diff --git a/cmd/ugit-uci/main.go b/cmd/ugit-uci/main.go
new file mode 100644
index 0000000000000000000000000000000000000000..e9105a908acfe0daae0a77624f1b6caf129ae420
--- /dev/null
+++ b/cmd/ugit-uci/main.go
@@ -0,0 +1,68 @@
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+
+	"github.com/go-git/go-git/v5"
+)
+
+func maine() error {
+	repoDir, ok := os.LookupEnv("UGIT_REPODIR")
+	if !ok {
+		panic("UGIT_REPODIR not set")
+	}
+
+	urlFlag := flag.String("url", "http://localhost:3448", "URL for UCI")
+	flag.StringVar(urlFlag, "u", *urlFlag, "--url")
+	repoDirFlag := flag.String("repo-dir", "", "Repo dir (including .git)")
+	flag.StringVar(repoDirFlag, "rd", *repoDirFlag, "--repo-dir")
+	manifestFlag := flag.String("manifest", ".uci.jsonnet", "Path to manifest in repo")
+	flag.StringVar(manifestFlag, "m", *manifestFlag, "--manifest")
+	flag.Parse()
+
+	if *repoDirFlag != "" {
+		repoDir = *repoDirFlag
+	}
+
+	repo, err := git.PlainOpen(repoDir)
+	if err != nil {
+		return fmt.Errorf("could not open git dir %q: %w", repoDir, err)
+	}
+
+	tree, err := repo.Worktree()
+	if err != nil {
+		return fmt.Errorf("could not get worktree: %w", err)
+	}
+
+	fi, err := tree.Filesystem.Open(*manifestFlag)
+	if err != nil {
+		return fmt.Errorf("could not open manifest %q: %w", *manifestFlag, err)
+	}
+	defer fi.Close()
+
+	data, err := io.ReadAll(fi)
+	if err != nil {
+		return fmt.Errorf("could not read manifest: %w", err)
+	}
+
+	resp, err := http.Post(*urlFlag, "application/jsonnet", bytes.NewReader(data))
+	if err != nil {
+		return fmt.Errorf("could not post manifest: %w", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("non-ok response: %s", resp.Status)
+	}
+
+	return nil
+}
+
+func main() {
+	if err := maine(); err != nil {
+		fmt.Println(err)
+	}
+}

diff --git a/flake.nix b/flake.nix
index b693a7a25666ae29a9f945bb776b84f42e8f4801..a7aedde25dd2d58ef845a996061106319e23ae97 100644
--- a/flake.nix
+++ b/flake.nix
@@ -35,7 +35,7 @@         inherit name;
         path = ./.;
       });
       pwd = ./.;
-      subPackages = ["cmd/ugitd"];
+      subPackages = ["cmd/ugitd" "cmd/ugit-uci"];
       CGO_ENABLED = 0;
       flags = [
         "-trimpath"