diff --git a/SKILL.md b/SKILL.md
index 1617194..04df10a 100644
--- a/SKILL.md
+++ b/SKILL.md
@@ -5,55 +5,46 @@ description: Use when working with the Grist double-entry accounting system - re
 
 # Grist Double-Entry Accounting System
 
-## Overview
+Double-entry accounting for sole proprietorship. Every transaction creates balanced journal entries (debits = credits).
 
-A complete double-entry accounting system for sole proprietorship service businesses. Every transaction creates balanced journal entries (debits = credits). Account balances roll up through parent-child hierarchy.
+## Quick Reference
+
+| Task | Action |
+|------|--------|
+| Record vendor invoice | Create Bill + BillLines + Transaction + TransactionLines, then audit |
+| Record payment | Create payment Transaction + BillPayment, update Bill status |
+| Query balances | Use `sql_query` on Accounts table |
+| Generate reports | See [queries.md](references/queries.md) |
 
 ## Recording Transactions: Decision Guide
 
 | Source Document | What to Create |
 |-----------------|----------------|
-| **Invoice/Bill PDF from vendor** | Bill + BillLines + Transaction + TransactionLines |
+| **Invoice/Bill from vendor** | Bill + BillLines + Transaction + TransactionLines |
 | **Receipt showing payment** | BillPayment + attach Receipt to existing Bill |
 | **Bank statement entry** | Transaction + TransactionLines only |
 | **Journal adjustment** | Transaction + TransactionLines only |
 
-**Key Rule:** If there's a vendor invoice number, always create a Bill record—not just a transaction. Bills provide:
-- Vendor tracking and AP aging
-- Invoice/Receipt attachment storage
-- Payment status tracking (Open/Partial/Paid)
+**Key Rule:** If there's a vendor invoice number, always create a Bill record.
 
-### Quick Reference: Vendor Invoice Paid by Owner
-
-When recording an invoice that was already paid by the owner:
-
-1. Upload Invoice attachment → get attachment_id
-2. Create Bill (Status: "Paid", Invoice: ["L", attachment_id])
-3. Create BillLine(s) with expense account and amount
-4. Create Transaction (debit Expense, credit Due to Owner)
-5. Create TransactionLines
-6. Update Bill.EntryTransaction to link to transaction
-7. Create BillPayment record
-8. Upload Receipt attachment if available
-
-## MCP Tools Available
+## MCP Tools
 
 | Tool | Purpose |
 |------|---------|
-| `mcp__grist-accounting__list_documents` | List accessible Grist documents |
-| `mcp__grist-accounting__list_tables` | List tables in a document |
-| `mcp__grist-accounting__describe_table` | Get column schema for a table |
-| `mcp__grist-accounting__get_records` | Fetch records (with optional filter, sort, limit) |
-| `mcp__grist-accounting__add_records` | Insert new records, returns `{"inserted_ids": [...]}` |
-| `mcp__grist-accounting__update_records` | Update existing records by ID |
-| `mcp__grist-accounting__delete_records` | Delete records by ID |
-| `mcp__grist-accounting__sql_query` | Run read-only SQL queries |
+| `list_documents` | List accessible Grist documents |
+| `list_tables` | List tables in a document |
+| `describe_table` | Get column schema |
+| `get_records` | Fetch records (filter, sort, limit) |
+| `add_records` | Insert records, returns `{"inserted_ids": [...]}` |
+| `update_records` | Update by ID |
+| `delete_records` | Delete by ID |
+| `sql_query` | Read-only SQL |
 
-The document name is `accounting` for all operations.
+Document name: `accounting`
 
 ## Date Handling
 
-All date fields use **Unix timestamps** (seconds since 1970-01-01 UTC).
+All dates use **Unix timestamps** (seconds since epoch).
 
 | Date | Timestamp |
 |------|-----------|
@@ -62,92 +53,6 @@ All date fields use **Unix timestamps** (seconds since 1970-01-01 UTC).
 | Dec 1, 2025 | 1764633600 |
 | Jan 1, 2026 | 1767312000 |
 
-Python: `int(datetime(2025, 10, 1).timestamp())`
-
-## Complete Table Schemas
-
-### Accounts
-| Column | Type | Notes |
-|--------|------|-------|
-| Code | Text | Account number (e.g., "5080") |
-| Name | Text | Account name |
-| Type | Choice | "Asset", "Liability", "Equity", "Income", "Expense" |
-| Parent | Ref:Accounts | Parent account for hierarchy (0 = top-level) |
-| Description | Text | |
-| IsActive | Bool | |
-| Balance | Formula | Calculated from transactions |
-
-### Vendors
-| Column | Type | Notes |
-|--------|------|-------|
-| Name | Text | Vendor name |
-| DefaultExpenseAccount | Ref:Accounts | Auto-fills on bill lines |
-| PaymentTerms | Choice | "Due on Receipt", "Net 15", "Net 30" |
-| Notes | Text | |
-| IsActive | Bool | |
-| Balance | Formula | Sum of unpaid bills |
-
-### Items
-| Column | Type | Notes |
-|--------|------|-------|
-| Name | Text | Item name (e.g., "Software Subscription") |
-| DefaultAccount | Ref:Accounts | Expense account for this item |
-| DefaultDescription | Text | Auto-fills on bill lines |
-| IsActive | Bool | |
-
-### Bills
-| Column | Type | Notes |
-|--------|------|-------|
-| Vendor | Ref:Vendors | Required |
-| BillNumber | Text | Invoice number from vendor |
-| BillDate | Date | Unix timestamp |
-| DueDate | Date | Unix timestamp |
-| Status | Choice | "Open", "Partial", "Paid" |
-| Memo | Text | |
-| EntryTransaction | Ref:Transactions | Link to journal entry |
-| Invoice | Attachments | Vendor invoice document (use `["L", id]` format) |
-| Receipt | Attachments | Payment receipt/confirmation (use `["L", id]` format) |
-| Amount | Formula | Sum of BillLines.Amount |
-| AmountPaid | Formula | Sum of BillPayments.Amount |
-| AmountDue | Formula | Amount - AmountPaid |
-
-### BillLines
-| Column | Type | Notes |
-|--------|------|-------|
-| Bill | Ref:Bills | Required |
-| Item | Ref:Items | Optional - auto-fills Account/Description |
-| Account | Ref:Accounts | Expense account |
-| Description | Text | |
-| Amount | Numeric | Line item amount |
-
-### Transactions
-| Column | Type | Notes |
-|--------|------|-------|
-| Date | Date | Unix timestamp |
-| Description | Text | Transaction description |
-| Reference | Text | Check number, invoice reference, etc. |
-| Status | Choice | "Draft", "Posted", "Cleared" |
-| Memo | Text | |
-| Total | Formula | Sum of debits |
-| IsBalanced | Formula | True if debits = credits |
-
-### TransactionLines
-| Column | Type | Notes |
-|--------|------|-------|
-| Transaction | Ref:Transactions | Required |
-| Account | Ref:Accounts | Required |
-| Debit | Numeric | Debit amount (or 0) |
-| Credit | Numeric | Credit amount (or 0) |
-| Memo | Text | |
-
-### BillPayments
-| Column | Type | Notes |
-|--------|------|-------|
-| Bill | Ref:Bills | Required |
-| Transaction | Ref:Transactions | Payment journal entry |
-| Amount | Numeric | Payment amount |
-| PaymentDate | Date | Unix timestamp |
-
 ## Key Account IDs
 
 | ID | Code | Name | Type |
@@ -157,478 +62,116 @@ Python: `int(datetime(2025, 10, 1).timestamp())`
 | 22 | 2203 | Due to Owner | Liability |
 | 36 | 5080 | Software & Subscriptions | Expense |
 
-Query all accounts:
-```sql
-SELECT id, Code, Name, Type FROM Accounts WHERE IsActive = true ORDER BY Code
-```
+Query all: `SELECT id, Code, Name, Type FROM Accounts WHERE IsActive = true ORDER BY Code`
 
