Alipay+ Session-Based API Client — Custom Wrapper for Indonesian E-Wallet (DANA) -- 2

Looking for an experienced developer with background in Alipay+
ecosystem or mPaaS-based wallet APIs to build a custom session-based
API client for internal reconciliation tooling.

PROJECT CONTEXT

The target wallet is DANA, an Indonesian e-wallet operating on top
of Alipay's mPaaS (Mobile Platform-as-a-Service) infrastructure.
This is the SAME underlying backend architecture used by GCash
(Philippines), TrueMoney (Thailand), TNG (Malaysia), and Kakao Pay
(South Korea) — all part of the Alipay+ cross-border wallet
ecosystem.

Due to this shared infrastructure, developers who have previously
built session-based API clients for ANY Alipay+ wallet, or who have
integrated with Alipay's merchant mPaaS SDK, will immediately
recognize the architecture and auth pattern.

WHAT I ALREADY KNOW TECHNICALLY

- Backend infrastructure: Alipay mPaaS (confirmed via traffic
observation)
- Primary auth mechanism: session cookie — specifically
ALIPAYJSESSIONID
- Session persistence: cookie-based, no complex CSRF rotation
- Transport: standard HTTPS over mPaaS gateway endpoints
- Session capture: already handled on my side (I have a working
Android companion that captures ALIPAYJSESSIONID from a logged-in
DANA account via VPN packet inspection)

WHAT I NEED FROM YOU

A server-side API client library + minimal dashboard that:

1. Accepts captured ALIPAYJSESSIONID cookie from my capture
endpoint
2. Makes authenticated requests to DANA's mPaaS gateway
3. Parses JSON/protobuf responses
4. Exposes clean REST endpoints to my internal services:
- GET /transaction-history (with pagination)
- GET /transaction/:id (detail)
- GET /balance
- POST /verify-recipient (nomor check)
5. Webhook callback on new incoming transaction
6. Session refresh handling + alert when session invalidated

ENDPOINT DISCOVERY

I will provide:
- Captured ALIPAYJSESSIONID cookies for testing (my own account)
- Known endpoint path hints (we have partial list from community)
- Reference tools (xtr4ct.com, decoder.id — existing commercial
solutions in this space, for reference only)

You should bring:
- Experience with Alipay+ endpoint discovery methodology
- Knowledge of mPaaS gateway URL structure (POST /mgw.htm pattern
or similar)
- Request body format expertise (mPaaS typically uses JSON with
specific header requirements)
- Session handling best practices

IDEAL CANDIDATE PROFILE

Must have at least ONE of these:
- Prior work building unofficial Alipay or Alipay+ wallet API
client (GCash/TrueMoney/TNG/DANA/Kakao)
- Experience with Alipay merchant mPaaS SDK integration
- Reverse engineering work on mobile fintech apps (Chinese or SEA)
- Published libraries or open-source projects in this space
(please link)

Nice to have:
- Chinese language ability (mPaaS official docs are in Chinese)
- Android reverse engineering experience (apktool, Frida, smali)
- Network traffic analysis (mitmproxy, Burp, Wireshark)
- SEA fintech ecosystem familiarity

TECHNICAL STACK

Backend (your choice):
- PHP 8.x + Laravel OR vanilla
- OR Node.js 18+ + Express/NestJS

Database: MySQL or PostgreSQL
Cache: Redis
Deployment: Linux VPS (Ubuntu/Debian)

DELIVERABLES

- Full source code (unencrypted, documented)
- Postman collection with all discovered endpoints
- Dashboard web UI (minimal, Bootstrap/Tailwind OK)
- Session refresh automation
- Webhook delivery system
- README with setup instructions
- 7-day post-handover support
- Signed NDA (I provide the template)

WHAT I AM NOT LOOKING FOR

- DANA Business/Merchant API integration (official API, different
product, not what I need)
- Generic payment gateway work (Midtrans, Xendit, etc. — not
relevant)
- Developers who need to "research from scratch" without existing
Alipay+ background
- Agencies that will subcontract to junior devs without niche
experience
- Full upfront payment requests

MILESTONES (3 phases)

Phase 1 (30%): Session validation + 1 working endpoint
(e.g., /balance) — proof of architecture understanding
Phase 2 (40%): All core endpoints + wrapper REST API
Phase 3 (30%): Dashboard + webhook + docs + handover

BUDGET

USD $400 — $800 fixed-price depending on your prior work in this
space. If you have an existing codebase that you can adapt
(license-wise allowed), I'm open to lower price for faster delivery.

Hourly option: USD $20-30/hr capped at 30 hours total.

Payment via Freelancer.com escrow, released per milestone.

BIDDING INSTRUCTIONS

Please include in your proposal:
1. Which Alipay+ wallet(s) you have prior experience with (be
specific — "I built a GCash transaction fetcher using session
cookies" is useful; "I know Alipay" is not)
2. Live portfolio link, GitHub repo, or video demo of relevant
work (REQUIRED — bids without this will be ignored)
3. Your technical approach: how you plan to discover unknown
endpoints (if any), handle session refresh, structure the
wrapper
4. Milestone breakdown with time estimates
5. Total price (fixed) or hourly rate

Any country freelancer developers
with relevant experience are especially welcome.

I will shortlist 3 candidates for a 15-minute video interview.
NDA will be sent before technical details are shared.

Thanks for reading. Looking forward to the right fit.