> For the complete documentation index, see [llms.txt](https://docs.talus.network/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.talus.network/talus-docs-v2.1.0/reference/move/nexus_interface/verifier.md).
# verifier
* [Struct `VerifierMethodId`](#struct-verifiermethodid)
* [Struct `LeaderStampData`](#struct-leaderstampdata)
* [Struct `RegisteredKeyStampData`](#struct-registeredkeystampdata)
* [Struct `ExternalVerifierStampData`](#struct-externalverifierstampdata)
* [Struct `RegisteredKeyAuxiliary`](#struct-registeredkeyauxiliary)
* [Struct `ToolInvocationNoncePreimage`](#struct-toolinvocationnoncepreimage)
* [Struct `CanonicalToolInput`](#struct-canonicaltoolinput)
* [Struct `VerificationVerdict`](#struct-verificationverdict)
* [Enum `ToolVerifierMode`](#enum-toolverifiermode)
* [Enum `FailureEvidenceKind`](#enum-failureevidencekind)
* [Enum `ToolVerifierSupport`](#enum-toolverifiersupport)
* [Enum `LeaderTarget`](#enum-leadertarget)
* [Enum `VerifierDecision`](#enum-verifierdecision)
* [Constants](#constants)
* [Function `verifier_mode_none`](#function-verifier_mode_none)
* [Function `verifier_mode_registered_key`](#function-verifier_mode_registered_key)
* [Function `verifier_mode_external`](#function-verifier_mode_external)
* [Function `failure_evidence_kind_tool_evidence`](#function-failure_evidence_kind_tool_evidence)
* [Function `failure_evidence_kind_leader_evidence`](#function-failure_evidence_kind_leader_evidence)
* [Function `committed_result_evidence_is_leader_failure`](#function-committed_result_evidence_is_leader_failure)
* [Function `committed_result_evidence_is_tool_failure`](#function-committed_result_evidence_is_tool_failure)
* [Function `new_method_id`](#function-new_method_id)
* [Function `method_tool_id`](#function-method_tool_id)
* [Function `support_registered_key`](#function-support_registered_key)
* [Function `support_external`](#function-support_external)
* [Function `support_matches_mode`](#function-support_matches_mode)
* [Function `support_method`](#function-support_method)
* [Function `leader_target_onchain`](#function-leader_target_onchain)
* [Function `leader_target_offchain`](#function-leader_target_offchain)
* [Function `leader_stamp_data`](#function-leader_stamp_data)
* [Function `leader_stamp_leader_cap_id`](#function-leader_stamp_leader_cap_id)
* [Function `leader_stamp_target`](#function-leader_stamp_target)
* [Function `leader_target_is_offchain`](#function-leader_target_is_offchain)
* [Function `leader_target_tool_id`](#function-leader_target_tool_id)
* [Function `leader_target_verifier_witness_id`](#function-leader_target_verifier_witness_id)
* [Function `registered_key_stamp_data`](#function-registered_key_stamp_data)
* [Function `registered_key_stamp_input_hash`](#function-registered_key_stamp_input_hash)
* [Function `registered_key_stamp_output_hash`](#function-registered_key_stamp_output_hash)
* [Function `registered_key_stamp_nonce`](#function-registered_key_stamp_nonce)
* [Function `external_stamp_data`](#function-external_stamp_data)
* [Function `external_stamp_output_hash`](#function-external_stamp_output_hash)
* [Function `registered_key_auxiliary`](#function-registered_key_auxiliary)
* [Function `auxiliary_input_hash`](#function-auxiliary_input_hash)
* [Function `auxiliary_nonce`](#function-auxiliary_nonce)
* [Function `auxiliary_leader_signature`](#function-auxiliary_leader_signature)
* [Function `auxiliary_tool_signature`](#function-auxiliary_tool_signature)
* [Function `tool_invocation_nonce`](#function-tool_invocation_nonce)
* [Function `registered_key_tool_signature_message`](#function-registered_key_tool_signature_message)
* [Function `output_sha256`](#function-output_sha256)
* [Function `new_none`](#function-new_none)
* [Function `new_accept`](#function-new_accept)
* [Function `new_reject`](#function-new_reject)
* [Function `new_registered_key_verdict`](#function-new_registered_key_verdict)
* [Function `verdict_witness_id`](#function-verdict_witness_id)
* [Function `verdict_decision`](#function-verdict_decision)
* [Function `verdict_output_hash`](#function-verdict_output_hash)
* [Function `consume_verdict`](#function-consume_verdict)
* [Function `decision_is_accept`](#function-decision_is_accept)
* [Function `decision_reason`](#function-decision_reason)
### Struct `VerifierMethodId`
Concrete non-generic external verifier target bound to one Tool.
