Build an RWA Platform: Developer Guide to Tokenization APIs and Infrastructure

If you are building a product on RWA infrastructure — a digital investment platform, a tokenized fund portal, a secondary trading application, or a compliance tool for digital securities — you face the same core question: what do you build, and what do you use from existing infrastructure?

This guide is for developers and technical founders who need to understand the full RWA infrastructure stack, evaluate build-vs-buy at each layer, and make informed decisions about API integration, blockchain architecture, and compliance system design.

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What Developers Need to Build an RWA Product

A production-grade RWA platform has six infrastructure layers. Understanding each layer's complexity and build cost is essential before committing to a development roadmap.

Layer 1: Blockchain and Token Contract Infrastructure

At the base layer, RWA tokens are deployed as smart contracts on a blockchain network. For compliant security tokens, ERC-3643 (T-REX) is the dominant standard — it embeds transfer restrictions and investor identity verification into the contract, blocking non-compliant transfers at the blockchain layer.

What this layer requires:

• Smart contract development and auditing (ERC-3643 compliant token contracts)
• Multi-chain deployment tooling (if you need to support multiple chains)
• Token contract upgrade mechanisms (regulations change; your contracts need to be upgradeable without token migration)
• Gas optimization for institutional transaction volumes
• On-chain event indexing for real-time cap table updates

Build complexity: HIGH. ERC-3643 contract development, formal security auditing ($40K–$150K per audit), and ongoing maintenance require specialized blockchain engineering expertise.

Build vs. buy decision: Most product builders should use an established, audited token contract standard rather than building from scratch.

Layer 2: Compliance Engine

The compliance engine enforces investor eligibility rules, whitelist management, AML/KYC verification, and sanctions screening.

What this layer requires:

• Integration with identity verification providers (Jumio, Onfido, Sum&Substance, or regional alternatives)
• Accreditation verification workflow (US Reg D, EU qualified investor, ADGM professional client)
• On-chain whitelist management
• Sanctions screening API integration (Chainalysis, TRM Labs, Elliptic, or OFAC direct feeds)
• AML transaction monitoring with configurable alert rules
• Jurisdiction-specific compliance module configuration

Build complexity: HIGH and ongoing. AML/KYC requirements change. Sanctions lists update daily. Each jurisdiction has different eligibility rules.

Build vs. buy decision: This is the layer where almost every serious RWA platform chooses to integrate rather than build. The regulatory risk of a compliance mistake is catastrophic for an institutional product.

Layer 3: Custody Integration

The custody layer handles private key management, transaction signing, asset segregation, and audit trail generation.

What this layer requires:

• Integration with an institutional custody provider (Fireblocks, Copper, BitGo) via their API
• Policy engine configuration: approval workflows for different transaction types and amounts
• Multi-party signing setup for high-value transactions
• Segregated vault structure for different deal or investor accounts
• Reconciliation between custody records and on-chain state

Build vs. buy decision: Build the integration layer; use an established custody provider's infrastructure. Do not build key management infrastructure from scratch for production assets.

Layer 4: Investor Onboarding and Portal

The investor-facing layer: account creation, KYC submission, portfolio view, document vault, distribution history, and secondary transfer requests.

Build complexity: MEDIUM. Standard full-stack web development with compliance-driven logic (blocking actions until KYC is complete, enforcing accreditation gating).

Build vs. buy decision: This is the most reasonable layer for custom development — it is the user-facing differentiator and branding surface.

Layer 5: Cap Table and Distribution Engine

The operational core: maintaining the definitive investor ownership record and processing distributions.

What this layer requires:

• Real-time cap table synchronized with on-chain token state
• Distribution calculation engine (pro-rata allocation from on-chain cap table)
• Payment processing integration (stablecoin distributions, bank wire file generation)
• Corporate action processing (capital calls, redemptions, PIK accrual)
• Reconciliation with fund administrator records
• Tax document generation (K-1 templates, PFIC statements, FATCA/CRS output)

Layer 6: Regulatory Reporting and Audit Trail

All on-chain and off-chain activity must be captured in a format suitable for regulatory examination: immutable event log, regulatory report generation (SEC Form D, AIFMD Annex IV, ADGM FSRA return templates), and audit export capability.

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Build vs. Buy: 18 Months vs. 8 Weeks

Layer	Build time	Engineering cost
Token contracts (audit included)	3-4 months	$80K-$200K
Compliance engine (multi-jurisdiction)	4-6 months	$120K-$300K
Custody integration	2-3 months	$50K-$120K
Investor portal	3-4 months	$80K-$200K
Cap table and distribution engine	2-3 months	$60K-$150K
Regulatory reporting	1-2 months	$30K-$80K
Total (sequential)	14-18 months	$420K-$1.05M

This assumes competent, full-time engineers with RWA experience. Most teams underestimate by 30–50%.

