JSON array project

json-array-project · version 1.0.0 · JSON & JSONL · free, no key needed

Select specific keys from each object in a JSON array.

Use when you need to: json array project · select keys from json array · pick json array fields.

Supported

• json array project
• select keys from json array
• pick json array fields

Not supported

• deep projection
• rename keys

Behavior

• Outputs a new array where each object only contains the specified keys.
• Keys that do not exist in an object are simply omitted from the result for that object.
• Output keys follow the order specified in the keys array.

Input

• array (array of object, required): max items 10000
• keys (array of string, required): min items 1; max items 32; each min length 1

Output

• result (array of object, required)
• count (integer, required)

Limits

• max array items: 10000
• max output items: 10000
• max keys: 32

Example

Request input:

{
  "array": [
    {
      "a": 1,
      "b": 2,
      "c": 3
    },
    {
      "a": 4,
      "c": 6
    }
  ],
  "keys": [
    "a",
    "c"
  ]
}

Response:

{
  "result": {
    "result": [
      {
        "a": 1,
        "c": 3
      },
      {
        "a": 4,
        "c": 6
      }
    ],
    "count": 2
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "json-array-project",
  "version": "1.0.0",
  "input": {
    "array": [
      {
        "a": 1,
        "b": 2,
        "c": 3
      },
      {
        "a": 4,
        "c": 6
      }
    ],
    "keys": [
      "a",
      "c"
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/json-array-project/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"array":[{"a":1,"b":2,"c":3},{"a":4,"c":6}],"keys":["a","c"]}'

The machine-readable contract is at /v1/tools/json-array-project/versions/1.0.0.

CLI

node cli.mjs run json-array-project 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• JSON array drop keys: Remove specific keys from each object in a JSON array.
• JSON array rename keys: Rename specific keys in each object in a JSON array.
• JSON pick pointers: Pick cloned JSON values at explicit RFC 6901 pointers into a null-prototype map.
• JSON array anti join: Anti join two JSON arrays of objects on exact keys.
• JSON array filter equals: Filter JSON array objects where a key equals a specific value.
• JSON array group by: Group an array of JSON objects by exact keys.