API ADDENDUM

This API Addendum (“Addendum”) governs Client’s access to and use of the Superbridge API. This Addendum supplements and forms part of the Superbridge Customer Agreement (“Customer Agreement”) between Blob Engineering Pte. Ltd. (“Superbridge”).

Capitalized terms used but not defined in this Addendum have the meanings given in the Customer Agreement. In the event of a conflict between this Addendum and the Customer Agreement with respect to API access, this Addendum controls.

1. Additional Definitions

The following additional definitions apply throughout this Addendum:

• “API Key” means the unique credential generated by Client through the Dashboard to authenticate API requests.
• “API Services” means the programmatic access to bridging routes, chain data, transaction submission, swap routing, and related functionality provided by Superbridge via the API.
• “Auto-Relay Route” means a bridging route where Superbridge handles the completion or finalization step of a native bridge transaction on Client’s behalf.
• “Dashboard” means the web-based platform provided by Superbridge through which Client configures and manages its API access and, where applicable, Bridge Interfaces.
• “Gasless Route” means a bridging route where Client signs an order (rather than a transaction that lands directly on-chain) and Superbridge or a designated third-party relayer submits the transaction to the blockchain.
• “Routing-Only Service” means the provision of bridging route data, quotes, step-by-step instructions, and chain information for Client’s use in constructing and submitting its own transactions.
• “Restricted Jurisdiction” means any of the following jurisdictions: Belarus, Cuba, Iran, Lebanon, North Korea, the Republic of the Congo, Russia, Syria, or the occupied territories of Ukraine (including the Crimea, Donetsk Oblast, and Luhansk Oblast). Where this Addendum is used together with the Customer Agreement, this definition is supplemental to and consistent with the definition in the Customer Agreement.
• “Swap Services” means the DEX aggregator functionality through which the API routes Client’s swap requests to third-party decentralized exchange liquidity providers.

2. API Access

2.1 Selective Access

Access to the API is granted at Superbridge’s sole and absolute discretion. Superbridge may decline to grant, condition, or revoke API access at any time, subject to the notice provisions Section 8.2.

2.2 API Key

Client may generate one or more API Keys through the Dashboard to authenticate requests. Client is solely responsible for maintaining the security and confidentiality of its API Keys. Client must:

• not share its API Key with any unauthorized third party;
• implement reasonable technical controls to prevent unauthorized access to or use of the API Key; and
• notify Superbridge immediately upon discovery of any actual or suspected compromise of an API Key.

Superbridge reserves the right to revoke or disable any API Key at any time for security reasons. Superbridge has no liability for losses arising from Client’s failure to secure its API Keys.

2.3 Permitted Use

Client may use the API Services solely for its own internal business operations and workflows. Client may not sublicense, resell, or make API access or API-derived data available to third parties without Superbridge’s prior written consent.

3. Description of API Services and Liability Allocation

The API Services operate in three distinct modes depending on the route type. Client’s use of each mode carries different risk and liability considerations as set out below.

3.1 Routing-Only Service

For standard routing requests, Superbridge acts solely as a data and routing information provider. Superbridge provides route data, indicative quotes, required steps, and chain information that Client uses to construct and submit its own on-chain transactions. Client is solely responsible for reviewing, validating, and executing any transaction constructed using Routing-Only Service data. Superbridge has no involvement in and no liability for the execution, outcome, or on-chain results of any such transaction. Superbridge’s liability under this mode is limited to claims arising from materially inaccurate route data provided by Superbridge, subject to the limitations in Section 7.

3.2 Gasless Routes

For gasless routes, Client signs an order that Superbridge or a designated third-party relayer submits to the blockchain on Client’s behalf. Client acknowledges and agrees that:

• Superbridge and any relayer act solely as Client’s agent for the limited purpose of submitting the signed order to the relevant blockchain;
• Superbridge does not guarantee the timing, inclusion, or success of any transaction submission;
• Superbridge is not liable for losses arising from relayer failure, network congestion, gas price volatility, transaction reversion, or mempool behavior; and
• Superbridge’s liability for losses arising from gasless route processing is limited to losses directly and proximately caused by Superbridge’s own gross negligence or willful misconduct in the order submission process, subject to the limitations in Section 7.

