Glossary

Vocabulary used across the vault. Current terms are live in code today. Target terms appear in 11-Target-Architecture / 12-Environments and are not yet in the codebase.

Account types

User Account

Retail/individual account. Surfaces: Buy, Sell, Send, Receive, Convert, Wallet (history + portfolio). See 03-Domains.

Merchant Account

Business account. Surfaces: Send, Receive, Invoicing, Payouts, API (user-stories/06-Merchant-API-QR-Payments), Wallet, plus planned Subaccounts.

Admin Account

Internal Daxchain operator account. Surfaces: Users, Transactions, Fees, Emails, plus planned Wallets / Pages / Logs / Subaccount review. See 06-Admin Console.

Core objects

Transaction

The single normalised operational object that connects an account, a provider event, a status, and a balance effect. Concrete schema in 04-Data Model (transactions table); modelling rules in 02-Architecture.

Ledger entry

The atomic balance change. Per-(user, asset) credit or debit row. Balance is SUM(credits) - SUM(debits). See 03-Domains#Wallet & Ledger and 04-Data Model (ledger_entries).

Invoice

Merchant-facing structured payment request. Distinct from a chain transaction. See user-stories/01-Invoicing.

Payout

Merchant-driven outgoing payment. Two modes: manual payout (CSV) and API-driven. See reference/payouts.

API order

Merchant-API-driven payment request. api_orders row identified by merchant-supplied orderId. See user-stories/06-Merchant-API-QR-Payments.

Pay-to order

Per-payer sub-vault created from a public /pay/to/<slug> link. Distinct from API orders. See 03-Domains#Pay-to.

Webhook event

Outbound HTTP delivery to a merchant for api_session settlement. Exponential backoff in worker/jobs/webhook.ts.

Audit log entry

Append-only record of system or admin actions. Spine for compliance + investigation. audit_log table.

Balance contexts

User balance

Value belonging to a user account.

Merchant balance

Value belonging to a merchant account.

Omnibus / platform wallet (target)

Platform-controlled operational wallet visible only to admin. Distinct from user/merchant balances. Appears in 11-Target-Architecture; admin surface planned in 06-Admin Console#Planned.

Accounting / ledger view (target)

Internal accounting-aligned interpretation of platform financial state. Today: Postgres ledger_entries. Target: TRES.

Providers (current)

Fireblocks

Custody / transactions / signing layer. Currently mocked (MockFireblocks). See 05-External Providers.

Elliptic

Decided. AML wallet-risk + sanctions screening (OFAC / EU / UK / UN) in a single product. Currently mocked. 24h cache per (address, network, currency) via lib/aml.

Mercuryo

Decided. Card acquirer + on/off-ramp + crypto-to-crypto swap, integrated as an iframe. PCI scope sits with Mercuryo. Currently mocked.

CEX.IO

Decided. REST rate oracle for quotes, invoice rate-freeze, and conversion previews. Live via CexioOracle against https://cex.io/api/last_prices/EUR, cached in a 30 s batch window with stale-on-failure fallback. Note it quotes USDT/USDC without network differentiation — USDT_ETH and USDT_TRX share a ticker.

Sumsub

KYC vendor. Currently mocked.

Email provider

Outbound mail. EMAIL_PROVIDER=mock writes mock_emails rows; EMAIL_PROVIDER=resend sends through Resend.

Providers (target only)

TRES (target)

Internal ledger / accounting layer in the AWS target state. Today the ledger lives in Postgres directly; TRES is a planned cutover for accounting/reconciliation visibility. Documented in 11-Target-Architecture.

AWS edge stack (target)

Route 53 (DNS) + CloudFront (CDN / TLS termination) + AWS WAF (managed + rate-based rules) + AWS Shield (DDoS). Replaces any third-party CDN/WAF in the production path. The MVP now starts on AWS ALB + regional WAF, and production is fully on AWS with no third-party network in the regulated boundary.

AWS IAM Identity Center (target)

SSO + MFA for admin entry, paired with a dedicated AWS WAF web ACL (IP allowlist, geo restriction). Replaces standalone admin-login + 2FA at the production boundary.

CoSigner

Fireblocks signing-related runtime model. Requires a dedicated EC2 parent instance + Nitro Enclave, kept separate from the application and worker containers.

Nitro Enclave

AWS isolated compute capability used as part of the Fireblocks CoSigner topology.

AWS components (target)

API Gateway

Public entry component for HTTP traffic. Sits behind CloudFront + AWS WAF.

internal Application Load Balancer (ALB)

Controlled routing layer between public entry and private application runtime.

App containers

Long-running Next.js standalone containers on EC2 serving user/merchant/admin-facing logic.

Worker containers

Long-running pg-boss worker containers on EC2 handling background and integration workloads.

pg-boss

Postgres-backed job queue. Durable background work (payouts, webhooks, mail, expiry sweeps, reconciliation) runs through it — there is no separate message broker or cache tier.

Secrets Manager / KMS

Credential and key management.

CloudWatch / CloudTrail / GuardDuty / Security Hub

Observability + audit + threat detection.

Concepts

Idempotency key

String that uniquely identifies an operation so retries don't double-apply. Table per operation in 02-Architecture#Idempotency keys.

Advisory lock

Postgres pg_advisory_xact_lock. Per-(account, asset) lock for financial mutations. See 02-Architecture#Concurrency model.

Tier

Per-user fee bracket. Keys: user, silver, gold, platinum, buy_external. Per-operation overrides on company tiers. See 03-Domains#Fee Tiers and user-stories/04-Admin-Fees.

