Domain keys

The Camunda Domain Type System replaces the bare String identifiers emitted by the OpenAPI generator with validated newtypes. Passing a ProcessInstanceKey where a JobKey is expected is a compile error, so whole classes of identifier mix-ups are caught before the request is sent.

Every key type exposes the same methods:

Method	Description
assume_exists(value: impl Into<String>) -> Self	Construct without validation. Use when side-loading values not received from an API call.
into_value(self) -> String	Consume the newtype and return the underlying string value.
is_valid(value: &str) -> bool	Returns true if the value satisfies this type's constraints.
try_new(value: impl Into<String>) -> Result<Self, CamundaKeyError>	Construct with constraint validation.
value(&self) -> &str	The underlying string value.

Key types

Key type	Description
AgentDefinitionKey	Identifier for an agent definition.
AgentHistoryItemKey	Identifier for an agent history item.
AgentInstanceKey	Identifier for an agent instance.
AuditLogEntityKey	System-generated entity key for an audit log entry.
AuditLogKey	Identifier for an audit log.
AuthorizationKey	Identifier for an authorization.
BatchOperationKey	System-generated key for an batch operation.
BusinessId	An optional, user-defined string identifier that identifies the process instance within the scope of a process definition (scoped by tenant). If provided and uniqueness enforcement is enabled, the engine will reject creation if another root process instance with the same business id is already active for the same process definition. Note that any active child process instances with the same business id are not taken into account.
CamundaKey	Shared behaviour for every Camunda Domain Type (semantic key newtype).
CamundaKeyError	Error returned when a value does not satisfy a Camunda Domain Type's constraints.
ClientId	Validated identifier newtype.
ClusterVariableName	Validated identifier newtype.
ConditionalEvaluationKey	Identifier for a conditional evaluation.
DecisionDefinitionId	Validated identifier newtype.
DecisionDefinitionKey	Identifier for a decision definition.
DecisionEvaluationInstanceKey	Identifier for a decision evaluation instance.
DecisionEvaluationKey	Identifier for a decision evaluation.
DecisionInstanceKey	Identifier for a decision instance.
DecisionRequirementsKey	Identifier for a decision requirements.
DeploymentKey	Identifier for a deployment.
DocumentId	Document Id that uniquely identifies a document.
ElementId	The model-defined id of an element.
ElementInstanceKey	Identifier for an element instance.
EndCursor	Validated identifier newtype.
FormId	The user-defined id for the form
FormKey	Identifier for a form.
GlobalListenerId	Validated identifier newtype.
GroupId	The unique identifier of a group.
HistoryItemId	The client-supplied identifier this item was created with.
IncidentKey	Identifier for an incident.
JobKey	Identifier for a job.
JobLeaseToken	An opaque, engine-minted fencing token identifying a single activation of a job. Returned by Activate Jobs as ActivatedJobResult.jobLeaseToken when the job is activated with a lease, and passed back under the same name on fenced job commands and on agent-instance creation/updates, to prove the caller holds the current lease. The token is opaque: clients may rely on its presence and equality only, and must never construct, parse, or otherwise interpret it beyond equality checks. It cannot be minted client-side; only the engine produces it, exactly once per leased activation, and clients must not depend on any particular internal format.
MappingRuleId	Validated identifier newtype.
MessageKey	Identifier for a message.
MessageSubscriptionKey	Identifier for a message subscription.
ProcessDefinitionId	Validated identifier newtype.
ProcessDefinitionKey	Identifier for a process definition.
ProcessInstanceKey	Identifier for a process instance.
RoleId	Validated identifier newtype.
ScopeKey	System-generated key for a scope. A scope can hold variables and represents either an element instance in a BPMN process or the process instance itself.
SignalKey	Identifier for a signal.
StartCursor	Validated identifier newtype.
Tag	Validated identifier newtype.
TenantId	Validated identifier newtype.
UserTaskKey	Identifier for an user task.
Username	Validated identifier newtype.
VariableKey	Identifier for a variable.

Each key also has a matching <Key>ExactMatch wrapper used by the search filter models to express an exact-value match.