[Feature] Integrate Circle CCTP cross-chain USDC bridging into the app (replace informational bridge page)

[Sendi0011]

Summary

Replace the currently informational bridge page (a static step-by-step guide to using CCTP manually) with an integrated cross-chain USDC deposit bridge so users can fund a pool from an external chain without leaving the app.

The existing page at frontend/app/[locale]/bridge/page.tsx only renders explanatory CCTP/Stellar-USDC steps — it performs no on-chain or wallet actions.

Requirements

1. Chain/token selector — pick source chain (Ethereum, Base, Arbitrum, Optimism, Polygon) and confirm USDC amount to bridge.
2. CCTP contract integration — call Circle's CCTP depositForBurn from a Solana/stellar-aware wallet (or via a relayer/API) on the source chain, and verify MessageSent events.
3. Attestation polling — poll Circle's Attestation Service until complete, then submit receiveMessage on Stellar to mint USDC.
4. Pool deposit hand-off — after funds arrive, prefill or trigger the existing deposit flow (/api/pools/deposit) so the bridged USDC lands in the user's pool.
5. Status tracking — persist bridge transactions in Supabase so the UI shows progress (pending → attested → received → deposited) and survives page refresh.
6. Error + refund handling — surface instantaneous Failure attestation statuses and link to Circle's block-explorer refund flow.

Notes / context

• The Stellar side of CCTP uses the Circle Mint/Redeem anchor; USDC arrives on Stellar as the native USDC asset.
• Reuse the existing web3-provider and the frontend/lib/csv-export.ts-style pure-logic convention where possible; keep wallet/network code testable behind a thin seam.
• Add unit tests for the attestation-state machine (pending → complete/failure) and the amount/rounding/balance logic, following frontend/lib/deposit-calendar.test.ts conventions.

Acceptance criteria

• Bridging USDC from at least one EVM chain to Stellar completes end-to-end
• Deposited funds are credited to the user's pool via the existing deposit route
• Bridge status persists and resumes across page refreshes
• Unit tests cover the attestation state machine and amount handling
• Linting, format, and all CI checks pass

[GiftedGiftB]

Hi Maintainer, i can get this work done in less than 30 minutes.

[ABEEGOLD]

Hello Maintainer,

I’d love to work on this issue.

I have 4 years of experience across backend, frontend, full-stack, and smart contract development. I reviewed the requirements and understand the end-to-end CCTP flow, including Circle burn/mint mechanics, attestation polling, Stellar settlement, persistent transaction tracking, and seamless hand-off into the existing pool deposit workflow.

My implementation plan is to:

• Replace the current informational bridge page with a fully integrated bridging experience.
• Build a chain/token selection flow supporting CCTP-compatible source networks and USDC transfers.
• Integrate Circle CCTP burn/deposit flows and verify emitted bridge events.
• Implement attestation polling with a robust state machine (pending → complete → failed).
• Complete Stellar-side message reception and USDC mint handling.
• Connect successful bridge settlements to the existing /api/pools/deposit flow so funds are deposited directly into the user's pool.
• Persist bridge transactions and statuses in Supabase to survive refreshes and support progress tracking.
• Implement failure handling, recovery guidance, and refund/explorer links where applicable.
• Add comprehensive unit tests for attestation lifecycle management, amount calculations, rounding behavior, and balance validation.
• Ensure code remains modular, testable, and aligned with the existing project architecture.

I can deliver a clean, efficient, well-tested solution with strong focus on reliability, maintainability, and user experience.

My PR will be submitted within 8 hours of assignment.

[Jaamaldeen]

Let me do this:
Approach:

Bridge Page: Replace static guide with integrated bridge UI. Chain/token selector (Ethereum, Base, Arbitrum, Optimism, Polygon). USDC amount input.

CCTP Integration: Call depositForBurn from EVM wallet. Listen for MessageSent events. Poll Circle Attestation Service for attestation. Submit receiveMessage on Stellar to mint USDC.

Pool Deposit: After funds arrive, trigger existing /api/pools/deposit flow—bridged USDC lands in user's pool.

Status Tracking: Persist bridge transactions in Supabase. State machine: pending → attested → received → deposited. Survives page refresh.

Error Handling: Surface failure attestation statuses. Link to Circle block-explorer refund flow.

Testability: Wallet/network code behind thin seam. Unit tests for attestation state machine and amount/rounding logic. Follow frontend/lib/deposit-calendar.test.ts conventions.

Files: frontend/app/[locale]/bridge/page.tsx (replace), hooks for CCTP, attestation polling, Supabase persistence, pool deposit trigger.

Submit with linting, format, CI passing. End-to-end bridge working.

[devJaja]

Can I handle this issue please

[grantfox-oss]

🦊 GrantFox — @devJaja has been assigned to this issue as part of the Third Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #253)
2. Your PR will be reviewed by the JointSave-org maintainers

Good luck! Track your progress on GrantFox.