> ## Documentation Index
> Fetch the complete documentation index at: https://phaseo.app/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Persist and Resume Runs

> Store Rust Agent SDK run state and continue after tools or human review.

`RunResult` is serializable with Serde. Store it in your own database, object store, or job record when a pause must survive a process restart.

## Save paused state

```rust theme={null}
let paused_json = serde_json::to_string_pretty(&paused)?;
std::fs::write("paused-run.json", paused_json)?;
```

## Restore state

```rust theme={null}
use phaseo_agent::RunResult;

let saved = std::fs::read_to_string("paused-run.json")?;
let paused: RunResult = serde_json::from_str(&saved)?;
```

Recreate the same agent definition and tools before continuing. Closures and `AgentDefinition` are not part of the serialized run.

The effective model and maximum step count are stored in `RunRecord`, so per-run overrides remain active after continuation.

## Human review

Use `human_review(...)` to inspect a completed model turn and request human input:

```rust theme={null}
use phaseo_agent::{AgentDefinition, HumanReviewRequest};
use serde_json::json;

let definition = AgentDefinition::new(
    "review-agent",
    "openai/gpt-5.6-sol",
)
.human_review(|context| {
    if context.response.message.content.contains("needs approval") {
        Some(HumanReviewRequest {
            reason: "Review the proposed action".to_string(),
            payload: json!({
                "draft": context.response.message.content
            }),
        })
    } else {
        None
    }
});
```

Resume with human input:

```rust theme={null}
use phaseo_agent::ContinueOptions;

let mut options = ContinueOptions::new(paused);
options.human_input = Some(
    "Approved. Continue and return the final result.".to_string(),
);

let completed = agent.continue_run(&mut client, options)?;
```

## Pause kinds

| `pause.kind`      | Required continuation value                 |
| ----------------- | ------------------------------------------- |
| `human_review`    | Non-empty `ContinueOptions.human_input`     |
| `tool_approval`   | `ToolDecision` entries by tool-call ID      |
| `external_output` | `ToolOutput` entries by tool-call ID        |
| `tool_input`      | A mixture of approvals and external outputs |

## Application-owned persistence

The Rust Agent SDK does not provide a hosted state backend or persistence adapter. Your application owns:

* encryption and retention of stored runs
* authorization for approvals and human input
* recreation of tool executors
* idempotency around resumed side effects

## Related

* [Tools and approvals](./agent-sdk-tools)
* [Events, retries, and errors](./agent-sdk-events-and-errors)