GPT-5.6 Luna

Text Generation • OpenAI

GPT-5.6 Luna is an OpenAI GPT-5.6 model optimized for cost-sensitive workloads, using the Responses API for efficient text generation.

Model Info
Context Window ↗	1,050,000 tokens
Terms and License	link ↗
More information	link ↗
Request formats	Responses
Pricing	View pricing in the Cloudflare dashboard ↗

const response = await env.AI.run(
  'openai/gpt-5.6-luna',
  {
    input: 'Summarize the benefits of API rate limiting in three bullets.',
    max_output_tokens: 256,
  },
)
console.log(response)

curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/v1/responses \
  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
  --header "Content-Type: application/json" \
  --data '{
  "model": "openai/gpt-5.6-luna",
  "input": "Summarize the benefits of API rate limiting in three bullets.",
  "max_output_tokens": 256
}'

Output
Raw response

- **Protects system stability:** Prevents overload, reduces outages, and ensures predictable performance during traffic spikes.
- **Ensures fair access:** Stops individual users or applications from consuming disproportionate resources.
- **Improves security and cost control:** Helps mitigate abuse, brute-force attacks, and unexpected infrastructure usage.

{
  "id": "resp_0e481f0cb46bf357016a4fe99bd5fc8194b6ce2049aa65ab08",
  "object": "response",
  "created_at": 1783622043,
  "status": "completed",
  "background": false,
  "billing": {
    "payer": "developer"
  },
  "completed_at": 1783622044,
  "error": null,
  "frequency_penalty": 0,
  "incomplete_details": null,
  "instructions": null,
  "max_output_tokens": 256,
  "max_tool_calls": null,
  "model": "gpt-5.6-luna",
  "moderation": null,
  "output": [
    {
      "id": "msg_0e481f0cb46bf357016a4fe99c2e288194a6fd0ce3f5f88786",
      "type": "message",
      "status": "completed",
      "content": [
        {
          "type": "output_text",
          "annotations": [],
          "logprobs": [],
          "text": "- **Protects system stability:** Prevents overload, reduces outages, and ensures predictable performance during traffic spikes.\n- **Ensures fair access:** Stops individual users or applications from consuming disproportionate resources.\n- **Improves security and cost control:** Helps mitigate abuse, brute-force attacks, and unexpected infrastructure usage."
        }
      ],
      "phase": "final_answer",
      "role": "assistant"
    }
  ],
  "parallel_tool_calls": true,
  "presence_penalty": 0,
  "previous_response_id": null,
  "prompt_cache_key": null,
  "prompt_cache_retention": "in_memory",
  "reasoning": {
    "context": "all_turns",
    "effort": "medium",
    "mode": "standard",
    "summary": null
  },
  "safety_identifier": null,
  "service_tier": "default",
  "store": false,
  "temperature": 1,
  "text": {
    "format": {
      "type": "text"
    },
    "verbosity": "medium"
  },
  "tool_choice": "auto",
  "tool_usage": {
    "image_gen": {
      "input_tokens": 0,
      "input_tokens_details": {
        "image_tokens": 0,
        "text_tokens": 0
      },
      "output_tokens": 0,
      "output_tokens_details": {
        "image_tokens": 0,
        "text_tokens": 0
      },
      "total_tokens": 0
    },
    "web_search": {
      "num_requests": 0
    }
  },
  "tools": [],
  "top_logprobs": 0,
  "top_p": 0.98,
  "truncation": "disabled",
  "usage": {
    "input_tokens": 19,
    "input_tokens_details": {
      "cache_write_tokens": 0,
      "cached_tokens": 0
    },
    "output_tokens": 66,
    "output_tokens_details": {
      "reasoning_tokens": 0
    },
    "total_tokens": 85
  },
  "user": null,
  "metadata": {}
}