Using white-label infrastructure:

Phase	Timeline
Platform configuration and branding	2-4 weeks
Compliance module setup (jurisdiction config)	2-3 weeks
Investor portal customization	1-2 weeks
First deal test and UAT	2-3 weeks
Total to first live deal	8-12 weeks

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AssetHaus API Overview

AssetHaus provides REST APIs for integrating RWA infrastructure into your product.

Token Issuance API

POST /api/v1/issuances

Creates a new token issuance. Parameters: asset details, token structure (equity/debt), jurisdiction configuration, distribution schedule, total supply, and investor whitelist rules.

GET /api/v1/issuances/{issuanceId}
POST /api/v1/issuances/{issuanceId}/mint
POST /api/v1/issuances/{issuanceId}/distribute

Investor Onboarding API

POST /api/v1/investors

Initiates investor KYC flow. Returns a KYC session URL for the investor to complete. Supports webhook callbacks when KYC status changes.

GET /api/v1/investors/{investorId}/kyc-status
POST /api/v1/investors/{investorId}/accreditation

Cap Table API

GET /api/v1/issuances/{issuanceId}/captable
GET /api/v1/issuances/{issuanceId}/captable/transfers
POST /api/v1/issuances/{issuanceId}/transfers

Real-time cap table with full transfer history. Transfer creation triggers compliance checks before signing.

Distribution API

POST /api/v1/issuances/{issuanceId}/distributions
GET /api/v1/issuances/{issuanceId}/distributions/{distributionId}/status

Creates a distribution event. The API calculates entitlements from the current cap table, generates payment files or initiates stablecoin transactions.

Reporting API

GET /api/v1/issuances/{issuanceId}/reports/captable
GET /api/v1/issuances/{issuanceId}/reports/audit-trail
GET /api/v1/issuances/{issuanceId}/reports/tax?format=k1&year=2025
GET /api/v1/issuances/{issuanceId}/reports/fatca

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Deployment Options

Cloud API (SaaS)

Access AssetHaus infrastructure via HTTPS API from your application. No infrastructure to manage. Standard SaaS uptime SLAs.

Suitable for: product builders without data residency requirements. Fastest integration path.

On-Premise SDK

Deploy the AssetHaus infrastructure stack in your own environment — your data center, private cloud, or cloud account. Investor data, KYC records, and custody configurations stay within your infrastructure boundary.

Technical requirements: Kubernetes cluster (3+ nodes), PostgreSQL 14+, Ethereum node access, and HSM hardware or MPC shard infrastructure for key management.

Suitable for: regulated institutions with data residency requirements, operators in jurisdictions with data localization rules.

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Integration Examples

Example 1: Fintech Investment Platform Adding Tokenized Products

A fintech with an existing investment platform wants to add tokenized real estate products:

• Map existing verified users to AssetHaus investor records via Investor API
• Embed AssetHaus token portfolio widget into existing portfolio dashboard
• Use Distribution API to trigger distributions; map stablecoin distributions to fiat payouts via existing payment infrastructure
• Use Reporting API for tax document generation

Example 2: Fund Manager Automating Distributions

A fund manager with 150 LPs across 8 jurisdictions wants to automate quarterly distribution processing:

• Use Cap Table API to maintain the authoritative investor record
• Connect fund administrator for NAV data; AssetHaus calculates per-LP entitlements automatically
• Distribution API generates USDC distributions to investor addresses and bank wire files
• Reporting API generates K-1 and FATCA outputs for year-end

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Frequently Asked Questions

What is the AssetHaus API built on?

The AssetHaus API is a REST API with JSON request/response bodies, OAuth 2.0 authentication (client credentials flow for server-to-server), and webhook callbacks for asynchronous events (KYC completion, transaction confirmation, distribution status).

Does AssetHaus support chains other than Ethereum?

Yes. The API supports Ethereum mainnet, Polygon, Avalanche C-Chain, and select other EVM-compatible networks. Chain selection is configurable per issuance.

Can AssetHaus integrate with my existing fund administrator?

Yes, for major fund administrators via API or file-based integration. Custom integrations are available for administrators without standard APIs.

What is the sandbox environment?

The sandbox is a non-production environment running on test blockchain networks with simulated compliance responses. It allows full integration testing without real-world compliance checks or real assets. Sandbox credentials are free; production credentials require a commercial agreement and compliance review.

Is on-premise deployment available for all platform features?

Yes. On-premise deployments include all platform features available in the cloud SaaS offering. Some third-party integrations require direct API agreements with those vendors in on-premise deployments.

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AssetHaus provides tokenization APIs and white-label infrastructure for RWA product builders. For sandbox access and technical onboarding, visit asset.haus/developers.