diff --git a/nix/packages/hyperhive-the-movie-milestones.txt b/nix/packages/hyperhive-the-movie-milestones.txt
new file mode 100644
index 000000000..fb656befb
--- /dev/null
+++ b/nix/packages/hyperhive-the-movie-milestones.txt
@@ -0,0 +1,70 @@
+# Milestones shown as captions in `nix run .#hyperhive-the-movie`, one per line:
+#   YYYY-MM-DD|caption
+# Lines starting with # and blank lines are ignored. Git tags are shown too
+# (tag name, at the tagged commit's date), so `git tag <name> <commit>` marks a
+# milestone without editing this file. Dates are where a component first
+# appears in the history; edit freely. Growth markers: commit counts doubling
+# from 512, every 50k lines overall, issue or PR ids doubling from 256, and
+# the first issue on the in-hive forge.
+2026-05-14|first commit
+2026-05-14|per-container web UI and dashboard
+2026-05-16|private forge in a container
+2026-05-20|first issue on the in-hive forge
+2026-05-20|512 commits
+2026-05-22|issue or PR 256
+2026-05-22|agents work through the forge
+2026-05-25|the hive-forge CLI
+2026-05-27|issue or PR 512
+2026-05-29|matrix chat
+2026-05-29|50k lines
+2026-05-30|hive-gateway in front of everything
+2026-05-31|1024 commits
+2026-05-31|CI runner on the forge
+2026-06-01|issue or PR 1024
+2026-06-02|hive-c0re drops root
+2026-06-03|hive-wide knowledge repo and matrix space
+2026-06-03|WireGuard mesh between hives
+2026-06-05|PRs without forks (agit)
+2026-06-13|audit trail of privileged actions
+2026-06-15|agents with accounts on other matrix homeservers
+2026-06-22|2048 commits
+2026-06-22|internal forge mandatory, federation between hives
+2026-06-27|issue or PR 2048
+2026-07-04|100k lines
+2026-07-06|job DAG queue
+2026-07-11|GitHub accounts for agents
+2026-07-14|accounts on external forges
+2026-07-20|GUI agents (screen MCP)
+2026-07-26|forge notifications
+2026-07-31|GitHub notifications for agents
+2026-08-05|swarm controller
+2026-08-05|Authelia, the swarm's identity provider
+2026-08-11|swarm UI
+2026-08-14|NATS messaging in the swarm
+2026-08-16|150k lines
+2026-08-16|swarm metrics in Grafana
+2026-08-16|VictoriaMetrics metrics store
+2026-08-18|OpenTelemetry collector for the swarm
+2026-08-24|swarm-wide log store
+2026-08-30|the swarm's secret store
+2026-08-31|4096 commits
+2026-09-08|issue or PR 4096
+2026-09-09|subagent daemon
+2026-09-11|OIDC client secrets published to the secret store
+2026-09-13|200k lines
+2026-09-20|swarm matrix starts replacing our own broker
+2026-09-29|ACP backends
+2026-10-11|250k lines
+2026-10-12|swarm builder and review classifier
+2026-10-14|claude login from the swarm UI
+2026-10-16|CI run metrics on a Grafana board
+2026-10-17|archetypes
+2026-10-17|300k lines
+2026-10-22|notification router
+2026-10-27|Attic binary cache as a swarm service
+2026-10-27|Squid egress proxy on every hive host
+2026-10-28|350k lines
+2026-10-29|egress allow list per agent
+2026-11-06|operator handbook
+2026-11-08|400k lines
+2026-11-10|restic backups of every agent's state
diff --git a/nix/packages/hyperhive-the-movie.nix b/nix/packages/hyperhive-the-movie.nix
index 8faf153ea..54378c16d 100644
--- a/nix/packages/hyperhive-the-movie.nix
+++ b/nix/packages/hyperhive-the-movie.nix
@@ -1,6 +1,9 @@
 # `nix run .#hyperhive-the-movie` — gource visualisation of the git
 # history of the repo it is run from. `-- --record` renders
-# gource-hyperhive.mp4 in the cwd instead of opening a window.
+# gource-hyperhive.webm in the cwd instead of opening a window: AV1 in WebM,
+# which plays in current Firefox and Chrome and compresses this flat,
+# dark picture far better than H.264. Milestones show as captions, from the git
+# tags of the repo and from `hyperhive-the-movie-milestones.txt`.
 {
   lib,
   writeShellApplication,
@@ -27,8 +30,39 @@ writeShellApplication {
     gnugrep
   ];
   text = ''
+    usage() {
+      cat <<'USAGE'
+    hyperhive-the-movie - gource visualisation of this repo's git history
+
+    Usage: nix run .#hyperhive-the-movie -- [--record | --help]
+
+      (no flag)   open a gource window and play the history
+      --record    render gource-hyperhive.webm in the current directory
+                  instead (1280x720, 30 fps, AV1 in WebM; plays in recent
+                  Firefox and Chrome). Needs no display.
+      -h, --help  show this text
+
+    Run it from inside the repo. Captions come from two places: the git tags
+    (shown at the tagged commit's date) and the milestones file,
+    nix/packages/hyperhive-the-movie-milestones.txt, one "YYYY-MM-DD|caption"
+    per line. Edit that file, or tag a commit with `git tag NAME COMMIT`.
+    USAGE
+    }
+
     record=false
-    [[ "''${1:-}" == "--record" ]] && record=true
+    case "''${1:-}" in
+      "") ;;
+      --record) record=true ;;
+      -h | --help)
+        usage
+        exit 0
+        ;;
+      *)
+        echo "hyperhive-the-movie: unknown argument '$1'" >&2
+        usage >&2
+        exit 2
+        ;;
+    esac
 