Sub-vault

Fireblocks deposit address minted per invoice or per pay-to order. Currently mocked.

Portfolio

User-facing or merchant-facing balance/value summary view. Derived from ledger; not a raw provider mirror. See 03-Domains#Portfolio.

History

Normalised user-facing or merchant-facing record of activity. Derived from transactions. Filtered through the platform's own status model, not raw provider events.

Subaccount (planned)

Merchant-created colleague access account with section-level permissions. Not in MVP. See 03-Domains#Subaccounts and 06-Admin Console#Planned.

Pages (planned)

Editable admin-managed content (info pages + policy pages with version-aware popup-on-login). Not in MVP.

Operations

Reconciliation

Process of reviewing and resolving mismatches across operational, transaction, and accounting state. Today: manual SQL + audit_log. Target: TRES-aided.

DR (Disaster Recovery)

DB backup / failover to a secondary region. Required for Test + Prod in 12-Environments; not required for Dev.

HA (High Availability)

Multi-AZ topology. Required for Test + Prod; not required for Dev.

DORA

Digital Operational Resilience Act. EU regulation governing financial-sector ICT resilience. See 14-Operations#Compliance themes.

MiCA

Markets in Crypto-Assets Regulation. EU regulation governing crypto-asset service providers. See 14-Operations#Compliance themes and 15-Compliance.

CASP

Crypto-Asset Service Provider. The mandatory MiCA authorisation (in force since 30 December 2024) for any firm offering crypto custody, exchange, transfer, or trading-platform services to EU customers. One license passports across all 27 member states. Replaces the patchwork of national VASP registrations.

Capital tiers (initial paid-in own funds):

• Class 1 — €50,000: order reception, advisory, portfolio management, transfer services.
• Class 2 — €125,000: Class 1 + custody/administration, exchange.
• Class 3 — €150,000: Class 2 + operating a trading platform.

Daxchain's working assumption is Class 2 based on shipped surfaces. See 15-Compliance#MiCA — CASP licensing and 09-Open Questions#CASP path.

NCA

National Competent Authority — the regulator in the EU member state that grants and supervises a CASP license. Choosing the NCA is a strategic decision (speed vs reputation vs cost vs how friendly to crypto-native ops). Examples: Estonia FSA, Lithuania Bank of Lithuania, Cyprus CySEC, Malta MFSA, France AMF, Germany BaFin. See 15-Compliance#Choosing the NCA.

VASP

Virtual Asset Service Provider. FATF terminology — broader than CASP and used in the Travel Rule. Daxchain is a VASP regardless of MiCA status. See 15-Compliance#FATF Travel Rule.

FATF Travel Rule

FATF Recommendation 16 extended to virtual assets (2019). Requires originator + beneficiary identity to ride with every crypto transfer above the local threshold (zero in the EU). Not implemented yet. See 15-Compliance#FATF Travel Rule.

TFR (Transfer of Funds Regulation)

EU's local implementation of the FATF Travel Rule — Regulation (EU) 2023/1113, in force since 30 December 2024. Notable: no de minimis — applies at any amount.

DAC8

EU Directive (EU) 2023/2226 — 8th amendment to the Directive on Administrative Cooperation. Requires CASPs to collect TIN + tax residence and report customer crypto activity annually to home tax authorities. Applies from 1 January 2026; first cycle 2027. Not implemented yet. See 15-Compliance#DAC8 / CARF.

CARF

Crypto-Asset Reporting Framework — the OECD spec that DAC8 aligns with. Defines the XML schema and exchange protocol used between tax authorities.

IVMS 101

InterVASP Messaging Standard. The data schema used to transport originator + beneficiary identity for Travel Rule compliance. Most vendors (Notabene, Veriscope, Sumsub Travel Rule, etc.) speak IVMS 101 over their transport.

TIN

Tax Identification Number. Country-specific (e.g. US SSN, EU NIF, UK NINO). Required per-customer under DAC8.

Sanctions screening

Real-time check against OFAC / EU consolidated / UK HMT / UN lists when sending or receiving funds. Required by Travel Rule + standalone AML obligations. Delivered through Elliptic in the target architecture (combined AML-risk + sanctions product). MVP only mocks AML risk; live cutover lights up sanctions automatically.

Acronyms

Acronym	Meaning
AML	Anti-Money-Laundering
API	Application Programming Interface
AZ	Availability Zone
BSA	Bank Secrecy Act (US)
CARF	Crypto-Asset Reporting Framework (OECD)
CASP	Crypto-Asset Service Provider
CDN	Content Delivery Network
DAC8	EU directive on tax reporting for crypto
DDoS	Distributed Denial of Service
DORA	Digital Operational Resilience Act
DR	Disaster Recovery
FATF	Financial Action Task Force
FCA	Financial Conduct Authority (UK)
FinCEN	Financial Crimes Enforcement Network (US)
HA	High Availability
HMAC	Hash-based Message Authentication Code
HSM	Hardware Security Module
IVMS 101	InterVASP Messaging Standard
KYB	Know Your Business
KYC	Know Your Customer
MAS	Monetary Authority of Singapore
MiCA	Markets in Crypto-Assets Regulation
NCA	National Competent Authority
NFT	Non-Fungible Token
OFAC	Office of Foreign Assets Control (US sanctions)
PII	Personally Identifiable Information
SG	Security Group
SLA	Service Level Agreement
TFR	Transfer of Funds Regulation (EU)
TIN	Tax Identification Number
TRP	Travel Rule Protocol
TTL	Time To Live
VASP	Virtual Asset Service Provider
WAF	Web Application Firewall