Update a Parser

Modifiy an existing parser's fields. Some changes generate a new version asynchronously, others are applied immediately.

PATCH https://aiparser.scraperapi.com/parsers/{parser_id}/{version}

When to use this endpoint

You have an existing parser, ran a few /parse calls, but the output isn't quite right:

• A field you want is missing → use add_fields.

• A field is being extracted wrong → use modify_fields with clearer description.

• A field name is awkward → use rename_fields.

• A field is no longer relevant → use remove_fields.

You can do any combination in a single request

Request body

{
  "api_key": "API_KEY",
  "add_fields": [
    { "name": "products.discount", "description": "Discount percentage as a number", "type": "number" }
  ],
  "modify_fields": [
    { "name": "price", "description": "Price in USD as a number, no currency symbol", "type": "number" }
  ],
  "rename_fields": [
    { "name": "products.name", "new_name": "products.title" }
  ],
  "remove_fields": ["obsolete_field"]
}

Only api_key is required. Include only the operations you need.

Response

Status	When	Body
200 OK	Only rename_fields and/or remove_fields were sent - changes apply immediatelly.	New version number
202 Accepted	add_fields or modify_fields were sent - a new version is generating asynchronously.	New version number

After a 202, poll GET /parsers/{id} until status is FINISHED before parsing with the new version.

Step-by-step Example

Suppose you create a parser and you get version: 0, but notice that the price field is being returned as string that includes the $ symbol. Here's how you would clean up the field and update the parser, so the price is returned in a more usable numeric format:

# Run the parser first
curl "https://aiparser.scraperapi.com/parse/<PARSER_ID>?api_key=API_KEY&url=URL"
# { "price": "$1,212.02" } - string with currency symbol

# PATCH with a clearer description
curl -X PATCH https://aiparser.scraperapi.com/parsers/<PARSER_ID> \
  -H "Content-Type: application/json" \
  -d '{
    "api_key": "API_KEY",
    "modify_fields": [
      { "name": "price", "description": "Price in USD as a number, excluding currency symbols and commas", "type": "number" }
    ]
  }'
# 202 Accepted - { "version": 1 }

# Wait for FINISHED status
curl "https://aiparser.scraperapi.com/parsers/<PARSER_ID>/1?api_key=API_KEY"

# Re-run with the new version
curl "https://aiparser.scraperapi.com/parse/<PARSER_ID>/1?api_key=API_KEY&url=URL"
# { "price": 1212.02 } - now returned as number

Field definition reference

Each entry in add_fields and modify_fields supports

Property	Required	Description
name	Yes	Field name. Use dot notation for nested fields (e.g. products.images.url)
description	Yes	Field description. The more specific - the better the results.
type	No	string, number or array.
selector	No	CSS or XPATH selector.

selectors are optional, but they often produce more reliable results.