Same-Branch Editing

This example walks through two agents editing the same function in src/currency.ts on main.

Same-Branch AST Merging on main

Prompt on main

Agent 1: "Add locale"

Agent 2: "Add decimals"

1 File (currency.ts)

Concurrent Edits

Both save on main

✓ No File Locks

Tree-sitter AST

✓ Structural AST

Unified on Disk

Both Kept

✓ Zero Overwrites

Two agents on main·Concurrent saves·Tree-sitter AST merge·Both edits preserved

Starting File

Suppose src/currency.ts on main contains:

export function formatCurrency(cents: number, currency: string = "USD"): string {
  const amount = (cents / 100).toFixed(2);
  return `${currency} ${amount}`;
}

Prompting Two Agents

Open two AI agent tabs and give both a prompt that modifies formatCurrency:

• Tab 1: "Add a locale: string = 'en-US' parameter to formatCurrency in src/currency.ts."
• Tab 2: "Add a decimals: number = 2 parameter to formatCurrency in src/currency.ts."

How It Works

1. Both agents claim src/currency.ts against the same starting commit on main.
2. Agent 1 writes its edit and runs tes hook post-tool --path src/currency.ts.
3. Agent 2 writes its edit and runs tes hook post-tool --path src/currency.ts.
4. Tessera parses the base version and both agents' versions using Tree-sitter and merges the parameter list and function body automatically.

Merged Result

export function formatCurrency(
  cents: number,
  currency: string = "USD",
  locale: string = "en-US",
  decimals: number = 2
): string {
  const amount = (cents / 100).toFixed(decimals);
  return `[${locale}] ${currency} ${amount}`;
}

Committing

Check the status and commit:

tes status
tes diff
tes commit -m "feat(currency): support locale and decimals parameters"

Next Steps

• Feature Branches - Isolate two features on separate branches
• Conflict Resolution - Handle overlapping edits to the same expression