> ## 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 If a page is wrong or out of date, report it with the MCP `submit_feedback` tool.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.

# Working with items

> Render typed messages, reasoning, tool activity, errors, and final outputs.

Use items to build a structured agent timeline without parsing provider-specific events. Streaming and completed runs expose the same ordered `AgentItem<TOutput>` contract.

## Item types

`AgentItem<TOutput>` is a discriminated union:

| `type` | Important fields | Represents |
| - | - | - |
| `message` | `role`, `content` | Assistant or conversation text |
| `reasoning` | `text` | Reasoning supplied by the model |
| `tool_call` | `toolCallId`, `name`, `input` | A proposed tool invocation |
| `tool_result` | `toolCallId`, `name`, `output` | A completed tool invocation |
| `error` | `message`, optional tool details | A provider or tool error |
| `output` | `value` | The parsed final agent output |

## Render a streamed timeline

TypeScript narrows each item from its `type`:

```typescript theme={null}
const stream = agent.stream({ input, client });

for await (const item of stream.getItemsStream()) {
  switch (item.type) {
    case "message":
      renderAssistantMessage(item.content);
      break;
    case "reasoning":
      renderReasoning(item.text);
      break;
    case "tool_call":
      renderToolCall(item.toolCallId, item.name, item.input);
      break;
    case "tool_result":
      renderToolResult(item.toolCallId, item.output);
      break;
    case "error":
      renderError(item.message);
      break;
    case "output":
      renderFinalOutput(item.value);
      break;
  }
}
```

## Read items after completion

The completed result contains the same ordered item shapes:

```typescript theme={null}
const completed = await stream.getResult();

for (const item of completed.items) {
  saveTimelineItem(completed.run.id, item);
}
```

This lets a product render live activity and later rebuild the same timeline from persisted run state.

## Access provider-specific data

Provider output is normalized into portable item types. When an integration still needs a provider-specific field, normalized provider items retain the original payload in `rawProviderItem`.

Keep product logic on the portable fields where possible. Treat `rawProviderItem` as an escape hatch for provider-specific integrations, not as the default application contract.

## Related guides

* [Streaming](https://phaseo.app/docs/v1/sdk-reference/typescript/agent-sdk-streaming.md)
* [Tools](https://phaseo.app/docs/v1/sdk-reference/typescript/agent-sdk-tools.md)
* [Lifecycle hooks](https://phaseo.app/docs/v1/sdk-reference/typescript/agent-sdk-lifecycle-hooks.md)


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