nightly-backup

name	nightly-backup
description	Run `hermes backup`, encrypt, upload to remote storage, prune old backups
when_to_use	["Scheduled nightly via cron","User requests an explicit backup","Before a risky config change"]
toolsets	["terminal","file"]
parameters	{"remote":{"type":"string","description":"Remote target. Supports s3://bucket/prefix, b2://bucket/prefix, ssh://user@host:/path, or \"local\"","default":"local"},"retain_days":{"type":"integer","default":30}}
security	{"trust":"trusted","notes":"No untrusted input. Handles the backup archive and encryption key\nmaterial — never logs key contents; the age identity/passphrase must\nlive outside this host's .env (see Security notes below).\n"}
model_hint	google/gemini-3.1-flash

nightly-backup — Hermes Backup Automation

Thin wrapper around hermes backup + encryption + optional remote upload + retention.

Procedure

1. Snapshot. Run:

   STAMP=$(date +%Y%m%d-%H%M%S)
   hermes backup --output /tmp/hermes-backup-$STAMP.tar
   

   This bundles config, sessions, skills, memory, and cron entries per Part 16.

2. Encrypt. Non-interactively — this runs from cron, so nothing may prompt.

   Route A — age with a keyfile (preferred):

   # One-time setup (NOT in the nightly run): generate the identity, store a
   # copy somewhere that is not this host.
   age-keygen -o ~/.age-backup-key && chmod 600 ~/.age-backup-key
   
   # Nightly: encrypt to the key's recipient (public half) — no prompt, and
   # the nightly path never needs the private key at all.
   age -r "$(age-keygen -y ~/.age-backup-key)" \
       -o /tmp/hermes-backup-$STAMP.tar.age /tmp/hermes-backup-$STAMP.tar
   

   (age -p is interactive passphrase mode — it cannot run from cron.)

   Route B — gpg symmetric with a passphrase:

   BACKUP_PASSPHRASE=$(hermes secrets get BACKUP_PASSPHRASE)
   gpg --batch --yes --symmetric --cipher-algo AES256 \
       --passphrase "$BACKUP_PASSPHRASE" \
       /tmp/hermes-backup-$STAMP.tar
   

   Then either way:

   shred -u /tmp/hermes-backup-$STAMP.tar
   

3. Upload. Based on remote: parameter:

   • s3://… → aws s3 cp <file> s3://bucket/prefix/
   • b2://… → rclone copy <file> b2:bucket/prefix/
   • ssh://… → rsync -av <file> user@host:/path/
   • local → move to ~/.hermes/backups/

4. Prune. Delete anything older than retain_days:

   • s3: use S3 lifecycle policy if possible; otherwise aws s3 ls + age filter
   • b2: rclone delete --min-age ${retain_days}d b2:bucket/prefix/
   • ssh: ssh host "find /path -mtime +${retain_days} -delete"
   • local: find ~/.hermes/backups -mtime +${retain_days} -delete

5. Verify. Download a random recent backup and test-decrypt:

   # Route A (age keyfile):
   age -d -i ~/.age-backup-key backup.tar.age > /tmp/verify.tar
   # Route B (gpg passphrase):
   # gpg --batch --passphrase "$BACKUP_PASSPHRASE" -d backup.tar.gpg > /tmp/verify.tar
   tar tf /tmp/verify.tar | head -5 && shred -u /tmp/verify.tar
   

   Fail loud if the verification fails — a backup you can't restore is not a backup.

6. Report. Send a line to your configured notify: channel:

   ✔ hermes backup 2026-04-17 — 284 MB, uploaded to s3://backups/hermes/, pruned 3 old
   

   On failure, send 🔴 with the specific error and skip pruning (keep old backups until the new one succeeds).

Cron wiring

# ~/.hermes/cron.yaml
- name: nightly-backup
  schedule: "0 3 * * *"
  task: /nightly-backup s3://my-backups/hermes/ 30
  notify: telegram_private

Security notes

• Never back up .env plaintext — hermes backup already excludes it. If you're using a fork, verify with tar tf backup.tar | grep .env and bail if it appears.
• The decryption secret must live outside this host's .env — Route A: keep an offline copy of ~/.age-backup-key (that file is the only way back into your archives); Route B: keep BACKUP_PASSPHRASE in a separate secret store. Otherwise a stolen Hermes host gets both the backups and the key to them.
• Rotate the backup key/passphrase yearly with skills/security/rotate-secrets, then re-encrypt (or at least re-verify) the archives you still need.