```move
public struct VerifierMethodId has copy, drop, store
```
Fields
`tool_id: sui::object::IDpackage_id: sui::object::IDmodule_name: std::ascii::Stringfunction_name: std::ascii::String`
#### Struct `LeaderStampData`
Exact data stored under the LeaderRegistry worksheet stamp.
```move
public struct LeaderStampData has copy, drop, store
```
Fields
`leader_cap_id: sui::object::IDtarget:` [`nexus_interface::verifier::LeaderTarget`](#nexus_interface_verifier_LeaderTarget)
#### Struct `RegisteredKeyStampData`
Hash bindings stored under the singleton RegisteredKey witness.
```move
public struct RegisteredKeyStampData has copy, drop, store
```
Fields
`input_hash: vectoroutput_hash: vectornonce: vector`
#### Struct `ExternalVerifierStampData`
Output binding stored under an External verifier witness.
```move
public struct ExternalVerifierStampData has copy, drop, store
```
Fields
`output_hash: vector`
#### Struct `RegisteredKeyAuxiliary`
Strict BCS auxiliary for the built-in two-signature scheme.
```move
public struct RegisteredKeyAuxiliary has copy, drop, store
```
Fields
`input_hash: vectornonce: vectorleader_signature: vectortool_signature: vector`
#### Struct `ToolInvocationNoncePreimage`
Canonical BCS identity for one logical off-chain Tool invocation.
```move
public struct ToolInvocationNoncePreimage has copy, drop, store
```
Fields
`execution_id: sui::object::IDwalk_index: u64vertex_name: vectoriteration: u64`
#### Struct `CanonicalToolInput`
One canonical port-name/data pair in the RegisteredKey input transcript.
```move
public struct CanonicalToolInput has copy, drop, store
```
Fields
`port_name: vectordata:` [`nexus_primitives::data::NexusData`](/talus-docs-v2.1.0/reference/move/nexus_primitives/data.md#nexus_primitives_data_NexusData)
#### Struct `VerificationVerdict`
Same-PTB hot potato produced by a verifier and consumed by offchain submission.
```move
public struct VerificationVerdict
```
Fields
`output:` [`nexus_primitives::tagged_output::TaggedOutput`](/talus-docs-v2.1.0/reference/move/nexus_primitives/tagged_output.md#nexus_primitives_tagged_output_TaggedOutput)`verifier_witness_id: std::option::Optiondecision:` [`nexus_interface::verifier::VerifierDecision`](#nexus_interface_verifier_VerifierDecision)
#### Enum `ToolVerifierMode`
Verification selected by one offchain DAG vertex.
```move
public enum ToolVerifierMode has copy, drop, store
```
Variants
Variant `None`Variant `RegisteredKey`Variant `External`
#### Enum `FailureEvidenceKind`
Identifies terminal failure evidence produced by a Tool execution or verifier.
```move
public enum FailureEvidenceKind has copy, drop, store
```
Variants
Variant `ToolEvidence`Variant `LeaderEvidence`
#### Enum `ToolVerifierSupport`
The one verified mode globally supported by an off-chain Tool.
```move
public enum ToolVerifierSupport has copy, drop, store
```
Variants
Variant `RegisteredKey`Variant `Externalmethod_id:` [`nexus_interface::verifier::VerifierMethodId`](#nexus_interface_verifier_VerifierMethodId)
#### Enum `LeaderTarget`
The execution target authenticated by the leader stamp.
```move
public enum LeaderTarget has copy, drop, store
```
Variants
Variant `Onchaintool_witness_id: sui::object::ID`Variant `Offchaintool_id: sui::object::IDverifier_witness_id: std::option::Option`
#### Enum `VerifierDecision`
The only decision a Tool verifier may make.
