CompletionResponse

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://raw.githubusercontent.com/api-evangelist/anthropic/main/json-schema/anthropic-completion-response-schema.json",
  "title": "CompletionResponse",
  "x-generated": "2026-09-23",
  "x-method": "derived",
  "x-generator": "derive-json-schema.py",
  "x-source": "openapi/anthropic-complete-api-openapi.yml#/components/schemas/CompletionResponse",
  "properties": {
    "completion": {
      "type": "string",
      "title": "Completion",
      "description": "The resulting completion up to and excluding the stop sequences."
    },
    "id": {
      "type": "string",
      "title": "Id",
      "description": "Unique object identifier.\n\nThe format and length of IDs may change over time."
    },
    "model": {
      "$ref": "#/$defs/Model"
    },
    "stop_reason": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Stop Reason",
      "description": "The reason that we stopped.\n\nThis may be one the following values:\n* `\"stop_sequence\"`: we reached a stop sequence — either provided by you via the `stop_sequences` parameter, or a stop sequence built into the model\n* `\"max_tokens\"`: we exceeded `max_tokens_to_sample` or the model's maximum"
    },
    "type": {
      "type": "string",
      "const": "completion",
      "title": "Type",
      "description": "Object type.\n\nFor Text Completions, this is always `\"completion\"`.",
      "default": "completion"
    }
  },
  "type": "object",
  "required": [
    "completion",
    "id",
    "model",
    "stop_reason",
    "type"
  ],
  "$defs": {
    "Model": {
      "title": "Model",
      "description": "The model that will complete your prompt.\n\nSee [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.",
      "anyOf": [
        {
          "type": "string"
        },
        {
          "const": "claude-sonnet-5",
          "description": "High-performance model for coding and agents",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-fable-5",
          "description": "Next generation of intelligence for the hardest knowledge work and coding problems",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-mythos-5",
          "description": "Most capable model for cybersecurity and biology research",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-opus-5",
          "description": "Powerful intelligence for long-running agents and coding",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-opus-4-8",
          "description": "Powerful intelligence for long-running agents and coding",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-opus-4-7",
          "description": "Powerful intelligence for long-running agents and coding",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-mythos-preview",
          "description": "New class of intelligence, strongest in coding and cybersecurity",
          "x-stainless-nominal": false,
          "deprecated": true,
          "x-stainless-deprecation-message": "Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.anthropic.com/en/docs/resources/model-deprecations for more information."
        },
        {
          "const": "claude-opus-4-6",
          "description": "Powerful intelligence for long-running agents and coding",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-sonnet-4-6",
          "description": "Best combination of speed and intelligence",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-haiku-4-5",
          "description": "Fastest model with near-frontier intelligence",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-haiku-4-5-20251001",
          "description": "Fastest model with near-frontier intelligence",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-opus-4-5",
          "description": "Powerful intelligence for long-running agents and coding",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-opus-4-5-20251101",
          "description": "Powerful intelligence for long-running agents and coding",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-sonnet-4-5",
          "description": "High-performance model for agents and coding",
          "x-stainless-nominal": false
        },
        {
          "const": "claude-sonnet-4-5-20250929",
          "description": "High-performance model for agents and coding",
          "x-stainless-nominal": false
        }
      ]
    }
  }
}