# IVerification

> TEE machine attestation and availability checks.

> For the complete documentation index, see [llms.txt](/llms.txt). Markdown versions of documentation pages are available by appending `.md` to the page URL.

Source: https://dev.flare.network/fcc/reference/IVerification

Public interface for `VerificationFacet` on the [`FlareTeeManager`](/fcc/reference/IFlareTeeManager) diamond.

A TEE machine stays trusted only while its **availability check** is valid. Nothing here is automatic: a caller requests attestation, FDC2 produces an availability-check proof, and someone submits that proof onchain.

Typical flow:

1.  `requestTeeAttestation` creates a challenge and sends an `F_REG` / `TEE_ATTESTATION` instruction to the machine. [`IMachineManager.register`](/fcc/reference/IMachineManager) already does this on first registration.
2.  `requestAvailabilityCheckAttestation` asks FDC2 for a `TeeAvailabilityCheck` proof. The challenge must still be valid or the call reverts with `ChallengeExpired` error.
3.  `confirmAvailability` verifies the proof for a `PRODUCTION` machine and extends `endTs`. First promotion `INITIALIZED → PRODUCTION` uses [`IMachineManager.toProduction`](/fcc/reference/IMachineManager) instead.

The `getAvailabilityCheckValidity` function returns that window. After `endTs`, anyone can suspend the machine with `IMachineManager.pause`.

Inherits shared [`ITeeCommonErrors`](/fcc/reference/ITeeCommonErrors).

## Constants[​](#constants "Direct link to Constants")

```
bytes32 constant TEE_SOURCE_ID = bytes32("TEE");
```

FDC2 source id for TEE availability-check attestations.

## Types[​](#types "Direct link to Types")

### `TeeAttestation`[​](#teeattestation "Direct link to teeattestation")

Body of the `TEE_ATTESTATION` instruction sent to the machine.

```
struct TeeAttestation {        IMachineManager.TeeMachineWithAttestationData teeMachine;        bytes32 challenge;    }
```

## Functions[​](#functions "Direct link to Functions")

### `requestTeeAttestation`[​](#requestteeattestation "Direct link to requestteeattestation")

Request attestation for a TEE machine. Emits TeeAttestationRequested event.

```
function requestTeeAttestation(        address _teeId,        address _claimBackAddress    )        external payable
```

**Parameters**

-   `_teeId`: The TEE machine id.
-   `_claimBackAddress`: An address that can claim back the fee if the instructions are not executed (optional).

### `requestAvailabilityCheckAttestation`[​](#requestavailabilitycheckattestation "Direct link to requestavailabilitycheckattestation")

Request availability check attestation for a TEE machine - triggers FDC2 availability check.

```
function requestAvailabilityCheckAttestation(        address _teeId,        bytes32 _instructionId,        address _testOnTeeId,        address _proofOwner,        address _claimBackAddress    )        external payable
```

**Parameters**

-   `_teeId`: The TEE machine id.
-   `_instructionId`: The instruction ID used for the TEE attestation check (challenge must match).
-   `_testOnTeeId`: The TEE machine id to test on, if address(0) a random active TEE machine will be used.
-   `_proofOwner`: The proof owner address (optional).
-   `_claimBackAddress`: An address that can claim back the fee if the instructions are not executed (optional).

### `confirmAvailability`[​](#confirmavailability "Direct link to confirmavailability")

Extend the availability check validity. Emits AvailabilityCheckValidityExtended event.

```
function confirmAvailability(        ITeeAvailabilityCheck.Proof calldata _proof    )        external
```

**Parameters**

-   `_proof`: The availability check proof. The machine must already be in `PRODUCTION`. First promotion uses `IMachineManager.toProduction` instead.

### `getCosigners`[​](#getcosigners "Direct link to getcosigners")

Returns the list of FDC2 cosigners and their threshold used for the TEE machine registration.

```
function getCosigners()        external view        returns (            address[] memory _cosigners,            uint64 _cosignersThreshold        )
```

**Returns**

-   `_cosigners`: The list of cosigners.
-   `_cosignersThreshold`: The cosigners threshold.

