Budget Tracking

The harness tracks knowledge access costs via an append-only budget ledger. This ensures agents can't exceed their knowledge budget.

How It Works

1. Each kcp_load call records the cost of loaded units
2. Running totals are maintained per currency
3. If a load would exceed the budget ceiling, the entire load is rejected (no partial loads)
4. Every spend/rejection is logged to the audit log

Configuration

Set a budget ceiling in harness.yaml:

governance:
  policy:
    budget:
      amount: 1.00
      currency: USDC
    context_budget: 50000  # token budget

Querying

Use the harness_budget MCP tool:

{
  "ceiling": { "amount": 1.00, "currency": "USDC" },
  "spent": { "USDC": 0.25 },
  "remaining": { "USDC": 0.75 },
  "entries": [...]
}

Ledger Properties

Property	Description
Append-only	Entries can't be modified or deleted
Itemized	Each entry records source, description, cost, and running total
Per-currency	Running totals tracked per currency (supports multi-currency)
Ceiling-enforced	Loads that would exceed ceiling are rejected atomically
Sequenced	Each entry has a monotonic sequence number

No Partial Loads

If a kcp_load would push spend over the ceiling, the entire load is rejected — not just the units that exceed the budget. This prevents the agent from getting an incomplete knowledge set that could lead to incorrect conclusions.