkFlagRequired("bucket")
+	fs.StringVar(&accessKey, "access-key", "", "Access key ID (replaces the AWS_ACCESS_KEY_ID env variable).")
+	return c
+}
+
+// `corso repo init s3 [<flag>...]`
+var s3InitCmd = &cobra.Command{
+	Use:   "s3",
+	Short: "Initialize a S3 repository",
+	Long:  `Bootstraps a new S3 repository and connects it to your m356 account.`,
+	Run:   initS3Cmd,
+	Args:  cobra.NoArgs,
+}
+
+// initializes a s3 repo.
+func initS3Cmd(cmd *cobra.Command, args []string) {
+	mv := getM365Vars()
+	av := getAwsVars()
+	fmt.Printf(
+		"Called -\n`corso repo init s3`\nbucket:\t%s\nkey:\t%s\n356Client:\t%s\nfound 356Secret:\t%v\nfound awsSecret:\t%v\n",
+		bucket,
+		av.accessKey,
+		mv.clientID,
+		len(mv.clientSecret) > 0,
+		len(av.accessSecret) > 0)
+
+	_, err := repository.Initialize(
+		cmd.Context(),
+		repository.ProviderS3,
+		repository.Account{
+			TenantID:     mv.tenantID,
+			ClientID:     mv.clientID,
+			ClientSecret: mv.clientSecret,
+		},
+		s3.NewConfig(av.bucket, av.accessKey, av.accessSecret),
+	)
+	if err != nil {
+		fmt.Printf("Failed to initialize a new S3 repository: %v", err)
+		os.Exit(1)
+	}
+}
+
+// `corso repo connect s3 [<flag>...]`
+var s3ConnectCmd = &cobra.Command{
+	Use:   "s3",
+	Short: "Connect to a S3 repository",
+	Long:  `Ensures a connection to an existing S3 repository.`,
+	Run:   connectS3Cmd,
+	Args:  cobra.NoArgs,
+}
+
+// connects to an existing s3 repo.
+func connectS3Cmd(cmd *cobra.Command, args []string) {
+	mv := getM365Vars()
+	av := getAwsVars()
+	fmt.Printf(
+		"Called -\n`corso repo connect s3`\nbucket:\t%s\nkey:\t%s\n356Client:\t%s\nfound 356Secret:\t%v\nfound awsSecret:\t%v\n",
+		bucket,
+		accessKey,
+		mv.clientID,
+		len(mv.clientSecret) > 0,
+		len(av.accessSecret) > 0)
+
+	_, err := repository.Connect(
+		cmd.Context(),
+		repository.ProviderS3,
+		repository.Account{
+			TenantID:     mv.tenantID,
+			ClientID:     mv.clientID,
+			ClientSecret: mv.clientSecret,
+		},
+		s3.NewConfig(av.bucket, av.accessKey, av.accessSecret),
+	)
+	if err != nil {
+		fmt.Printf("Failed to connect to the S3 repository: %v", err)
+		os.Exit(1)
+	}
+}
+
+// aggregates aws details from flag and env_var values.
+type awsVars struct {
+	accessKey    string
+	accessSecret string
+	bucket       string
+}
+
+// helper for aggregating aws connection details.
+func getAwsVars() awsVars {
+	ak := os.Getenv("AWS_ACCESS_KEY_ID")
+	if len(accessKey) > 0 {
+		ak = accessKey
+	}
+	return awsVars{
+		accessKey:    ak,
+		accessSecret: os.Getenv("AWS_SECRET_ACCESS_KEY"),
+		bucket:       bucket,
+	}
+}