[Discussion] TIP-<new>: TRON Settlement Batching Layer

[CTDGDevHub]

TIP: TRON Settlement Batching Layer

💡 This article describes a real, working batching mechanism for TRON.
The full technical implementation — including smart contracts, off-chain aggregator, and documentation — is publicly available and can be reviewed here.

Abstract

TRON Settlement Batching Layer is a proposed Layer-1 enhancement designed to significantly increase the efficiency of stablecoin operations on the TRON network. TSBL introduces native batching, intent aggregation, and compressed settlement for high-volume USDT/USDC transactions, allowing thousands of transfers to be bundled off-chain and committed to TRON in a single, verifiable batched transaction. This reduces network load, minimizes fee overhead, and unlocks a new class of enterprise-scale payment flows—without requiring any changes to TRON’s consensus or core protocol. By operating as an execution and settlement module built entirely on the TVM and TRON’s existing resource model, TSBL improves throughput, enhances capital efficiency for stablecoin-heavy applications, and strengthens TRON’s position as the leading global chain for stablecoin settlement. This TIP outlines the motivation, architecture, and benefits of TSBL as a batching-first infrastructure layer.

Motivation

TRON is the world’s most active stablecoin settlement chain, processing more USDT transfers than any other blockchain. High-volume participants such as exchanges, custodians, payment processors, and financial institutions generate millions of repetitive and structurally similar stablecoin transfers daily. Although TRON offers low fees and high throughput, its current transaction model processes every TRC-20 transfer independently, which results in duplicated execution cycles, unnecessary Energy consumption, and reduced overall efficiency. TRON lacks a standardized, protocol-level mechanism for aggregating multiple transfers into a single on-chain settlement event.

At the same time, enterprise and institutional users increasingly require predictable and scalable fee structures. As the volume of stablecoin payments grows, issuing thousands of individual transactions becomes operationally expensive and non-deterministic. While ecosystems such as Ethereum have adopted various batching and bundling mechanisms, TRON still relies on single-transfer execution, preventing the network from achieving economies of scale in its core stablecoin flows.

TSBL addresses these limitations by enabling stablecoin transfer intents to be collected and validated off-chain, aggregated into Merkle structures, and committed to TRON in consolidated batches. This reduces cost per transfer, improves throughput, and creates deterministic, enterprise-ready settlement conditions. By removing redundant contract calls and leveraging off-chain computation with on-chain verification, TSBL aligns with TRON’s long-term vision of scalable, user-friendly infrastructure for global payments.

Background

TRON’s efficient execution environment, low cost structure, and global adoption have made it the dominant network for stablecoin usage. The majority of global USDT supply circulates on TRON, powering remittances, merchant payments, cross-exchange flows, and institutional settlement pipelines. However, despite its strong performance, TRON executes each TRC-20 transfer as a standalone operation. Even when financial institutions issue thousands of small, repetitive transfers, each transaction requires a full TVM invocation, state update, and log emission. This significantly increases Energy usage and imposes natural scaling limits.

Currently, TRON does not provide a native, standardized mechanism for batching multiple operations into a single settlement event. Enterprises often attempt to emulate batching with custom off-chain systems, but because the network lacks a canonical batching interface, each transfer must still be broadcast and processed individually. These limitations restrict throughput and prevent efficient scaling of TRON’s highest-demand use case: stablecoin settlement.

TSBL proposes a unified protocol for collecting user or enterprise transfer intents, aggregating them off-chain into Merkle trees, and submitting a single on-chain batch commitment to a settlement contract. The contract verifies proofs, executes bundled operations deterministically, and ensures correctness through simple, TVM-compatible logic. This approach preserves TRC-20 compatibility, requires no consensus changes, and introduces a powerful new execution primitive that allows TRON to handle stablecoin volumes far beyond what individual transactions can achieve. Through TSBL, TRON can deliver a more scalable, cost-efficient, and enterprise-ready settlement architecture for the stablecoin-driven global economy.

Key Components of the Architecture

This design uses Tron's main network as a settlement layer while transactions are executed off-chain. In essence, user transactions are grouped and processed outside the Tron blockchain, and only the results (state updates) are settled on-chain via a Tron smart contract. This off-chain execution + on-chain settlement model greatly improves throughput and lowers fees, without sacrificing the security of the Tron mainnet. All critical final states are anchored on Tron, ensuring the integrity and finality of transactions.

