> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.loreos.app/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.loreos.app/_mcp/server.

# Usage Message Costs

GET https://api.loreos.app/v1/usage/message-costs

Message-level cost drilldown for the app behind this runtime key.

This complements ``GET /v1/usage``. The aggregate usage endpoint stays a
compact ledger rollup; this endpoint is the audit/drilldown surface for
reply and image costs by end-user/character pair.

Reference: https://docs.loreos.app/api-reference/account/usage-message-costs

## Authentication

- `Authorization` header (bearer token, required) — LoreOS runtime API key (`ck_...`), sent as `Authorization: Bearer <key>`.

## Servers

- `https://api.loreos.app` (Production, default)
- `http://127.0.0.1:8000` (Local development)

## Request

### Query parameters

- `view` (string, optional, default: users)
- `from` (string, optional, nullable)
- `to` (string, optional, nullable)
- `external_user_ref` (string, optional, nullable)
- `character_slug` (string, optional, nullable)
- `session_id` (string, optional, nullable)
- `modality` (enum, optional, default: all)
  - Allowed values: `all`, `text`, `image`
- `limit` (integer, optional, default: 20)
- `messages_per_pair` (integer, optional, default: 5)
- `include_preview` (boolean, optional, default: false)

## Response

### 200

Successful Response

- `schema_version` ("v0", required) — LoreOS success-envelope version.
- `data` (V1SuccessEnvelopeUnionMessageCostsUsersDataMessageCostsCharactersDataData, required)
- `next_actions` (list of V1NextAction, required) — Concrete follow-up API actions; empty when no action is required.

## Errors

### 401 Unauthorized Error

Runtime API key is missing, invalid, expired, or revoked.

- `detail` (V1ErrorDetail, required) — Stable public error core; domain-specific fields may be added alongside it.

### 422 Unprocessable Entity Error

View, time window, session, modality, limit, or preview query validation failed.

- `detail` (V1ErrorDetail, required) — Stable public error core; domain-specific fields may be added alongside it.

## Types

### V1SuccessEnvelopeUnionMessageCostsUsersDataMessageCostsCharactersDataData

### V1NextAction

- `command` (string, required) — The next API command an agent can execute.
- `description` (string, required) — Why or when to execute the command.

### V1ErrorDetail

Stable public error core; domain-specific fields may be added alongside it.

- `code` (string, required)
- `message` (string, required)
- `fix` (string, required)

### MessageCostsUsersData

- `app_id` (string, required)
- `from` (datetime, required, nullable)
- `to` (datetime, required, nullable)
- `unit` ("credits_usd", required)
- `totals` (MessageCostTotals, required)
- `pairs` (list of MessageCostPair, required)
- `filters` (MessageCostFilters, required)
- `billing_note` (string, required)
- `view` ("users", required)
- `external_users` (list of ExternalUserMessageCosts, required)

### MessageCostsCharactersData

- `app_id` (string, required)
- `from` (datetime, required, nullable)
- `to` (datetime, required, nullable)
- `unit` ("credits_usd", required)
- `totals` (MessageCostTotals, required)
- `pairs` (list of MessageCostPair, required)
- `filters` (MessageCostFilters, required)
- `billing_note` (string, required)
- `view` ("characters", required)
- `characters` (list of CharacterMessageCosts, required)

### MessageCostTotals

- `total_credits` (double, required)
- `text_credits` (double, required)
- `image_credits` (double, required)
- `raw_cost_usd` (double, required)
- `events` (integer, required)
- `pairs` (integer, required)
- `text_reply_count` (integer, required)
- `proactive_reply_count` (integer, required)
- `image_count` (integer, required)
- `delivered_event_count` (integer, required)
- `incurred_without_delivery_credits` (double, required)
- `avg_text_reply_credits` (double, required)
- `last_usage_at` (datetime, required, nullable)

