Count Tokens

Estimate token count for a set of messages without making an LLM call

POST /v1/count_tokens

Count tokens

cURL

curl --request POST \
  --url https://api.edgee.ai/v1/count_tokens \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "openai/gpt-5.2",
  "messages": [
    {
      "role": "system",
      "content": "You are a helpful assistant."
    },
    {
      "role": "user",
      "content": "What is the capital of France?"
    }
  ]
}
'

200

{
  "input_tokens": 42
}

Estimates the number of input tokens for a set of messages without sending the request to an LLM provider. Useful for pre-flight cost estimation, rate-limit planning, and prompt optimization.

Authorizations

Authorization · string · header · required

Bearer authentication header of the form Bearer <token>, where <token> is your API key. More info here

Body

application/json

model · string · required

ID of the target model. Format: {author_id}/{model_id}. The gateway uses this to pick the appropriate tokenizer when tokenizer is not provided.

Example:

"openai/gpt-5.2"

messages · object[]

Optional array of message objects to count tokens for. Accepts both OpenAI chat format (with system, user, assistant roles) and Anthropic Messages format; the format is auto-detected from the message structure. Defaults to an empty array.

Show child attributes

system · string object[]

Optional system prompt. Accepts a plain string or an array of Anthropic content blocks. Used when counting tokens for an Anthropic-style request.

tokenizer · enum<string>

Explicit tokenizer override. When omitted, the gateway picks one based on model.

Available options: cl100k_base, o200k_base

Response

200

application/json

Token count estimated successfully

input_tokens · integer · required

Estimated number of input tokens for the provided messages. This is an approximation, counts may differ from provider-native tokenizers. Use for estimation and budgeting, not exact billing.

Required range: x >= 0

Example:

42