PolicyPool

The PolicyPool is the main contract that keeps track of active policies and receives the spending allowances. It's a single PolicyPool for each instance of the protocol. One of its attributes is currency(), which points to the coin (ERC20) used throughout the protocol. So far we support only USDC as currency.

It has methods for LP to deposit/withdraw, acting as a gateway for the eTokens. The PolicyPool is connected to a set of eTokens, premiums accounts, and risk modules.

This contract also follows the ERC721 standard, minting an NFT for each policy created. The owner of the NFT is who will receive the payout in case there's any.

Roles

The roles and functions of the contract are as follows:

Role	Description	Methods Accessible
LEVEL1_ROLE	High impact changes like upgrades or other critical operations	addComponent: Adds a new component to the protocol. removeComponent: Removes a component from the protocol. changeComponentStatus: Change the status of a componenent. setTreasury: Changes the treasury address. unpause: Unpauses the smart contract.
LEVEL2_ROLE	Mid-impact changes like changing some parameters.	setBaseURI: Changes the base URI of policy NFTs.
GUARDIAN_ROLE	For emergency operations oriented to protect the protocol in case of attacks or hacking.	changeComponentStatus: Changes the status of a component.

Interactions

Parameters

Field	Type	Description
treasury	address	This is the address of the Ensuro Treasury, that receives the protocol fees (see Ensuro commission)

Policy database

One of the responsibilities of the PolicyPool contract is to keep track of active policies with all the (immutable) data.

Given the Policy struct has many fields and storage is expensive on-chain, the struct isn't stored as a storage variable of the contracts.

Instead, when the policy is created, only a hash of the struct is stored and an event with all the fields is emitted. Then, for any operation with the Policy (like resolution or expiration), all the policy needs to be sent as a parameter. The PolicyPool contract computes the hash of the parameter and compares it with the stored one.

The mapping from policyId to hash is stored in the _policies attribute.

Events

NewPolicy

event NewPolicy(contract IRiskModule riskModule, struct Policy.PolicyData policy)

Event emitted every time a new policy is added to the pool. Contains all the data about the policy that is later required for doing operations with the policy like resolution or expiration.

Name	Type	Description
riskModule	contract IRiskModule	The risk module that created the policy
policy	struct Policy.PolicyData	The {Policy-PolicyData} struct with all the immutable fields of the policy.

PolicyResolved

event PolicyResolved(contract IRiskModule riskModule, uint256 policyId, uint256 payout)

Event emitted every time a policy is removed from the pool. If the policy expired, the payout is 0, otherwise is the amount transferred to the policyholder.

Name	Type	Description
riskModule	contract IRiskModule	The risk module where that created the policy initially.
policyId	uint256	The unique id of the policy
payout	uint256	The payout that has been paid to the policy holder. 0 when the policy expired.

ComponentChanged

event ComponentChanged(enum IAccessManager.GovernanceActions action, address value)

Event emitted when the treasury changes.

Name	Type	Description
action	enum IAccessManager.GovernanceActions	The type of governance action (just setTreasury in this contract for now)
value	address	The address of the new treasury

ComponentStatusChanged

event ComponentStatusChanged(contract IPolicyPoolComponent component, enum PolicyPool.ComponentKind kind, enum PolicyPool.ComponentStatus newStatus)

Event emitted when a new component added/removed to the pool or the status changes.

Name	Type	Description
component	contract IPolicyPoolComponent	The address of the component, it can be an {EToken}, {RiskModule} or {PremiumsAccount}
kind	enum PolicyPool.ComponentKind	Value indicating the kind of component. See {ComponentKind}
newStatus	enum PolicyPool.ComponentStatus	The status of the component after the operation. See {ComponentStatus}

External Methods

newPolicy

function newPolicy(struct Policy.PolicyData policy, address caller, address policyHolder, uint96 internalId) external returns (uint256)

Creates a new Policy. Must be called from an active RiskModule

Requirements:

• msg.sender must be an active RiskModule

• caller approved the spending of currency() for at least policy.premium

• internalId must be unique within policy.riskModule and not used before

Events:

• {PolicyPool-NewPolicy}: with all the details about the policy

• {ERC20-Transfer}: does several transfers from caller address to the different receivers of the premium (see Premium Split in the docs)

Name	Type	Description
policy	struct Policy.PolicyData	A policy created with {Policy-initialize}
caller	address	The pricer that's creating the policy and will pay for the premium
policyHolder	address	The address of the policy holder and the payer of the premiums
internalId	uint96	A unique id within the RiskModule, that will be used to compute the policy id

Name	Type	Description
[0]	uint256	The policy id, identifying the NFT and the policy

resolvePolicy

function resolvePolicy(struct Policy.PolicyData policy, uint256 payout) external

Resolves a policy with a payout. Must be called from an active RiskModule

Requirements:

• policy: must be a Policy previously created with newPolicy (checked with policy.hash()) and not resolved before and not expired (if payout > 0).

• payout: must be less than equal to policy.payout.