 ## Account Types
 
-| Type | Normal Balance | Increases With | Examples |
-|------|----------------|----------------|----------|
-| Asset | Debit | Debit | Cash, AR, Prepaid |
-| Liability | Credit | Credit | AP, Credit Cards, Due to Owner |
-| Equity | Credit | Credit | Owner's Investment, Draws, Retained Earnings |
-| Income | Credit | Credit | Service Revenue, Interest Income |
-| Expense | Debit | Debit | Rent, Utilities, Office Supplies |
-
-## Complete Workflows
-
-### Create a Vendor
-
-```python
-add_records("Vendors", [{
-    "Name": "Acme Corp",
-    "DefaultExpenseAccount": 36,  # Software & Subscriptions
-    "PaymentTerms": "Due on Receipt",
-    "Notes": "Software vendor",
-    "IsActive": True
-}])
-# Returns: {"inserted_ids": [vendor_id]}
-```
-
-### Create Items for Common Purchases
-
-```python
-add_records("Items", [{
-    "Name": "Monthly Software",
-    "DefaultAccount": 36,
-    "DefaultDescription": "Monthly SaaS subscription",
-    "IsActive": True
-}])
-```
-
-### Complete Bill Entry (5 Steps)
-
-**Step 1: Create Bill Header**
-```python
-add_records("Bills", [{
-    "Vendor": 1,  # vendor_id
-    "BillNumber": "INV-001",
-    "BillDate": 1759708800,  # Unix timestamp
-    "DueDate": 1759708800,
-    "Status": "Open",
-    "Memo": "October services"
-}])
-# Returns: {"inserted_ids": [bill_id]}
-```
-
-**Step 2: Create Bill Line(s)**
-```python
-add_records("BillLines", [{
-    "Bill": 1,  # bill_id from step 1
-    "Item": 1,  # optional - auto-fills Account/Description
-    "Account": 36,  # expense account
-    "Description": "Monthly subscription",
-    "Amount": 100.00
-}])
-```
-
-**Step 3: Create Journal Entry**
-```python
-# Transaction header
-add_records("Transactions", [{
-    "Date": 1759708800,
-    "Description": "Acme Corp - October services",
-    "Reference": "INV-001",
-    "Status": "Posted"
-}])
-# Returns: {"inserted_ids": [txn_id]}
-
-# Transaction lines: Debit expense, Credit AP
-add_records("TransactionLines", [
-    {"Transaction": 1, "Account": 36, "Debit": 100.00, "Credit": 0, "Memo": "Monthly subscription"},
-    {"Transaction": 1, "Account": 4, "Debit": 0, "Credit": 100.00, "Memo": "Monthly subscription"}
-])
-```
-
-**Step 4: Link Bill to Transaction**
-```python
-update_records("Bills", [{"id": 1, "fields": {"EntryTransaction": 1}}])
-```
-
-**Step 5: Upload Invoice (if available)**
-
-If an invoice PDF is available, upload and link it to the Invoice field:
-```bash
-# Get session token, then upload to Invoice field
-bash /path/to/scripts/upload-attachment.sh invoice.pdf Bills 1 $TOKEN Invoice
-```
-
-Or for batch uploads, use a script (see Batch Operations).
-
-### Pay Bill from Checking Account
-
-```python
-# Step 1: Create payment transaction
-add_records("Transactions", [{
-    "Date": 1760832000,
-    "Description": "Payment - Acme Corp INV-001",
-    "Reference": "Check #1001",
-    "Status": "Cleared"
-}])
-# Returns: {"inserted_ids": [txn_id]}
-
-# Step 2: Debit AP, Credit Checking
-add_records("TransactionLines", [
-    {"Transaction": 2, "Account": 4, "Debit": 100.00, "Credit": 0, "Memo": "Pay INV-001"},
-    {"Transaction": 2, "Account": 14, "Debit": 0, "Credit": 100.00, "Memo": "Pay INV-001"}
-])
-
-# Step 3: Create BillPayment record
-add_records("BillPayments", [{
-    "Bill": 1,
-    "Transaction": 2,
-    "Amount": 100.00,
-    "PaymentDate": 1760832000
-}])
-
-# Step 4: Update bill status
-update_records("Bills", [{"id": 1, "fields": {"Status": "Paid"}}])
-
-# Step 5: Upload receipt (if available)
-bash /path/to/scripts/upload-attachment.sh receipt.pdf Bills 1 $TOKEN Receipt
-```
-
-### Pay Bill via Owner Reimbursement
-
-When the owner pays a business expense personally:
-
-```python
-# Step 1: Create payment transaction
-add_records("Transactions", [{
-    "Date": 1760832000,
-    "Description": "Owner payment - Acme Corp INV-001",
-    "Reference": "Owner Reimb",
-    "Status": "Posted"
-}])
-
-# Step 2: Debit AP, Credit Due to Owner (not Checking)
-add_records("TransactionLines", [
-    {"Transaction": 2, "Account": 4, "Debit": 100.00, "Credit": 0, "Memo": "Pay INV-001"},
-    {"Transaction": 2, "Account": 22, "Debit": 0, "Credit": 100.00, "Memo": "Owner paid"}
-])
-
-# Step 3: Create BillPayment record
-add_records("BillPayments", [{
-    "Bill": 1,
-    "Transaction": 2,
-    "Amount": 100.00,
-    "PaymentDate": 1760832000
-}])
-
-# Step 4: Update bill status
-update_records("Bills", [{"id": 1, "fields": {"Status": "Paid"}}])
-
-# Step 5: Upload receipt (if available)
-bash /path/to/scripts/upload-attachment.sh receipt.pdf Bills 1 $TOKEN Receipt
-```
-
-### Reimburse Owner
-
-When business pays back the owner:
-
-```python
-add_records("Transactions", [{
-    "Date": 1762041600,
-    "Description": "Owner reimbursement",
-    "Reference": "Transfer",
-    "Status": "Cleared"
-}])
-
-add_records("TransactionLines", [
-    {"Transaction": 3, "Account": 22, "Debit": 500.00, "Credit": 0, "Memo": "Reimburse owner"},
-    {"Transaction": 3, "Account": 14, "Debit": 0, "Credit": 500.00, "Memo": "Reimburse owner"}
-])
-```
-
-## Batch Operations
-
-When entering multiple bills efficiently:
-
-1. **Create all Bills first** → collect inserted IDs
-2. **Create all BillLines** referencing bill IDs
-3. **Create all Transactions** → collect inserted IDs
-4. **Create all TransactionLines** referencing transaction IDs
-5. **Update all Bills** with EntryTransaction links in one call
-6. (If paying) Create payment transactions, lines, and BillPayments
-7. **Upload invoice attachments** if files are available
-
-### Batch Attachment Uploads
-
-When invoice files are available, upload them after bill entry:
-
-1. Request session token with write permission (1 hour TTL for batch work)
-2. Create a mapping of bill_id → invoice file path
-3. Loop: upload each file, link to corresponding bill
-
-```bash
-# Example batch upload pattern for invoices
-TOKEN=$(request_session_token with write permission)
-for each (bill_id, invoice_path):
-    curl -X POST -H "Authorization: Bearer $TOKEN" \
-         -F "file=@$invoice_path" \
-         https://grist-mcp.bballou.com/api/v1/attachments
-    # Returns attachment_id
-    update_records("Bills", [{"id": bill_id, "fields": {"Invoice": ["L", attachment_id]}}])
-
-# For receipts (after payment):
-    update_records("Bills", [{"id": bill_id, "fields": {"Receipt": ["L", attachment_id]}}])
-```
-
-Example batch update:
-```python
-update_records("Bills", [
-    {"id": 1, "fields": {"EntryTransaction": 1}},
-    {"id": 2, "fields": {"EntryTransaction": 2}},
-    {"id": 3, "fields": {"EntryTransaction": 3}}
-])
-```
-
-## Common Queries
-
-### Unpaid Bills by Vendor
-```sql
-SELECT v.Name, b.BillNumber, b.BillDate, b.Amount, b.AmountDue
-FROM Bills b
-JOIN Vendors v ON b.Vendor = v.id
-WHERE b.Status IN ('Open', 'Partial')
-ORDER BY b.DueDate
-```
-
-### Bills Summary by Vendor
-```sql
-SELECT v.Name as Vendor, COUNT(b.id) as Bills, SUM(b.Amount) as Total, SUM(b.AmountDue) as Due
-FROM Bills b
-JOIN Vendors v ON b.Vendor = v.id
-GROUP BY v.Name
-ORDER BY Total DESC
-```
-
-### Account Balances (Non-Zero)
-```sql
-SELECT Code, Name, Type, Balance
-FROM Accounts
-WHERE Balance != 0
-ORDER BY Code
-```
-
-### Owner Reimbursement Balance
-```sql
-SELECT Balance FROM Accounts WHERE Code = '2203'
-```
-
-### Expense Summary by Account
-```sql
-SELECT a.Code, a.Name, a.Balance
-FROM Accounts a
-WHERE a.Type = 'Expense' AND a.Balance != 0
-ORDER BY a.Balance DESC
-```
-
-### Transaction History for Account
-```sql
-SELECT t.Date, t.Description, t.Reference, tl.Debit, tl.Credit
-FROM TransactionLines tl
-JOIN Transactions t ON tl.Transaction = t.id
-WHERE tl.Account = 36
-ORDER BY t.Date DESC
-```
-
-### Verify All Transactions Balance
-```sql
-SELECT id, Description, Total, IsBalanced
-FROM Transactions
-WHERE IsBalanced = false
-```
-
-## Financial Reports
-
-### Balance Sheet
-
-Shows Assets = Liabilities + Equity at a point in time.
-
-**Important:** Parent accounts roll up child balances. Query only top-level parents (Parent = 0) to avoid double-counting.
-
-```sql
--- Assets, Liabilities, Equity (top-level only)
-SELECT Code, Name, Type, Balance
-FROM Accounts
-WHERE Type IN ('Asset', 'Liability', 'Equity')
-  AND Parent = 0
-ORDER BY Type, Code
-```
-
-```sql
--- Net Income (for Equity section)
--- Query leaf expense accounts only (no children)
-SELECT
-  COALESCE(SUM(CASE WHEN Type = 'Income' THEN Balance ELSE 0 END), 0) -
-  COALESCE(SUM(CASE WHEN Type = 'Expense' THEN Balance ELSE 0 END), 0) as NetIncome
-FROM Accounts
-WHERE Type IN ('Income', 'Expense')
-  AND id NOT IN (SELECT DISTINCT Parent FROM Accounts WHERE Parent != 0)
-```
-
-**Presentation:**
-| **Assets** | |
-|---|---:|
-| Cash & Bank Accounts | $X.XX |
-| Accounts Receivable | $X.XX |
-| **Total Assets** | **$X.XX** |
-
-| **Liabilities** | |
-|---|---:|
-| Accounts Payable | $X.XX |
-| Due to Owner | $X.XX |
-| **Total Liabilities** | **$X.XX** |
-
-| **Equity** | |
-|---|---:|
-| Retained Earnings | $X.XX |
-| Net Income (Loss) | $X.XX |
-| **Total Equity** | **$X.XX** |
-
-| **Total Liabilities + Equity** | **$X.XX** |
-
-### Income Statement
-
-Shows Revenue - Expenses = Net Income for a period.
-
-```sql
--- All income and expense accounts (leaf accounts only)
-SELECT Code, Name, Type, Balance
-FROM Accounts
-WHERE Type IN ('Income', 'Expense')
-  AND Balance != 0
-  AND id NOT IN (SELECT DISTINCT Parent FROM Accounts WHERE Parent != 0)
-ORDER BY Type DESC, Code
-```
-
-**Presentation:**
-| **Income** | |
-|---|---:|
-| Service Revenue | $X.XX |
-| **Total Income** | **$X.XX** |
-
-| **Expenses** | |
-|---|---:|
-| Software & Subscriptions | $X.XX |
-| Professional Services | $X.XX |
-| **Total Expenses** | **$X.XX** |
-
-| **Net Income (Loss)** | **$X.XX** |
-
-### Trial Balance
-
-Lists all accounts with non-zero balances. Debits should equal Credits.
-
-```sql
-SELECT
-  Code,
-  Name,
-  Type,
-  CASE WHEN Type IN ('Asset', 'Expense') THEN Balance ELSE 0 END as Debit,
-  CASE WHEN Type IN ('Liability', 'Equity', 'Income') THEN Balance ELSE 0 END as Credit
-FROM Accounts
-WHERE Balance != 0
-  AND id NOT IN (SELECT DISTINCT Parent FROM Accounts WHERE Parent != 0)
-ORDER BY Code
-```
-
-### Accounts Payable Aging
-
-```sql
-SELECT
-  v.Name as Vendor,
-  b.BillNumber,
-  b.BillDate,
-  b.DueDate,
-  b.AmountDue,
-  CASE
-    WHEN b.DueDate >= strftime('%s', 'now') THEN 'Current'
-    WHEN b.DueDate >= strftime('%s', 'now') - 2592000 THEN '1-30 Days'
-    WHEN b.DueDate >= strftime('%s', 'now') - 5184000 THEN '31-60 Days'
-    ELSE '60+ Days'
-  END as Aging
-FROM Bills b
-JOIN Vendors v ON b.Vendor = v.id
-WHERE b.Status IN ('Open', 'Partial')
-ORDER BY b.DueDate
-```
+| Type | Normal Balance | Increases With |
+|------|----------------|----------------|
+| Asset | Debit | Debit |
+| Liability | Credit | Credit |
+| Equity | Credit | Credit |
+| Income | Credit | Credit |
+| Expense | Debit | Debit |
+
+## Bill Entry Workflow (6 Steps)
+
+1. Create Bill header with Vendor, BillNumber, BillDate, DueDate, Status="Open"
+2. Create BillLine(s) with expense Account and Amount
+3. Create Transaction + TransactionLines (Dr Expense, Cr AP)
+4. Link Bill.EntryTransaction to transaction ID
+5. Upload Invoice attachment if available
+6. **Run post-entry audit (REQUIRED)**
+
+For detailed code: see [workflows.md](references/workflows.md)
+
+## Payment Workflows
+
+**Pay from Checking:**
+1. Create Transaction (Dr AP, Cr Checking)
+2. Create BillPayment record
+3. Update Bill.Status = "Paid"
+4. Upload Receipt if available
+5. **Run post-payment audit**
+
+**Owner pays personally:**
+Same as above but Cr Due to Owner (id=22) instead of Checking
+
+For detailed code: see [workflows.md](references/workflows.md)
 