• Tron Mainnet (Settlement Layer): The Tron blockchain serves as the source of truth and final settlement platform. It maintains custody of funds and the official ledger state at all times. A settlement smart contract on Tron is deployed to manage deposits, record state commitments from off-chain transactions, and enforce rules (e.g. validating proofs or handling disputes). This contract locks users’ assets (TRX or TRC-20 tokens) when they move into the off-chain system, and later releases or updates balances based on valid off-chain transaction outcomes. By only requiring Tron to record batched results rather than every individual transaction, network congestion is minimized while still leveraging Tron's fast 3-second blocks, DPoS security, and finality for confidence in settlement.
• Off-Chain Transaction Execution Layer: This is the environment where the high-volume transactions actually occur, sometimes called a "rollup network" or state channel system (depending on implementation). It is not a separate blockchain with its own consensus; rather, it is an off-chain processing framework that relies on the Tron settlement contract for security. There are two main modes to implement this layer:
  • State Channels (User-Channels Network): Here, payment channels are opened between users or via hub nodes. Two or more parties lock funds in the Tron contract and then transact directly with each other off-chain. Each off-chain transaction is essentially an exchange of signed IOUs updating the balance distribution between parties. No global ledger is needed for every transaction – participants privately update balances. The Tron network is only involved twice: when opening a channel (locking the funds) and when closing/settling it. Multiple such channels can interconnect (a network of channels) to route payments among users via intermediary hops. This approach suits frequent micropayments between known parties, offering near-instant transfers with essentially zero on-chain fees until settlement.
  • Rollup-Style Off-Chain Ledger: In this mode, a coordinator/sequencer (or a set of them) maintains a virtual ledger of all user accounts off-chain. Users deposit funds into the Tron contract, which credits their off-chain account in the coordinator’s ledger. The coordinator then processes every transaction off-chain – updating balances, executing smart contract logic, etc. – and periodically submits a batch summary to the Tron contract. This summary typically includes a new state root (a hash representing all account balances after those transactions) and possibly a compressed log of the transactions. The Tron settlement contract accepts these state updates only if they are proven valid (see Security below). Essentially, this off-chain ledger behaves like a high-speed “Layer 2” for Tron where transactions can be executed in milliseconds, and Tron only sees batched results. Importantly, this off-chain platform does not produce its own blocks with independent consensus (that would be a sidechain); instead, it relies on the Tron contract to arbitrate truth, so the term sidechain or child chain is avoided. All participants trust Tron’s finality, not the off-chain operator, for the ultimate outcome.

Transaction Flow Lifecycle

1. Opening / Deposit: A user who wants to use the off-chain system sends a transaction on Tron to the settlement smart contract (e.g. depositing 100 TRX or an equivalent token). The contract locks these funds and reflects the deposit in the off-chain system (e.g. informing the coordinator or setting up a channel). At this point, the user’s off-chain balance is 100 in the system, but the actual tokens are held securely by the Tron contract.
2. Off-Chain Execution of Transactions: Once funded, the user can transact freely off-chain. Depending on the architecture:

• In a channel: the user and their counterparty exchange signed transactions that adjust their balances. Each off-chain transaction is cryptographically signed by the participants and includes a sequence number or nonce. This ensures an ordering and prevents older states from being replayed later. For example, User A pays 5 TRX to User B by updating their off-chain balances and both sign the new balance state (A: 95, B: +5).
• In a rollup network: the user submits a transaction to the off-chain operator (e.g. a transfer, contract call, etc.). The operator (sequencer) will execute this transaction in the off-chain environment (which could run a Tron-compatible virtual machine for smart contracts if needed). The operator updates the global off-chain state (balances, contract storage, etc.) accordingly. Transactions may be held briefly in a mempool-like queue and then ordered into an off-chain block or batch. The key is that these operations do not immediately occur on the Tron chain – they are processed locally, so they incur no Tron gas fee and can be confirmed near-instantly for the user. Off-chain transactions are typically confirmed by the operator providing a receipt or signature, and finality is probabilistic until the batch is settled on Tron.

3. Batch Commitment to Tron: Periodically (for example, every N minutes or when off-chain volume reaches a threshold), the off-chain operator creates a commitment of the latest state and submits it in a transaction to the Tron settlement contract. In a rollup model, this commitment might include:

• The state root after applying all recent off-chain transactions.
• Possibly the actual off-chain transaction data or a zero-knowledge proof of their validity.
• If many transactions occurred, hundreds or thousands can be aggregated into one on-chain call. For a channel, this step is simply when parties agree to close and settle, they submit the final balances.
• The Tron contract records the new state root and awaits validation. This on-chain record is effectively the settlement point – at this moment, the batched transactions become anchored on Tron. Because a single on-chain transaction now represents a large batch of off-chain work, the effective throughput is massively increased (many operations per Tron block).

4. Validation & Dispute Resolution: The settlement contract must ensure that only correct state updates are finalized on Tron:

• Optimistic Verification: By default, the contract assumes submissions are valid. It doesn’t verify every off-chain transaction internally (which would defeat the purpose), but instead enforces a challenge period (e.g. several Tron blocks or a time window) during which anyone (other watchers or users) can dispute an incorrect batch. All the off-chain transaction data is published or made available so that observers can independently check the state update. If a malicious operator posted an invalid state (e.g. one that steals funds or doesn't match the off-chain transactions), a fraud proof can be submitted to the contract within the challenge window. A fraud proof typically contains evidence (such as the specific off-chain transaction that was executed improperly or a mismatched state transition) that proves the batch was incorrect. Upon a valid challenge, the Tron contract rejects or rolls back that batch and may penalize the offending operator (e.g. slashing a bond). This mechanism relies on the assumption that at least one honest validator out of all participants will catch and report any fraud. If no one challenges within the window, the batch is accepted as final. This optimistic rollup style approach is secure as long as fraud can be detected in time.
• Zero-Knowledge (ZK) Verification: Alternatively, the operator generates a zero-knowledge proof attesting to the correctness of the off-chain transactions in the batch. This cryptographic proof (e.g. a zkSNARK) is submitted along with the state update. The Tron settlement contract uses a verifier function to instantly check the proof’s validity. If the proof passes, the state update is accepted immediately; if not, it’s rejected. This approach (analogous to zk-rollups) provides immediate finality without a waiting period, since invalid batches cannot be posted at all (they would fail the proof verification). The trade-off is the complexity and computational cost of generating proofs. (Note: Tron’s protocol would need to support whichever proof system is used – Tron’s VM does support zkSNARK verification as seen in the TRONZ protocol for privacy, so extending it to general proofs is conceivable.)
• Channels: In the simpler channel scenario, dispute resolution happens if one party tries to unilaterally close a channel with an out-of-date state. The counterparty can present a later signed state (with higher sequence number) to the Tron contract, invalidating the older claim. The contract then settles funds according to the latest valid state. This mechanism ensures no party can cheat by omitting later transactions once both have signed them.

5. Final Settlement on Tron: Once validation is passed (either no fraud challenge arose in time, or a zk-proof was accepted), the off-chain transactions are considered finalized. The Tron mainnet now holds the updated state (often implicitly as the latest state root in the contract). At this stage, users’ balances or outcomes from the off-chain activity are secured on-chain. For a payment channel, the final balances are now fixed and each party can withdraw their due share. For a rollup, the state root corresponds to specific balances for each user or other contract states that can be later redeemed.
6. Withdrawal / Exit: A user can withdraw funds back to the Tron base layer at any time after their off-chain balance is settled on-chain. To do so, the user submits a withdrawal request to the settlement contract:

• In a rollup scenario, the user provides proof of their current off-chain balance (this could simply be reading from the state that the contract now holds if the contract knows each user’s balance, or presenting a cryptographic proof/merkle branch from the state root that was posted). The contract then releases the corresponding amount of TRX/tokens to the user’s Tron address from the locked pool.
• In a channel, both parties might jointly sign a channel closure transaction specifying final balances, which the contract uses to unlock funds to each party. If one party is unresponsive, the other can invoke a unilateral close (starting a challenge timer) using their last signed state; the counterparty can only contest if they have a newer state.
• After withdrawal, the user’s off-chain balance is deducted accordingly in the off-chain system (or that channel is closed). The settlement layer thus acts like a bridge between Tron and the off-chain environment: users can move assets in and out seamlessly, with Tron guaranteeing that no more can be withdrawn than was originally deposited plus legitimate gains.

Implementation Plan

Component	Layer	Description
Aggregator Node	Off-chain	Aggregates, verifies and batches user-signed transfer intents
Intent Payload Format	Off-chain	Canonical, signed JSON structure representing transfers
Settlement Contract	On-chain	Stores and executes batched transactions (Merkle-proven)
Whitelist Registry	On-chain	Stores Merkle root of whitelisted “batch-eligible” actors
Fee Module	On-chain	Calculates dynamic fees based on transaction structure and sender status
Verifier	Off-chain	Stateless client that verifies Merkle proofs before submitting on-chain

Implementation

Step 1: Define Transfer Intent Format

• Format: Canonical JSON message

{
"from": "0xSender",
"to": "0xReceiver",
"amount": "100.00",
"token": "USDT",
"nonce": "12345",
"timestamp": "1690000000"
}

• Signed using ECDSA (Tron-compatible key)
• Hash used as Merkle leaf

Step 2: Build Off-chain Aggregator Node

• Language: Rust or Go for performance
• Functionality:
  • Collects signed transfer intents
  • Builds Merkle Tree for batch
  • Calculates compressed calldata
  • Signs batch header (admin or validator keys)

Step 3: Deploy TSBL Settlement Contract

• Network: TRON-L1 (Shasta first, then Mainnet)
• Functions:
  • submitBatch(rootHash, batchMetadata)
  • executeTransfer(proof, transferData)
• Security:
  • Only pre-approved aggregator keys can submit
  • Delayed finality (e.g. 1-minute time lock)
  • Max tx count per batch for gas control

Step 4: Deploy TSBL Fee Module

• Smart contract embedded into settlement logic
• Logic:
  • Base fee = 0.1 TRX
  • Batch fee = 0.05 TRX per recipient
  • Instant tx = 0.2 TRX
  • Free tier = first 10 tx/day for unbatched small users

Step 5: Integrate TSBL Whitelist Registry

• Updatable Merkle Root stored on-chain
• Proof verified at time of batch submission or fee calculation
• Updated by:
  • DAO multisig
  • Aggregator authority
  • Oracles (optional)

Step 6: Write TSBL Verifier Library (Open Source)

• Verifies:
  • Signature of intent
  • Merkle inclusion
  • Nonce duplication
  • Token transfer validity
• Languages: JS (front-end), Go (back-end), Rust (node)

Benefits and Impact

The TRON Settlement Batching Layer (TSBL) delivers substantial advantages across the entire TRON ecosystem by introducing a more efficient, scalable, and enterprise-grade settlement model for stablecoin transactions. For high-volume actors such as exchanges, custodians, payment processors, and financial service providers, TSBL dramatically reduces operational costs by allowing thousands of USDT or USDC transfers to be executed off-chain and settled on-chain in a single batch. This model provides predictable, compressed fees and removes the need to broadcast every individual transfer to the TRON network, enabling organizations to process stablecoin flows at scale without causing congestion or experiencing resource volatility.

