# Costs (/docs/costs)

Every response tells you exactly what it cost, so you can track spend per request, per user or per feature without estimating from token counts. Charges are in Credits: **1 USD = 250,000 Credits**.

| Where | What you find |
|---|---|
| [Models](https://www.ohmygpt.com/models) | The price of every model |
| [Usage](https://www.ohmygpt.com/usage) | Every request, its model and its cost |
| [Billing](https://www.ohmygpt.com/billing) | Your balance and top-ups |

## Cost of a non-streaming request [#cost-of-a-non-streaming-request]

The `X-Cost-Credits` response header carries the charge, and `X-Request-ID` identifies the request:

```bash
curl -si https://api.ohmygpt.com/v1/chat/completions \
  -H "Authorization: Bearer $OHMYGPT_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "zhipu/glm-5.3-flash", "messages": [{"role": "user", "content": "Hi"}]}' \
  | grep -iE '^x-(cost-credits|request-id)'
```

```http
X-Cost-Credits: 28
X-Request-Id: 01a19b5d-aa2f-71df-a0c2-a97e1d14040b
```

SDKs hide headers by default. Ask for the raw response:

```python tab="Python"
raw = client.chat.completions.with_raw_response.create(
    model="zhipu/glm-5.3-flash",
    messages=[{"role": "user", "content": "Hi"}],
)
print(raw.headers["x-cost-credits"], raw.headers["x-request-id"])
completion = raw.parse()
```

```ts tab="TypeScript"
const { data: completion, response } = await client.chat.completions
  .create({
    model: 'zhipu/glm-5.3-flash',
    messages: [{ role: 'user', content: 'Hi' }],
  })
  .withResponse()
console.log(response.headers.get('x-cost-credits'), response.headers.get('x-request-id'))
```

## Cost of a streaming request [#cost-of-a-streaming-request]

Headers go out before the model has finished, so streams carry the charge as an SSE comment just before the final event:

```text
data: {"id":"...","object":"chat.completion.chunk","choices":[],"usage":{"prompt_tokens":36,"completion_tokens":16,"total_tokens":52}}

: x-cost-credits: 2
data: [DONE]
```

Chat Completions puts it before `data: [DONE]`, Responses before `response.completed`, and Anthropic Messages before `message_stop`. SDKs skip comment lines, so read it if you parse the stream yourself. With an SDK, or on a Gemini stream, look the request up by its ID as shown below.

## Look up a request [#look-up-a-request]

`GET /v1/generation?id=<X-Request-ID>` returns the receipt for any of your requests, streaming or not:

```bash
curl "https://api.ohmygpt.com/v1/generation?id=01a1a024-b4db-7110-a49f-76360d332aa9" \
  -H "Authorization: Bearer $OHMYGPT_API_KEY"
```

```json
{
  "data": {
    "object": "request_receipt",
    "id": "01a1a024-b4db-7110-a49f-76360d332aa9",
    "status": "succeeded",
    "created_at": "2026-11-03T06:42:04.462Z",
    "model": { "id": "deepseek/deepseek-v4.1-flash-1017", "provider": "tencent" },
    "usage": {
      "input_tokens": 31,
      "output_tokens": 1,
      "reasoning_tokens": 1,
      "cache_read_tokens": 0,
      "cache_creation_tokens": 0
    },
    "cost": {
      "credits": 3,
      "list_credits": 4,
      "lines": [
        { "kind": "text.input", "quantity": 31, "price_credits": 32850, "list_price_credits": 73000, "credits": 2 },
        { "kind": "text.output", "quantity": 1, "price_credits": 131400, "list_price_credits": 292000, "credits": 1 }
      ]
    },
    "timing": { "duration_ms": 4412 },
    "receipt": { "available": true, "warnings": [] }
  }
}
```

| Field | Meaning |
|---|---|
| `cost.credits` | What you were charged |
| `cost.list_credits` | The same usage at the model's list price. When it is higher than `credits`, the difference is what you saved. |
| `cost.lines` | One line per priced item: `quantity`, the unit price you paid (`price_credits`), the list unit price (`list_price_credits`), and the line total. Unit prices are Credits per 1,000,000 units. |
| `usage` | Token counts, including reasoning and cached tokens |
| `model.provider` | The provider that served the request |
| `timing.first_token_ms` | Time to first token, on streaming requests |

Each line is rounded up to a whole Credit on its own. On a request this small the rounding shows: every unit price above is 45% of list, yet the request paid 3 Credits against 4 at list price. On normal-sized requests the two ratios match.

## Keep prompt caching effective [#keep-prompt-caching-effective]

Cached input costs less than fresh input. In a multi-turn conversation, send the same per-conversation value on every turn so repeated prompts keep hitting the cache:

| Endpoint | Field |
|---|---|
| Chat Completions, Responses | `prompt_cache_key`, or `provider.conversation_id` (up to 256 bytes) |
| Anthropic Messages | `metadata.user_id` |

```bash
curl https://api.ohmygpt.com/v1/responses \
  -H "Authorization: Bearer $OHMYGPT_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "openai/gpt-5.4-nano", "prompt_cache_key": "conv-8f2c", "input": "Hi"}'
```

Claude Code sends its session ID on every request, so it works out of the box. A request's receipt shows the cached input in `usage.cache_read_tokens`.

## Review many requests [#review-many-requests]

To review many requests at once, filter and page through [`GET /v1/usage`](/docs/api/usage/listUsage), or open the [Usage](https://www.ohmygpt.com/usage) page.

Every response, errors included, carries an `X-Request-ID`. Include it when you contact support about a request.