3.3 Auto-Relay Routes

For auto-relay routes, Superbridge handles the completion or finalization step of a native bridge transaction on Client’s behalf. Client acknowledges and agrees that:

• auto-relay is subject to network conditions, gas costs, Protocol availability, and other factors outside Superbridge’s control;
• Superbridge will use commercially reasonable efforts to complete the relay in a timely manner;
• Superbridge is not liable for losses arising from delays or failures caused by network conditions, Protocol behavior, or third-party factors; and
• Superbridge’s liability for losses from auto-relay is limited to losses directly and proximately caused by Superbridge’s own gross negligence or willful misconduct in the completion process, subject to the limitations in Section 7.

3.4 Route and Quote Accuracy

All route data, quotes, fee estimates, and timing information provided via the API are indicative and based on conditions at the time of the request. Superbridge does not guarantee that any quoted route, fee, timing, or outcome will remain available or accurate at the time of execution. Client is responsible for validating all data before acting on it.

3.5 Route Availability

Superbridge does not guarantee that any specific route, chain, asset, or bridge provider will be available at any given time. Route availability depends on third-party bridge provider status, Protocol availability, network conditions, and compliance screening outcomes.

4. Rate Limits and Fair Use

4.1 Current Rate Limits

As of the date of this Addendum, Superbridge does not impose rate limits on API requests. Superbridge reserves the right to introduce rate limits at any time on reasonable advance notice to Client.

4.2 Fair Use

Client must use the API Services in a fair and reasonable manner consistent with normal commercial use. Superbridge may, in its sole discretion, throttle or temporarily suspend Client’s API access if Client’s usage materially degrades service quality for other clients.

5. Swap Services

5.1 DEX Aggregator

The Swap Services operate as a DEX aggregator. Superbridge routes Client’s swap requests through third-party decentralized exchange protocols and liquidity providers. Superbridge does not itself provide liquidity, act as a market maker, or take the other side of any swap transaction. Client is transacting directly with the relevant third-party liquidity protocol.

5.2 Indicative Pricing

All prices, rates, and quotes provided through the Swap Services are indicative only and reflect market conditions at the time the quote is generated. Superbridge does not guarantee that any quoted price will be available at execution. Actual execution prices may differ materially from quoted prices due to market movements, liquidity changes, or network latency.

5.3 Slippage

Superbridge will not route a swap transaction where projected slippage exceeds 10% at the time the request is processed. Client acknowledges that: (a) actual slippage may differ from projected slippage; (b) Superbridge has no liability for slippage outcomes; and (c) the 10% threshold is a protective measure and does not constitute a guarantee of any slippage level.

5.4 No Best-Execution Obligation

Superbridge does not represent that the Swap Services will identify or obtain the best available price for any swap. Client is solely responsible for evaluating whether any quoted route or price meets its requirements before initiating a swap.

5.5 Third-Party Risks

Swap transactions are subject to the terms, risks, and smart contract logic of the relevant third-party liquidity protocols. These risks include smart contract vulnerabilities, liquidity pool imbalances, front-running, MEV extraction, and protocol-level failures. Superbridge is not responsible for the acts, omissions, or failures of any third-party liquidity provider.

6. Compliance

6.1 Wallet Screening

Superbridge applies monitoring of API-initiated transactions and operations via internal systems, TRM Labs, Chainalysis, ZeroShadow, and other providers as required. Superbridge may decline to process any transaction or route that triggers alerts or involves addresses flagged for sanctions, fraud, or other compliance concerns. Superbridge has no liability for losses arising from its refusal to process a transaction on compliance grounds.

6.2 Restricted Parties and Jurisdictions

Client must not use the API to process transactions for or on behalf of any person or entity that is: (a) subject to economic sanctions administered by any governmental authority; (b) located or organized in a Restricted Jurisdiction; or (c) otherwise prohibited from using the Services under applicable law. Client is responsible for implementing its own sanctions and restricted party screening.

