fix(l402): refuse unknown/unbounded invoice amount even with no max (#71) - #11
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…#71) The L402 amount/budget gate short-circuited when no `max_amount_sats` was configured (`if effective_max is None: return`) and paid ANY invoice — an unbounded, unaudited spend whenever a caller merely forgot to set a ceiling. Split the gate into two independent rules: 1. Unknown/unbounded amount (amountless, unparseable, or <= 0 — all reported as None by the decoder) is ALWAYS refused, whether or not a max is set. This is the fail-closed core of ledger #71. 2. The `amount > max` ceiling comparison applies ONLY when a max is configured. A KNOWN positive amount with no ceiling is still paid — the caller's documented opt-out — so this does not force every payment to declare a max. Flips the security-regression test that pinned the fail-open pay behavior to assert refusal, and adds a companion test proving a known amount with no ceiling is still paid. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Ledger #71 — fail-closed the L402 amount/budget gate
The L402 amount/budget gate short-circuited when no
max_amount_satswas configured (if effective_max is None: return) and paid anything — an unbounded, unaudited spend whenever a caller merely forgot to set a ceiling.Change
L402Client._check_amount_against_maxis split into two independent rules:<= 0(all reported asNoneby_decode_invoice_amount_sats). Fail-closed core of #71.amount > max→ refuse) applies only when a max is configured.Result: unknown amount → refuse (even with no max); known positive amount + no max → pay (caller's opt-out); known positive amount + over max → refuse. It does not force every payment to declare a max.
Tests (failing-test-first)
test_unparseable_invoice_still_paid_when_no_budget_configured→test_unparseable_invoice_refused_even_when_no_budget_configured(was RED against pre-fix code: it paid; now GREEN). Mutation-checked: reverting the fix makes it pay again.test_known_amount_paid_when_no_budget_configuredpinning the opt-out half.Full suite: 211 → 212 passing (net +1 test).
Not published, no version bump.