### MessageCostPair

- `external_user_id` (string, required)
- `external_user_ref` (string, required, nullable)
- `external_user_display_name` (string, required, nullable)
- `character_id` (string, required)
- `character_slug` (string, required, nullable)
- `character_display_name` (string, required, nullable)
- `total_credits` (double, required)
- `text_credits` (double, required)
- `image_credits` (double, required)
- `raw_cost_usd` (double, required)
- `events` (integer, required)
- `text_reply_count` (integer, required)
- `proactive_reply_count` (integer, required)
- `image_count` (integer, required)
- `delivered_event_count` (integer, required)
- `incurred_without_delivery_credits` (double, required)
- `avg_text_reply_credits` (double, required)
- `last_usage_at` (datetime, required, nullable)
- `messages` (list of MessageCostEvent, required)

### MessageCostFilters

- `external_user_ref` (string, required, nullable)
- `character_slug` (string, required, nullable)
- `session_id` (string, required, nullable)
- `modality` (enum, required)
  - Allowed values: `all`, `text`, `image`
- `include_preview` (boolean, required)

### ExternalUserMessageCosts

- `external_user_id` (string, required)
- `external_user_ref` (string, required, nullable)
- `display_name` (string, required, nullable)
- `total_credits` (double, required)
- `text_credits` (double, required)
- `image_credits` (double, required)
- `raw_cost_usd` (double, required)
- `events` (integer, required)
- `text_reply_count` (integer, required)
- `proactive_reply_count` (integer, required)
- `image_count` (integer, required)
- `delivered_event_count` (integer, required)
- `incurred_without_delivery_credits` (double, required)
- `last_usage_at` (datetime, required, nullable)
- `characters` (list of MessageCostPair, required)

### CharacterMessageCosts

- `character_id` (string, required)
- `character_slug` (string, required, nullable)
- `display_name` (string, required, nullable)
- `total_credits` (double, required)
- `text_credits` (double, required)
- `image_credits` (double, required)
- `raw_cost_usd` (double, required)
- `events` (integer, required)
- `text_reply_count` (integer, required)
- `proactive_reply_count` (integer, required)
- `image_count` (integer, required)
- `delivered_event_count` (integer, required)
- `incurred_without_delivery_credits` (double, required)
- `last_usage_at` (datetime, required, nullable)
- `users` (list of MessageCostPair, required)

### MessageCostEvent

- `usage_event_id` (string, required)
- `session_id` (string, required, nullable)
- `trace_id` (string, required, nullable) — Opaque correlator matching send_message.run_ref and session trace rows.
- `resource_type` (enum, required)
  - Allowed values: `reply`, `proactive_reply`, `image_generation`
- `usage_class` (string, required)
- `modality` (enum, required)
  - Allowed values: `text`, `image`
- `credits` (double, required)
- `raw_cost_usd` (double, required)
- `created_at` (datetime, required, nullable)
- `delivered` (boolean, required)
- `delivered_event_id` (string, required, nullable)
- `delivered_event_type` (string, required, nullable)
- `delivered_at` (datetime, required, nullable)
- `text_preview` (string, required, nullable)
- `image_kind` (string, required, nullable)
- `image_request_id` (string, required, nullable)

