What is the JMESPath free API?

A serverless endpoint that evaluates JMESPath expressions on JSON you send in the request body. It is ideal for prototyping, demos, and low-volume automations without deploying infrastructure.

How do I use the JMESPath free API on this page?

Copy a snippet from the Quick Start tabs (cURL, JavaScript, Python) and send a JSON body with two fields: data (object or array) and query (JMESPath expression). The API returns the evaluated result as JSON.

Can I call the JMESPath free API from a browser or no-code tool?

Yes. CORS is enabled, so you can call it directly from browsers and tools like Zapier, Make, or n8n.

What kinds of JSON transformations does JMESPath support?

Filtering, projections, sorting with sort_by, reversing, slicing, and reshaping into flat objects.

Is the JMESPath free API suitable for production or high-volume use?

It is intended for testing and low-volume scenarios. For SLAs or guaranteed throughput, host a dedicated instance or handle transformations in your backend.

How are errors returned?

Malformed expressions return HTTP 400 with a descriptive error message.

Do you store the JSON I send to the JMESPath free API?

The endpoint processes your request and returns the result. It is not intended to persist or share payloads. Avoid sending secrets or highly sensitive data.

How do I use the JMESPath free API with Note API Connector?

Call the endpoint as a step to reshape API responses before syncing to Notion. See the documentation linked in the Examples section.

Free API

JMESPath Free API:
Transform JSON Data Instantly

The JMESPath free API gives you a ready-to-use, serverless endpoint for running JSON transformations with the JMESPath query language. It’s public, and perfect for prototyping and testing low-volume automations.

Instead of spinning up infrastructure, you can run JMESPath requests in seconds. Below you’ll find the endpoint, sample code, error format, and ideas for integrating it with your tooling.

https://noteapiconnector-tools.vercel.app/api/jmespath

Quick Start

curl -X POST https://noteapiconnector-tools.vercel.app/api/jmespath \
  -H "content-type: application/json" \
  -d '{
    "data": {
      "people": [
        { "name": "Ana", "age": 30 },
        { "name": "Bob", "age": 20 }
      ]
    },
    "query": "people[?age>`25`].name"
  }'

fetch('https://noteapiconnector-tools.vercel.app/api/jmespath', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    data: {
      people: [
        { name: "Ana", age: 30 },
        { name: "Bob", age: 20 }
      ]
    },
    query: 'people[?age>`25`].name'
  })
})
.then(res => res.json())
.then(data => console.log(data));

import requests

response = requests.post(
  'https://noteapiconnector-tools.vercel.app/api/jmespath',
  json={
    "data": {
      "people": [
        { "name": "Ana", "age": 30 },
        { "name": "Bob", "age": 20 }
      ]
    },
    "query": "people[?age>`25`].name"
  }
)
print(response.json())

RESPONSE

["Ana"]

API Reference

URL


                    https://noteapiconnector-tools.vercel.app/api/jmespath

Method

POST

Headers

content-type: application/json

Request Body

data JSON object or array to transform

query JMESPath expression string

CORS enabled: Call directly from browsers, low-code tools, and automation platforms. No authentication required for testing.

Common Use Cases

Filter Data

Extract only the records that meet your criteria before syncing to Notion databases.

Reshape Objects

Transform nested API responses into flat structures perfect for spreadsheets.

Sort & Rank

Order results by any field and grab top performers for dashboards and reports.

Examples

Need inspiration? Copy any of the curl commands below, hit the JMESPath free API, and tweak the JSON to match your own workflow. For more examples, check our documentation.

Filter Unfinished Tasks

Returns only tasks where completed is false.

curl -X POST https://noteapiconnector-tools.vercel.app/api/jmespath \
  -H "content-type: application/json" \
  -d '{
    "data": {
      "tasks": [
        { "title": "Draft docs", "completed": false, "priority": 2 },
        { "title": "Send invoice", "completed": true, "priority": 1 },
        { "title": "Plan launch", "completed": false, "priority": 3 }
      ]
    },
    "query": "tasks[?completed==`false`].title"
  }'

RESPONSE

["Draft docs", "Plan launch"]

Project Nested Contact Fields

Grabs each customer's name and email from a nested payload.

curl -X POST https://noteapiconnector-tools.vercel.app/api/jmespath \
  -H "content-type: application/json" \
  -d '{
    "data": {
      "customers": [
        {
          "name": "Asha Patel",
          "contact": { "email": "[email protected]", "city": "Austin" }
        },
        {
          "name": "Lee Wong",
          "contact": { "email": "[email protected]", "city": "Seattle" }
        }
      ]
    },
    "query": "customers[].{name: name, email: contact.email}"
  }'

RESPONSE

[
  {
    "name": "Asha Patel",
    "email": "[email protected]"
  },
  {
    "name": "Lee Wong",
    "email": "[email protected]"
  }
]

Sort and Choose Top Results

Orders products by rating and returns the top two names.

curl -X POST https://noteapiconnector-tools.vercel.app/api/jmespath \
  -H "content-type: application/json" \
  -d '{
    "data": {
      "products": [
        { "name": "Starter", "rating": 4.2 },
        { "name": "Pro", "rating": 4.8 },
        { "name": "Enterprise", "rating": 4.6 }
      ]
    },
    "query": "reverse(sort_by(products, &rating))[:2].name"
  }'

RESPONSE

["Pro", "Enterprise"]

Error Handling

Invalid Query Response (400)

Malformed expressions return descriptive error messages:

{
  "error": "RuntimeError: Invalid token: Parse error at column 11..."
}

JMESPath Free API:
Transform JSON Data Instantly

Quick Start

API Reference

Common Use Cases

Filter Data

Reshape Objects

Sort & Rank

Examples

Filter Unfinished Tasks

Project Nested Contact Fields

Sort and Choose Top Results

Error Handling

Invalid Query Response (400)

Frequently Asked Questions

Leave a Comment

JMESPath Free API:Transform JSON Data Instantly

Quick Start

API Reference

Common Use Cases

Filter Data

Reshape Objects

Sort & Rank

Examples

Filter Unfinished Tasks

Project Nested Contact Fields

Sort and Choose Top Results

Error Handling

Invalid Query Response (400)

Frequently Asked Questions

Leave a Comment

JMESPath Free API:
Transform JSON Data Instantly