diff --git a/.ots/prev-commit.txt b/.ots/prev-commit.txt
index 2fe79b2..9687ed2 100644
--- a/.ots/prev-commit.txt
+++ b/.ots/prev-commit.txt
@@ -1 +1 @@
-4a6f5ed0c12315b0bc8a0fa5815ada1bd20e5963
+46aded7b9582bbed673843e2cf8a3f8fa742ad91
diff --git a/.ots/proof.ots b/.ots/proof.ots
index 8542c60..14d73c1 100644
Binary files a/.ots/proof.ots and b/.ots/proof.ots differ
diff --git a/backfill-proofs.sh b/backfill-proofs.sh
new file mode 100755
index 0000000..6fbc16e
--- /dev/null
+++ b/backfill-proofs.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+# backfill-proofs.sh - Generate/upgrade OpenTimestamp proofs for all commits
+# Usage: backfill-proofs.sh [repository-path]
+
+set -e
+
+REPO_PATH="${1:-.}"
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+cd "$REPO_PATH"
+
+# Verify we're in a git repository
+if ! git rev-parse --git-dir > /dev/null 2>&1; then
+    echo "Error: not a git repository" >&2
+    exit 1
+fi
+
+# Find the generate-proof.sh script
+GENERATE_SCRIPT=""
+
+# Check if generate-proof.sh is in the same directory as this script
+if [ -f "$SCRIPT_DIR/generate-proof.sh" ]; then
+    GENERATE_SCRIPT="$SCRIPT_DIR/generate-proof.sh"
+# Check in repository root
+elif [ -f "generate-proof.sh" ]; then
+    GENERATE_SCRIPT="./generate-proof.sh"
+# Check if skill is installed globally
+elif [ -f "$HOME/.openclaw/workspace/skills/git-ots-hook/scripts/generate-proof.sh" ]; then
+    GENERATE_SCRIPT="$HOME/.openclaw/workspace/skills/git-ots-hook/scripts/generate-proof.sh"
+else
+    echo "Error: generate-proof.sh not found" >&2
+    exit 1
+fi
+
+chmod +x "$GENERATE_SCRIPT"
+
+# Ensure .ots directory exists
+mkdir -p .ots
+
+echo "[ots-backfill] Scanning commit history..."
+
+# Get all commit hashes (oldest to newest)
+COMMITS=$(git rev-list --reverse HEAD)
+TOTAL=$(echo "$COMMITS" | wc -l)
+CURRENT=0
+
+# Track if any proofs were updated
+UPDATED=0
+
+for COMMIT in $COMMITS; do
+    CURRENT=$((CURRENT + 1))
+    echo "[ots-backfill] Processing commit $CURRENT/$TOTAL: ${COMMIT:0:8}"
+    
+    # Check if proof exists for this commit
+    PROOF_FILE=".ots/${COMMIT}.ots"
+    
+    if [ -f "$PROOF_FILE" ]; then
+        # Try to upgrade existing proof
+        echo "  Upgrading existing proof..."
+        if ots upgrade "$PROOF_FILE" 2>/dev/null; then
+            echo "  ✓ Upgraded to attested"
+            UPDATED=$((UPDATED + 1))
+        else
+            echo "  - Still pending (no upgrade available)"
+        fi
+    else
+        # Generate new proof for this commit
+        echo "  Generating new proof..."
+        "$GENERATE_SCRIPT" "$COMMIT" "$PROOF_FILE" >/dev/null 2>&1
+        echo "  ✓ Generated proof"
+        UPDATED=$((UPDATED + 1))
+    fi
+done
+
+# Create/update latest proof symlink
+LATEST_COMMIT=$(git rev-parse HEAD)
+if [ -f ".ots/${LATEST_COMMIT}.ots" ]; then
+    cp ".ots/${LATEST_COMMIT}.ots" ".ots/proof.ots"
+    echo "[ots-backfill] Updated .ots/proof.ots for latest commit"
+fi
+
+# Save previous commit chain info
+echo "[ots-backfill] Saving commit chain..."
+git rev-list HEAD | while read COMMIT; do
+    PREV=$(git rev-parse ${COMMIT}^1 2>/dev/null || echo "")
+    if [ -n "$PREV" ]; then
+        echo "$COMMIT:$PREV" >> ".ots/commit-chain.txt"
+    fi
+done
+
+echo ""
+echo "[ots-backfill] Complete! Processed $TOTAL commits, updated $UPDATED proofs"
+echo ""
+echo "Proofs stored in: .ots/"
+echo "  - Individual proofs: .ots/<commit-hash>.ots"
+echo "  - Latest proof: .ots/proof.ots"
+echo "  - Commit chain: .ots/commit-chain.txt"
diff --git a/install-ots-hook.sh b/install-ots-hook.sh
index ff425a5..06c7f63 100755
--- a/install-ots-hook.sh
+++ b/install-ots-hook.sh
@@ -1,10 +1,11 @@
 #!/bin/bash
 # install-ots-hook.sh - Install OpenTimestamp post-commit hook
-# Usage: install-ots-hook.sh [repository-path]
+# Usage: install-ots-hook.sh [repository-path] [backfill]
 
