diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index 4f2c458..fb4d76a 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -1,4 +1,4 @@
-# Runs on the Nix runner on nexus (label `nixos`, host executor).
+# Runs on a self-hosted Nix runner (label `nixos`, host executor).
 name: ci
 on: [push, pull_request]
 
diff --git a/README.md b/README.md
index 3aeba05..786ea24 100644
--- a/README.md
+++ b/README.md
@@ -10,9 +10,11 @@ change its own code.
 
 ## Start
 
-You need [Nix](https://nixos.org/download) with flakes.
+You need [Nix](https://nixos.org/download) with flakes, and an API token for
+an LLM (OpenAI Responses or Anthropic Messages API).
 
 ```sh
+git clone https://gitea.surma.technology/surma/sausage && cd sausage
 nix run -- init     # creates ./world and builds the agent (a few minutes)
 nix run -- run      # starts the world and a console
 ```
@@ -26,12 +28,13 @@ folder as an argument, for example `nix run -- run my-world`.
 To keep a world on the newest version, run it in a loop:
 
 ```sh
-nix run .#loop -- my-world            # or .#loop-internal (Gitea on the LAN)
+nix run .#loop -- my-world
 ```
 
-The loop runs `nix run --refresh git+ssh://…/surma/sausage -- run my-world`.
+The loop runs `nix run --refresh git+https://gitea.surma.technology/surma/sausage -- run my-world`.
 When the host crashes or an actor sends `@broker {"type":"exit"}`, the loop
-fetches the newest commit and starts it again. `/quit` ends the loop.
+fetches the newest commit and starts it again. `/quit` ends the loop. Set
+`SAUSAGE_FLAKE` to run another flake URL instead, for example your fork.
 
 In the console:
 
diff --git a/flake.nix b/flake.nix
index 576e530..6fa8678 100644
--- a/flake.nix
+++ b/flake.nix
@@ -36,15 +36,14 @@
           meta.mainProgram = "sausage";
         };
         # `nix run .#loop -- <world>` runs the newest `sausage run <world>`
-        # from the Gitea repo, again and again: after a crash or a broker
+        # from the public repo, again and again: after a crash or a broker
         # `exit` request it refreshes the flake and starts the host again,
         # so the world updates itself. `/quit` (exit code 0) ends the loop.
-        # `--internal` (or `.#loop-internal`) uses Gitea's SSH port on the LAN.
-        publicUrl = "git+ssh://containeruser@gitea.surma.technology:2222/surma/sausage";
-        internalUrl = "git+ssh://containeruser@10.0.0.2:2222/surma/sausage";
-        loop = name: url: pkgs.writeShellScriptBin name ''
-          url="${url}"
-          if [ "''${1:-}" = "--internal" ]; then url="${internalUrl}"; shift; fi
+        # SAUSAGE_FLAKE overrides where it fetches from (any flake URL,
+        # e.g. a fork or a local checkout).
+        repoUrl = "git+https://gitea.surma.technology/surma/sausage";
+        loop = pkgs.writeShellScriptBin "sausage-loop" ''
+          url="''${SAUSAGE_FLAKE:-${repoUrl}}"
           if [ $# -eq 0 ]; then set -- world; fi
           while true; do
             nix run --refresh "$url#default" -- run "$@"
@@ -72,8 +71,7 @@
         });
 
         apps.default = { type = "app"; program = "${sausage}/bin/sausage"; };
-        apps.loop = { type = "app"; program = "${loop "sausage-loop" publicUrl}/bin/sausage-loop"; };
-        apps.loop-internal = { type = "app"; program = "${loop "sausage-loop-internal" internalUrl}/bin/sausage-loop-internal"; };
+        apps.loop = { type = "app"; program = "${loop}/bin/sausage-loop"; };
 
         devShells.default = pkgs.mkShell {
           packages = [ rust pkgs.wasmtime pkgs.wasm-tools ];