 ## Validation Checklist
 
-After entering bills, verify:
-
-- [ ] Total bills match expected: `SELECT SUM(Amount) FROM Bills`
-- [ ] All transactions balanced: `SELECT * FROM Transactions WHERE IsBalanced = false`
-- [ ] AP balance correct: `SELECT Balance FROM Accounts WHERE Code = '2000'`
-- [ ] Expense accounts increased appropriately
-- [ ] Vendor balances reflect unpaid bills
-- [ ] Invoices attached: `SELECT id, BillNumber FROM Bills WHERE Invoice IS NULL`
-- [ ] Receipts attached for paid bills: `SELECT id, BillNumber FROM Bills WHERE Status = 'Paid' AND Receipt IS NULL`
+After entering bills:
+- [ ] `SELECT * FROM Transactions WHERE IsBalanced = false` returns empty
+- [ ] `SELECT Balance FROM Accounts WHERE Code = '2000'` shows correct AP
+- [ ] `SELECT id, BillNumber FROM Bills WHERE Invoice IS NULL` - upload missing
 
 ## Common Mistakes
 
 | Mistake | Fix |
 |---------|-----|
-| Transaction not balanced | Ensure SUM(Debit) = SUM(Credit) before saving |
-| Wrong debit/credit direction | Assets/Expenses increase with debit; Liabilities/Equity/Income increase with credit |
-| Posting to parent account | Post to leaf accounts (1001 Checking, not 1000 Cash) |
-| Forgetting AP entry for bills | Bills need both the expense debit AND the AP credit |
-| Missing EntryTransaction link | Always update Bill.EntryTransaction after creating journal entry |
-| Bill status not updated | Manually set Status to "Paid" after full payment |
-| Using string dates | Dates must be Unix timestamps (seconds), not strings |
-| Missing invoice/receipt | Upload invoice after bill entry, receipt after payment |
+| Transaction not balanced | Ensure SUM(Debit) = SUM(Credit) |
+| Wrong debit/credit direction | Assets/Expenses: debit increases; Liabilities/Equity/Income: credit increases |
+| Posting to parent account | Post to leaf accounts (1001 not 1000) |
+| Missing EntryTransaction link | Always link Bill to Transaction |
+| Using string dates | Use Unix timestamps |
 
 ## Uploading Attachments
 
-Attachments (invoices, receipts) are uploaded via the HTTP proxy endpoint, not MCP tools. This is efficient for binary files.
-
-### Workflow
-
-1. **Request session token** with write permission via MCP
-2. **Upload file** via `POST /api/v1/attachments` with multipart/form-data
-3. **Link attachment** to record via `update_records`
-
-### Upload Script
-
-Use `scripts/upload-attachment.sh` in this skill directory:
-
 ```bash
-# Get session token first (via MCP request_session_token tool)
-# Then run:
-bash scripts/upload-attachment.sh invoice.pdf Bills 13              # Invoice column (default)
-bash scripts/upload-attachment.sh invoice.pdf Bills 13 $TOKEN       # With token
-bash scripts/upload-attachment.sh receipt.pdf Bills 13 $TOKEN Receipt  # Receipt column
-
-# Environment variable for custom endpoint:
-GRIST_MCP_URL=https://custom.example.com bash scripts/upload-attachment.sh ...
+# Get session token, then:
+bash scripts/upload-attachment.sh invoice.pdf Bills {id} $TOKEN Invoice
+bash scripts/upload-attachment.sh receipt.pdf Bills {id} $TOKEN Receipt
 ```
 
-Run `bash scripts/upload-attachment.sh` without arguments for full usage.
+## Audit Subagent
 
-### Linking Attachments Manually
+**REQUIRED:** Run audit checks after every bill entry before considering complete.
 
