Vaults

DEPRECATED for product scope (2026-07-11). DAY is a yield router, not vault tech. Keep only as historical notes. See 38-technical-architecture.md.

DAY — Vaults (product + architecture)

Date: 2026-07-11
Status: DEPRECATED — yield router only; vault product out of scope
Brand: DAY · Site: https://dayprotocol.com
Authority: docs/00-product-constitution.md (no custody, fee on yield only, owner sovereign)
Peers: Superform Forms (superform-core / src/forms)

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1. What “vaults” means for DAY (three layers)

Layer	Who holds assets	What DAY builds	Superform analog
L0 — Venue vaults	Suilend / NAVI / Scallop / Kamino / …	Adapters only (read_apy, deposit, withdraw)	Underlying ERC-4626 vault
L1 — DAY Form (wrapper)	Still venue + DAY position object	Form that wraps one venue market under DAY policy	ERC4626Form / Form instance
L2 — DAY Vault (product)	DAY vault object (shared) + user/agent shares	Curated / strategy vault users & agents deposit into	SuperVault / multi-source product

Historical note only — we do NOT build L2 vault product. L0 stays external; we never reimplement Suilend.

Agent / Owner
    │  deposit / withdraw / harvest (x402-callable)
    ▼
┌──────────────────────────────┐
│  DAY Vault (L2)              │  strategy, share accounting, fee skim on yield
│  · policy: venues, caps      │
│  · Auto Yield OFF by default │
└──────────────┬───────────────┘
               │ via Forms
               ▼
┌──────────────────────────────┐
│  DAY Form (L1)               │  one venue market adapter binding
└──────────────┬───────────────┘
               ▼
         Venue vault (L0)

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2. Constitution constraints on vaults (non-negotiable)

Rule	Vault implication
No team custody	Vault is an on-chain object; ops keys never own principal
Always withdraw	Share redeem → assets to owner (or position), not team
Fee only on yield	Performance skim at harvest/compound inside vault waterfall; 0% on deposit/withdraw
Stake/deploy OFF default	Vault may hold liquid until owner enables Auto Yield / strategy arm
Agent cannot withdraw principal	Agent can deposit (if allowed) + harvest path; redeem principal = owner
Honest numbers	Vault APY from adapter read_apy / NAV math; null → N/A
Permissionless harvest	Keeper can harvest vault yield (bounty); cannot invent amounts

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3. Vault types we ship (phased)

V1 — Single-venue DAY Form Vault (MVP)

• One vault → one venue market (e.g. Suilend USDC)
• Share token / position object = claim on that market under DAY fee policy
• Superform: one Form ↔ one vault

Use cases: simplest agent deposit, cleanest audit surface.

V2 — Strategy Vault (allocation)

• One vault → N Forms (e.g. 70% Suilend, 30% NAVI)
• Rebalance under owner/policy caps (not free-for-all agent)
• Superform SuperVault energy without EVM multi-chain day-1

V3 — Owner- or agent-linked Vault

• Vault shares sit in owner position / vault policy
• Auto Pay residual from vault yield after survival
• This is the “autonomous capital” product

Not day-1

• Permissionless anyone-lists-any-vault (Superform factory) — allowlist first
• Cross-chain vault share bridging as product core
• Fee-on-deposit vaults

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4. Core objects (Sui-first sketch)

4.1 VaultConfig (shared)

VaultConfig {
  id,
  name,
  asset,                    // e.g. USDC type
  fee_skim_bps,             // default 500; yield only
  auto_deploy_default_off,  // true
  allowed_forms[],          // Form ids / venue bindings
  max_tvl_micros?,
  paused: bool,
}

4.2 Vault (shared) — accounting

Vault {
  id,
  config_id,
  total_assets_micros,      // liquid + deployed (NAV)
  total_shares,
  liquid_micros,            // not yet in venue
  deployed_by_form,         // form_id → amount
}

4.3 VaultShare / position (owned by owner or agent)

// Option A: fungible share coin (if we mint a share type)
// Option B: Position object { vault_id, shares, owner }

MVP recommendation: Position object (clearer agent policy + clawback rules); fungible shares later if needed.

4.4 Form (shared binding)

Form {
  id,
  vault_id?,                // or registry global
  venue_id,                 // suilend | navi | …
  market_id,                // venue-specific
  adapter_version,
  ready: bool,
}

Maps 1:1 to Superform “vault added to a Form.”