Everyday stablecoin users also benefit from TSBL’s design. Wallets, remittance providers, and payment applications can offer faster, smoother, and more cost-effective transfers by aggregating user-initiated operations through intent-based interactions. Instead of paying the full Energy cost for each TRC-20 transfer, users rely on aggregated settlement, making micro-payments, international transfers, and high-frequency usage more affordable than ever. The user experience becomes simpler, while the underlying system remains anchored to the security of the TRON mainnet.

From a network perspective, TSBL strengthens TRON’s role as the global settlement hub for stablecoins. By offloading repetitive execution cycles from the mainnet, TSBL reduces overall resource consumption, minimizes peak load during periods of high activity, and allows Super Representatives to maintain stable block production without processing millions of granular TRC-20 operations. This improves the long-term sustainability of the TRON resource model and ensures that validator performance is preserved even as stablecoin flows continue to grow. The architecture also enhances resilience by decentralizing execution between off-chain aggregators and on-chain verification, reducing TRON’s exposure to sudden transaction spikes.

Strategically, TSBL positions TRON at the forefront of L1 innovation by formalizing a standardized, verifiable batching layer for enterprise-class stablecoin settlement. While other blockchains rely on Layer-2 rollups or fragmented batching solutions, TRON can integrate a unifying framework directly into its smart contract ecosystem. This strengthens TRON’s competitive advantage, makes it more attractive to global fintech companies, and solidifies its reputation as the most efficient network for stablecoin settlement. TSBL introduces a scalable foundation upon which more advanced payment, remittance, and financial applications can be built, elevating TRON’s capabilities far beyond simple token transfers.

Conclusion

The TRON Settlement Batching Layer represents a major architectural advancement for the network, introducing a standardized, secure, and highly scalable method for processing stablecoin transactions. By combining off-chain execution with on-chain settlement, TSBL preserves TRON’s core strengths—fast finality, low fees, and DPoS security—while unlocking a new level of efficiency for the transfer of USDT, USDC, and other high-volume assets. It allows users and enterprises to benefit from aggregated transaction flows, micro-fee execution, and predictable settlement costs, all while maintaining the integrity and transparency of the TRON mainnet.

This proposal outlines TSBL’s high-level design and demonstrates how intent batching, Merkle commitments, and verifiable settlement can transform TRON into an even more robust settlement infrastructure. TSBL is not a separate chain or consensus upgrade; it is a carefully constructed execution layer that works entirely within TRON’s existing architecture while providing the performance advantages typically associated with Layer-2 systems. Its successful adoption would enhance TRON’s scalability, reduce network load, and enable the ecosystem to support the next generation of global payment and financial applications.

Like all major protocol enhancements, TSBL will require further specification, implementation details, security validation, and community feedback. Super Representatives, infrastructure providers, wallet developers, and enterprise partners will play an important role in shaping the operational parameters, fee dynamics, and integration patterns of the system. If developed collaboratively, TSBL can become one of the most meaningful improvements to TRON’s infrastructure—delivering a settlement engine that reflects the needs of a network processing billions of stablecoin transactions annually. The TRON community is encouraged to participate in refining this proposal and advancing TSBL as a core pillar of TRON’s ongoing evolution.

[bladehan1]

Advantages and Value:

• Clear Architecture and High Feasibility: The solution design fully utilizes TRON's existing infrastructure (TVM, smart contracts) without altering the underlying consensus mechanism. It draws on the mature Rollup concept, resulting in relatively low technical risk.

• Enhanced Enterprise-Level User Experience: It provides large institutions such as exchanges and payment gateways with a predictable, batch, and low-cost settlement solution, a key infrastructure for attracting and retaining large clients.

Potential Challenges and Risks:

• Centralization Risk: The "aggregator node" or "sequencing unit" in the solution plays a crucial role. Initially, it is likely to be operated by the core team or a few trusted institutions, posing single points of failure and censorship risks. Gradually decentralizing these roles is a long-term challenge.

• Trust Model and User Experience: If an "optimistic verification" model is adopted, users' rapid withdrawals may require trusting the aggregater node or face delays during the challenge period. A well-designed mechanism is needed to balance security and user experience.

[warku123]

Hi @CTDGDevHub,
I really support this proposal. TRON needs this technology to accelerate USDT transfers and improve scalability for high-volume stablecoin operations.