```move
public enum VerifierDecision has copy, drop, store
```
Variants
Variant `Accept`Variant `Rejectreason: std::option::Option>`
#### Constants
```move
#[error]
const EInvalidVerifierData: vector = b"Verifier hashes, nonce, or signatures have invalid lengths";
```
```move
#[error]
const EInvalidVerifierMethod: vector = b"Verifier module and function must be non-empty";
```
```move
#[error]
const EWrongLeaderTarget: vector = b"Leader target kind does not match the requested field";
```
```move
const SHA256_LEN: u64 = 32;
```
```move
const ED25519_SIGNATURE_LEN: u64 = 64;
```
```move
const MAX_REJECT_REASON_LEN: u64 = 1024;
```
```move
const DEFAULT_REJECT_REASON: vector = vector[84, 111, 111, 108, 32, 118, 101, 114, 105, 102, 105, 99, 97, 116, 105, 111, 110, 32, 102, 97, 105, 108, 101, 100];
```
```move
const INVOCATION_NONCE_DOMAIN: vector = vector[110, 101, 120, 117, 115, 46, 100, 105, 114, 101, 99, 116, 46, 118, 51, 46, 105, 110, 118, 111, 99, 97, 116, 105, 111, 110, 45, 110, 111, 110, 99, 101];
```
```move
const TOOL_RESPONSE_DOMAIN: vector = vector[110, 101, 120, 117, 115, 46, 100, 105, 114, 101, 99, 116, 46, 118, 51, 46, 116, 111, 111, 108, 45, 114, 101, 115, 112, 111, 110, 115, 101];
```
```move
const RAW_OUTPUT_DOMAIN: vector = vector[110, 101, 120, 117, 115, 46, 100, 105, 114, 101, 99, 116, 46, 118, 51, 46, 114, 97, 119, 45, 111, 117, 116, 112, 117, 116];
```
#### Function `verifier_mode_none`
```move
public fun verifier_mode_none(): nexus_interface::verifier::ToolVerifierMode
```
#### Function `verifier_mode_registered_key`
```move
public fun verifier_mode_registered_key(): nexus_interface::verifier::ToolVerifierMode
```
#### Function `verifier_mode_external`
```move
public fun verifier_mode_external(): nexus_interface::verifier::ToolVerifierMode
```
#### Function `failure_evidence_kind_tool_evidence`
```move
public fun failure_evidence_kind_tool_evidence(): nexus_interface::verifier::FailureEvidenceKind
```
#### Function `failure_evidence_kind_leader_evidence`
```move
public fun failure_evidence_kind_leader_evidence(): nexus_interface::verifier::FailureEvidenceKind
```
#### Function `committed_result_evidence_is_leader_failure`
```move
public fun committed_result_evidence_is_leader_failure(evidence: &std::option::Option): bool
```
#### Function `committed_result_evidence_is_tool_failure`
```move
public fun committed_result_evidence_is_tool_failure(evidence: &std::option::Option): bool
```
#### Function `new_method_id`
```move
public fun new_method_id(tool_id: sui::object::ID, package_id: sui::object::ID, module_name: std::ascii::String, function_name: std::ascii::String): nexus_interface::verifier::VerifierMethodId
```
#### Function `method_tool_id`
```move
public fun method_tool_id(self: &nexus_interface::verifier::VerifierMethodId): sui::object::ID
```
#### Function `support_registered_key`
```move
public fun support_registered_key(): nexus_interface::verifier::ToolVerifierSupport
```
#### Function `support_external`
```move
public fun support_external(method_id: nexus_interface::verifier::VerifierMethodId): nexus_interface::verifier::ToolVerifierSupport
```
#### Function `support_matches_mode`
```move
public fun support_matches_mode(self: &nexus_interface::verifier::ToolVerifierSupport, mode: nexus_interface::verifier::ToolVerifierMode): bool
```
#### Function `support_method`
```move
public fun support_method(self: &nexus_interface::verifier::ToolVerifierSupport): std::option::Option
```
#### Function `leader_target_onchain`
```move
public fun leader_target_onchain(tool_witness_id: sui::object::ID): nexus_interface::verifier::LeaderTarget
```
#### Function `leader_target_offchain`
```move
public fun leader_target_offchain(tool_id: sui::object::ID, verifier_witness_id: std::option::Option): nexus_interface::verifier::LeaderTarget
```
#### Function `leader_stamp_data`
```move
public fun leader_stamp_data(leader_cap_id: sui::object::ID, target: nexus_interface::verifier::LeaderTarget): nexus_interface::verifier::LeaderStampData
```
#### Function `leader_stamp_leader_cap_id`
```move
public fun leader_stamp_leader_cap_id(self: &nexus_interface::verifier::LeaderStampData): sui::object::ID
```
#### Function `leader_stamp_target`
```move
public fun leader_stamp_target(self: &nexus_interface::verifier::LeaderStampData): nexus_interface::verifier::LeaderTarget
```
#### Function `leader_target_is_offchain`
```move
public fun leader_target_is_offchain(self: &nexus_interface::verifier::LeaderTarget): bool
```
#### Function `leader_target_tool_id`
```move
public fun leader_target_tool_id(self: &nexus_interface::verifier::LeaderTarget): sui::object::ID
```
#### Function `leader_target_verifier_witness_id`
```move
public fun leader_target_verifier_witness_id(self: &nexus_interface::verifier::LeaderTarget): std::option::Option
```
#### Function `registered_key_stamp_data`
```move
