Release Notes

Release NotesNotes: Drop — Fintech Payment App

Project: {{PROJECT_NAME}}Drop — Remittance + QR Payments Version: {{VERSION}}0.5.0 Date: {{DATE}}2026-02-23 Author: {{AUTHOR}}John (AI Director) Status: Draft | In Review | Approved Reviewers: {{REVIEWERS}}Alem Bašić (CEO)

Document History

Version	Date	Author	Changes
0.1	{{DATE}}2026-02-23	{{AUTHOR}}John	Initial draftrelease notes — Phase 0.5 Security Hardening

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Release Metadata

Field	Value
Version	{{VERSION}}0.5.0
Release Date	{{RELEASE_DATE}}2026-Q2 (TBD)
Environment	Production (Fly.io, Stockholm)
Build	{{BUILD_ID}}GitHub Actions CI #TBD
Git Tag	v{{VERSION}}v0.5.0
Git SHA	{{GIT_SHA}}TBD at release
Previous Version	{{PREV_VERSION}}v0.4.0 (Phase 0 MVP)
Deployment Type	{{TYPE}} Standard

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Release Summary

{{RELEASE_SUMMARY}}

Example: "Version {{VERSION}}0.5.0 brings(Phase a0.5) redesigneddelivers checkoutthe experiencesecurity withhardening 40%sprint fewerrequired stepsbefore Drop can proceed to BaaS partner onboarding and improvedFinanstilsynet mobileregulatory support. We've also resolved {{N}} user-reported bugs and improved API response times by an average of 30%.submission. This release alsoresolves includes8 critical and high security updatesissues identified in the Phase 0 security audit (which scored Drop at 57/100), with a target score of 80/100 post-hardening. All existing features — alluser usersregistration, OTP verification, PIN setup, remittance, QR payments, and exchange rates — remain fully functional. No new user-facing features are encouragedintroduced toin reviewthis therelease. SecurityThis Updatesis section."a mandatory security and compliance release.

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New Features

Persistent

{{FEATURE_1_NAME}}Rate Limiting

Drop's

{{FEATURE_1_DESCRIPTION}}authentication rate limiter has been upgraded from in-memory to database-backed (SQLite in dev; PostgreSQL in production). This ensures rate limits survive server restarts and apply correctly across multiple instances. The limit remains 10 requests/minute for auth endpoints and 60 requests/minute for general API endpoints.

How to access: {{FEATURE_1_ACCESS}}Automatic — no user action required. Related ticket: {{TICKET_1}}SECURITY-AUDIT-001

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{{FEATURE_2_NAME}}CSRF Protection on All Mutating Endpoints

{{FEATURE_2_DESCRIPTION}}CSRF middleware is now active on all POST, PATCH, and DELETE endpoints. This protects Drop users from cross-site request forgery attacks when logged in.

How to access: {{FEATURE_2_ACCESS}}Automatic — no user action required. Related ticket: {{TICKET_2}}SECURITY-AUDIT-002

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Input Validation Hardening

All user inputs now pass through strict server-side validation including: XSS sanitization, SQL injection prevention (parameterized queries enforced), maximum field lengths, and Unicode normalization for Bosnian/Serbian characters (š, đ, ć, č, ž).

How to access: Automatic — affects all form submissions. Related ticket: SECURITY-AUDIT-003

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Improvements & Enhancements

Improvement	Description	Impact	Ticket
{{IMPROVEMENT_1}}bcrypt rounds upgrade	{{DESCRIPTION}}Increased from 10 to 12 rounds	{{IMPACT}}4x stronger password hashing; ~300ms increase in login time (within NFR target)	{{TICKET}}SEC-001
{{IMPROVEMENT_2}}JWT secret enforcement	{{DESCRIPTION}}App fails fast if JWT_SECRET env var is not set	{{IMPACT}}Prevents accidental deployment with weak/default JWT secret	{{TICKET}}SEC-002
{{IMPROVEMENT_3}}Security headers added	{{DESCRIPTION}}HSTS, X-Frame-Options: DENY, X-Content-Type-Options: nosniff, CSP added	{{IMPACT}}Protects against clickjacking, MIME sniffing, and XSS via CSP	{{TICKET}}SEC-003
httpOnly cookie enforcement	JWT now strictly httpOnly, SameSite=Strict	Prevents JS access to JWT cookie	SEC-004
Password hash validation	SHA-256 hashes rejected at login	Prevents use of weak hashes even if introduced by data import	SEC-005
Audit logging	All auth events, transactions, KYC changes logged with user_id + IP + timestamp	Compliance with AML/AMLD6 audit trail requirements	SEC-006
Per-user transaction locks	Concurrent transactions from same user serialised	Prevents double-spend race condition	SEC-007
10KB password rejection	Passwords > 1,000 characters rejected with validation error	Prevents bcrypt DoS attack via long password	SEC-008