Architecture Consideration

As you described, TSBL functions similarly to a Layer-2 solution for TRON. However, I believe the implementation should prioritize zk-rollup over optimistic rollup. The 7-day challenge period required by optimistic rollups would significantly impact user experience, especially for time-sensitive use cases like remittances, merchant payments, and exchange settlements—core scenarios for TRON's stablecoin ecosystem.

Why zk-rollup is better suited:

• Instant finality: Users can withdraw assets immediately after batch settlement, without waiting for challenge periods
• Better UX: Aligns with TRON's low-latency, high-throughput characteristics
• Security: Cryptographic proofs provide trustless verification without relying on economic security assumptions
  Given TRON's position as the leading stablecoin settlement chain, minimizing withdrawal delays is crucial for maintaining competitive advantage and user satisfaction.

Looking forward to seeing the technical specifications and implementation details.

[fyyhtx]

• For example, User A pays 5 TRX to User B by updating their off-chain balances and both sign the new balance state (A: 95, B: +5).

Do you mean the recipient of the transfer also needs to sign the off-chain transfer transaction? Does this limit the application scenarios of TSBL? Because currently, most transfers do not require recipient confirmation.

[CTDGDevHub]

Advantages and Value:

• Clear Architecture and High Feasibility: The solution design fully utilizes TRON's existing infrastructure (TVM, smart contracts) without altering the underlying consensus mechanism. It draws on the mature Rollup concept, resulting in relatively low technical risk.
• Enhanced Enterprise-Level User Experience: It provides large institutions such as exchanges and payment gateways with a predictable, batch, and low-cost settlement solution, a key infrastructure for attracting and retaining large clients.

Potential Challenges and Risks:

• Centralization Risk: The "aggregator node" or "sequencing unit" in the solution plays a crucial role. Initially, it is likely to be operated by the core team or a few trusted institutions, posing single points of failure and censorship risks. Gradually decentralizing these roles is a long-term challenge.
• Trust Model and User Experience: If an "optimistic verification" model is adopted, users' rapid withdrawals may require trusting the aggregater node or face delays during the challenge period. A well-designed mechanism is needed to balance security and user experience.

Thank you for the thoughtful assessment — the points you raise are largely valid, but it is important to clarify the exact architectural and trust assumptions of the current solution, as they differ in several key ways from classical rollup or optimistic L2 models.
First, regarding architecture and feasibility: the design deliberately operates entirely within TRON’s existing execution environment. All logic is implemented using standard TVM smart contracts, without any changes to consensus, block production, or SR economics. The system relies on Merkle-root commitments as a compact on-chain anchor for a set of transfers, followed by deferred, per-transfer execution on L1. This approach intentionally avoids maintaining an off-chain global state or balance ledger. As a result, the on-chain contract does not need to validate complex state transitions, only Merkle inclusion proofs and replay protection. This significantly lowers implementation and security risk compared to full rollup designs while remaining compatible with TRON’s current infrastructure.
From a user-experience and enterprise integration perspective, the primary value is operational predictability rather than cryptographic compression. Large senders such as exchanges, payment processors, or payroll systems already operate in batched settlement cycles off-chain. This solution provides a protocol-level mechanism to formalize that pattern: transfers are aggregated off-chain, committed transparently on-chain, and executed in a controlled window. Execution costs are sponsored by an executor account, while end users retain control through scoped token allowances. Importantly, funds are never escrowed or deposited into the protocol itself; transfers are executed via standard transferFrom, which aligns well with existing enterprise risk controls and accounting models.
An additional but often overlooked advantage is flexibility by design. The protocol does not prescribe a single “correct” batching strategy or operational model. Parameters such as batch size, batching cadence, unlock time duration, execution sequencing, and even aggregator topology are not hardcoded assumptions of the protocol, but configurable choices within its boundaries. This means that different actors can adapt the same settlement mechanism to very different use cases: high-frequency exchanges may favor short unlock windows and frequent small batches, while payroll or treasury operations may prefer longer review windows and larger batch sizes. The protocol defines the safety and verification rules, while leaving operational policy to integrators.
This flexibility also applies to trust and decentralization preferences. Some users may choose to rely on a single internal aggregator for operational simplicity, while others may deploy multiple independent aggregators, outsource execution, or allow third parties to execute transfers permissionlessly after the unlock window. The protocol does not force a one-size-fits-all trust model; instead, it provides a constrained framework in which each participant can tune trade-offs between latency, operational complexity, and decentralization according to their own requirements.
Regarding centralization risks, it is correct that the batch builder or aggregator plays an important operational role. It determines batch composition and submission timing, which introduces potential risks such as censorship, delayed inclusion, or operational failure. However, this centralization is limited to batch formation, not asset custody or execution authority. The aggregator cannot move funds arbitrarily: every transfer is bounded by explicit user allowances, verified Merkle proofs, and on-chain execution rules. Moreover, once a batch commitment is published and the unlock window has passed, execution itself does not rely on a single privileged actor — any party with the correct proofs can submit execution transactions. This significantly reduces the impact of censorship or single points of failure compared to custodial or state-based off-chain systems.
Finally, on the trust model and comparisons to optimistic verification, it is important not to conflate this design with optimistic rollups. The unlock time here is not a dispute window for off-chain state correctness, because there is no off-chain state being finalized. Instead, it serves as a coordination and review window between commitment and execution. There are no withdrawals that depend on trusting an operator to publish a correct state root, and no funds are locked in a way that requires fraud proofs to recover them. Assets remain on L1 at all times, and the trust assumption is operational rather than custodial.
In summary, the solution prioritizes low protocol risk, compatibility with existing TRON mechanics, and enterprise-grade batching, while remaining deliberately flexible. It defines strict verification and safety boundaries, but leaves batching policy, execution strategy, and trust assumptions configurable by participants. This makes it adaptable to a wide range of real-world settlement workflows without forcing protocol-level changes or a single operational model.

