diff --git a/PR_INVESTIGATION_FINDINGS.md b/PR_INVESTIGATION_FINDINGS.md
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+# Investigation Findings: Missing PRs in Main Branch
+
+## Executive Summary
+
+**Issue**: When examining the repository with a shallow clone, it appeared that some merged PRs were missing from the main branch history.
+
+**Root Cause**: The repository was cloned with `--depth=1` (shallow clone), which only fetched the most recent commit, making the full history appear to be missing.
+
+**Resolution**: After running `git fetch --unshallow`, all merged PRs were confirmed to be present in the repository history.
+
+## Detailed Analysis
+
+### Last 6 Merged PRs (by merge date)
+
+1. **PR #77** - "Update dockerfile and add workflow"
+   - Merged: 2025-03-26T20:22:16Z
+   - Commit SHA: bc7d41cf98b83766b7a223b6f1b90a7b909fc820
+   - Status: ✅ Present in git history
+
+2. **PR #78** - "adding hack for lco bug fix"
+   - Merged: 2025-04-03T19:31:41Z
+   - Commit SHA: b829883da6faf53b3bdf3d25103f14df18b5a16a
+   - Status: ✅ Present in git history
+
+3. **PR #79** - "Adds new endpoint for bulk query by altid"
+   - Merged: 2025-04-18T14:51:06Z
+   - Commit SHA: fbe64d36d12a2756c29cd1cee754c03fb35c2bd7
+   - Status: ✅ Present in git history
+
+4. **PR #80** - "Updates the default release to DR19"
+   - Merged: 2025-06-26T20:41:27Z
+   - Commit SHA: 56a793dcc31381c64105b66895459a40a6f59dab
+   - Status: ✅ Present in git history
+
+5. **PR #83** - "Adds new route for legacy data lookup"
+   - Merged: 2025-09-19T18:35:30Z
+   - Commit SHA: abe4a4a9212c9f50a90ca2358c1d80d01a2bd6ed
+   - Status: ✅ Present in git history
+
+6. **PR #84** - "Move to uv and bumps to Python 12"
+   - Merged: 2025-10-10T20:19:07Z
+   - Commit SHA: 13bcc87a7b9f6b86aa10c2c135a7a36490ec450a
+   - Status: ✅ Present in git history
+
+Most recent (7th):
+- **PR #85** - "Adds support for IPL-4"
+  - Merged: 2025-11-05T16:18:23Z
+  - Commit SHA: f081ff4bfe9da55b4c7c49ba693201bb5c6045ad
+  - Status: ✅ Present in git history
+
+### Missing PR Numbers
+
+**PR #81** and **PR #82** were never created. These PR numbers do not exist in the GitHub repository (confirmed with 404 responses from GitHub API).
+
+## Technical Details
+
+### Initial State
+```bash
+$ git log --oneline -20
+c93f129 (HEAD -> copilot/investigate-missing-prs) Initial plan
+f081ff4 (grafted) Adds support for IPL-4 (#85)
+```
+
+The presence of "(grafted)" indicated a shallow clone. Verification:
+```bash
+$ cat .git/shallow
+f081ff4bfe9da55b4c7c49ba693201bb5c6045ad
+```
+
+### Resolution
+```bash
+$ git fetch --unshallow
+```
+
+This command fetched the complete history (1,459 objects) and removed the shallow file.
+
+### Verification
+After unshallowing, all merge commits for PRs #77, #78, #79, #80, #83, #84, and #85 were verified to exist in the repository:
+
+```bash
+$ git cat-file -t <sha>
+commit  # for all 7 PRs
+```
+
+## Conclusion
+
+**No PRs are actually missing from the main branch.** All merged pull requests are present in the complete git history. The issue was caused by:
+
+1. A shallow clone that only included the most recent commit
+2. This made it appear that historical commits (and their associated PRs) were missing
+
+## Recommendations
+
+### For CI/CD Systems
+1. **Avoid shallow clones for analysis tasks**: When examining git history, relationships between commits, or PR verification, always use a full clone or unshallow the repository first.
+
+2. **Use appropriate clone depth**: If shallow clones are necessary for performance:
+   - Use `--depth=N` where N is sufficient for your needs
+   - Document that history analysis requires unshallowing
+   - Add a step to unshallow when needed
+
+### For Developers
+1. **Check for shallow clones**: Before analyzing git history, check if the repository is shallow:
+   ```bash
+   [ -f .git/shallow ] && echo "Shallow clone detected"
+   ```
+
+2. **Unshallow when needed**: If you need full history:
+   ```bash
+   git fetch --unshallow
+   ```
+
+3. **Use GitHub API for PR verification**: When verifying merged PRs, the GitHub API is authoritative and not affected by local git clone depth.
