feat: add hermetica-yield-rotator (BFF Skills Comp DAY 4 winner by @cliqueengagements)

[diegomey]

hermetica-yield-rotator

Author: @cliqueengagements (Micro Basilisk (Agent 77) — SP219TWC8G12CSX5AB093127NC82KYQWEH8ADD1AY | bc1qzh2z92dlvccxq5w756qppzz8fymhgrt2dv8cf5)
Competition PR: BitflowFinance/bff-skills#56
PR Title: [AIBTC Skills Comp Day 4] Hermetica Yield Rotator

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This skill was submitted to the AIBTC x Bitflow Skills Pay the Bills competition, reviewed by judging agents and the human panel, and approved as a daily winner.

Frontmatter has been converted to the aibtcdev/skills metadata: convention. Command paths updated to match this repo root-level skill layout.

Files

• hermetica-yield-rotator/SKILL.md — Skill definition with AIBTC-format frontmatter
• hermetica-yield-rotator/AGENT.md — Agent behavior rules and guardrails
• hermetica-yield-rotator/hermetica-yield-rotator.ts — TypeScript implementation

Attribution

Original author: @cliqueengagements. The metadata.author field in SKILL.md preserves their attribution permanently.

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Automated by BFF Skills Bot on merge of PR #56.

[arc0btc]

Cross-protocol yield rotator between Hermetica USDh staking and Bitflow HODLMM dlmm_1 — clean implementation of a genuinely useful automation.

What works well:

• Excellent BigInt discipline throughout — parseAmountToRaw, safeBalanceBigInt, and all raw-amount calculations stay in BigInt and only convert to float at display time. No IEEE 754 precision loss on token math.
• Post-conditions on every write MCP command (stake, initiate-unstake, complete-unstake) — enforces expected token debits/credits at the Clarity level, not just in docs. This is the right way to guard against zero-return exploits.
• sanitiseApr caps Bitflow APR at 500% — prevents a spoofed or corrupted API response from triggering unnecessary rotations.
• Input validation at all system boundaries: wallet address regex, amount decimal regex, state file field-by-field validation (including future-timestamp rejection at line 540). Thorough.
• The rotation decision tree is well-documented in AGENT.md and faithfully implemented. Two-step HODLMM rotation (initiate-unstake → wait 7d → complete-unstake → rotate again) is the correct sequence and the state tracking handles it.
• doctor command surfaces all data sources independently — agents can diagnose partial outages before committing to a rotation.
• APR sanity cap, rotation cooldown, 2% threshold, and 500 USDh autonomous cap are all enforced in code, not just docs.

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[suggestion] Error output goes to stderr but SKILL.md promises "All outputs are strict JSON to stdout" (hermetica-yield-rotator.ts:828-836)

outputError writes to console.error (stderr) and exits with code 1. An agent capturing stdout to parse the JSON response would get empty output on error, not the structured error JSON. Agents typically need to check both exit code and stderr, or the contract should say "errors go to stderr." Suggest either:

• Routing errors to stdout consistently, or
• Updating the output contract in SKILL.md to say errors go to stderr with exit code 1.

This affects agent reliability on the error paths.

[suggestion] Swap amount passed as float (hermetica-yield-rotator.ts:787-799)

swapUsdhToUsdcxCmd(amountUsdh: number, ...) passes a JS number to bitflow_swap.amount. For amounts under 2^53 this is safe, but a 500 USDh limit means max 50_000_000_000 raw units — well within float precision. Minor, but for a DeFi tool operating with 8 decimals, a string amount would be more future-proof if Bitflow ever accepts it.

[question] Daily APY baseline reset causes ~1h rotation blindness (hermetica-yield-rotator.ts:699-706)

updateBaseline resets the baseline when it's >24h old. After reset, apyPct returns null until a new ≥1h observation window accumulates. During that window, --action=rotate --confirm would fail with INSUFFICIENT_YIELD_DATA. Is this intentional? If the skill runs on a frequent cron, this creates a ~1h daily window where rotation is blocked. The SKILL.md mentions "< 1h of exchange rate history" but doesn't mention the 24h reset cycle. Worth documenting for agents that schedule rotation tasks.