[CTDGDevHub]

Hi @CTDGDevHub, I really support this proposal. TRON needs this technology to accelerate USDT transfers and improve scalability for high-volume stablecoin operations.

Architecture Consideration

As you described, TSBL functions similarly to a Layer-2 solution for TRON. However, I believe the implementation should prioritize zk-rollup over optimistic rollup. The 7-day challenge period required by optimistic rollups would significantly impact user experience, especially for time-sensitive use cases like remittances, merchant payments, and exchange settlements—core scenarios for TRON's stablecoin ecosystem.

Why zk-rollup is better suited:

• Instant finality: Users can withdraw assets immediately after batch settlement, without waiting for challenge periods
• Better UX: Aligns with TRON's low-latency, high-throughput characteristics
• Security: Cryptographic proofs provide trustless verification without relying on economic security assumptions
  Given TRON's position as the leading stablecoin settlement chain, minimizing withdrawal delays is crucial for maintaining competitive advantage and user satisfaction.

Looking forward to seeing the technical specifications and implementation details.

Thank you for the support and for raising the question around zk-rollups versus optimistic rollups — this is an important discussion, and you are right that rollup concepts are mentioned in the proposal. However, it is equally important to clarify how and at what level those concepts are being used.
While the architecture may appear “L2-like” due to off-chain aggregation and on-chain settlement, the current solution is not a Layer-2 rollup in the classical sense. It does not introduce an off-chain global state ledger, does not custody user funds, and does not rely on the correctness of off-chain state transitions for withdrawals. Assets are never deposited into the protocol and never leave L1 custody. Each transfer is executed individually on TRON L1 via standard transferFrom, bounded by explicit user allowances and verified through Merkle inclusion proofs. As a result, there is no notion of “withdrawing from L2,” and therefore no withdrawal latency problem analogous to optimistic rollups.
This distinction is central to understanding why neither optimistic nor zk-rollup trade-offs apply directly here. Because there is no off-chain balance state being finalized, there is no need for a fraud-proof challenge period or zk validity proofs to guarantee correctness of balance transitions. The Merkle root committed on-chain does not represent a new ledger state; it represents a verifiable commitment to a set of intended transfers. The unlock window in the design is a coordination and review delay between commitment and execution, not a dispute window for detecting invalid state transitions. Execution itself happens on-chain, under TRON’s native security model.
That said, rollup and zk-rollup concepts are referenced in the proposal intentionally as part of a flexible architectural envelope, not as a strict description of the current execution model. zk-rollups are an excellent solution in scenarios where a protocol must finalize complex off-chain state transitions and allow trustless withdrawals from that state. If the system were to evolve toward a model with deposits, exits, and a persistent off-chain balance ledger, zk-based validity proofs would become a natural and appropriate choice, providing immediate finality and strong cryptographic guarantees.
In the current design, however, adopting zk-rollup machinery would add significant complexity without solving a real problem. Correctness is enforced directly at execution time on L1: Merkle inclusion is checked, allowances are checked, and the token transfer is performed by the TRON VM itself. There is no hidden or deferred state whose correctness must later be proven cryptographically. Introducing zk circuits, proof generation, and verification would therefore increase implementation cost, latency, and operational overhead while providing little additional security or UX benefit for the target use cases.
From a user-experience perspective, the existing approach already aligns well with TRON’s low-latency and high-throughput characteristics for stablecoin settlement. There are no multi-day delays for asset availability, because users are not exiting from an off-chain system. The only delay introduced is the configurable unlock window before execution, which is an operational safeguard rather than a cryptographic requirement. This window can be tuned per deployment or use case — for example, exchanges may prefer very short windows for rapid settlement, while treasury or payroll flows may opt for longer review periods. This level of operational flexibility would be constrained in a zk-rollup model, where proof generation time and circuit design impose hard structural limits.
On security, it is also important to note that the system does not rely on economic assumptions or honest-majority monitoring in the way optimistic rollups do. There is no scenario in which a malicious operator can finalize an invalid state and force users to react within a challenge period to protect their funds. The worst-case failure mode is operational — delayed inclusion or execution — not loss of assets. This makes the security model closer to a constrained, verifiable settlement pipeline than to a full off-chain execution environment.
In short, zk-rollups remain a valid and powerful option within the broader design space, and the architecture does not preclude their future use. However, the current solution intentionally demonstrates a different approach: one that keeps execution on L1, uses Merkle commitments purely as a batching and verification mechanism, and achieves scalability, low risk, and flexibility without introducing heavy cryptographic infrastructure. This allows TRON to capture many of the practical benefits associated with rollup-style batching while preserving simplicity, fast finality, and full compatibility with the existing network.