+
+### For Repository Maintainers
+1. **No action needed**: The repository history is intact and correct.
+2. **Consider adding documentation**: If CI/CD commonly uses shallow clones, document the need to unshallow for certain operations.
+
+## Summary Table
+
+| PR # | Status | In Git History | Notes |
+|------|--------|----------------|-------|
+| 77 | Merged | ✅ Yes | |
+| 78 | Merged | ✅ Yes | |
+| 79 | Merged | ✅ Yes | |
+| 80 | Merged | ✅ Yes | |
+| 81 | N/A | N/A | PR never created |
+| 82 | N/A | N/A | PR never created |
+| 83 | Merged | ✅ Yes | |
+| 84 | Merged | ✅ Yes | |
+| 85 | Merged | ✅ Yes | Most recent |
+
+**Result**: All merged PRs are accounted for. No data loss or git history issues detected.
diff --git a/SHALLOW_CLONE_ISSUE.md b/SHALLOW_CLONE_ISSUE.md
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+# Quick Guide: Shallow Clone Issue
+
+## TL;DR
+
+**Problem**: Git history appears incomplete, merged PRs seem missing.
+**Cause**: Repository was cloned with `--depth=1` (shallow clone).
+**Solution**: Run `git fetch --unshallow` to get full history.
+
+## How to Fix
+
+```bash
+# Check if you have a shallow clone
+[ -f .git/shallow ] && echo "Shallow clone detected"
+
+# Unshallow to get full history
+git fetch --unshallow
+
+# Verify history is complete
+git log --oneline | wc -l  # Should show many more commits
+```
+
+## Quick Verification
+
+Use the provided script to verify PRs are in history:
+
+```bash
+./scripts/verify_pr_history.sh
+```
+
+## Full Details
+
+See [PR_INVESTIGATION_FINDINGS.md](./PR_INVESTIGATION_FINDINGS.md) for complete investigation details, findings, and recommendations.
+
+## Summary of Findings
+
+✅ **All merged PRs are present in git history**
+- Last 6 merged PRs (77, 78, 79, 80, 83, 84) - all verified
+- Most recent PR #85 - verified
+- PR #81 and #82 never existed (were never created)
+
+❌ **No data loss or corruption detected**
+
+⚠️ **Root cause**: Shallow clone made history appear incomplete
diff --git a/scripts/verify_pr_history.sh b/scripts/verify_pr_history.sh
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+#!/bin/bash
+# Script to verify that merged PRs are present in git history
+# Usage: ./verify_pr_history.sh [number_of_prs_to_check]
+
+set -e
+
+# Default to checking last 10 PRs
+NUM_PRS=${1:-10}
+
+echo "PR History Verification Script"
+echo "==============================="
+echo ""
+
+# Check if this is a shallow clone
+if [ -f .git/shallow ]; then
+    echo "⚠️  WARNING: This is a shallow clone!"
+    echo "    Some history may not be available."
+    echo "    Run 'git fetch --unshallow' to get full history."
+    echo ""
+    read -p "Would you like to unshallow now? (y/n) " -n 1 -r
+    echo
+    if [[ $REPLY =~ ^[Yy]$ ]]; then
+        echo "Unshallowing repository..."
+        git fetch --unshallow
+        echo "✅ Repository unshallowed successfully"
+        echo ""
+    fi
+fi
+
+# Get the repo info from git remote
+REMOTE_URL=$(git remote get-url origin)
+REPO_PATH=$(echo $REMOTE_URL | sed -E 's/.*github\.com[:/]([^/]+\/[^/.]+)(\.git)?/\1/')
+
+echo "Repository: $REPO_PATH"
+echo "Checking last $NUM_PRS merged PRs..."
+echo ""
+
+# Note: This script requires gh CLI or manual API calls
+# For simplicity, we'll just check git history for PR references
+
+echo "Searching for PR merge commits in git history..."
+echo ""
+
+# Find commits with PR references in the last 50 commits
+git log --oneline -50 --grep="#[0-9]" | while read -r commit; do
+    # Extract PR number
+    pr_num=$(echo "$commit" | grep -oE '#[0-9]+' | head -1 | tr -d '#')
+    commit_sha=$(echo "$commit" | awk '{print $1}')
+    
+    if [ -n "$pr_num" ]; then
+        # Verify commit exists
+        if git cat-file -e "$commit_sha" 2>/dev/null; then
+            echo "✅ PR #$pr_num - Commit $commit_sha exists"
+        else
+            echo "❌ PR #$pr_num - Commit $commit_sha MISSING"
+        fi
+    fi
+done
+
+echo ""
+echo "Verification complete!"
+echo ""
+echo "Note: This script only checks commits that reference PRs in their message."
+echo "      For comprehensive verification, use the GitHub API to list all merged PRs."