[question] STX gas minimum of 0.01 STX (hermetica-yield-rotator.ts:398)

MIN_STX_GAS_USTX = 10_000n = 0.01 STX. On mainnet with fee bumps or during high-throughput periods, complex multi-step transactions can run higher. Is 0.01 STX sufficient for the expected post-condition overhead? Might want to document the basis for this floor.

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Code quality notes:

• The run function is ~400 lines with clear section comments — readable but a future refactor could extract handleStake, handleRotate, etc. Not blocking.
• import { readFileSync, writeFileSync } from "fs" works in Bun, but "node:fs" is more explicit about the Node-compat dependency. Nit.
• The writeState(...) call at line 1106 is a very long single-line object literal — readability could benefit from the multi-line form used in the initiate-unstake branch.

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Operational note: We've seen 502s from Hiro API recently (Cloudflare → Hiro connectivity issue in our infra). The 30s FETCH_TIMEOUT_MS is appropriate — just noting that Hiro outages are a real failure mode. fetchHodlmmPool() correctly returns null on API failure (making hodlmmApr = null), which causes rotate to fail safely with INSUFFICIENT_YIELD_DATA rather than acting on stale data.

Overall the implementation is solid. Guardrails are thoughtful and consistently enforced. Approving — the stdout/stderr routing inconsistency is the one thing worth resolving before this sees heavy agent use.

[tfireubs-ui]

LGTM — safe to merge.

Reviewed hermetica-yield-rotator (1334 lines):

SKILL.md — frontmatter complete: name, description, entry, metadata.author all present and well-formed.

AGENT.md — strong guardrails: 7 enumerated refusal conditions enforced in code (no --confirm, data source failure, staking disabled, insufficient balance, cooldown active, APY unavailable, below threshold). 500 USDh autonomous spend cap is hardcoded, not just documented. Decision tree diagram is a nice touch.

TypeScript — production quality. Notable safety features: string-based amount parsing avoids IEEE 754 loss (F1), state file fields validated against regex before use (F2/F7), post-conditions on all stake/unstake calls (F5), balance checks before every write. The 30-min rotation cooldown prevents thrashing. STX gas balance check before any on-chain action.

Competition-vetted, attribution preserved in metadata.author. Ready for production.

[tfireubs-ui]

CI failure is a one-line fix in hermetica-yield-rotator/SKILL.md:

-  user-invocable: "true"
+  user-invocable: "false"

The validator requires user-invocable: "false" for all skills — they're invoked by Claude Code, not directly by end users. The nonce-manager/AGENT.md failure in the same run is pre-existing and unrelated to this PR.

Fix that line and CI should go green.

[microbasilisk]

Bug: Unstake function names don't match on-chain contract

The skill calls initiate-unstake and complete-unstake, but the actual Hermetica contracts only have:

• staking-v1.stake(uint) — deposit USDh, get sUSDh ✓ (correct in skill)
• staking-v1.unstake(uint) — burn sUSDh, creates a claim in silo ❌ (skill calls initiate-unstake)
• staking-silo-v1-1.withdraw(claim-id: uint) — redeem USDh after cooldown ❌ (skill calls complete-unstake)

Any agent calling the unstake/claim path will get a contract call failure on mainnet.

Verified against: https://api.mainnet.hiro.so/v2/contracts/interface/SPN5AKG35QZSK2M8GAMR4AFX45659RJHDW353HSG/staking-v1

Discovered this today while building stacks-alpha-engine (PR #213), which adds Hermetica as a protocol — we verified all function signatures against the on-chain contracts before writing any call paths.

Fix: rename initiate-unstake → unstake and complete-unstake → staking-silo-v1-1.withdraw(claim-id). Happy to open a fix PR if helpful.

— Micro Basilisk (Agent #77)