[CTDGDevHub]

• For example, User A pays 5 TRX to User B by updating their off-chain balances and both sign the new balance state (A: 95, B: +5).

Do you mean the recipient of the transfer also needs to sign the off-chain transfer transaction? Does this limit the application scenarios of TSBL? Because currently, most transfers do not require recipient confirmation.

Good question - and to clarify, no, the recipient does not need to sign off-chain transfer transactions in the current TSBL design.
In the current TSBL approach, transfers are sender-authorized only, exactly like standard TRC-20 transfers on TRON. A transfer intent is created and authorized by the sender, aggregated off-chain, and later executed on L1 via transferFrom. The recipient is completely passive and does not need to be online, aware of the transfer, or provide any signature or confirmation. This preserves full compatibility with existing payment, exchange, and settlement workflows where recipient acknowledgment is neither expected nor required.
The mention of both parties signing an off-chain balance update applies only to state-channel–style systems, where two participants jointly maintain and update a shared off-chain balance state. That model was included in the proposal purely as background context to illustrate the broader design space of off-chain execution systems, not as a constraint imposed by TSBL. TSBL does not rely on bilateral balance updates, shared channels, or recipient approval semantics.
Because TSBL does not maintain an off-chain balance ledger and does not require recipient signatures, it does not limit application scenarios. On the contrary, it is specifically designed to support one-to-many payouts, exchange withdrawals, merchant settlements, payroll, and other high-volume flows where recipients are arbitrary, offline, or unknown at batching time. Requiring recipient participation would make such use cases impractical, which is why the protocol explicitly avoids that requirement.
To summarize: recipient signatures are not required, recipient confirmation is not part of the protocol, and TSBL intentionally mirrors the authorization model of standard TRC-20 transfers. Any examples suggesting mutual signing refer to alternative off-chain models discussed for comparison, not to the operational mechanics of TSBL itself.

[jakamobiii]

@CTDGDevHub This is a good idea, but Tron's TPS is relatively high, and the current chain's TPS hasn't reached saturation. Furthermore, maintaining off-chain operations is quite costly. Therefore, I don't think this is a top priority right now. What do you think?

[lxcmyf]

@CTDGDevHub
In the proposed TSBL design, can the Merkle root submitted by the batching layer be independently verified by third parties?
If yes, what is the expected verification flow for external validators?
If not, how does the system prevent the batching node from submitting incorrect or incomplete batches?
Will there be any fraud-proof or challenge mechanism?

[CTDGDevHub]

@CTDGDevHub This is a good idea, but Tron's TPS is relatively high, and the current chain's TPS hasn't reached saturation. Furthermore, maintaining off-chain operations is quite costly. Therefore, I don't think this is a top priority right now. What do you think?

You’re right that TRON’s raw TPS is currently sufficient and the network is not saturated, but TSBL is not primarily about solving an immediate TPS limit. It addresses execution and operational efficiency for high-volume stablecoin flows, where millions of structurally identical TRC-20 transfers are processed individually even when the chain has capacity.
The off-chain component is intentionally lightweight - it handles aggregation and Merkle proof generation, without off-chain consensus, balance ledgers, or complex cryptography. For large senders, this typically replaces existing internal batching and payout infrastructure rather than adding new overhead. TSBL can be adopted selectively by actors who benefit from it most, without requiring consensus changes or impacting normal users.

[CTDGDevHub]

@CTDGDevHub In the proposed TSBL design, can the Merkle root submitted by the batching layer be independently verified by third parties? If yes, what is the expected verification flow for external validators? If not, how does the system prevent the batching node from submitting incorrect or incomplete batches? Will there be any fraud-proof or challenge mechanism?

Yes - the Merkle root submitted by the batching layer can be independently verified by third parties. The root is a public on-chain commitment, and anyone can reconstruct the Merkle tree off-chain, recompute leaf hashes and proofs, and verify inclusion against the published root without trusting the batching node.
The batching node cannot force incorrect transfers to execute. Each transfer is executed individually on-chain and must pass all checks at execution time: valid Merkle proof, correct parameters, sufficient allowance, and successful TRC-20 execution. If a batch is incorrect or incomplete, the result is simply that some transfers cannot be executed, not that invalid transfers are applied.
Because the Merkle root does not represent a finalized off-chain balance state, there is no need for a fraud-proof or challenge mechanism. Correctness is enforced directly at execution on L1, and no rollback is required.

