diff --git a/README.md b/README.md
index 975c12a..761bf81 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,9 @@ jobs:
 - `image`: exactly as petersweb-infra pins it, without tag or digest.
 - `infra-file`: the petersweb-infra file with `<image>@sha256:<digest>`
   (`nixos/linux.nix`, or e.g. `nixos/arion-riverside/arion-compose.nix`).
-- Optional: `name` (branch and PR title; default the image's last path
+- Optional: `server` (default https://forge.quinefoundation.com; not the
+  runner-reported address, which can be localhost), `name` (branch and PR
+  title; default the image's last path
   part), `context` (default `.`), `containerfile`, `platform` (default
   `linux/amd64`), `infra-repo`.
 
diff --git a/action.yml b/action.yml
index e858ccd..d036a71 100644
--- a/action.yml
+++ b/action.yml
@@ -37,6 +37,12 @@ inputs:
   infra-repo:
     description: The infra repo
     default: Cold-Air-Networks/petersweb-infra
+  server:
+    description: >-
+      The forge's address, for cloning, the API and links. Not
+      github.server_url: a runner next to Forgejo (the forge VM's) is told
+      http://localhost:3000, which a job container can't reach.
+    default: https://forge.quinefoundation.com
 
 outputs:
   digest:
@@ -82,11 +88,12 @@ runs:
         INFRA_REPO: ${{ inputs.infra-repo }}
         INFRA_TOKEN: ${{ inputs.infra-token }}
         NAME: ${{ inputs.name }}
+        SERVER: ${{ inputs.server }}
         DIGEST: ${{ steps.push.outputs.digest }}
         SHA: ${{ github.sha }}
       run: |
         set -euo pipefail
-        server=$GITHUB_SERVER_URL
+        server=$SERVER
         name=${NAME:-${IMAGE##*/}}
         short=${SHA:0:7}
         branch="bump-$name-$short"