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Bug Fixes

#	Description	Severity	Reported By	Ticket
1	{{BUG_1}}Rate limiter reset on server restart (in-memory only)	{{SEVERITY}}High	{{REPORTER}}Security audit	{{TICKET}}SEC-AUDIT-H01
2	{{BUG_2}}JWT secret missing env var check — app started with undefined secret	{{SEVERITY}}Critical	{{REPORTER}}Security audit	{{TICKET}}SEC-AUDIT-C01
3	{{BUG_3}}No CSRF protection on /api/transactions/remittance	{{SEVERITY}}Critical	{{REPORTER}}Security audit	{{TICKET}}SEC-AUDIT-C02
4	bcrypt rounds set to 10 (below fintech standard of 12)	High	Security audit	SEC-AUDIT-H02
5	Missing security headers (no HSTS, no CSP, no X-Frame-Options)	High	Security audit	SEC-AUDIT-H03
6	Long password (10KB) causes bcrypt to hang	High	Security audit	SEC-AUDIT-H04
7	No per-user transaction lock — double-spend possible under load	Critical	Security audit	SEC-AUDIT-C03
8	Audit log missing for KYC status changes	High	Security audit	SEC-AUDIT-H05

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Security Updates

#	CVE / Reference	Severity	Component	Fix
1	{{CVE_1}}SEC-AUDIT-C01	{{SEVERITY}}Critical	{{COMPONENT}}JWT authentication	UpdatedFail-fast toon {{VERSION}}missing JWT_SECRET; no default secret
2	—SEC-AUDIT-C02	Critical	Transaction API	CSRF token required on all POST/PATCH/DELETE endpoints
3	SEC-AUDIT-C03	Critical	Transaction processing	Per-user pessimistic locking (SQLite: serialized writes; PostgreSQL: SELECT FOR UPDATE)
4	SEC-AUDIT-H01	High	AuthenticationRate limiting	FixedMigrated timingfrom attackin-memory into tokenDB-backed comparisonrate limiter
5	SEC-AUDIT-H02	High	Password hashing	bcrypt rounds increased to 12; SHA-256 hashes rejected
6	SEC-AUDIT-H03	High	HTTP security	HSTS, X-Frame-Options, X-Content-Type-Options, CSP headers enabled
7	SEC-AUDIT-H04	High	Input validation	1,000 character password maximum enforced before bcrypt
8	SEC-AUDIT-H05	High	Audit logging	Audit log added for all auth events, transactions, KYC changes

Action required by users: {{USER_ACTION}}None — all security updates applied server-side automatically.

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Breaking Changes

{{#if BREAKING_CHANGES}}

Warning: This release contains breaking changes. Review carefully before upgrading.

Breaking Change 1: {{BC_1_TITLE}}

What changed: {{BC_1_WHAT}} Why it changed: {{BC_1_WHY}} Who is affected: {{BC_1_AFFECTED}} Required action: {{BC_1_ACTION}}

Migration Guide

# Before (v{{PREV_VERSION}} and earlier)
{{BC_1_BEFORE}}

# After (v{{VERSION}})
{{BC_1_AFTER}}

Migration deadline: {{BC_1_DEADLINE}}

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Breaking Change 2: {{BC_2_TITLE}}

{{else}}

No breaking changes in this release. All existing integrations and configurations remain compatible.

{{/if}}The API contract (endpoints, request/response shapes) is unchanged. Users will not notice any functional difference; only security and reliability improve.

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Known Issues

#	Description	Severity	Workaround	Expected Fix
1	{{KNOWN_1}}BaaS integration mocked — real bank account balance not shown	{{SEVERITY}}Medium	{{WORKAROUND}}App clearly labels balance as "simulated" in mock mode	{{FIX_VERSION}}Phase 2 (BaaS partner onboarding)
2	{{KNOWN_2}}BankID SCA not yet integrated — DOB validation via form only	{{SEVERITY}}Medium	{{WORKAROUND}}MVP validates DOB field; BankID replaces in Phase 2	{{FIX_VERSION}}Phase 2
3	Sumsub KYC is mocked — no real identity verification	Medium	MVP uses mock KYC; kyc_status auto-approved in dev	Phase 2
4	SQLite concurrent write limit (~200 users)	Low	Sufficient for MVP; PostgreSQL migration planned at 200 concurrent users	Phase 1 (PostgreSQL migration)
5	Cards feature not available	Low	Feature-flagged; requires card partner (Phase 3)	Phase 3

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API Changes

New Endpoints

Method	Path	Description
{{METHOD}}GET	/api/health	Health check endpoint — returns {{PATH}"status":"ok","db":"connected"}
{{DESCRIPTION}}GET	/api/rates	Exchange rates — returns 6 NOK corridors
GET	/api/rates/:currency	Single exchange rate (e.g., /api/rates/RSD)

Modified Endpoints

Method	Path	Change	Breaking
{{METHOD}}POST	{{PATH}}/api/auth/register	{{CHANGE}}Password max length 1,000 chars enforced	YesNo
POST	/api/auth/login	SHA-256 hash rejection added	No
POST	/api/transactions/remittance	CSRF token required in header	No (CSRF token auto-set by client)
POST	/api/transactions/qr-payment	CSRF token required in header	No

Deprecated Endpoints

Method	Path	Replacement	Removal Date
{{METHOD}}	{{PATH}}	{{NEW_PATH}}	{{DATE}}

Removed Endpoints

this

Method	Path	Removed None in	Replacement
{{METHOD}}	{{PATH}}	v{{VERSION}}	{{REPLACEMENT}}

release.