-Grist attachment columns use format: `["L", attachment_id]`
+### Behavior
 
-```python
-# Link invoice to bill
-update_records("Bills", [{"id": 13, "fields": {"Invoice": ["L", 1]}}])
+Claude MUST run post-entry audit checks. The audit:
+1. Executes independently from entry workflow
+2. Validates all aspects of newly created records
+3. Reports findings in structured format
+4. Does not auto-correct - alerts user to take action
 
-# Link receipt to bill (after payment)
-update_records("Bills", [{"id": 13, "fields": {"Receipt": ["L", 2]}}])
+### Audit Categories
+
+| Category | Severity | Description |
+|----------|----------|-------------|
+| Transaction Balance | Critical | Debits must equal credits |
+| Account Usage | Error | Correct account types |
+| Bill Linkage | Error | EntryTransaction and Vendor set |
+| Amount Match | Error | Bill.Amount matches transaction |
+| PDF Verification | Warning | Document values match database |
+| Missing Attachments | Warning | Invoice/Receipt attached |
+
+### Quick Audit
+
+```sql
+-- Check transaction balanced
+SELECT IsBalanced FROM Transactions WHERE id = {txn_id}
+
+-- Check bill integrity
+SELECT id, Vendor, EntryTransaction, Amount FROM Bills WHERE id = {bill_id}
 ```
 
-## Formula Columns (Auto-Calculated)
+### Output Format
 
-| Table.Column | Description |
-|--------------|-------------|
-| Accounts.Balance | OwnBalance + ChildrenBalance |
-| Transactions.IsBalanced | True if sum of debits = sum of credits |
-| Transactions.Total | Sum of debit amounts |
-| Bills.Amount | Sum of BillLines.Amount |
-| Bills.AmountPaid | Sum of BillPayments.Amount |
-| Bills.AmountDue | Amount - AmountPaid |
-| Vendors.Balance | Sum of AmountDue for unpaid bills |
+| Check | Status | Details |
+|-------|--------|---------|
+| Transaction Balanced | PASS/FAIL | ... |
+| Bill Integrity | PASS/FAIL | ... |
+| PDF Verification | PASS/WARN/SKIP | ... |
+
+For full audit queries and remediation: see [audit.md](references/audit.md)
+
+## Reference Files
+
+| File | Contents |
+|------|----------|
+| [references/schema.md](references/schema.md) | Complete table schemas |
+| [references/workflows.md](references/workflows.md) | Detailed code examples |
+| [references/queries.md](references/queries.md) | SQL queries and financial reports |
+| [references/audit.md](references/audit.md) | Audit queries and remediation |
diff --git a/references/audit.md b/references/audit.md
new file mode 100644
index 0000000..eeec090
--- /dev/null
+++ b/references/audit.md
@@ -0,0 +1,161 @@
+# Audit Reference
+
+Detailed audit queries, workflows, and remediation steps.
+
+## Contents
+- [Audit SQL Queries](#audit-sql-queries)
+- [PDF Verification Workflow](#pdf-verification-workflow)
+- [Post-Entry Audit Checklist](#post-entry-audit-checklist)
+- [Output Formats](#output-formats)
+- [Remediation Steps](#remediation-steps)
+
+## Audit SQL Queries
+
+### Check 1: Unbalanced Transactions
+```sql
+-- Simple check using formula column
+SELECT id, Date, Description, IsBalanced FROM Transactions WHERE IsBalanced = 0
+
+-- Detailed check with actual sums (for debugging)
+SELECT t.id, t.Description,
+       (SELECT SUM(Debit) FROM TransactionLines WHERE Transaction = t.id) as TotalDebit,
+       (SELECT SUM(Credit) FROM TransactionLines WHERE Transaction = t.id) as TotalCredit
+FROM Transactions t
+WHERE t.IsBalanced = 0
+```
+
+### Check 2: Invalid Account Usage
+
+Detect debits to non-debit-normal accounts or credits to non-credit-normal accounts:
+```sql
+SELECT t.id, t.Description, tl.id as LineId, a.Name, a.Type,
+       tl.Debit, tl.Credit
+FROM TransactionLines tl
+JOIN Transactions t ON tl.Transaction = t.id
+JOIN Accounts a ON tl.Account = a.id
+WHERE (tl.Debit > 0 AND a.Type NOT IN ('Asset', 'Expense'))
+   OR (tl.Credit > 0 AND a.Type NOT IN ('Liability', 'Equity', 'Income'))
+```
+
+Note: This query flags unusual patterns. Some are valid (e.g., paying down AP debits a Liability). Review flagged items manually.
+
+### Check 3: Bills Missing Required Links
+```sql
+SELECT b.id, b.BillNumber, b.Status, b.EntryTransaction, b.Vendor
+FROM Bills b
+WHERE b.EntryTransaction IS NULL
+   OR b.Vendor IS NULL
+```
+
+### Check 4: Bill/Transaction Amount Mismatch
+```sql
+SELECT b.id, b.BillNumber, b.Amount as BillAmount,
+       (SELECT SUM(tl.Debit) FROM TransactionLines tl
+        JOIN Accounts a ON tl.Account = a.id
+        WHERE tl.Transaction = b.EntryTransaction AND a.Type = 'Expense') as TxnExpense
+FROM Bills b
+WHERE b.EntryTransaction IS NOT NULL
+  AND b.Amount != (SELECT SUM(tl.Debit) FROM TransactionLines tl
+                   JOIN Accounts a ON tl.Account = a.id
+                   WHERE tl.Transaction = b.EntryTransaction AND a.Type = 'Expense')
+```
+
+### Check 5: Paid Bills Without BillPayments
+```sql
+SELECT b.id, b.BillNumber, b.Amount, b.AmountPaid, b.Status
+FROM Bills b
+WHERE b.Status = 'Paid' AND (b.AmountPaid IS NULL OR b.AmountPaid = 0)
+```
+
+### Check 6: Bills Missing Attachments
+```sql
+SELECT b.id, b.BillNumber, b.Invoice, b.Receipt, b.Status
+FROM Bills b
+WHERE b.Invoice IS NULL
+   OR (b.Status = 'Paid' AND b.Receipt IS NULL)
+```
+
+## PDF Verification Workflow
+
+When an invoice attachment exists, verify its contents match the bill record:
+
+1. **Download attachment**
+   ```bash
+   bash scripts/download-attachment.sh <attachment_id> /tmp/invoice.pdf $TOKEN
+   ```
+
+2. **Extract invoice data**
+   ```bash
+   python scripts/verify-pdf.py /tmp/invoice.pdf --json
+   ```
+
+3. **Compare extracted values**
+   - Invoice number vs Bill.BillNumber
+   - Date vs Bill.BillDate (allow 1 day tolerance)
+   - Amount vs Bill.Amount (must match within $0.01)
+   - Vendor name vs Vendors.Name (fuzzy match)
+
+4. **Report discrepancies** with severity levels
+
+## Post-Entry Audit Checklist
+
+After completing a bill entry, run these checks on the newly created records:
+
+**Step 1: Transaction Balance**
+```sql
+SELECT IsBalanced FROM Transactions WHERE id = {txn_id}
+```
+Expected: `true`
+
+**Step 2: Account Usage**
+Verify the transaction lines use correct accounts:
+- Expense account (Type = 'Expense') for the debit
+- AP account (id=4, code 2000) for the credit
+
+**Step 3: Bill Integrity**
+```sql
+SELECT id, Vendor, EntryTransaction, Amount
+FROM Bills WHERE id = {bill_id}
+```
+Expected: All fields populated, Amount > 0
+
+**Step 4: PDF Verification** (if Invoice attachment exists)
+Run the PDF verification workflow above.
+
+## Output Formats
+
+### Single Entry Audit
+| Check | Status | Details |
+|-------|--------|---------|
+| Transaction Balanced | PASS | Debits = Credits = $X.XX |
+| Account Usage | PASS | Expense: 5080, AP: 2000 |
+| Bill Integrity | PASS | All required fields set |
+| PDF Verification | WARN | Date mismatch: PDF shows 10/5, Bill has 10/6 |
+
+### Full Audit Report
+| Category | Severity | Count | Details |
+|----------|----------|-------|---------|
+| Unbalanced Transactions | Critical | 0 | None |
+| Account Misuse | Warning | 2 | Txn #5, #12 |
+| Missing Bill Links | Error | 1 | Bill #123 |
+| Amount Mismatches | Error | 0 | None |
+| PDF Discrepancies | Warning | 3 | Bills #1, #2, #5 |
+| Missing Attachments | Warning | 5 | Bills #3, #4, #6, #7, #8 |
+
+### Severity Levels
+- **PASS**: Check passed
+- **WARN**: Minor discrepancy, review recommended
+- **ERROR**: Significant issue, correction required
+- **CRITICAL**: Data integrity problem, must fix immediately
+
+## Remediation Steps
