Closes task #44 ahead of v1.0.7-rc1 tag. Dispute-class webhooks
(axis-1 P1.6, v1.0.8 scope) may carry metadata beyond the typical
1-5 KB event size — a 64KB cap created a non-zero risk of silent
drops that exactly the wrong class of event to lose. 256KB gives
10x headroom above the inflated-dispute ceiling while staying
tightly bounded against log-spam DoS: sustained ceiling at the
rate-limit floor is ~25MB/s, cleaned daily.
Rationale documented in the comment above the const so future
readers see the reasoning before the number. The rate limit
remains the primary DoS defense; this cap is defense in depth.
No live Hyperswitch docs verification (no internet access in this
session) — decision based on typical PSP webhook shapes + user's
explicit flag that losing a legit dispute = weekend lost. Task
#44 closed with that caveat noted; a proper docs review can
re-tune if observed traffic shows the 256KB ceiling is also too
aggressive (unlikely).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Every POST /webhooks/hyperswitch delivery now writes a row to
`hyperswitch_webhook_log` regardless of signature-valid or
processing outcome. Captures both legitimate deliveries and attack
probes — a forensics query now has the actual bytes to read, not
just a "webhook rejected" log line. Disputes (axis-1 P1.6) ride
along: the log captures dispute.* events alongside payment and
refund events, ready for when disputes get a handler.
Table shape (migration 984):
* payload TEXT — readable in psql, invalid UTF-8 replaced with
empty (forensics value is in headers + ip + timing for those
attacks, not the binary body).
* signature_valid BOOLEAN + partial index for "show me attack
attempts" being instantaneous.
* processing_result TEXT — 'ok' / 'error: <msg>' /
'signature_invalid' / 'skipped'. Matches the P1.5 action
semantic exactly.
* source_ip, user_agent, request_id — forensics essentials.
request_id is captured from Hyperswitch's X-Request-Id header
when present, else a server-side UUID so every row correlates
to VEZA's structured logs.
* event_type — best-effort extract from the JSON payload, NULL
on malformed input.
Hardening:
* 64KB body cap via io.LimitReader rejects oversize with 413
before any INSERT — prevents log-spam DoS.
* Single INSERT per delivery with final state; no two-phase
update race on signature-failure path. signature_invalid and
processing-error rows both land.
* DB persistence failures are logged but swallowed — the
endpoint's contract is to ack Hyperswitch, not perfect audit.
Retention sweep:
* CleanupHyperswitchWebhookLog in internal/jobs, daily tick,
batched DELETE (10k rows + 100ms pause) so a large backlog
doesn't lock the table.
* HYPERSWITCH_WEBHOOK_LOG_RETENTION_DAYS (default 90).
* Same goroutine-ticker pattern as ScheduleOrphanTracksCleanup.
* Wired in cmd/api/main.go alongside the existing cleanup jobs.
Tests: 5 in webhook_log_test.go (persistence, request_id auto-gen,
invalid-JSON leaves event_type empty, invalid-signature capture,
extractEventType 5 sub-cases) + 4 in cleanup_hyperswitch_webhook_
log_test.go (deletes-older-than, noop, default-on-zero,
context-cancel). Migration 984 applied cleanly to local Postgres;
all indexes present.
Also (v107-plan.md):
* Item G acceptance gains an explicit Idempotency-Key threading
requirement with an empty-key loud-fail test — "literally
copy-paste D's 4-line test skeleton". Closes the risk that
item G silently reopens the HTTP-retry duplicate-charge
exposure D closed.
Out of scope for E (noted in CHANGELOG):
* Rate limit on the endpoint — pre-existing middleware covers
it at the router level; adding a per-endpoint limit is
separate scope.
* Readable-payload SQL view — deferred, the TEXT column is
already human-readable; a convenience view is a nice-to-have
not a ship-blocker.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