Events:

• {PolicyPool-PolicyResolved}: with the payout

• {ERC20-Transfer}: to the policyholder with the payout

Name	Type	Description
policy	struct Policy.PolicyData	A policy previously created with newPolicy
payout	uint256	The amount to paid to the policyholder

resolvePolicyFullPayout

function resolvePolicyFullPayout(struct Policy.PolicyData policy, bool customerWon) external

Resolves a policy with a payout that can be either 0 or the maximum payout of the policy

Requirements:

• policy: must be a Policy previously created with newPolicy (checked with policy.hash()) and not resolved before and not expired (if customerWon).

Events:

• {PolicyPool-PolicyResolved}: with the payout

• {ERC20-Transfer}: to the policyholder with the payout

Name	Type	Description
policy	struct Policy.PolicyData	A policy previously created with newPolicy
customerWon	bool	Indicated if the payout is zero or the maximum payout

expirePolicy

function expirePolicy(struct Policy.PolicyData policy) external

Resolves a policy with a payout 0, unlocking the solvency. Can be called by anyone, but only after Policy.expiration.

Requirements:

• policy: must be a Policy previously created with newPolicy (checked with policy.hash()) and not resolved before

• Policy expired: Policy.expiration <= block.timestamp

Events:

• {PolicyPool-PolicyResolved}: with payout == 0

Name	Type	Description
policy	struct Policy.PolicyData	A policy previously created with newPolicy

deposit

function deposit(contract IEToken eToken, uint256 amount) external

Deposits liquidity into an eToken. Forwards the call to {EToken-deposit}, after transferring the funds. The user will receive etokens for the same amount deposited.

Requirements:

• msg.sender approved the spending of currency() for at least amount

• eToken is an active eToken installed in the pool.

Events:

• {EToken-Transfer}: from 0x0 to msg.sender, reflects the eTokens minted.

• {ERC20-Transfer}: from msg.sender to address(eToken)

Name	Type	Description
eToken	contract IEToken	The address of the eToken to which the user wants to provide liquidity
amount	uint256	The amount to deposit

withdraw

function withdraw(contract IEToken eToken, uint256 amount) external returns (uint256)

Withdraws an amount from an eToken. Forwards the call to {EToken-withdraw}. amount of eTokens will be burned and the user will receive the same amount in currency().

Requirements:

• eToken is an active (or deprecated) eToken installed in the pool.

Events:

• {EToken-Transfer}: from msg.sender to 0x0, reflects the eTokens burned.

• {ERC20-Transfer}: from address(eToken) to msg.sender

Name	Type	Description
eToken	contract IEToken	The address of the eToken from where the user wants to withdraw liquidity
amount	uint256	The amount to withdraw. If equal to type(uint256).max, means full withdrawal. If the balance is not enough or can't be withdrawn (locked as SCR), it withdraws as much as it can, but doesn't fails.

Name	Type	Description
[0]	uint256	Returns the actual amount withdrawn.

access

function access() external view virtual returns (contract IAccessManager)

Reference to the {AccessManager} contract, this contract manages the access controls.

Name	Type	Description
[0]	contract IAccessManager	The address of the AccessManager contract

currency

function currency() external view virtual returns (contract IERC20Metadata)

Reference to the main currency (ERC20) used in the protocol

Name	Type	Description
[0]	contract IERC20Metadata	The address of the currency (e.g. USDC) token used in the protocol

treasury

function treasury() external view returns (address)

Returns the address of the treasury, the one that receives the protocol fees.

Others

addComponent

function addComponent(contract IPolicyPoolComponent component, enum PolicyPool.ComponentKind kind) external

Adds a new component (either an {EToken}, {RiskModule} or {PremiumsAccount}) to the protocol. The component status will be active.

Requirements:

• Must be called by a user with the {LEVEL1_ROLE}

• The component wasn't added before.

Events:

• Emits {ComponentStatusChanged} with status active.

Name	Type	Description
component	contract IPolicyPoolComponent	The address of component contract. Must be an {EToken}, {RiskModule} or {PremiumsAccount} linked to this specific {PolicyPool} and matching the kind specified in the next paramter.
kind	enum PolicyPool.ComponentKind	The type of component to be added.

removeComponent

function removeComponent(contract IPolicyPoolComponent component) external

Removes a component from the protocol. The component needs to be in deprecated status before doing this operation.

Requirements:

• Must be called by a user with the {LEVEL1_ROLE}

• The component status is deprecated.

Events:

• Emits {ComponentStatusChanged} with status inactive.

Name	Type	Description
component	contract IPolicyPoolComponent	The address of component contract. Must be a component added before.

changeComponentStatus

function changeComponentStatus(contract IPolicyPoolComponent component, enum PolicyPool.ComponentStatus newStatus) external

Changes the status of a component.

Requirements:

• Must be called by a user with the {LEVEL1_ROLE} if the new status is active or deprecated.

• Must be called by a user with the {GUARDIAN_ROLE} if the new status is suspended.

Events:

• Emits {ComponentStatusChanged} with the new status.

Name	Type	Description
component	contract IPolicyPoolComponent	The address of component contract. Must be a component added before.
newStatus	enum PolicyPool.ComponentStatus	The new status, must be either active, deprecated or suspended.