Examples

Pull Request Description — Using instructions for a cost-sensitive drafting task

TypeScript
cURL

const response = await env.AI.run(
  'openai/gpt-5.6-luna',
  {
    input:
      'Write a brief pull request description for a bug fix that prevents duplicate webhook deliveries.',
    instructions: 'Keep it under 100 words.',
    max_output_tokens: 256,
  },
)
console.log(response)

curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/v1/responses \
  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
  --header "Content-Type: application/json" \
  --data '{
  "model": "openai/gpt-5.6-luna",
  "input": "Write a brief pull request description for a bug fix that prevents duplicate webhook deliveries.",
  "instructions": "Keep it under 100 words.",
  "max_output_tokens": 256
}'

Output
Raw response

## Summary
Prevents duplicate webhook deliveries by ensuring each event is processed only once, even when retries or concurrent requests occur.

## Changes
- Added idempotency checks for webhook events.
- Prevented duplicate delivery attempts.
- Added regression tests covering retries and concurrent processing.

## Testing
All existing and new tests pass.

{
  "id": "resp_0bed05adeda548a1016a4fe99d1e408194bb0375bad96ab71a",
  "object": "response",
  "created_at": 1783622045,
  "status": "completed",
  "background": false,
  "billing": {
    "payer": "developer"
  },
  "completed_at": 1783622046,
  "error": null,
  "frequency_penalty": 0,
  "incomplete_details": null,
  "instructions": "Keep it under 100 words.",
  "max_output_tokens": 256,
  "max_tool_calls": null,
  "model": "gpt-5.6-luna",
  "moderation": null,
  "output": [
    {
      "id": "msg_0bed05adeda548a1016a4fe99daa748194992854423ba08e72",
      "type": "message",
      "status": "completed",
      "content": [
        {
          "type": "output_text",
          "annotations": [],
          "logprobs": [],
          "text": "## Summary\nPrevents duplicate webhook deliveries by ensuring each event is processed only once, even when retries or concurrent requests occur.\n\n## Changes\n- Added idempotency checks for webhook events.\n- Prevented duplicate delivery attempts.\n- Added regression tests covering retries and concurrent processing.\n\n## Testing\nAll existing and new tests pass."
        }
      ],
      "phase": "final_answer",
      "role": "assistant"
    }
  ],
  "parallel_tool_calls": true,
  "presence_penalty": 0,
  "previous_response_id": null,
  "prompt_cache_key": null,
  "prompt_cache_retention": "in_memory",
  "reasoning": {
    "context": "all_turns",
    "effort": "medium",
    "mode": "standard",
    "summary": null
  },
  "safety_identifier": null,
  "service_tier": "default",
  "store": false,
  "temperature": 1,
  "text": {
    "format": {
      "type": "text"
    },
    "verbosity": "medium"
  },
  "tool_choice": "auto",
  "tool_usage": {
    "image_gen": {
      "input_tokens": 0,
      "input_tokens_details": {
        "image_tokens": 0,
        "text_tokens": 0
      },
      "output_tokens": 0,
      "output_tokens_details": {
        "image_tokens": 0,
        "text_tokens": 0
      },
      "total_tokens": 0
    },
    "web_search": {
      "num_requests": 0
    }
  },
  "tools": [],
  "top_logprobs": 0,
  "top_p": 0.98,
  "truncation": "disabled",
  "usage": {
    "input_tokens": 33,
    "input_tokens_details": {
      "cache_write_tokens": 0,
      "cached_tokens": 0
    },
    "output_tokens": 69,
    "output_tokens_details": {
      "reasoning_tokens": 0
    },
    "total_tokens": 102
  },
  "user": null,
  "metadata": {}
}

Parameters

Input
Output

▶input

one ofrequired

instructions

string

temperature

numberminimum: 0maximum: 2

max_output_tokens

numberexclusiveMinimum: 0

top_p

numberminimum: 0maximum: 1

stream

boolean

▶tools[]

array

tool_choice

▶text{}

object

▶reasoning{}

object

string

object

stringconst: response

created_at

number

model

string

▶output[]

array

output_text

string

status

stringenum: in_progress, completed, failed, incomplete

▶usage{}

object

API Schemas (Raw)

Input

Output