Response Healing

The Response Healing plugin automatically validates and repairs malformed JSON responses from AI models. When models return imperfect formatting – missing brackets, trailing commas, markdown wrappers, or mixed text – this plugin attempts to repair the response so you receive valid, parseable JSON.

Overview

Response Healing provides:

Automatic JSON repair: Fixes missing brackets, commas, quotes, and other syntax errors
Markdown extraction: Extracts JSON from markdown code blocks

How It Works

The plugin activates for non-streaming requests when you set text.format in a Responses API request (or response_format on Chat Completions) to either type: "json_schema" or type: "json_object", and include the response-healing plugin in your plugins array. See the Complete Example below for a full implementation.

What Gets Fixed

The Response Healing plugin handles common issues in LLM responses:

JSON Syntax Errors

Input: Missing closing bracket

{"name": "Alice", "age": 30

Output: Fixed

{"name": "Alice", "age": 30}

Markdown Code Blocks

Input: Wrapped in markdown

```json
{"name": "Bob"}
```

Output: Extracted

{"name": "Bob"}

Mixed Text and JSON

Input: Text before JSON

Here's the data you requested:
{"name": "Charlie", "age": 25}

Output: Extracted

{"name": "Charlie", "age": 25}

Trailing Commas

Input: Invalid trailing comma

{"name": "David", "age": 35,}

Output: Fixed

{"name": "David", "age": 35}

Unquoted Keys

Input: JavaScript-style

{name: "Eve", age: 40}

Output: Fixed

{"name": "Eve", "age": 40}

Complete Example

const response = await fetch('https://openrouter.ai/api/v1/responses', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer <OPENROUTER_API_KEY>',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model: 'google/gemini-2.5-flash',
    input: 'Generate a product listing with name, price, and description',
    text: {
      format: {
        type: 'json_schema',
        name: 'Product',
        schema: {
          type: 'object',
          properties: {
            name: {
              type: 'string',
              description: 'Product name'
            },
            price: {
              type: 'number',
              description: 'Price in USD'
            },
            description: {
              type: 'string',
              description: 'Product description'
            }
          },
          required: ['name', 'price']
        }
      }
    },
    plugins: [
      { id: 'response-healing' }
    ]
  }),
});

const data = await response.json();
const message = [...data.output].reverse().find((item: { type: string }) => item.type === 'message');
const text = message?.content.find((part: { type: string; text?: string }) => part.type === 'output_text')?.text;
if (text === undefined) {
  throw new Error('No output_text in response');
}
// The plugin attempts to repair malformed JSON syntax
const product = JSON.parse(text);
console.log(product.name, product.price);

import requests
import json

response = requests.post(
  "https://openrouter.ai/api/v1/responses",
  headers={
    "Authorization": f"Bearer <OPENROUTER_API_KEY>",
    "Content-Type": "application/json",
  },
  json={
    "model": "google/gemini-2.5-flash",
    "input": "Generate a product listing with name, price, and description",
    "text": {
      "format": {
        "type": "json_schema",
        "name": "Product",
        "schema": {
          "type": "object",
          "properties": {
            "name": {
              "type": "string",
              "description": "Product name"
            },
            "price": {
              "type": "number",
              "description": "Price in USD"
            },
            "description": {
              "type": "string",
              "description": "Product description"
            }
          },
          "required": ["name", "price"]
        }
      }
    },
    "plugins": [
      {"id": "response-healing"}
    ]
  }
)

data = response.json()
message = next(item for item in reversed(data["output"]) if item["type"] == "message")
product = json.loads(
  next(part["text"] for part in message["content"] if part["type"] == "output_text")
)
# The plugin attempts to repair malformed JSON syntax
print(product["name"], product["price"])

Limitations

Non-Streaming Requests OnlyResponse Healing only applies to non-streaming requests.

Will not repair all JSONSome malformed JSON responses may still be unrepairable. In particular, if the response is truncated by max_output_tokens, the plugin will not be able to repair it.

Overview

Models & Routing

Tool Calling

Features

Observability

Authentication

Ori

Developer Tools

Privacy

Best Practices

Providers

Community

Overview

How It Works

What Gets Fixed

JSON Syntax Errors

Markdown Code Blocks

Mixed Text and JSON

Trailing Commas

Unquoted Keys

Complete Example

Limitations