Stage 3 of 4. Read the project prerequisites before starting; this stage builds on the preceding contracts.
What changes
A reservation is a ceiling, not an invoice. When a request finishes, remove its hold and add actual spending. On cancellation, release the hold with zero spending.
A reported actual cost above the reservation is an accounting violation. Preserve the old ledger and raise an error so the caller can reconcile rather than silently producing a negative balance.
Work through one concrete case
A 70-unit hold with an actual 20-unit receipt releases 50 and moves 20 into spending. A missing receipt preserves the 70-unit hold; a reported 71 triggers reconciliation instead of silently increasing the budget.
pj agent budget planner 3
Change the lab inputs and calculate the result before reading its metrics. The figure computes from those inputs; the implementation tests below remain the source of completion evidence.
Implement the contract
Implement settle against the stated contract.
Use the public API contract and the typed starter signatures. Return values from core functions and let the supplied driver own file input, argument parsing and presentation.
Store closed request ids so a duplicate receipt cannot spend twice. Read the old state after an exception and prove that it is unchanged.
Verify and inspect
From the repository root, initialize once with python3 scripts/project_test.py agent-budget-planner --init learning-artifacts/agent-budget-planner. Then grade cumulatively:
python3 scripts/project_test.py agent-budget-planner --stage 3 --path learning-artifacts/agent-budget-planner --strictA fresh workspace should fail until you implement the contract. After every stage is complete, run your actual artifact from the supplied sample:
cd learning-artifacts/agent-budget-planner
python3 cli.py samples/input.json --mode execute --output budget.jsonInvestigate the failure boundary
The integration callback throws after doing work. Explain why releasing the reservation would hide an unknown liability.