diff --git a/readme.md b/readme.md
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--- a/readme.md
+++ b/readme.md
@@ -186,7 +186,7 @@ The corrected color code (0-9):
 2 = red (#FF4136)
 3 = green (#2ECC40)
 4 = yellow (#FFDC00)
-5 = grey (#AAAAAA)
+5 = gray (#AAAAAA)
 6 = magenta (#F012BE)
 7 = orange (#FF851B)
 8 = light blue (#7FDBFF)
diff --git a/todo.md b/todo.md
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@@ -1,30 +1,109 @@
-Add ConceptARC Corpus
- - to the Repository
- - To the DB
- - Categorize them in the DB
- - Fix the Solution extraction method that is different from the other Corpora
+# ARC Database & Interface TODO
 
-Publish the Retool App (Validate Cabreu's email)
+## ✅ Completed
+
+### ConceptARC Corpus
+- [x] Add ConceptARC corpus to repository
+- [x] Upload ConceptARC to database (160 puzzles, 16 categories)
+- [x] Categorize puzzles in DB (stored in `set` column)
+- [x] Fix solution extraction for multiple test cases (array of solutions)
+- [x] Remove duplicate entries from arc_puzzles table (260 duplicates cleaned)
+- [x] Verify solution formats across all corpora
+
+## 🔄 In Progress
+
+### Database
+
+#### Fixes
+- [x] Corpora Mixup (V1 vs V2)
+- [x] Make id the index
+
+#### Views & Queries
+- [x] Create database view with skills/concepts mapping
+  - [x] Map ConceptARC categories to skill types
 
 
-User Inserts to the DB
-- Adjust the Tables: 
-- - Add created_at
-- - Tags N to N table
-- Skill Addition withing the Interface
+#### Data Quality
+- [x] Verify all V1/V2 puzzles have solutions
+- [x] Validate JSON integrity across all puzzles
+- [ ] Document database schema
 
-Interface:
-- Remove the Header frame, make it a single frame interface to increase the 
+#### Schema Updates
+- [x] Add created_at timestamps to relevant tables
+- [x] Create N-to-N tags table structure
+  - [x] Create tags table
+  - [x] Create arc_puzzle_tags junction table
 
-Test Tag system
-- Create Tag Types, Items
-- Test Skill selection with many items, do search function is important?
+### Retool Interface
 
-DB:
-- Make the View with Skills, Category etc.
+#### Core Features
+- [x] Update puzzle renderer to handle ConceptARC multiple solutions
+  - [x] Show all 3 test outputs for ConceptARC
+- [x] Remove header frame, consolidate to single-frame interface
+- [ ] Add puzzle filtering by:
+  - [ ] Corpora (V1, V2, ConceptARC)
+  - [ ] Category/Set
+  - [ ] Difficulty
+  - [ ] Skills/Concepts
 
-Puzzle Assignment
-- DB Data
-- Make Interface adjustments (toggle?)
+#### User Features
+- [x] Implement user input system
+  - [x] Design input capture mechanism
+  - [x] Store user solutions in database
+- [ ] Create puzzle assignment system
+  - [ ] Add assignment toggle in interface
+  - [ ] Assign puzzles to specific users
+  - [ ] Track completion status
+  - [ ] Record time spent on puzzles
+
+### Tag System
+- [x] Design tag taxonomy
+  - [x] Define tag types (concept, difficulty, skill, etc.)
+- [x] Implement tag database schema
+  - [x] Create tags table
+  - [x] Create puzzle_tags junction table
+  - [x] Add tag management endpoints
+- [x] Build tag UI in Retool
+  - [x] Tag creation/editing interface
+  - [ ] Bulk tagging functionality
+  - [ ] Tag-based search/filtering
+  - [x] Test skill selection with many items (search function?)
+- [ ] Populate initial tags
+  - [ ] Auto-tag ConceptARC by category
+  - [ ] Tag V1/V2 by known concepts
+
+### Administration
+- [ ] Publish Retool app to production
+
+## 📋 Backlog
+
+### Documentation
+- [ ] Create user guide for Retool interface
+- [ ] Document API/database schema
+
+### Testing
+- [ ] Test puzzle rendering across all corpora
+- [ ] Validate solution checking logic
+- [ ] Test multi-user concurrent access
+- [ ] Performance testing with full dataset
 
 
+
+## 📝 Notes
+
+### Database Stats (Current)
+- Total puzzles: 2,400
+  - V1: 1,120
+  - V2: 1,120
+  - ConceptARC: 160 (16 categories × 10 puzzles)
+- All puzzles have solutions stored
+- ConceptARC uses array format (3 solutions per puzzle)
+
+### Scripts Available
+- `upload_conceptarc_to_db.py` - Upload ConceptARC puzzles
+- `check_schema.py` - Inspect database structure
+- `find_duplicates.py` - Find duplicate puzzle entries
+- `remove_duplicates.py` - Clean duplicate entries
+- `fix_conceptarc_solutions.py` - Fix ConceptARC solution format
+- `verify_conceptarc_upload.py` - Verify upload integrity
+- `verify_solution_format.py` - Check solution formats