DINO Secondary

Dino Secondary is the shared secondary market rail of the T-REX ecosystem.

It is a smart contract deployed on the T-REX Ledger that lets investors, distributors, and broker-dealers:

• Publish on-chain intents (offers) to buy or sell ERC-3643 (T-REX) tokens

• Partially or fully take existing offers

• Share liquidity across multiple platforms and dApps, instead of fragmenting it into isolated OTC channels

Every offer is created and settled directly onchain, with:

• Built-in compliance integration for ERC-3643

• Freezing of RWA tokens instead of moving them to escrow which helps maintain the integrity of the onchain cap tables at all times

• Configurable fee mechanisms for both the ecosystem and the asset issuer/operator

Dino Secondary is not a single UI. It is the neutral onchain marketplace layer that any T-REX-compatible application can plug into.

Key Features

Intent-Based Trading

• Offer creation – Any investor or participant can publish an offer expressing their intent to:

  • Sell an ERC-3643 token for another token (e.g. stablecoin), or

  • Buy an ERC-3643 token by offering another token.

• Flexibility – Offers specify:

  • The token being offered (tokenOut)

  • The token requested (tokenIn)

  • The respective amounts

  • An expiration time

Partial Fills & Offer States

• Offers can be partially filled multiple times until:

  • Fully filled

  • Cancelled by the creator

  • Pruned after expiry or if conditions are no longer met

• The contract tracks:

  • Total offered amount

  • Filled amount

  • Remaining amount

  • Status (Active, Filled, Cancelled, Expired)

Two Token Handling Modes

Dino Secondary supports two ways to handle the asset vs payment tokens:

• Freeze mode for ERC-3643 tokens When the offer is selling the ERC-3643 token:

  • The RWA tokens remain in the seller’s wallet

  • They are frozen using the ERC-3643 token’s built-in freeze mechanism

  • When the offer (or part of it) is taken, the relevant amount is unfrozen and transferred

• Escrow mode for standard ERC-20 tokens When the offer is selling a non-ERC-3643 token:

  • Tokens are transferred to the Dino Secondary contract on offer creation

  • They stay in escrow until the offer is taken, cancelled, or pruned

This design ensures:

• RWA tokens remain tightly coupled with their identity/compliance logic

• Standard ERC-20s are handled with a classic escrow pattern

Compliance-Aware by Design

Dino Secondary is built for ERC-3643 tokens:

• At least one leg of every trade must involve the configured ERC-3643 token for this Dino Secondary instance.

• Transfers of that token are subject to the token’s existing compliance rules:

  • Identity registry checks

  • Eligibility / jurisdiction rules

  • Freeze/unfreeze controls

• If a transfer would violate compliance, the trade simply cannot be executed.

Shared Liquidity on the T-REX Ledger

All offers for a given ERC-3643 token are stored in the same contract instance on the T-REX Ledger. That means:

• Any dApp, broker-dealer, or platform integrating Dino Secondary taps into the same pool of offers.

• Liquidity is aggregated at the contract level, not at the UI level.

• New interfaces can appear (white-label platforms, wallets, institutional portals, aggregators) and immediately see and use the existing offer book.

Actors & Roles

At a conceptual level, Dino Secondary involves:

• Offer Creators (Makers) Investors or institutions who post offers to buy or sell the ERC-3643 token.

• Offer Takers Counterparties who accept offers (fully or partially), triggering settlement.

• Issuers / Operators Entities responsible for the ERC-3643 token and the market around it. They benefit from shared liquidity and may configure fees and operational parameters.

• Platforms & dApps Any interface building on top of Dino Secondary: broker portals, investor dashboards, wallet integrations, etc.

• Dino Secondary Contract The on-chain engine:

  • Stores & updates offers

  • Manages freezing / escrow of tokens

  • Enforces expiry and pruning

  • Handles fees

  • Relies on ERC-3643 compliance checks at settlement time

At the admin level, the contract uses an AccessManager with roles (such as ADMIN_ROLE and FEE_MANAGER_ROLE) to control pausing and fee configuration. Those details are described on the Admin & Management page.

Trading Model & Offer Lifecycle

1. Offer Creation

A maker:

1. Chooses:

   • Which token they are offering (tokenOut)

   • Which token they want in return (tokenIn)

   • Amounts and expiry

2. Calls createOffer(...) via their preferred dApp or platform.

Under the hood:

• If tokenOut is the ERC-3643 token:

  • Dino Secondary checks that the maker’s free (unfrozen) balance is sufficient

  • Freezes the offered amount in the maker’s wallet

• If tokenOut is a standard ERC-20:

  • Transfers the offered amount into escrow (the Dino Secondary contract)

• Records the offer in storage and emits an OfferCreated event

• Charges the relevant ecosystem fee for offer creation

2. Taking an Offer

A taker:

1. Selects an offer and decides how much to take (can be partial).

2. Approves the appropriate token if needed (e.g. payment token).

3. Calls takeOffer(offerID, amount).

Dino Secondary:

• Validates the offer is still active and not expired

• If the offer is no longer valid, it is automatically pruned and cannot be taken.

