> ## 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.

> ## Agent Instructions
> Phaseo Gateway base URL: https://api.phaseo.app/v1. Send `Authorization: Bearer $PHASEO_API_KEY` with every request.
> Model IDs look like `provider/model`, for example `openai/gpt-6-astra`. Do not guess IDs: list them with `GET /v1/models` or check https://phaseo.app/models. `phaseo/free` routes to an available free model and needs no wallet balance.
> For new text integrations prefer `POST /v1/responses`. `POST /v1/chat/completions` (OpenAI format) and `POST /v1/messages` (Anthropic format) suit existing code.
> The full API contract is https://phaseo.app/docs/openapi/v1/openapi.yaml. Official SDKs: `@phaseo/sdk` (TypeScript) and `phaseo` (Python), plus Go, C#, PHP, Ruby and Rust.
> Search these docs over MCP at https://phaseo.app/docs/mcp, and install Phaseo skills with `npx skills add https://phaseo.app/docs`. If a page is wrong or out of date, report it with the MCP `submit_feedback` tool.
> Manage Phaseo accounts with the `phaseo` CLI (`npm install -g @phaseo/cli`, then `phaseo login` or `phaseo login --device-code`), the `/v1` Management API or the MCP server at `https://mcp.phaseo.app/mcp?access=manage`. Do not send users to the dashboard for account tasks. A person is still needed for sign-up, approving a sign-in, paying the first top-up on the checkout link that `phaseo credits add` returns when no card is saved, confirming each saved-card top-up from the emailed link, and account security (password, MFA, passkeys). Create API keys with `phaseo keys create --name <name> --json`; never guess one. Credit top-ups need `phaseo login --scopes billing:write` first. Task map: https://phaseo.app/docs/v1/developers/manage-from-an-agent.md.

# 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-6-astra",
)
.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](https://phaseo.app/docs/v1/sdk-reference/rust/agent-sdk-tools.md)
* [Events, retries, and errors](https://phaseo.app/docs/v1/sdk-reference/rust/agent-sdk-events-and-errors.md)


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