 set -e
 
 REPO_PATH="${1:-.}"
+ENABLE_BACKFILL="${2:-}"  # Second arg: "backfill" to enable pre-commit backfill hook
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
 cd "$REPO_PATH"
@@ -18,7 +19,7 @@ fi
 HOOKS_DIR="$(git rev-parse --git-dir)/hooks"
 POST_COMMIT_HOOK="$HOOKS_DIR/post-commit"
 
-echo "Installing OpenTimestamp hook in: $REPO_PATH"
+echo "Installing OpenTimestamp hooks in: $REPO_PATH"
 
 # Create the post-commit hook
 cat > "$POST_COMMIT_HOOK" << 'HOOK_SCRIPT'
@@ -66,10 +67,23 @@ HOOK_SCRIPT
 chmod +x "$POST_COMMIT_HOOK"
 
 echo "✓ Post-commit hook installed successfully"
+
+# Optionally install pre-commit backfill hook
+if [ "$ENABLE_BACKFILL" = "backfill" ]; then
+    PRE_COMMIT_HOOK="$HOOKS_DIR/pre-commit"
+    cp "$SCRIPT_DIR/pre-commit-backfill" "$PRE_COMMIT_HOOK"
+    chmod +x "$PRE_COMMIT_HOOK"
+    echo "✓ Pre-commit backfill hook installed (will backfill proofs before each commit)"
+fi
+
 echo ""
 echo "Next steps:"
-echo "1. Ensure generate-proof.sh is accessible (copy to repo root or install skill globally)"
+echo "1. Ensure scripts are accessible (copy to repo root or install skill globally)"
 echo "2. Verify ots CLI or @opentimestamps/ots is installed"
-echo "3. Make a test commit to verify the hook works"
+echo "3. Make a test commit to verify the hooks work"
 echo ""
-echo "To uninstall, run: rm $POST_COMMIT_HOOK"
+echo "To uninstall:"
+echo "  rm $POST_COMMIT_HOOK"
+if [ "$ENABLE_BACKFILL" = "backfill" ]; then
+    echo "  rm $PRE_COMMIT_HOOK"
+fi
diff --git a/pre-commit-backfill b/pre-commit-backfill
new file mode 100755
index 0000000..3ff9a7d
--- /dev/null
+++ b/pre-commit-backfill
@@ -0,0 +1,32 @@
+#!/bin/bash
+# Pre-commit hook: backfill proofs for all commits before creating new commit
+# This ensures all historical commits have attested proofs
+
+set -e
+
+# Get the directory where this hook is installed
+HOOKS_DIR="$(git rev-parse --git-dir)/hooks"
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+# Find the backfill-proofs.sh script
+BACKFILL_SCRIPT=""
+
+if [ -f "$SCRIPT_DIR/backfill-proofs.sh" ]; then
+    BACKFILL_SCRIPT="$SCRIPT_DIR/backfill-proofs.sh"
+elif [ -f ".git/hooks/backfill-proofs.sh" ]; then
+    BACKFILL_SCRIPT=".git/hooks/backfill-proofs.sh"
+elif [ -f "backfill-proofs.sh" ]; then
+    BACKFILL_SCRIPT="./backfill-proofs.sh"
+elif [ -f "$HOME/.openclaw/workspace/skills/git-ots-hook/scripts/backfill-proofs.sh" ]; then
+    BACKFILL_SCRIPT="$HOME/.openclaw/workspace/skills/git-ots-hook/scripts/backfill-proofs.sh"
+else
+    # Silently skip if backfill script not found
+    exit 0
+fi
+
+chmod +x "$BACKFILL_SCRIPT"
+
+echo "[ots] Backfilling proofs before commit..."
+"$BACKFILL_SCRIPT" .
+
+echo "[ots] Ready to commit"
diff --git a/test4.txt b/test4.txt
new file mode 100644
index 0000000..6a11e80
--- /dev/null
+++ b/test4.txt
@@ -0,0 +1 @@
+# Test pre-commit backfill