diff --git a/cmd/disttown/project.go b/cmd/disttown/project.go
index a2e2411..5334458 100644
--- a/cmd/disttown/project.go
+++ b/cmd/disttown/project.go
@@ -57,6 +57,60 @@ var cmdProject = &cli.Command{
 				return nil
 			},
 		},
+		{
+			Name:      "set",
+			Usage:     "update a project's optional fields (only the flags you pass change)",
+			ArgsUsage: "<name>",
+			Flags: []cli.Flag{
+				&cli.StringFlag{Name: "display-name", Usage: "human-facing name"},
+				&cli.StringFlag{Name: "description", Usage: "brief description"},
+				&cli.StringFlag{Name: "source", Usage: "source repository: an at:// record uri (e.g. your sh.tangled.repo — same-DID sources are self-authenticated) or an https:// forge URL"},
+				&cli.StringFlag{Name: "website", Usage: "project homepage, distinct from source"},
+			},
+			Action: func(c *cli.Context) error {
+				if c.Args().Len() != 1 {
+					return fmt.Errorf("usage: disttown project set <name> --source <uri> ...")
+				}
+				name := canon.NormalizeName(c.Args().First())
+				if err := canon.ValidateName(name); err != nil {
+					return err
+				}
+				if !c.IsSet("display-name") && !c.IsSet("description") && !c.IsSet("source") && !c.IsSet("website") {
+					return fmt.Errorf("nothing to change: pass at least one of --display-name, --description, --source, --website")
+				}
+				s, err := atsession.Get(c.Context)
+				if err != nil {
+					return err
+				}
+				out, err := atproto.RepoGetRecord(c.Context, s.Client, "", canon.NSIDProject, s.DID, name)
+				if err != nil {
+					return fmt.Errorf("reading project %q: %w", name, err)
+				}
+				rec, ok := out.Value.Val.(*gen.Project)
+				if !ok {
+					return fmt.Errorf("record %q is not a project", name)
+				}
+				set := func(flag string, field **string) {
+					if c.IsSet(flag) {
+						if v := c.String(flag); v == "" {
+							*field = nil // explicit empty clears the field
+						} else {
+							*field = &v
+						}
+					}
+				}
+				set("display-name", &rec.DisplayName)
+				set("description", &rec.Description)
+				set("source", &rec.Source)
+				set("website", &rec.Website)
+				w := updateElem(canon.NSIDProject, name, rec)
+				if err := applyWrites(c.Context, s, []*atproto.RepoApplyWrites_Input_Writes_Elem{w}); err != nil {
+					return err
+				}
+				fmt.Printf("updated project %s\n  %s\n", name, atURI(s.DID, canon.NSIDProject, name))
+				return nil
+			},
+		},
 		{
 			Name:      "rename",
 			Usage:     "rename a project: a successor record is created and the old record persists as a permanent alias",
diff --git a/web/src/routes/docs/cli/+page.md b/web/src/routes/docs/cli/+page.md
index c309a16..98d118b 100644
--- a/web/src/routes/docs/cli/+page.md
+++ b/web/src/routes/docs/cli/+page.md
@@ -131,6 +131,19 @@ Create a bare project record (e.g. an umbrella; publish creates leaf projects on
 - `--display-name <value>` — human-facing name
 - `--description <value>` — brief description
 
+### project set
+
+```sh
+disttown project set <name>
+```
+
+Update a project's optional fields (only the flags you pass change)
+
+- `--display-name <value>` — human-facing name
+- `--description <value>` — brief description
+- `--source <value>` — source repository: an at:// record uri (e.g. your sh.tangled.repo — same-DID sources are self-authenticated) or an https:// forge URL
+- `--website <value>` — project homepage, distinct from source
+
 ### project rename
 
 ```sh