## Examples

**Response**

```json
{
  "schema_version": "v0",
  "data": {
    "app_id": "66666666-6666-6666-6666-666666666666",
    "view": "users",
    "from": null,
    "to": null,
    "unit": "credits_usd",
    "totals": {
      "total_credits": 0.0034,
      "text_credits": 0.0034,
      "image_credits": 0,
      "raw_cost_usd": 0.002871,
      "events": 1,
      "pairs": 1,
      "text_reply_count": 1,
      "proactive_reply_count": 0,
      "image_count": 0,
      "delivered_event_count": 1,
      "incurred_without_delivery_credits": 0,
      "avg_text_reply_credits": 0.0034,
      "last_usage_at": "2026-06-19T09:04:10Z"
    },
    "pairs": [
      {
        "external_user_id": "33333333-3333-3333-3333-333333333333",
        "external_user_ref": "user_123",
        "external_user_display_name": "User 123",
        "character_id": "11111111-1111-1111-1111-111111111111",
        "character_slug": "mira-demo",
        "character_display_name": "Mira",
        "total_credits": 0.0034,
        "text_credits": 0.0034,
        "image_credits": 0,
        "raw_cost_usd": 0.002871,
        "events": 1,
        "text_reply_count": 1,
        "proactive_reply_count": 0,
        "image_count": 0,
        "delivered_event_count": 1,
        "incurred_without_delivery_credits": 0,
        "avg_text_reply_credits": 0.0034,
        "last_usage_at": "2026-06-19T09:04:10Z",
        "messages": [
          {
            "usage_event_id": "99999999-9999-9999-9999-999999999999",
            "session_id": "00000000-0000-0000-0000-000000000000",
            "trace_id": "trace_0000000000000000",
            "resource_type": "reply",
            "usage_class": "sandbox",
            "modality": "text",
            "credits": 0.0034,
            "raw_cost_usd": 0.002871,
            "created_at": "2026-06-19T09:04:10Z",
            "delivered": true,
            "delivered_event_id": "77777777-7777-7777-7777-777777777777",
            "delivered_event_type": "message.created",
            "delivered_at": "2026-06-19T09:04:10Z",
            "text_preview": null,
            "image_kind": null,
            "image_request_id": null
          }
        ]
      }
    ],
    "external_users": [
      {
        "external_user_id": "33333333-3333-3333-3333-333333333333",
        "external_user_ref": "user_123",
        "display_name": "User 123",
        "total_credits": 0.0034,
        "text_credits": 0.0034,
        "image_credits": 0,
        "raw_cost_usd": 0.002871,
        "events": 1,
        "text_reply_count": 1,
        "proactive_reply_count": 0,
        "image_count": 0,
        "delivered_event_count": 1,
        "incurred_without_delivery_credits": 0,
        "last_usage_at": "2026-06-19T09:04:10Z",
        "characters": []
      }
    ],
    "filters": {
      "external_user_ref": null,
      "character_slug": null,
      "session_id": "00000000-0000-0000-0000-000000000000",
      "modality": "text",
      "include_preview": false
    },
    "billing_note": "credits are the customer-facing usage ledger; provider work is settled before this readback."
  },
  "next_actions": []
}
```

**SDK Code**

```python
import requests

url = "https://api.loreos.app/v1/usage/message-costs"

querystring = {"view":"users","session_id":"00000000-0000-0000-0000-000000000000","modality":"text","include_preview":"false"}

headers = {"Authorization": "Bearer <token>"}

response = requests.get(url, headers=headers, params=querystring)

print(response.json())
```

```javascript
const url = 'https://api.loreos.app/v1/usage/message-costs?view=users&session_id=00000000-0000-0000-0000-000000000000&modality=text&include_preview=false';
const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.loreos.app/v1/usage/message-costs?view=users&session_id=00000000-0000-0000-0000-000000000000&modality=text&include_preview=false"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.loreos.app/v1/usage/message-costs?view=users&session_id=00000000-0000-0000-0000-000000000000&modality=text&include_preview=false")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Get.new(url)
request["Authorization"] = 'Bearer <token>'

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.get("https://api.loreos.app/v1/usage/message-costs?view=users&session_id=00000000-0000-0000-0000-000000000000&modality=text&include_preview=false")
  .header("Authorization", "Bearer <token>")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://api.loreos.app/v1/usage/message-costs?view=users&session_id=00000000-0000-0000-0000-000000000000&modality=text&include_preview=false', [
  'headers' => [
    'Authorization' => 'Bearer <token>',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.loreos.app/v1/usage/message-costs?view=users&session_id=00000000-0000-0000-0000-000000000000&modality=text&include_preview=false");
var request = new RestRequest(Method.GET);
request.AddHeader("Authorization", "Bearer <token>");
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Authorization": "Bearer <token>"]

let request = NSMutableURLRequest(url: NSURL(string: "https://api.loreos.app/v1/usage/message-costs?view=users&session_id=00000000-0000-0000-0000-000000000000&modality=text&include_preview=false")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "GET"
request.allHTTPHeaderFields = headers

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```