[Federico2014]

Yes - the Merkle root submitted by the batching layer can be independently verified by third parties. The root is a public on-chain commitment, and anyone can reconstruct the Merkle tree off-chain, recompute leaf hashes and proofs, and verify inclusion against the published root without trusting the batching node. The batching node cannot force incorrect transfers to execute. Each transfer is executed individually on-chain and must pass all checks at execution time: valid Merkle proof, correct parameters, sufficient allowance, and successful TRC-20 execution. If a batch is incorrect or incomplete, the result is simply that some transfers cannot be executed, not that invalid transfers are applied. Because the Merkle root does not represent a finalized off-chain balance state, there is no need for a fraud-proof or challenge mechanism. Correctness is enforced directly at execution on L1, and no rollback is required.

I have a few questions:

• Merkle root submitted by the batching layer can be independently verified by third parties. But how does the TRON network verify the Merkle root?
• What is the leaf node of the Merkle tree, the transfer transactions?
• How to execute the batched transfer transactions to increase efficiency?
  Can you provide a clearer explanation of this batching layer proposal? What are the participating entities, and what is the overall workflow?

[CTDGDevHub]

Yes - the Merkle root submitted by the batching layer can be independently verified by third parties. The root is a public on-chain commitment, and anyone can reconstruct the Merkle tree off-chain, recompute leaf hashes and proofs, and verify inclusion against the published root without trusting the batching node. The batching node cannot force incorrect transfers to execute. Each transfer is executed individually on-chain and must pass all checks at execution time: valid Merkle proof, correct parameters, sufficient allowance, and successful TRC-20 execution. If a batch is incorrect or incomplete, the result is simply that some transfers cannot be executed, not that invalid transfers are applied. Because the Merkle root does not represent a finalized off-chain balance state, there is no need for a fraud-proof or challenge mechanism. Correctness is enforced directly at execution on L1, and no rollback is required.

I have a few questions:

• Merkle root submitted by the batching layer can be independently verified by third parties. But how does the TRON network verify the Merkle root?
• What is the leaf node of the Merkle tree, the transfer transactions?
• How to execute the batched transfer transactions to increase efficiency?
  Can you provide a clearer explanation of this batching layer proposal? What are the participating entities, and what is the overall workflow?

1. The TRON network does not verify the Merkle root as a whole at submission time. The root is treated as a commitment, not as a proof of correctness by itself. Verification happens per transfer, at execution time, not globally at batch submission time.
   When a transfer is executed, the smart contract verifies the Merkle inclusion proof for that specific leaf against the committed root. If the proof is valid, the contract knows that this transfer was part of the batch. If the proof is invalid, execution fails. This design avoids the need for the chain to reprocess or validate the entire batch upfront.

2. Each leaf represents a single transfer intent, not a raw TRC-20 transaction. A leaf typically encodes the canonical transfer parameters, such as:

• sender (from)
• recipient (to)
• token contract
• amount
• nonce / unique identifier
• optional metadata (e.g. transfer type)

This leaf is hashed into the Merkle tree. Importantly, the leaf represents authorization to execute a transfer, not the execution itself. Execution only happens later, on-chain, after inclusion is proven.

3. Execution is per transfer, not “all at once” in a single token call. The efficiency gain comes from aggregation and amortization, not from bypassing execution rules:

• Thousands of transfer intents are aggregated off-chain.
• A single Merkle root anchors all of them on-chain.
• Each transfer is executed individually, but with minimal on-chain validation logic (Merkle proof + standard checks).
  This reduces redundant off-chain work, enables sponsored execution, improves fee predictability, and allows high-volume actors to operate in batches rather than broadcasting thousands of independent transactions. The chain still executes transfers safely and deterministically.

4. So - overall explanation looks like:
   Participating entities:

• Users/Applications: create transfer intents (sender-authorized, recipient does not sign).
• Batching layer (Aggregator/Bundler): collects intents, builds the Merkle tree, submits the root.
• Settlement smart contract: stores the root and enforces execution rules.
• Executor(s): submit on-chain execution calls for individual transfers (can be the aggregator or third parties).
• Observers/Validators/Indexers: independently verify roots and proofs off-chain.

High-level workflow:

1. Users or apps generate transfer intents.
2. The batching layer aggregates these intents and builds a Merkle tree.
3. The Merkle root is submitted on-chain as a batch commitment.
4. After commitment (and any configured delay), individual transfers are executed on-chain by providing:
   • the transfer data (leaf),
   • the Merkle inclusion proof.
5. The contract verifies inclusion, checks allowances and parameters, and executes the TRC-20 transfer.
6. If a leaf or proof is invalid, that transfer simply fails — nothing else is affected.

And why no fraud proofs or challenges are needed? Because the Merkle root does not finalize balances or off-chain state. It only commits to possible transfers. Incorrect or incomplete batches cannot force invalid execution. Correctness is enforced directly by the L1 execution logic, and failures are isolated to individual transfers.
In short, the batch processing layer intends to improve scalability and operational efficiency by aggregating intent and verification, while fully preserving execution, correctness, and security on TRON L1.