Where is JMESPath used in practice?

AWS CLI's `--query` flag, Ansible filters, Azure CLI, Terraform providers, and many API client libraries. If you've used `aws ec2 describe-instances --query ...`, you've used JMESPath.

How do I filter a list of objects?

Use `[?property=='value']`. For example `Reservations[*].Instances[?State.Name=='running']` pulls running EC2 instances from a describe-instances response.

What's the difference between `|` and `.`?

`.` applies the next expression to each element in a projection; `|` stops the projection and applies the next expression to the whole result. Useful when you want to sort or slice the filtered list.

Does JMESPath support arithmetic?

Only through built-in functions (length, sum, avg, min_by, max_by, etc.). There are no infix math operators — JMESPath is a query language, not a calculator.

JMESPath Tester | DevTools Surf

DevTools Surf

Example: JMESPath Tester

A worked example, rendered from real sample data. Sign in to run the tool on your own input.

Input

users[*].name
{"users":[{"name":"Ada","age":36},{"name":"Grace","age":85},{"name":"Linus","age":55}]}

Output

[
  {
    "name": "Ada",
    "age": 36
  },
  {
    "name": "Grace",
    "age": 85
  },
  {
    "name": "Linus",
    "age": 55
  }
]

About JMESPath Tester

Query JSON with JMESPath expressions + live result + examples. Part of the DevTools Surf developer suite. Browse more tools in the JSON collection.

Use Cases

Extract specific fields from a large AWS CLI response
Prototype filters before using them in Ansible or AWS CLI
Learn JMESPath syntax by seeing live output
Write event-filter expressions for CloudWatch or EventBridge

Tips

Put the JMESPath expression on line 1 and JSON from line 2 onward
Use users[*].name to project a field across an array
Bracket indexes [0], [-1] are supported

Fun Facts

JMESPath is used by the AWS CLI — every --query you've ever written is JMESPath syntax.
JMESPath was created by James Saryerwinnie at Amazon and has official implementations in Python, Go, JavaScript, Java, PHP, Ruby, Lua, and Rust.
Unlike JSONPath, JMESPath has a formal ABNF grammar specification, making it one of the few JSON query languages with deterministic behavior across implementations.

FAQ

Where is JMESPath used in practice?: AWS CLI's `--query` flag, Ansible filters, Azure CLI, Terraform providers, and many API client libraries. If you've used `aws ec2 describe-instances --query ...`, you've used JMESPath.
How do I filter a list of objects?: Use `[?property=='value']`. For example `Reservations[*].Instances[?State.Name=='running']` pulls running EC2 instances from a describe-instances response.
What's the difference between `|` and `.`?: `.` applies the next expression to each element in a projection; `|` stops the projection and applies the next expression to the whole result. Useful when you want to sort or slice the filtered list.
Does JMESPath support arithmetic?: Only through built-in functions (length, sum, avg, min_by, max_by, etc.). There are no infix math operators — JMESPath is a query language, not a calculator.

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