# Interface Checkpoint

A snapshot of graph execution state at a given step boundary. Contains all information needed to resume execution.

interface Checkpoint {
id: string;
executionId: string;
schemaVersion: number;
stepNumber: number;
state: Readonly<GraphState>;
pendingNodeIds: readonly string[];
completedResults: readonly NodeResult[];
createdAt: string;
metadata?: Record<string, unknown>;
interrupt?: CheckpointInterrupt;
}

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:63

##### Index

### Properties

id
executionId
schemaVersion
stepNumber
state
pendingNodeIds
completedResults
createdAt
metadata?
interrupt?

## Properties

### `Readonly` id

id: string

Unique checkpoint ID.

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:65

### `Readonly` executionId

executionId: string

Execution ID this checkpoint belongs to.

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:67

### `Readonly` schemaVersion

schemaVersion: number

Schema version for deserialization.

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:69

### `Readonly` stepNumber

stepNumber: number

Step number when this checkpoint was taken.

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:71

### `Readonly` state

state: Readonly<GraphState>

Full graph state at this point.

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:73

### `Readonly` pendingNodeIds

pendingNodeIds: readonly string[]

IDs of nodes ready to run next.

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:75

### `Readonly` completedResults

completedResults: readonly NodeResult[]

Results of all completed nodes so far.

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:77

### `Readonly` createdAt

createdAt: string

ISO timestamp when checkpoint was created.

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:79

### `Optional` `Readonly` metadata

metadata?: Record<string, unknown>

Optional metadata for debugging.

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:81

### `Optional` `Readonly` interrupt

interrupt?: CheckpointInterrupt

If present, the checkpoint was created because a node returned an Interrupt. The resume API uses this to know which node to re-run and which interrupt id to match resume values against. (#1895)

- Defined in packages/nexus-agents/src/orchestration/graph/checkpoint-types.ts:87