+
+| Issue | Remediation |
+|-------|-------------|
+| Unbalanced transaction | Review TransactionLines, add/adjust lines until SUM(Debit) = SUM(Credit) |
+| Wrong account type | Update TransactionLine.Account to correct account |
+| Missing EntryTransaction | Link bill to transaction: `update_records("Bills", [{"id": X, "fields": {"EntryTransaction": Y}}])` |
+| Missing Vendor | Set Bill.Vendor to appropriate vendor ID |
+| Amount mismatch | Review bill lines and transaction lines, correct the discrepancy |
+| PDF mismatch | Verify source document, update bill fields if database is wrong |
+| Missing attachment | Upload invoice/receipt using `scripts/upload-attachment.sh` |
diff --git a/references/queries.md b/references/queries.md
new file mode 100644
index 0000000..58ff36c
--- /dev/null
+++ b/references/queries.md
@@ -0,0 +1,181 @@
+# SQL Queries and Reports
+
+Common queries and financial report templates.
+
+## Contents
+- [Common Queries](#common-queries)
+- [Financial Reports](#financial-reports)
+  - [Balance Sheet](#balance-sheet)
+  - [Income Statement](#income-statement)
+  - [Trial Balance](#trial-balance)
+  - [AP Aging](#accounts-payable-aging)
+
+## Common Queries
+
+### Unpaid Bills by Vendor
+```sql
+SELECT v.Name, b.BillNumber, b.BillDate, b.Amount, b.AmountDue
+FROM Bills b
+JOIN Vendors v ON b.Vendor = v.id
+WHERE b.Status IN ('Open', 'Partial')
+ORDER BY b.DueDate
+```
+
+### Bills Summary by Vendor
+```sql
+SELECT v.Name as Vendor, COUNT(b.id) as Bills, SUM(b.Amount) as Total, SUM(b.AmountDue) as Due
+FROM Bills b
+JOIN Vendors v ON b.Vendor = v.id
+GROUP BY v.Name
+ORDER BY Total DESC
+```
+
+### Account Balances (Non-Zero)
+```sql
+SELECT Code, Name, Type, Balance
+FROM Accounts
+WHERE Balance != 0
+ORDER BY Code
+```
+
+### Owner Reimbursement Balance
+```sql
+SELECT Balance FROM Accounts WHERE Code = '2203'
+```
+
+### Expense Summary by Account
+```sql
+SELECT a.Code, a.Name, a.Balance
+FROM Accounts a
+WHERE a.Type = 'Expense' AND a.Balance != 0
+ORDER BY a.Balance DESC
+```
+
+### Transaction History for Account
+```sql
+SELECT t.Date, t.Description, t.Reference, tl.Debit, tl.Credit
+FROM TransactionLines tl
+JOIN Transactions t ON tl.Transaction = t.id
+WHERE tl.Account = {account_id}
+ORDER BY t.Date DESC
+```
+
+### Verify All Transactions Balance
+```sql
+SELECT id, Description, Total, IsBalanced
+FROM Transactions
+WHERE IsBalanced = false
+```
+
+## Financial Reports
+
+### Balance Sheet
+
+Shows Assets = Liabilities + Equity at a point in time.
+
+**Important:** Parent accounts roll up child balances. Query only top-level parents (Parent = 0) to avoid double-counting.
+
+```sql
+-- Assets, Liabilities, Equity (top-level only)
+SELECT Code, Name, Type, Balance
+FROM Accounts
+WHERE Type IN ('Asset', 'Liability', 'Equity')
+  AND Parent = 0
+ORDER BY Type, Code
+```
+
+```sql
+-- Net Income (for Equity section)
+SELECT
+  COALESCE(SUM(CASE WHEN Type = 'Income' THEN Balance ELSE 0 END), 0) -
+  COALESCE(SUM(CASE WHEN Type = 'Expense' THEN Balance ELSE 0 END), 0) as NetIncome
+FROM Accounts
+WHERE Type IN ('Income', 'Expense')
+  AND id NOT IN (SELECT DISTINCT Parent FROM Accounts WHERE Parent != 0)
+```
+
+**Presentation:**
+| **Assets** | |
+|---|---:|
+| Cash & Bank Accounts | $X.XX |
+| Accounts Receivable | $X.XX |
+| **Total Assets** | **$X.XX** |
+
+| **Liabilities** | |
+|---|---:|
+| Accounts Payable | $X.XX |
+| Due to Owner | $X.XX |
+| **Total Liabilities** | **$X.XX** |
+
+| **Equity** | |
+|---|---:|
+| Retained Earnings | $X.XX |
+| Net Income (Loss) | $X.XX |
+| **Total Equity** | **$X.XX** |
+
+| **Total Liabilities + Equity** | **$X.XX** |
+
+### Income Statement
+
+Shows Revenue - Expenses = Net Income for a period.
+
+```sql
+SELECT Code, Name, Type, Balance
+FROM Accounts
+WHERE Type IN ('Income', 'Expense')
+  AND Balance != 0
+  AND id NOT IN (SELECT DISTINCT Parent FROM Accounts WHERE Parent != 0)
+ORDER BY Type DESC, Code
+```
+
+**Presentation:**
+| **Income** | |
+|---|---:|
+| Service Revenue | $X.XX |
+| **Total Income** | **$X.XX** |
+
+| **Expenses** | |
+|---|---:|
+| Software & Subscriptions | $X.XX |
+| Professional Services | $X.XX |
+| **Total Expenses** | **$X.XX** |
+
+| **Net Income (Loss)** | **$X.XX** |
+
+### Trial Balance
+
+Lists all accounts with non-zero balances. Debits should equal Credits.
+
+```sql
+SELECT
+  Code,
+  Name,
+  Type,
+  CASE WHEN Type IN ('Asset', 'Expense') THEN Balance ELSE 0 END as Debit,
+  CASE WHEN Type IN ('Liability', 'Equity', 'Income') THEN Balance ELSE 0 END as Credit
+FROM Accounts
+WHERE Balance != 0
+  AND id NOT IN (SELECT DISTINCT Parent FROM Accounts WHERE Parent != 0)
+ORDER BY Code
+```
+
+### Accounts Payable Aging
+
+```sql
+SELECT
+  v.Name as Vendor,
+  b.BillNumber,
+  b.BillDate,
+  b.DueDate,
+  b.AmountDue,
+  CASE
+    WHEN b.DueDate >= strftime('%s', 'now') THEN 'Current'
+    WHEN b.DueDate >= strftime('%s', 'now') - 2592000 THEN '1-30 Days'
+    WHEN b.DueDate >= strftime('%s', 'now') - 5184000 THEN '31-60 Days'
+    ELSE '60+ Days'
+  END as Aging
+FROM Bills b
+JOIN Vendors v ON b.Vendor = v.id
+WHERE b.Status IN ('Open', 'Partial')
+ORDER BY b.DueDate
+```
diff --git a/references/schema.md b/references/schema.md
new file mode 100644
index 0000000..d093b50
--- /dev/null
+++ b/references/schema.md
@@ -0,0 +1,97 @@
+# Database Schema
+
+Complete table schemas for the Grist accounting system.
+
+## Accounts
+| Column | Type | Notes |
+|--------|------|-------|
+| Code | Text | Account number (e.g., "5080") |
+| Name | Text | Account name |
+| Type | Choice | "Asset", "Liability", "Equity", "Income", "Expense" |
+| Parent | Ref:Accounts | Parent account for hierarchy (0 = top-level) |
+| Description | Text | |
+| IsActive | Bool | |
+| Balance | Formula | Calculated from transactions |
+
+## Vendors
+| Column | Type | Notes |
+|--------|------|-------|
+| Name | Text | Vendor name |
+| DefaultExpenseAccount | Ref:Accounts | Auto-fills on bill lines |
+| PaymentTerms | Choice | "Due on Receipt", "Net 15", "Net 30" |
+| Notes | Text | |
+| IsActive | Bool | |
+| Balance | Formula | Sum of unpaid bills |
+
+## Items
+| Column | Type | Notes |
+|--------|------|-------|
+| Name | Text | Item name (e.g., "Software Subscription") |
+| DefaultAccount | Ref:Accounts | Expense account for this item |
+| DefaultDescription | Text | Auto-fills on bill lines |
+| IsActive | Bool | |
+
+## Bills
+| Column | Type | Notes |
+|--------|------|-------|
+| Vendor | Ref:Vendors | Required |
+| BillNumber | Text | Invoice number from vendor |
+| BillDate | Date | Unix timestamp |
+| DueDate | Date | Unix timestamp |
+| Status | Choice | "Open", "Partial", "Paid" |
+| Memo | Text | |
+| EntryTransaction | Ref:Transactions | Link to journal entry |
+| Invoice | Attachments | Vendor invoice document (use `["L", id]` format) |
+| Receipt | Attachments | Payment receipt/confirmation (use `["L", id]` format) |
+| Amount | Formula | Sum of BillLines.Amount |
+| AmountPaid | Formula | Sum of BillPayments.Amount |
+| AmountDue | Formula | Amount - AmountPaid |
+
+## BillLines
+| Column | Type | Notes |
+|--------|------|-------|
+| Bill | Ref:Bills | Required |
+| Item | Ref:Items | Optional - auto-fills Account/Description |
+| Account | Ref:Accounts | Expense account |
+| Description | Text | |
+| Amount | Numeric | Line item amount |
+
+## Transactions
+| Column | Type | Notes |
+|--------|------|-------|
+| Date | Date | Unix timestamp |