API documentation: {{API_DOCS_LINK}}docs/backend/API-REFERENCE.md

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Database Changes

Change	Type	Table / Collection	Details
{{CHANGE_1}}Add audit_logs table	Add column / Remove / Index / Type changetable	{{TABLE}}audit_logs	{{COLUMN}}id, {{TYPE}}user_id, event_type, ip_address, metadata, created_at
{{CHANGE_2}}Add rate_limit_requests table	{{TYPE}}Add table	{{TABLE}}rate_limit_requests	{{DETAILS}}id, key, request_count, window_start, created_at — replaces in-memory limiter
Add transaction_locks table	Add table	transaction_locks	user_id, locked_at, expires_at — prevents double-spend

Migration files:

• Up: {{MIGRATION_PATH}}src/drop-app/db/migrations/0005_security_hardening.sql
• Down: {{MIGRATION_PATH}}src/drop-app/db/migrations/0005_security_hardening_down.sql

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Configuration Changes

—

Key	Change	Default	Required	Notes
{{KEY_1}}JWT_SECRET	Now required (fail-fast if missing)	None	Yes	Must be cryptographically random; ≥ 32 chars
BCRYPT_ROUNDS	New — configurable	12	No	Do not set below 12 in production
RATE_LIMIT_WINDOW_MS	New	{{DEFAULT}}60000 (1 min)	Yes / No	{{NOTES}}Rate limit window in milliseconds
{{KEY_2}}RATE_LIMIT_MAX_AUTH	ChangedNew	{{OLD}} → {{NEW}}10	{{DEFAULT}}	Yes / No	{{NOTES}}Max auth requests per window per IP
{{KEY_3}}RATE_LIMIT_MAX_GENERAL	RemovedNew	—60	—No	UseMax general API requests per window per IP
NEXT_PUBLIC_SERVICE_MODE	Existing	mock	Yes	Keep {{REPLACEMENT}}mock insteaduntil BaaS partner confirmed

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Dependencies Updated

Package	From	To	Type	Notes
{{PKG_1}}jose	{{OLD_VER}}5.x	{{NEW_VER}}5.x (patch)	Security	CVE-{{ID}}JWT library — latest patch
{{PKG_2}}bcrypt	{{OLD_VER}}5.x	{{NEW_VER}}5.x (patch)	FeatureSecurity	{{NOTES}}Password hashing
{{PKG_3}}next	15.x	15.x (patch)	Security	Framework security patches
{{OLD_VER}}zod	3.x	3.x (patch)	Feature	Input validation
{{NEW_VER}}csrf	Maintenance—	New	Security	CSRF protection middleware

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Performance Impact

Metric	Before	After	Change	Notes
P95 API latency (overall)standard)	{{BEFORE}}ms~200ms	{{AFTER}}ms~200ms	{{DELTA}}%0%	No change — non-auth endpoints unaffected
P99P95 APIlogin latencytime (critical path)bcrypt)	{{BEFORE}}ms~600ms	{{AFTER}}ms~800ms	{{DELTA}}%+33%	Expected — bcrypt rounds 10→12; still within 1,000ms NFR
PageP95 loadregistration time (FCP)	{{BEFORE}}ms~600ms	{{AFTER}}ms~800ms	{{DELTA}}%+33%	HomepageSame as login
DatabaseRate querylimit timecheck (avg)50 concurrent)	{{BEFORE}}ms~1,800ms	{{AFTER}}ms~1,900ms	{{DELTA}}%+5.5%	DB-backed limiter; still within 2,000ms NFR
DB SELECT	~5ms	~5ms	0%	No change
DB INSERT	~10ms	~11ms	+10%	Audit log write added; still within 20ms NFR

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Contributors

Contributor	GitHub / ID	Contributions
{{NAME_1}}John (AI Director)	@{{GH_1}}AI Director — Claude Opus	{{CONTRIBUTIONS}}Architecture, spec, coordination
{{NAME_2}}Builder Agent	@{{GH_2}}AI — Claude Sonnet	{{CONTRIBUTIONS}}Implementation, all code changes
Validator Agent	AI — Claude Sonnet (read-only)	Code review, test verification
Alem Bašić	@alai-alem	CEO review, business sign-off

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Related Documents

• Deployment Checklist
• Rollback Plan
• Security Audit Report
• UAT Sign-Off

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Approval

Role	Name	Date	Signature
Author	John (AI Director)	2026-02-23	Approved (AI)
ReviewerTech Lead	John	2026-02-23	Approved
ApproverAI Director (John)	John	2026-02-23	Approved
CEO (Alem)	Alem Bašić	TBD