### `getSettings`[​](#getsettings "Direct link to getsettings")

Returns the settings.

```
function getSettings()        external view        returns (            uint256 _availabilityCheckValidityDurationSeconds,            uint256 _challengeValidityDurationSeconds        )
```

**Returns**

-   `_availabilityCheckValidityDurationSeconds`: The availability check validity duration.
-   `_challengeValidityDurationSeconds`: The challenge validity duration.

The `SettingsUpdated` event also records `signingPolicyValidityDurationInRewardEpochs`. That value is not returned here.

### `getAvailabilityCheckValidity`[​](#getavailabilitycheckvalidity "Direct link to getavailabilitycheckvalidity")

Returns the availability check validity for a TEE machine.

```
function getAvailabilityCheckValidity(        address _teeId    )        external view        returns (            uint64 _endTs,            uint32 _lastSigningPolicyId        )
```

**Parameters**

-   `_teeId`: The TEE machine id.

**Returns**

-   `_endTs`: The end timestamp of the availability check validity.
-   `_lastSigningPolicyId`: The last signing policy id.

## Events[​](#events "Direct link to Events")

### `SettingsUpdated`[​](#settingsupdated "Direct link to settingsupdated")

```
event SettingsUpdated(        uint64 availabilityCheckValidityDurationSeconds,        uint64 signingPolicyValidityDurationInRewardEpochs,        uint64 challengeValidityDurationSeconds    )
```

**Parameters**

-   `availabilityCheckValidityDurationSeconds` (`uint64 availabilityCheckValidityDurationSeconds`)
-   `signingPolicyValidityDurationInRewardEpochs` (`uint64 signingPolicyValidityDurationInRewardEpochs`)
-   `challengeValidityDurationSeconds` (`uint64 challengeValidityDurationSeconds`)

### `CosignersSet`[​](#cosignersset "Direct link to cosignersset")

```
event CosignersSet(        address[] cosigners,        uint64 cosignersThreshold    )
```

**Parameters**

-   `cosigners` (`address[] cosigners`)
-   `cosignersThreshold` (`uint64 cosignersThreshold`)

### `TeeAttestationRequested`[​](#teeattestationrequested "Direct link to teeattestationrequested")

```
event TeeAttestationRequested(        address indexed teeId,        bytes32 challenge    )
```

**Parameters**

-   `teeId` (`address indexed teeId`)
-   `challenge` (`bytes32 challenge`)

### `AvailabilityCheckValidityExtended`[​](#availabilitycheckvalidityextended "Direct link to availabilitycheckvalidityextended")

```
event AvailabilityCheckValidityExtended(        address indexed teeId,        address indexed owner,        uint256 endTs    )
```

**Parameters**

-   `teeId` (`address indexed teeId`)
-   `owner` (`address indexed owner`)
-   `endTs` (`uint256 endTs`)

## Errors[​](#errors "Direct link to Errors")

Facet-specific errors are listed here. The interface also inherits shared [`ITeeCommonErrors`](/fcc/reference/ITeeCommonErrors). The `confirmAvailability` function uses those for later checks: `AvailabilityCheckTimestampInvalid` if the proof header timestamp is outside `[challengeTs, now)`, and `InvalidResponseData` if the proof's response body fails (code hash, platform, signing policy, or state).

### `ChallengeExpired`[​](#challengeexpired "Direct link to challengeexpired")

The attestation challenge for this machine is no longer valid. The `challengeTs` value is when the challenge was created. Thrown by `requestAvailabilityCheckAttestation` if you wait longer than `challengeValidityDurationSeconds` after `requestTeeAttestation`, and again when a proof is verified if that window has already closed. Call `requestTeeAttestation` again to mint a fresh challenge.

```
error ChallengeExpired(uint256 challengeTs)
```

**Parameters**

-   `challengeTs`: Timestamp when the expired challenge was created.

### `InvalidAttestation`[​](#invalidattestation "Direct link to invalidattestation")

The proof is not a TEE availability-check attestation. Thrown when verifying a proof whose FDC2 header does not have `attestationType = TeeAvailabilityCheck`, `sourceId = TEE`, and `thresholdBIPS = 0`.

```
error InvalidAttestation()
```

### `InvalidRequestBody`[​](#invalidrequestbody "Direct link to invalidrequestbody")

The proof's request body does not match the machine onchain. Thrown when verifying a proof whose `url`, `teeProxyId`, or `challenge` differs from the registered TEE machine and the stored challenge.

```
error InvalidRequestBody()
```