+| Description | Text | Transaction description |
+| Reference | Text | Check number, invoice reference, etc. |
+| Status | Choice | "Draft", "Posted", "Cleared" |
+| Memo | Text | |
+| Total | Formula | Sum of debits |
+| IsBalanced | Formula | True if debits = credits |
+
+## TransactionLines
+| Column | Type | Notes |
+|--------|------|-------|
+| Transaction | Ref:Transactions | Required |
+| Account | Ref:Accounts | Required |
+| Debit | Numeric | Debit amount (or 0) |
+| Credit | Numeric | Credit amount (or 0) |
+| Memo | Text | |
+
+## BillPayments
+| Column | Type | Notes |
+|--------|------|-------|
+| Bill | Ref:Bills | Required |
+| Transaction | Ref:Transactions | Payment journal entry |
+| Amount | Numeric | Payment amount |
+| PaymentDate | Date | Unix timestamp |
+
+## Formula Columns (Auto-Calculated)
+
+| Table.Column | Description |
+|--------------|-------------|
+| Accounts.Balance | OwnBalance + ChildrenBalance |
+| Transactions.IsBalanced | True if sum of debits = sum of credits |
+| Transactions.Total | Sum of debit amounts |
+| Bills.Amount | Sum of BillLines.Amount |
+| Bills.AmountPaid | Sum of BillPayments.Amount |
+| Bills.AmountDue | Amount - AmountPaid |
+| Vendors.Balance | Sum of AmountDue for unpaid bills |
diff --git a/references/workflows.md b/references/workflows.md
new file mode 100644
index 0000000..64e7ed5
--- /dev/null
+++ b/references/workflows.md
@@ -0,0 +1,229 @@
+# Workflow Examples
+
+Detailed code examples for common accounting operations.
+
+## Contents
+- [Create a Vendor](#create-a-vendor)
+- [Create Items](#create-items-for-common-purchases)
+- [Complete Bill Entry](#complete-bill-entry-6-steps)
+- [Pay Bill from Checking](#pay-bill-from-checking-account)
+- [Pay Bill via Owner](#pay-bill-via-owner-reimbursement)
+- [Reimburse Owner](#reimburse-owner)
+- [Batch Operations](#batch-operations)
+
+## Create a Vendor
+
+```python
+add_records("Vendors", [{
+    "Name": "Acme Corp",
+    "DefaultExpenseAccount": 36,  # Software & Subscriptions
+    "PaymentTerms": "Due on Receipt",
+    "Notes": "Software vendor",
+    "IsActive": True
+}])
+# Returns: {"inserted_ids": [vendor_id]}
+```
+
+## Create Items for Common Purchases
+
+```python
+add_records("Items", [{
+    "Name": "Monthly Software",
+    "DefaultAccount": 36,
+    "DefaultDescription": "Monthly SaaS subscription",
+    "IsActive": True
+}])
+```
+
+## Complete Bill Entry (6 Steps)
+
+**Step 1: Create Bill Header**
+```python
+add_records("Bills", [{
+    "Vendor": 1,  # vendor_id
+    "BillNumber": "INV-001",
+    "BillDate": 1759708800,  # Unix timestamp
+    "DueDate": 1759708800,
+    "Status": "Open",
+    "Memo": "October services"
+}])
+# Returns: {"inserted_ids": [bill_id]}
+```
+
+**Step 2: Create Bill Line(s)**
+```python
+add_records("BillLines", [{
+    "Bill": 1,  # bill_id from step 1
+    "Item": 1,  # optional - auto-fills Account/Description
+    "Account": 36,  # expense account
+    "Description": "Monthly subscription",
+    "Amount": 100.00
+}])
+```
+
+**Step 3: Create Journal Entry**
+```python
+# Transaction header
+add_records("Transactions", [{
+    "Date": 1759708800,
+    "Description": "Acme Corp - October services",
+    "Reference": "INV-001",
+    "Status": "Posted"
+}])
+# Returns: {"inserted_ids": [txn_id]}
+
+# Transaction lines: Debit expense, Credit AP
+add_records("TransactionLines", [
+    {"Transaction": 1, "Account": 36, "Debit": 100.00, "Credit": 0, "Memo": "Monthly subscription"},
+    {"Transaction": 1, "Account": 4, "Debit": 0, "Credit": 100.00, "Memo": "Monthly subscription"}
+])
+```
+
+**Step 4: Link Bill to Transaction**
+```python
+update_records("Bills", [{"id": 1, "fields": {"EntryTransaction": 1}}])
+```
+
+**Step 5: Upload Invoice (if available)**
+```bash
+bash scripts/upload-attachment.sh invoice.pdf Bills 1 $TOKEN Invoice
+```
+
+**Step 6: Post-Entry Audit (REQUIRED)**
+
+Run audit checks before concluding. See [Audit Reference](audit.md) for details.
+
+```sql
+-- Check 1: Transaction balanced
+SELECT IsBalanced FROM Transactions WHERE id = {txn_id}
+-- Expected: true
+
+-- Check 2: Bill integrity
+SELECT id, Vendor, EntryTransaction, Amount FROM Bills WHERE id = {bill_id}
+-- Expected: All fields populated, Amount > 0
+```
+
+## Pay Bill from Checking Account
+
+```python
+# Step 1: Create payment transaction
+add_records("Transactions", [{
+    "Date": 1760832000,
+    "Description": "Payment - Acme Corp INV-001",
+    "Reference": "Check #1001",
+    "Status": "Cleared"
+}])
+# Returns: {"inserted_ids": [txn_id]}
+
+# Step 2: Debit AP, Credit Checking
+add_records("TransactionLines", [
+    {"Transaction": 2, "Account": 4, "Debit": 100.00, "Credit": 0, "Memo": "Pay INV-001"},
+    {"Transaction": 2, "Account": 14, "Debit": 0, "Credit": 100.00, "Memo": "Pay INV-001"}
+])
+
+# Step 3: Create BillPayment record
+add_records("BillPayments", [{
+    "Bill": 1,
+    "Transaction": 2,
+    "Amount": 100.00,
+    "PaymentDate": 1760832000
+}])
+
+# Step 4: Update bill status
+update_records("Bills", [{"id": 1, "fields": {"Status": "Paid"}}])
+
+# Step 5: Upload receipt (if available)
+# bash scripts/upload-attachment.sh receipt.pdf Bills 1 $TOKEN Receipt
+
+# Step 6: Post-Payment Audit (REQUIRED)
+# Verify payment transaction balances and bill status updated correctly
+```
+
+## Pay Bill via Owner Reimbursement
+
+When the owner pays a business expense personally:
+
+```python
+# Step 1: Create payment transaction
+add_records("Transactions", [{
+    "Date": 1760832000,
+    "Description": "Owner payment - Acme Corp INV-001",
+    "Reference": "Owner Reimb",
+    "Status": "Posted"
+}])
+
+# Step 2: Debit AP, Credit Due to Owner (not Checking)
+add_records("TransactionLines", [
+    {"Transaction": 2, "Account": 4, "Debit": 100.00, "Credit": 0, "Memo": "Pay INV-001"},
+    {"Transaction": 2, "Account": 22, "Debit": 0, "Credit": 100.00, "Memo": "Owner paid"}
+])
+
+# Step 3: Create BillPayment record
+add_records("BillPayments", [{
+    "Bill": 1,
+    "Transaction": 2,
+    "Amount": 100.00,
+    "PaymentDate": 1760832000
+}])
+
+# Step 4: Update bill status
+update_records("Bills", [{"id": 1, "fields": {"Status": "Paid"}}])
+
+# Step 5: Upload receipt (if available)
+# bash scripts/upload-attachment.sh receipt.pdf Bills 1 $TOKEN Receipt
+
+# Step 6: Post-Payment Audit (REQUIRED)
+```
+
+## Reimburse Owner
+
+When business pays back the owner:
+
+```python
+add_records("Transactions", [{
+    "Date": 1762041600,
+    "Description": "Owner reimbursement",
+    "Reference": "Transfer",
+    "Status": "Cleared"
+}])
+
+add_records("TransactionLines", [
+    {"Transaction": 3, "Account": 22, "Debit": 500.00, "Credit": 0, "Memo": "Reimburse owner"},
+    {"Transaction": 3, "Account": 14, "Debit": 0, "Credit": 500.00, "Memo": "Reimburse owner"}
+])
+```
+
+## Batch Operations
+
+When entering multiple bills efficiently:
+
+1. **Create all Bills first** → collect inserted IDs
+2. **Create all BillLines** referencing bill IDs
+3. **Create all Transactions** → collect inserted IDs
+4. **Create all TransactionLines** referencing transaction IDs
+5. **Update all Bills** with EntryTransaction links in one call
+6. (If paying) Create payment transactions, lines, and BillPayments
+7. **Upload invoice attachments** if files are available
+
+### Batch Attachment Uploads
+
+```bash
+# Example batch upload pattern
+TOKEN=$(request_session_token with write permission)
+for each (bill_id, invoice_path):
