Custom metadata labels

You can add custom metadata to generateContent and streamGenerateContent API calls by using labels. This page explains what labels are, and shows you how to use them to break down your billed charges.

What are labels?

A label is a key-value pair that you can assign to generateContent and streamGenerateContent API calls. They help you organize these calls and manage your costs at scale, with the granularity you need. You can attach a label to each call, then filter the calls based on their labels. Information about labels is forwarded to the billing system that lets you break down your billed charges by label. With built-in billing reports, you can filter and group costs by labels. You can also use labels to query billing data exports.

Requirements for labels

The labels applied to an API call must meet the following requirements:

• Each API call can have up to 64 labels.
• Each label must be a key-value pair.
• Keys have a minimum length of 1 character and a maximum length of 63 characters, and cannot be empty. Values can be empty, and have a maximum length of 63 characters.
• Keys and values can contain only lowercase letters, numeric characters, underscores, and dashes. All characters must use UTF-8 encoding, and international characters are allowed. Keys must start with a lowercase letter or international character.
• The key portion of a label must be unique within a single API call. However, you can use the same key with multiple calls.

These limits apply to the key and value for each label, and to the individual API call that have labels. There is no limit on how many labels you can apply across all API calls within a project.

Common uses of labels

Here are some common use cases for labels:

• Team or cost center labels: Add labels based on team or cost center to distinguish API calls owned by different teams (for example, team:research and team:analytics). You can use this type of label for cost accounting or budgeting.

• Component labels: For example, component:redis, component:frontend, component:ingest, and component:dashboard.

• Environment or stage labels: For example, environment:production and environment:test.

• Ownership labels: Used to identify the teams that are responsible for operations, for example: team:shopping-cart.

We don't recommend creating large numbers of unique labels, such as for timestamps or individual values for every API call. The problem with this approach is that when the values change frequently or with keys that clutter the catalog, this makes it difficult to effectively filter and report on API calls.

Add a label to an API call

To add a label to a generateContent or streamGenerateContent API call, do the following:

cat > request.json << 'EOF'
{
  "contents": {
    "role": "ROLE",
    "parts": { "text": "PROMPT_TEXT" }
  },
  "labels": {
    "LABEL_KEY": "LABEL_VALUE"
  },
}
EOF

curl -X POST \
     -H "Authorization: Bearer $(gcloud auth print-access-token)" \
     -H "Content-Type: application/json; charset=utf-8" \
     -d @request.json \
     "https://LOCATION-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/publishers/google/models/MODEL_ID:GENERATE_RESPONSE_METHOD"

@'
{
  "contents": {
    "role": "ROLE",
    "parts": { "text": "PROMPT_TEXT" }
  },
  "labels": {
    "LABEL_KEY": "LABEL_VALUE"
  },
}
'@  | Out-File -FilePath request.json -Encoding utf8

$cred = gcloud auth print-access-token
$headers = @{ "Authorization" = "Bearer $cred" }

Invoke-WebRequest `
    -Method POST `
    -Headers $headers `
    -ContentType: "application/json; charset=utf-8" `
    -InFile request.json `
    -Uri "https://LOCATION-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/publishers/google/models/MODEL_ID:GENERATE_RESPONSE_METHOD" | Select-Object -Expand Content

{
  "candidates": [
    {
      "content": {
        "role": "model",
        "parts": [
          {
            "text": Generative AI is a type of artificial intelligence (AI) that can **create new
            content**, like text, images, audio, video, and even code.
          }
        ]
      },
      "finishReason": "STOP",
      "safetyRatings": [
        {
          "category": "HARM_CATEGORY_HATE_SPEECH",
          "probability": "NEGLIGIBLE",
          "probabilityScore": 0.037841797,
          "severity": "HARM_SEVERITY_NEGLIGIBLE",
          "severityScore": 0.06347656
        },
        {
          "category": "HARM_CATEGORY_DANGEROUS_CONTENT",
          "probability": "NEGLIGIBLE",
          "probabilityScore": 0.053466797,
          "severity": "HARM_SEVERITY_NEGLIGIBLE",
          "severityScore": 0.08496094
        },
        {
          "category": "HARM_CATEGORY_HARASSMENT",
          "probability": "NEGLIGIBLE",
          "probabilityScore": 0.08154297,
          "severity": "HARM_SEVERITY_NEGLIGIBLE",
          "severityScore": 0.033203125
        },
        {
          "category": "HARM_CATEGORY_SEXUALLY_EXPLICIT",
          "probability": "NEGLIGIBLE",
          "probabilityScore": 0.071777344,
          "severity": "HARM_SEVERITY_NEGLIGIBLE",
          "severityScore": 0.083984375
        }
      ],
      "avgLogprobs": -0.40486351219383448
    }
  ],
  "usageMetadata": {
    "promptTokenCount": 5,
    "candidatesTokenCount": 555,
    "totalTokenCount": 560
  }
}

Google Cloud products report usage and cost data to Cloud Billing processes at varying intervals. As a result, you might see a delay between your use of Google Cloud services, and the usage and costs being available to view in Cloud Billing. Typically, your costs are available within a day, but can sometimes take more than 24 hours.