• Computes the corresponding counter-amount using the offer’s price ratio.

• Executes settlements:

  • Unfreezing & transfer when selling ERC-3643

  • Escrow release when selling standard ERC-20

  • Transfers the requested token from taker to maker

• Applies volume-based fees and any configured fixed fees.

• Updates the offer’s filled amount and marks it:

  • Partially filled (still active with reduced remaining size), or

  • Filled (fully executed and closed)

• Emits events (partially filled / filled) and charges ecosystem fees.

3. Cancelling an Offer

Makers can cancel their own active offers:

• Call cancelOffer(offerID).

• Dino Secondary:

  • Unfreezes ERC-3643 tokens or releases escrow as needed

  • Marks the offer as Cancelled

  • Emits OfferCancelled and charges the ecosystem fee for cancellation

4. Pruning Expired or Invalid Offers

Any address can trigger pruning via pruneOffer(offerID):

• If the offer:

  • Has expired, or

  • Is underfunded (e.g. maker moved their frozen tokens away or no longer has enough balance)

• Then:

  • Dino Secondary releases any frozen/escrowed tokens

  • Marks the offer as Expired

  • Emits OfferPruned

Pruning prevents stale or unsafe offers from being executed and keeps the active offer set clean.

Compliance & ERC-3643 Integration

Dino Secondary is designed to align with all compliance guarantees of ERC-3643:

• The ERC-3643 token itself:

  • Validates transfers against its Identity Registry

  • Enforces eligibility rules (KYC/AML, jurisdiction, investor type, etc.)

  • Manages freeze/unfreeze states

• Dino Secondary always interacts with the token using its standard interfaces, which means:

  • If a transfer would violate compliance, the token reverts and the trade cannot be settled.

  • Freeze/unfreeze operations respect existing identity and permission structures.

As a result, secondary market activity remains fully compliant with the same rules as primary issuance and transfers.

Fees & Incentives (High-Level)

Dino Secondary supports multiple fee layers:

• T-REX Ecosystem Fees Collected via the shared Ecosystem Fee Collector, with different multipliers depending on the operation (offer creation, taking, cancellation).

• Asset / Market-Level Fees Configurable by authorized operators (via the FEE_MANAGER_ROLE), including:

  • A fixed fee per trade

  • A volume-based fee (percentage) capped to protect users

Details on how to configure, calculate, and monitor these fees are covered in the Admin & Management page.

Integration Patterns for Platforms & dApps

A typical integration with Dino Secondary follows these steps:

1. Discovery & Display

   • Query the list of open offers for a given ERC-3643 token.

   • Display:

     • Maker, price, remaining size, expiry, direction (buy/sell).

2. Offer Creation (Maker UI)

   • Provide a form where users choose:

     • Sell token / buy token

     • Amounts and expiry

   • Guide them through:

     • Approving tokens (if needed)

     • Calling createOffer(...)

3. Offer Taking (Taker UI)

   • Allow users to:

     • Select any open offer

     • Choose full or partial amount

   • Use preview helpers (from the Developer Reference) to show:

     • Exact amounts they will send/receive

     • Applicable fees

   • Call takeOffer(...) and display results.

4. Offer Management

   • Expose “My Offers” view:

     • List of user-created offers

     • Status, remaining amount, time to expiry

   • Provide actions to:

     • Cancel offers

     • Trigger pruning of expired or invalid offers

Because Dino Secondary is shared infrastructure on the T-REX Ledger, one integration lets your platform:

• Access all offers for that token

• Co-exist with other platforms and broker-dealers on the same liquidity pool

Dino Secondary in the T-REX Apps Stack

Within the broader T-REX ecosystem:

• DinoPrimary handles compliant subscription & redemption (primary market).

• DinoSecondary handles intent-based secondary trading for the same ERC-3643 tokens.

• DinoFactory deploys both contracts and configures their access control consistently.

• T-REX Engine exposes APIs to read offers and interact with Dino Secondary programmatically.

• DINO Secondary dApp (and any other integrated front-ends) provide user-facing UIs on top of this shared contract.

Related Documentation

For more details:

• Dino Secondary – Admin & Management Roles, pausing, fee configuration, and operational best practices.

• Dino Secondary – Developer Reference Solidity interfaces, function signatures, events, error codes, and concrete integration examples.