+    curl -X POST -H "Authorization: Bearer $TOKEN" \
+         -F "file=@$invoice_path" \
+         https://grist-mcp.bballou.com/api/v1/attachments
+    # Returns attachment_id
+    update_records("Bills", [{"id": bill_id, "fields": {"Invoice": ["L", attachment_id]}}])
+```
+
+### Batch Update Example
+
+```python
+update_records("Bills", [
+    {"id": 1, "fields": {"EntryTransaction": 1}},
+    {"id": 2, "fields": {"EntryTransaction": 2}},
+    {"id": 3, "fields": {"EntryTransaction": 3}}
+])
+```
diff --git a/scripts/download-attachment.sh b/scripts/download-attachment.sh
new file mode 100644
index 0000000..2f823f7
--- /dev/null
+++ b/scripts/download-attachment.sh
@@ -0,0 +1,56 @@
+#!/bin/bash
+# download-attachment.sh - Download attachment from Grist via MCP proxy
+# Usage: ./download-attachment.sh <attachment_id> <output_file> [token]
+#
+# Examples:
+#   ./download-attachment.sh 11 invoice.pdf                    # prompts for token
+#   ./download-attachment.sh 11 invoice.pdf sess_abc123...     # with token
+
+set -e
+
+ATTACHMENT_ID="$1"
+OUTPUT_FILE="$2"
+TOKEN="$3"
+
+if [[ -z "$ATTACHMENT_ID" || -z "$OUTPUT_FILE" ]]; then
+    echo "Usage: $0 <attachment_id> <output_file> [token]"
+    echo ""
+    echo "Arguments:"
+    echo "  attachment_id   ID of the attachment to download"
+    echo "  output_file     Path to save the downloaded file"
+    echo "  token           Session token (optional, will prompt if not provided)"
+    echo ""
+    echo "Examples:"
+    echo "  $0 11 invoice.pdf                    # Download attachment 11"
+    echo "  $0 11 invoice.pdf \$TOKEN            # With pre-obtained token"
+    echo ""
+    echo "To get attachment IDs, query the Bills table:"
+    echo "  SELECT id, BillNumber, Invoice FROM Bills"
+    exit 1
+fi
+
+# Get token if not provided
+if [[ -z "$TOKEN" ]]; then
+    echo "Paste session token (from request_session_token MCP call with read permission):"
+    read -r TOKEN
+fi
+
+# Base URL for the grist-mcp proxy
+BASE_URL="${GRIST_MCP_URL:-https://grist-mcp.bballou.com}"
+
+# Download attachment
+echo "Downloading attachment $ATTACHMENT_ID to $OUTPUT_FILE..."
+HTTP_CODE=$(curl -s -w "%{http_code}" -o "$OUTPUT_FILE" \
+    -H "Authorization: Bearer $TOKEN" \
+    "$BASE_URL/api/v1/attachments/$ATTACHMENT_ID")
+
+if [[ "$HTTP_CODE" -eq 200 ]]; then
+    FILE_SIZE=$(stat -f%z "$OUTPUT_FILE" 2>/dev/null || stat -c%s "$OUTPUT_FILE" 2>/dev/null)
+    echo "Success! Downloaded $FILE_SIZE bytes to $OUTPUT_FILE"
+else
+    echo "Download failed with HTTP $HTTP_CODE"
+    echo "Response:"
+    cat "$OUTPUT_FILE"
+    rm -f "$OUTPUT_FILE"
+    exit 1
+fi
diff --git a/scripts/verify-pdf.py b/scripts/verify-pdf.py
new file mode 100644
index 0000000..d92a9ef
--- /dev/null
+++ b/scripts/verify-pdf.py
@@ -0,0 +1,380 @@
+#!/usr/bin/env python3
+"""
+verify-pdf.py - Extract and verify invoice data from PDF files
+
+Usage:
+    python verify-pdf.py <pdf_file> [--bill-id N] [--json]
+
+Examples:
+    python verify-pdf.py invoice.pdf
+    python verify-pdf.py invoice.pdf --bill-id 1
+    python verify-pdf.py invoice.pdf --json
+
+Dependencies:
+    pip install pdfplumber pytesseract pillow pdf2image python-dateutil
+
+System packages (for OCR):
+    tesseract-ocr poppler-utils
+"""
+
+import argparse
+import json
+import re
+import sys
+from datetime import datetime
+from decimal import Decimal, InvalidOperation
+from pathlib import Path
+
+# PDF extraction
+try:
+    import pdfplumber
+    HAS_PDFPLUMBER = True
+except ImportError:
+    HAS_PDFPLUMBER = False
+
+# OCR fallback
+try:
+    import pytesseract
+    from pdf2image import convert_from_path
+    HAS_OCR = True
+except ImportError:
+    HAS_OCR = False
+
+# Date parsing
+try:
+    from dateutil import parser as dateparser
+    HAS_DATEUTIL = True
+except ImportError:
+    HAS_DATEUTIL = False
+
+
+def extract_text_pdfplumber(pdf_path: str) -> str:
+    """Extract text from PDF using pdfplumber (fast, text-based PDFs)."""
+    if not HAS_PDFPLUMBER:
+        return ""
+
+    text_parts = []
+    try:
+        with pdfplumber.open(pdf_path) as pdf:
+            for page in pdf.pages:
+                page_text = page.extract_text()
+                if page_text:
+                    text_parts.append(page_text)
+    except Exception as e:
+        print(f"pdfplumber error: {e}", file=sys.stderr)
+        return ""
+
+    return "\n".join(text_parts)
+
+
+def extract_text_ocr(pdf_path: str) -> str:
+    """Extract text from PDF using OCR (slower, handles scanned documents)."""
+    if not HAS_OCR:
+        return ""
+
+    text_parts = []
+    try:
+        images = convert_from_path(pdf_path, dpi=200)
+        for i, image in enumerate(images):
+            page_text = pytesseract.image_to_string(image)
+            if page_text:
+                text_parts.append(page_text)
+    except Exception as e:
+        print(f"OCR error: {e}", file=sys.stderr)
+        return ""
+
+    return "\n".join(text_parts)
+
+
+def extract_text(pdf_path: str) -> tuple[str, str]:
+    """
+    Extract text from PDF with OCR fallback.
+    Returns (text, method) where method is 'pdfplumber', 'ocr', or 'none'.
+    """
+    # Try text extraction first (fast)
+    text = extract_text_pdfplumber(pdf_path)
+    if len(text.strip()) >= 50:
+        return text, "pdfplumber"
+
+    # Fall back to OCR for scanned documents
+    text = extract_text_ocr(pdf_path)
+    if text.strip():
+        return text, "ocr"
+
+    return "", "none"
+
+
+def parse_invoice_number(text: str) -> str | None:
+    """Extract invoice number from text."""
+    patterns = [
+        r'(?:Invoice|Inv|Invoice\s*#|Invoice\s*Number|Invoice\s*No\.?)[:\s]*([A-Z0-9][-A-Z0-9]{3,})',
+        r'(?:Order|Order\s*#|Order\s*Number)[:\s]*([A-Z0-9][-A-Z0-9]{3,})',
+        r'(?:Reference|Ref|Ref\s*#)[:\s]*([A-Z0-9][-A-Z0-9]{3,})',
+        r'#\s*([A-Z0-9][-A-Z0-9]{5,})',  # Generic # followed by alphanumeric
+    ]
+
+    for pattern in patterns:
+        match = re.search(pattern, text, re.IGNORECASE)
+        if match:
+            return match.group(1).strip()
+
+    return None
+
+
+def parse_date(text: str) -> tuple[str | None, int | None]:
+    """
+    Extract date from text.
+    Returns (date_string, unix_timestamp) or (None, None).
+    """
+    if not HAS_DATEUTIL:
+        return None, None
+
+    # Look for labeled dates first
+    date_patterns = [
+        r'(?:Invoice\s*Date|Date|Issued)[:\s]*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})',
+        r'(?:Invoice\s*Date|Date|Issued)[:\s]*(\w+\s+\d{1,2},?\s+\d{4})',
+        r'(?:Invoice\s*Date|Date|Issued)[:\s]*(\d{4}[/-]\d{1,2}[/-]\d{1,2})',
+    ]
+
+    for pattern in date_patterns:
+        match = re.search(pattern, text, re.IGNORECASE)
+        if match:
+            date_str = match.group(1)
+            try:
+                parsed = dateparser.parse(date_str)
+                if parsed:
+                    return date_str, int(parsed.timestamp())
+            except:
+                pass
+
+    # Try to find any date-like pattern
+    generic_patterns = [
+        r'(\d{1,2}[/-]\d{1,2}[/-]\d{4})',
+        r'(\d{4}[/-]\d{1,2}[/-]\d{1,2})',
+        r'(\w+\s+\d{1,2},?\s+\d{4})',
+    ]
+
+    for pattern in generic_patterns:
+        matches = re.findall(pattern, text)
+        for date_str in matches[:3]:  # Check first 3 matches
+            try:
+                parsed = dateparser.parse(date_str)
+                if parsed and 2020 <= parsed.year <= 2030:
+                    return date_str, int(parsed.timestamp())
+            except:
+                pass
+
+    return None, None
+
+
+def parse_amount(text: str) -> tuple[str | None, Decimal | None]:
+    """
+    Extract total amount from text.
+    Returns (amount_string, decimal_value) or (None, None).
+    """
+    # Look for labeled totals (prioritize these)
+    total_patterns = [
+        r'(?:Total|Amount\s*Due|Grand\s*Total|Balance\s*Due|Total\s*Due)[:\s]*\$?([\d,]+\.?\d*)',
+        r'(?:Total|Amount\s*Due|Grand\s*Total|Balance\s*Due|Total\s*Due)[:\s]*USD?\s*([\d,]+\.?\d*)',
+    ]
+
+    for pattern in total_patterns:
+        match = re.search(pattern, text, re.IGNORECASE)
+        if match:
+            amount_str = match.group(1).replace(',', '')
+            try:
+                return match.group(1), Decimal(amount_str)
+            except InvalidOperation:
+                pass
+
+    # Look for currency amounts (less reliable)
+    currency_pattern = r'\$\s*([\d,]+\.\d{2})'
+    matches = re.findall(currency_pattern, text)
+    if matches:
+        # Return the largest amount found (likely the total)
+        amounts = []
+        for m in matches:
+            try:
+                amounts.append((m, Decimal(m.replace(',', ''))))
+            except:
+                pass
+        if amounts:
+            amounts.sort(key=lambda x: x[1], reverse=True)
+            return amounts[0]
+
+    return None, None
+
+
+def parse_vendor(text: str) -> str | None:
+    """
+    Extract vendor name from text.
+    Usually appears in the header/letterhead area.
+    """
+    lines = text.split('\n')[:10]  # Check first 10 lines
+
+    # Filter out common non-vendor lines
+    skip_patterns = [
+        r'^invoice',
+        r'^date',
+        r'^bill\s*to',
+        r'^ship\s*to',
+        r'^\d',
+        r'^page',
+        r'^total',
+    ]
+
+    for line in lines:
+        line = line.strip()
+        if not line or len(line) < 3 or len(line) > 100:
+            continue
+
+        # Skip lines matching patterns
+        skip = False
+        for pattern in skip_patterns:
+            if re.match(pattern, line, re.IGNORECASE):
+                skip = True
+                break
+
+        if skip:
+            continue
+
+        # Return first substantial line (likely company name)
+        if re.match(r'^[A-Z]', line) and len(line) >= 3:
+            return line
+
+    return None
+
+
+def extract_invoice_data(pdf_path: str) -> dict:
+    """Extract all invoice data from a PDF file."""
+    result = {
+        'file': pdf_path,
+        'extraction_method': None,
+        'invoice_number': None,
+        'date_string': None,
+        'date_timestamp': None,
+        'amount_string': None,
+        'amount_decimal': None,
+        'vendor': None,
+        'raw_text_preview': None,
+        'errors': [],
+    }
+
+    # Check file exists
+    if not Path(pdf_path).exists():
+        result['errors'].append(f"File not found: {pdf_path}")
+        return result
+
+    # Extract text
+    text, method = extract_text(pdf_path)
+    result['extraction_method'] = method
+    result['raw_text_preview'] = text[:500] if text else None
+
+    if not text:
+        result['errors'].append("Could not extract text from PDF")
+        return result
+
+    # Parse fields
+    result['invoice_number'] = parse_invoice_number(text)
+    result['date_string'], result['date_timestamp'] = parse_date(text)
+    result['amount_string'], amount = parse_amount(text)
+    result['amount_decimal'] = float(amount) if amount else None
+    result['vendor'] = parse_vendor(text)
+
+    return result
+
+
+def compare_with_bill(extracted: dict, bill: dict) -> list[dict]:
+    """
+    Compare extracted PDF data with bill record.
+    Returns list of discrepancies.
+    """
+    issues = []
+
+    # Compare invoice number
+    if extracted.get('invoice_number') and bill.get('BillNumber'):
+        if extracted['invoice_number'].upper() != bill['BillNumber'].upper():
+            issues.append({
+                'field': 'invoice_number',
+                'severity': 'WARNING',
+                'pdf_value': extracted['invoice_number'],
+                'bill_value': bill['BillNumber'],
+                'message': f"Invoice number mismatch: PDF has '{extracted['invoice_number']}', bill has '{bill['BillNumber']}'"
+            })
+
+    # Compare amount
+    if extracted.get('amount_decimal') and bill.get('Amount'):
+        pdf_amount = Decimal(str(extracted['amount_decimal']))
+        bill_amount = Decimal(str(bill['Amount']))
+        if abs(pdf_amount - bill_amount) > Decimal('0.01'):
+            issues.append({
+                'field': 'amount',
+                'severity': 'ERROR',
+                'pdf_value': float(pdf_amount),
+                'bill_value': float(bill_amount),
+                'message': f"Amount mismatch: PDF has ${pdf_amount}, bill has ${bill_amount}"
+            })
+
+    # Compare date (allow 1 day tolerance)
+    if extracted.get('date_timestamp') and bill.get('BillDate'):
+        pdf_ts = extracted['date_timestamp']
+        bill_ts = bill['BillDate']
+        diff_days = abs(pdf_ts - bill_ts) / 86400
+        if diff_days > 1:
+            issues.append({
+                'field': 'date',
+                'severity': 'WARNING',
+                'pdf_value': extracted['date_string'],
+                'bill_value': datetime.fromtimestamp(bill_ts).strftime('%Y-%m-%d'),
+                'message': f"Date mismatch: PDF has '{extracted['date_string']}', bill has {datetime.fromtimestamp(bill_ts).strftime('%Y-%m-%d')}"
+            })
+
+    return issues
+
+
+def main():
+    parser = argparse.ArgumentParser(description='Extract and verify invoice data from PDF')
+    parser.add_argument('pdf_file', help='Path to the PDF file')
+    parser.add_argument('--bill-id', type=int, help='Bill ID to compare against (for future use)')
+    parser.add_argument('--json', action='store_true', help='Output as JSON')
+    args = parser.parse_args()
+
+    # Check dependencies
+    missing = []
+    if not HAS_PDFPLUMBER:
+        missing.append('pdfplumber')
+    if not HAS_DATEUTIL:
+        missing.append('python-dateutil')
+
+    if missing:
+        print(f"Warning: Missing packages: {', '.join(missing)}", file=sys.stderr)
+        print("Install with: pip install " + ' '.join(missing), file=sys.stderr)
+
+    if not HAS_OCR:
+        print("Note: OCR support unavailable (install pytesseract, pdf2image)", file=sys.stderr)
+
+    # Extract data
+    result = extract_invoice_data(args.pdf_file)
+
+    if args.json:
+        print(json.dumps(result, indent=2, default=str))
+    else:
+        print(f"File: {result['file']}")
+        print(f"Extraction method: {result['extraction_method']}")
+        print(f"Invoice #: {result['invoice_number'] or 'NOT FOUND'}")
+        print(f"Date: {result['date_string'] or 'NOT FOUND'}")
+        print(f"Amount: ${result['amount_decimal']:.2f}" if result['amount_decimal'] else "Amount: NOT FOUND")
+        print(f"Vendor: {result['vendor'] or 'NOT FOUND'}")
+
+        if result['errors']:
+            print("\nErrors:")
+            for err in result['errors']:
+                print(f"  - {err}")
+
+        if result['raw_text_preview']:
+            print(f"\nText preview:\n{'-' * 40}")
+            print(result['raw_text_preview'][:300])
+
+
+if __name__ == '__main__':
+    main()