feat: replace deprecated Stably USDS with Sky USDS

[MantisClone]

Problem

The token list contains the old deprecated Stably USDS token (address 0xA4Bdb11dc0a2bEC88d24A3aa1E6Bb17201112eBe) which has been superseded by Sky USDS (address 0xdC035D45d973E3EC169d2276DDab16f1e407384F). Additionally, the token list uses ID USDS-sky-mainnet while Request Finance's API uses USDS-mainnet, creating naming inconsistency.

Background on Stably USDS deprecation:
According to Etherscan, "StableUSD has been renamed to Stably USD Classic (USDSC) and is no longer supported by the issuer." The token has been deprecated and Stably is no longer maintaining this stablecoin. For more information, see https://stably.io/usdsc.

Proposed Solution

• Remove the deprecated Stably USDS token entry
• Rename USDS-sky-mainnet to USDS-mainnet (reusing the freed ID)

This aligns the token list with Request Finance's currency endpoint naming convention.

Considerations

Context:
This change was originally proposed by @pclaesen in #12. At that time, I preserved the old Stably USDS token for backward compatibility concerns. After database verification confirmed zero production usage of the old token (address 0xA4Bdb11dc0a2bEC88d24A3aa1E6Bb17201112eBe), it's now safe to complete the migration that @pclaesen originally intended.

Why reusing the ID is safe:

• Database verification confirmed zero requests in production use the old Stably USDS token
• Request Finance already uses USDS-mainnet for Sky USDS (not Stably), which implies they also never used the deprecated Stably USDS token
• Request Network stores currency by contract address in IPFS, not by token list ID
• Token list IDs are only used during request creation, not retrieval or processing
• The old and new tokens have completely different addresses (0xA4Bdb... vs 0xdC035D...), preventing any collision

Impact:

• No breaking changes for existing requests (old token never used)
• New requests will use consistent USDS-mainnet ID matching Request Finance API
• Removes confusion from having two USDS-related entries

Co-authored-by: @pclaesen

[coderabbitai]

Note

Other AI code review bot(s) detected

CodeRabbit has detected other AI code review bot(s) in this pull request and will avoid duplicating their findings in the review comments. This may lead to a less comprehensive review.

Walkthrough

The pull request updates the USDS token entry in the token list, consolidating multiple USDS variants into a single entry. Two USDS entries are removed, and the remaining USDS-mainnet entry is updated with new decimals (18) and a revised contract address (0xdC035D45d973E3EC169d2276DDab16f1e407384F).

Changes

Cohort / File(s)	Summary
Token List Update tokens/token-list.json	Removed two USDS-related entries (StableUSD variant with decimals 6 and auxiliary USDS-sky-mainnet). Updated the primary USDS-mainnet entry: changed decimals from 6 to 18, updated contract address to 0xdC035D45d973E3EC169d2276DDab16f1e407384F.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

• Verify the new contract address (0xdC035D45d973E3EC169d2276DDab16f1e407384F) is correct and valid
• Confirm the decimal change from 6 to 18 aligns with the token's actual specifications
• Ensure the token list JSON structure remains valid after the removal of entries

Possibly related PRs

• feat: Add GHO, USDS (Sky), and MetaMask USD tokens #12: Adds the USDS-sky-mainnet entry at address 0xdC035..., which is the address now used for the consolidated USDS-mainnet entry in this PR.

Suggested reviewers

• rodrigopavezi
• bassgeta

Pre-merge checks and finishing touches

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The PR title accurately describes the main change: replacing deprecated Stably USDS with Sky USDS, which aligns with the primary objective of the changeset.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch feat/replace-stably-usds

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[Copilot]

Pull Request Overview

This PR removes a duplicate USDS token entry from the token list. The change consolidates two USDS token entries on mainnet by removing the older "StableUSD" token (with ID "USDS-mainnet") that had 6 decimals and address 0xA4Bdb11dc0a2bEC88d24A3aa1E6Bb17201112eBe, keeping only the current USDS token with 18 decimals and address 0xdC035D45d973E3EC169d2276DDab16f1e407384F.

• Removed the deprecated StableUSD token entry with ID "USDS-mainnet"
• Consolidated the USDS token entries to keep only the active token

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.