6.3 Client’s Own Compliance Obligations

Superbridge’s TRM screening is provided for Superbridge’s own risk management purposes and does not constitute compliance services for Client. Client is solely responsible for satisfying its own AML, KYC, sanctions screening, and other regulatory obligations applicable to its business. Superbridge makes no representation that its compliance measures satisfy Client’s regulatory requirements.

7. Limitation of Liability (API-Specific)

7.1 Routing-Only

FOR CLAIMS ARISING FROM THE ROUTING-ONLY SERVICE, SUPERBRIDGE’S LIABILITY IS LIMITED TO DIRECT LOSSES ARISING FROM MATERIALLY INACCURATE ROUTE DATA PROVIDED BY SUPERBRIDGE. SUPERBRIDGE HAS NO LIABILITY FOR EXECUTION OUTCOMES INCLUDING TRANSACTION FAILURES, SLIPPAGE, ON-CHAIN ERRORS, OR LOSSES ARISING FROM CLIENT’S USE OF ROUTE DATA.

7.2 Gasless and Auto-Relay Routes

FOR CLAIMS ARISING FROM GASLESS ROUTES OR AUTO-RELAY ROUTES, SUPERBRIDGE’S LIABILITY IS LIMITED TO DIRECT LOSSES DIRECTLY AND PROXIMATELY CAUSED BY SUPERBRIDGE’S OWN GROSS NEGLIGENCE OR WILLFUL MISCONDUCT IN THE RELAYING OR COMPLETION PROCESS. IN NO EVENT WILL SUPERBRIDGE BE LIABLE FOR LOSSES ARISING FROM NETWORK CONDITIONS, PROTOCOL BEHAVIOR, GAS PRICE VOLATILITY, OR THIRD-PARTY RELAYER FAILURES.

7.3 Overall Cap

Superbridge’s aggregate liability under this Addendum is subject to the aggregate liability cap in the Customer Agreement.

7.4 Limitation Period

Any claim arising out of or relating to this Addendum must be brought within one (1) year of the first event or occurrence giving rise to the claim. Claims not brought within this period are permanently barred.

7.5 No Liability for Digital Asset Losses

SUPERBRIDGE IS NOT A CUSTODIAN AND DOES NOT HOLD CLIENT’S OR ANY END USER’S DIGITAL ASSETS AT ANY POINT DURING AN API-INITIATED TRANSACTION (EXCEPT TRANSIENTLY FOR GASLESS ROUTE SUBMISSION). SUPERBRIDGE HAS NO LIABILITY FOR THE LOSS, THEFT, OR INACCESSIBILITY OF ANY DIGITAL ASSETS HELD IN CLIENT’S OR ANY THIRD PARTY’S WALLET.

8. Modifications and Discontinuation

8.1 API Changes

Superbridge may modify, update, or deprecate any aspect of the API at any time. Superbridge will use commercially reasonable efforts to provide advance notice of breaking changes. Superbridge is not liable for losses arising from API changes where reasonable advance notice was given.

8.2 Discontinuation of API Access

Superbridge may discontinue Client’s API access on ninety (90) days’ written notice, or immediately in the event of Client’s material breach of this Addendum or the Customer Agreement, or in the event of any legal, regulatory, or compliance requirement necessitating immediate suspension.

9. Governing Law, Dispute Resolution, and General Provisions

9.1 Where Customer Agreement Applies

Where this Addendum is executed together with the Customer Agreement, all governing law, dispute resolution, confidentiality, limitation of liability (except as modified herein), indemnification, and general provisions of the Customer Agreement apply to this Addendum.

9.2 Negotiated Governing Law for Institutional Clients

For institutional API clients, Superbridge may agree in writing to alternative governing law provisions as set out in the applicable Order Form. In the absence of any such written agreement, Singapore law governs.

Date last updated: April 28, 2026