public fun registered_key_stamp_data(input_hash: vector, output_hash: vector, nonce: vector): nexus_interface::verifier::RegisteredKeyStampData
```
#### Function `registered_key_stamp_input_hash`
```move
public fun registered_key_stamp_input_hash(self: &nexus_interface::verifier::RegisteredKeyStampData): vector
```
#### Function `registered_key_stamp_output_hash`
```move
public fun registered_key_stamp_output_hash(self: &nexus_interface::verifier::RegisteredKeyStampData): vector
```
#### Function `registered_key_stamp_nonce`
```move
public fun registered_key_stamp_nonce(self: &nexus_interface::verifier::RegisteredKeyStampData): vector
```
#### Function `external_stamp_data`
```move
public fun external_stamp_data(output_hash: vector): nexus_interface::verifier::ExternalVerifierStampData
```
#### Function `external_stamp_output_hash`
```move
public fun external_stamp_output_hash(self: &nexus_interface::verifier::ExternalVerifierStampData): vector
```
#### Function `registered_key_auxiliary`
```move
public fun registered_key_auxiliary(input_hash: vector, nonce: vector, leader_signature: vector, tool_signature: vector): nexus_interface::verifier::RegisteredKeyAuxiliary
```
#### Function `auxiliary_input_hash`
```move
public fun auxiliary_input_hash(self: &nexus_interface::verifier::RegisteredKeyAuxiliary): vector
```
#### Function `auxiliary_nonce`
```move
public fun auxiliary_nonce(self: &nexus_interface::verifier::RegisteredKeyAuxiliary): vector
```
#### Function `auxiliary_leader_signature`
```move
public fun auxiliary_leader_signature(self: &nexus_interface::verifier::RegisteredKeyAuxiliary): vector
```
#### Function `auxiliary_tool_signature`
```move
public fun auxiliary_tool_signature(self: &nexus_interface::verifier::RegisteredKeyAuxiliary): vector
```
#### Function `tool_invocation_nonce`
Derives the nonce for one logical off-chain Tool invocation.
```move
public fun tool_invocation_nonce(execution_id: sui::object::ID, walk_index: u64, vertex_name: vector, iteration: u64): vector
```
#### Function `registered_key_tool_signature_message`
Builds the exact nonce-bound message signed by a RegisteredKey Tool.
```move
public fun registered_key_tool_signature_message(leader_signature: vector, nonce: vector, output_hash: vector): vector
```
#### Function `output_sha256`
Hashes the canonical response body under the existing direct protocol domain.
```move
public fun output_sha256(output: &nexus_primitives::tagged_output::TaggedOutput): vector
```
#### Function `new_none`
Builds an accepted verdict for a vertex configured as `None`.
```move
public fun new_none(output: nexus_primitives::tagged_output::TaggedOutput): nexus_interface::verifier::VerificationVerdict
```
#### Function `new_accept`
Builds an External accept verdict and stamps the exact output hash.
```move
public fun new_accept(worksheet: &mut nexus_primitives::proof_of_uid::ProofOfUID, output: nexus_primitives::tagged_output::TaggedOutput, witness_uid: &sui::object::UID): nexus_interface::verifier::VerificationVerdict
```
#### Function `new_reject`
Builds an External reject verdict and normalizes its optional reason.
```move
public fun new_reject(worksheet: &mut nexus_primitives::proof_of_uid::ProofOfUID, output: nexus_primitives::tagged_output::TaggedOutput, witness_uid: &sui::object::UID, reason: std::option::Option>): nexus_interface::verifier::VerificationVerdict
```
#### Function `new_registered_key_verdict`
Builds and stamps the verdict produced by the built-in RegisteredKey verifier.
```move
public fun new_registered_key_verdict(worksheet: &mut nexus_primitives::proof_of_uid::ProofOfUID, output: nexus_primitives::tagged_output::TaggedOutput, input_hash: vector, nonce: vector, witness_uid: &sui::object::UID, accepted: bool): nexus_interface::verifier::VerificationVerdict
```
#### Function `verdict_witness_id`
```move
public fun verdict_witness_id(self: &nexus_interface::verifier::VerificationVerdict): std::option::Option
```
#### Function `verdict_decision`
```move
public fun verdict_decision(self: &nexus_interface::verifier::VerificationVerdict): nexus_interface::verifier::VerifierDecision
```
#### Function `verdict_output_hash`
```move
public fun verdict_output_hash(self: &nexus_interface::verifier::VerificationVerdict): vector
```
#### Function `consume_verdict`
```move
public fun consume_verdict(self: nexus_interface::verifier::VerificationVerdict): (nexus_primitives::tagged_output::TaggedOutput, std::option::Option, nexus_interface::verifier::VerifierDecision)
```
#### Function `decision_is_accept`
```move
public fun decision_is_accept(self: &nexus_interface::verifier::VerifierDecision): bool
```
#### Function `decision_reason`
```move
public fun decision_reason(self: nexus_interface::verifier::VerifierDecision): std::option::Option>
```
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