Summary

zest_withdraw and zest_repay MCP tools fail for positions that live on the newer v0-4-market contracts (SP1A27KFY4XERQCCRCARCYD1CC5N7M6688BSYADJ7.v0-4-market). The tools only target the legacy v2 contracts.

Reproduction

1. Have a position on SP1A27KFY4XERQCCRCARCYD1CC5N7M6688BSYADJ7.v0-4-market (confirmed via v0-market-vault.get-position)
2. Call zest_withdraw(asset="sBTC", amount="102976") → tx aborts with (err none)
3. Call zest_repay(asset="sBTC", amount="1") → tx aborts with (err u30000)

Failed TXs:

• Withdraw: 42579342f52264c8e449ab3221d37e241447e3ff41df14cf543b398dfe631ade
• Repay: 496dbf8ce4441b9eaa55cdb39ef0297dacf03ba56624d06477d04839a6f856ca

Root Cause

The MCP server's Zest implementation calls SP2VCQJGH7PHP2DJK7Z0V48AGBHQAW3R3ZW1QF4N.borrow-helper-v2-1-5 with:

• LP: zsbtc-v2-0
• Pool reserve: pool-0-reserve-v2-0
• Oracle: stx-btc-oracle-v1-4

These are the legacy Zest v2 contracts. Positions that were migrated (or created) on the v0-4-market (SP1A27KFY4XERQCCRCARCYD1CC5N7M6688BSYADJ7) are invisible to these tools because:

1. zest_get_position queries the v2 pool — returns 0/0 for migrated positions
2. zest_withdraw calls borrow-helper-v2-1-5.withdraw — no position found → (err none)
3. zest_repay calls borrow-helper-v2-1-5.repay — no position found → (err u30000)

Position Data (confirmed on-chain)

Calling SP1A27KFY4XERQCCRCARCYD1CC5N7M6688BSYADJ7.v0-market-vault.get-position returns:

• Collateral: asset ID 3, amount 102,976 (zsBTC shares)
• Debt: asset ID 2, scaled 1 (dust)
• Position ID: 415

What's Needed

The v0-4-market contract exposes different functions:

• collateral-remove(ft, amount, receiver, price-feeds) — withdraw collateral
• collateral-remove-redeem(ft, amount, min-underlying, receiver, price-feeds) — withdraw + redeem to underlying
• repay(ft, amount, on-behalf-of) — repay debt

To support v0-4-market positions, the MCP server needs:

1. A way to detect which market version holds a user's position (v2 vs v4)
2. New contract references for v4: the correct zsBTC ft trait, Pyth price feed buffers
3. Updated zest_get_position to also query v0-market-vault.get-position
4. Updated zest_withdraw / zest_repay to route to the correct contract version

Environment

• MCP server version: v1.33.1
• Network: mainnet
• Wallet: SP4DXVEC16FS6QR7RBKGWZYJKTXPC81W49W0ATJE

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