     cd "$(git rev-parse --show-toplevel)"
 
@@ -50,13 +84,28 @@ writeShellApplication {
       fi
     done < <(git log --format='%an' | sort -u)
 
+    # Milestone captions, `unix time|text`, sorted by time: the tracked
+    # milestones file (`YYYY-MM-DD|text`) and the repo's git tags.
+    captions="$(mktemp)"
+    trap 'rm -f "$captions"' EXIT
+    {
+      while IFS='|' read -r day text; do
+        [[ -z "$day" || "$day" == \#* ]] && continue
+        echo "$(date -d "$day" +%s)|$text"
+      done < ${./hyperhive-the-movie-milestones.txt}
+      git for-each-ref --format='%(creatordate:unix)|%(refname:short)' refs/tags
+    } | sort -n > "$captions"
+
     # Catppuccin Mocha, as in frontend/packages/shared/src/colors.css.
     args=(
       -s 1 -1280x720 --auto-skip-seconds 1 --multi-sampling --stop-at-end
+      --date-format "%Y-%m-%d"
+      --caption-file "$captions" --caption-size 28 --caption-duration 4
+      --caption-colour f9e2af
       --background-colour 1e1e2e --font-colour cdd6f4
       --highlight-colour f9e2af --highlight-users --highlight-dirs
       --filename-colour 585b70 --dir-colour 89b4fa
-      --bloom-multiplier 1.5 --bloom-intensity 0.75 --elasticity 0.3
+      --bloom-multiplier 1.5 --bloom-intensity 0.75 --elasticity 0.1
       --title hyperhive
       --logo ${logo} --logo-offset 20x20
       --user-image-dir "$avatar_dir"
@@ -68,8 +117,8 @@ writeShellApplication {
         gource "''${args[@]}" --output-ppm-stream - --output-framerate 30 \
         | ffmpeg -y -r 30 -f image2pipe -vcodec ppm -i - \
           -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" \
-          -vcodec libx264 -preset ultrafast -pix_fmt yuv420p -crf 1 -threads 0 -bf 0 \
-          gource-hyperhive.mp4
+          -c:v libsvtav1 -preset 6 -crf 34 -g 300 -pix_fmt yuv420p \
+          gource-hyperhive.webm
     else
       gource "''${args[@]}"
     fi