Problems We Faced
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Lack of Control

- No possibility for metagovernance

- Lots of token transfers == high gas cost

- Could not support some tokens
- General lack of flexibility

Long Iteration Cycles

- Purpose build contracts are often not versatile

- Audits take long and are expensive

- DeFi moves fast and so should we

Contract size limit

- Single contract having all functionality quickly run into size limits.

PieVaults

What we Wanted

- Versatility

- Fast iteration cycle

- Low audit cost and short duration

- A "Facet" per functionality type
- Can have many facets

- Good code separation

- Easy to upgrade

- New facets for extra functionality


Invented by Nick Mudge

The Diamond Standard

PieVault Facets

- ERC20Facet
- BasketFacet

- CallFacet

ERC20 Facet

- Balances

- Allowances

- Approvals

- Transfers

- Token Name

- Token Symbol

- Minting

- Burning

Basket Facet

- Track underlying assets

- Joining (minting pie)

- Exiting (burning pie)

- Adding tokens

- Removing facets

- Entry fee

- Exit fee

- Streaming fee

Call Facet

- Allow arbitrary transactions from the Pie

- Adding callers

- Removing callers

- Calling back into the Pie

CallManagers

- Can execute whitelisted functions from the Pie

- Lending/StakingManager

- RSI Manager