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5. User / agent flows

Deposit

1. Owner/agent calls deposit(vault, amount) with asset
2. Shares minted by NAV (amount / price_per_share)
3. Assets enter Vault.liquid
4. If Auto Yield / strategy enabled by owner → Form.deploy(liquid→venue)
5. Else stay liquid until owner arms strategy

Withdraw

1. Owner only (or account owner) burns shares
2. If needed: Form.withdraw from venue (min amount)
3. Asset out to owner (or position)
4. No fee on withdraw

Harvest (permissionless keeper)

1. Form.claim venue yield → vault
2. Skim fee_bps of yield only → fee sink
3. Net yield compounds to vault NAV (or Auto Pay residual policy)
4. Event: VaultHarvested { gross, skim, net }

Rescue (steal Superform)

• Bridge-funded deposit below minOut → no share mint / reverse; funds to owner path
• Never leave principal in ops wallet

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6. API / product surface (dayprotocol.com)

Route	Role
/markets	Browse L0 venues + L1/L2 DAY vaults (yield MTD first)
/vaults	DAY vault list (product)
/vaults/:id	NAV, yield, allocation, Deposit, withdraw (owner), strategy toggle
/providers/:id	Group Forms/vaults by venue protocol
Agent	POST /v1/vaults/:id/deposit · previewDeposit · x402 pay path for fees/gas only — not principal custody

Schemas (versioned):

• day-vault.v1.json
• day-vault-plan.v1.json (deposit | withdraw | harvest | rebalance)
• Keep existing day-*-v1 for routing/enablement

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7. Superform → DAY vault steal list (vault-specific)

Steal	Superform	DAY vault
Form = adapter to one vault	Forms	Form per venue market
Single router entry	SuperformRouter	VaultRouter / plan executor
StateRequest	typed action	day-vault-plan.v1
Shares after success	SuperPositions	mint shares only after assets in vault
actual vs quote	updateDepositPayload	bridge reconcile before mint
rescueFailedDeposit	yes	vault deposit rescue
Core immutable	non-upgradeable core	freeze fee/withdraw/share math package
Permissionless list	createSuperform	later; allowlist Forms at launch

Don’t steal for vault MVP: multi-AMB stack, SuperPositions as UX requirement, EVM-only 4626 assumptions (Sui objects first).

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8. Fee model inside vaults

gross_yield (from venue claim)
  → protocol_skim = gross * fee_skim_bps / 10000   // default 500
  → net_yield to vault NAV / compound
deposit amount → 0 fee
withdraw amount → 0 fee

Optional later: strategist fee as slice of skim, not extra deposit fee — still yield-only.

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9. Implementation order

Wave	Deliverable	Done when
W0	Spec + schemas day-vault.v1	This doc + JSON schema
W1	Move: VaultConfig + Vault + share/position + deposit/withdraw (liquid only)	Unit tests; no venue yet
W2	Form + Suilend Form deploy/withdraw	Live prepare-only mainnet evidence
W3	Harvest skim + events + keeper	Permissionless harvest path
W4	FE /vaults + /vaults/:id Deposit	dayprotocol.com
W5	Multi-form allocation vault	V2 strategy
W6	Position binding + Auto Pay from vault residual	consumer integration

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10. Repo layout (versioned)

contracts/sui/
  sources/
    day.move              # protocol fee primitives (existing)
    vault.move            # Vault + shares (new)
    form.move             # Form registry (new)
schemas/
  day-vault.v1.json
  day-vault-plan.v1.json
runtime/
  vaults/                 # offchain planner / NAV helpers
  adapters/               # L0 venue adapters (existing)

Package versioning: vault money math freezes with core major; new Forms = minor/adapters (see docs/22-versioning-strategy.md).

Copyright: Limitless Labs (see docs/23-copyright-and-licensing.md).

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11. Success criteria

• User/agent can Deposit into a DAY vault and see shares/NAV
• Owner can fully exit without team
• Yield harvest takes ≤5% of yield, never principal
• Strategy arm is opt-in
• Vault listed on markets with honest yield (or N/A)
• Contracts open-sourceable as a versioned immutable core when audit+UpgradeCap gate pass

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12. Bottom line

Yes — DAY builds vaults, not only “route to someone else’s market.”

• Forms wrap venues (Superform lesson)
• Vaults are the product agents deposit into
• Constitution still wins: no custody, fee-on-yield, owner exit, default-off deploy
• Version vault core like Superform core; evolve Forms fast

Next concrete step: schemas/day-vault.v1.json + Move vault.move skeleton (W0–W1).