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

# Media and costs

> Read completed artifacts, reuse media in follow-ups, and select final results.

Use the [quickstart client](/docs/documentation/agent/sdk/quickstart#create-a-client). Replace uppercase IDs with your resource IDs.

Pending generation appears as a `fal.operation`.
Completed media appears in `response.artifacts` as a `fal.artifact`.

## Read artifacts

`artifacts.retrieve(id, { revision }?)` returns an `AgentArtifact`. Omit `revision` to read the available version. Media artifacts use revision `1`.
An unavailable revision returns `404`.
Each artifact has an ID, revision, and optional files.
A file includes its role, URL, MIME type, and optional URL expiry.

```ts theme={null}
import { agent } from "./client.ts";

const artifact =
  await agent.artifacts.retrieve("ARTIFACT_ID");
console.log(artifact.files);
```

Artifact reads enforce ownership and retention.
An artifact ID is different from a library asset-record ID.

## Refine an existing result

Reference a completed artifact alongside the new instruction to reuse media without uploading it again.

```ts theme={null}
import { agent } from "./client.ts";

const response = await agent.run({
  conversation: "CONVERSATION_ID",
  input: [
    {
      role: "user",
      content: [
        {
          type: "input_text",
          text: "Make the lighting warmer.",
        },
        {
          type: "fal.input_artifact",
          artifact_id: "ARTIFACT_ID",
        },
      ],
    },
  ],
});

console.log(response.status, response.artifacts);
```

A `fal.input_artifact` part accepts an optional `revision` of `1`. Omit it to use the available artifact.
This creates a new response in the same conversation.
A media refinement can incur new generation charges.

For an external image, use `{ type: "input_image", image_url }`.
For a file, use `{ type: "input_file", file_url, mime_type }`.
The URL must be accessible to the runtime. These content parts reference files and do not upload them.

## Select final results

Completion does not mark every artifact as a final result.
After the response finishes, select final artifacts with its current sequence number.

```ts theme={null}
import { agent } from "./client.ts";

const response =
  await agent.responses.retrieve("RESPONSE_ID");

await agent.responses.selectFinalArtifacts(
  response.id,
  {
    artifact_ids: ["ARTIFACT_ID"],
    expected_sequence_number:
      response.fal.sequence_number,
  },
);
```

The returned `final_artifacts` reflects the selection.
Pass an empty array to clear it. On a `409`, retrieve the current response and apply the selection to that version.

## Inspect generation costs

```ts theme={null}
import { agent } from "./client.ts";

const summary =
  await agent.conversations.generationSummary(
    "CONVERSATION_ID",
  );
console.log(summary);
```

The summary reports generation costs and unpriced requests for that conversation.
`totalCostNanoUsd` and `costsNanoUsd` use billionths of a US dollar. Divide by `1_000_000_000` for USD.
`unpricedRequestCount` counts requests without a price. The reported total excludes those costs and LLM usage.

## Handle partial results

A failed response can retain usable artifacts.
Inspect each operation for generation failures and the response error for execution failure.
Export blocks can contain download links without a corresponding SDK artifact.
Render their `fallback_text` when your application does not understand the block kind.