Form response diff

form-response-diff · version 1.0.0 · Forms · free, no key needed

Reconcile two form response sets by exact respondent id.

Use when you need to: diff form responses · reconcile form respondents.

Supported

• diff form responses
• reconcile form respondents

Not supported

• fuzzy respondent matching
• inferred identity
• definition migration
• html extraction

Behavior

• Join responses by exact respondent_id. Duplicate ids are rejected. Ids are not trimmed or normalized.
• Added and removed respondents include their answers. Identical respondents are listed by id only.
• A changed respondent carries the shared-definition answer diff and its precedence: invalid before added, removed, changed, or order_only.
• Both nulls compare equal and do not by themselves mark the respondent changed. This comparison is not a completeness check.
• Answer key order does not matter. Output answer keys follow the definition order, then unknown keys.
• counts.added + counts.removed + counts.changed + counts.unchanged equals the respondent union.

Input

• definition (object, required)
• left (array of object, required)
• right (array of object, required)

Output

• added_respondents (array of any, required)
• removed_respondents (array of any, required)
• changed_respondents (array of any, required)
• unchanged_respondent_ids (array of string, required)
• counts (object, required)

Limits

• max input bytes: 262144
• max output bytes: 262144
• max input depth: 16
• max input nodes: 20000
• max fields: 100
• max choices: 50
• max respondents: 100
• max id bytes: 128
• max label bytes: 256
• max choice bytes: 128
• max answer string bytes: 4096
• max answer depth: 6
• max answer nodes: 50
• max changes: 500
• max mapping: 100

Example

Request input:

{
  "definition": {
    "fields": [
      {
        "id": "name",
        "label": "Name",
        "type": "string",
        "required": true
      }
    ]
  },
  "left": [
    {
      "respondent_id": "r1",
      "answers": {
        "name": "Ada"
      }
    },
    {
      "respondent_id": "r2",
      "answers": {
        "name": "Lin"
      }
    }
  ],
  "right": [
    {
      "respondent_id": "r2",
      "answers": {
        "name": "Lin"
      }
    },
    {
      "respondent_id": "r3",
      "answers": {
        "name": "Grace"
      }
    }
  ]
}

Response:

{
  "result": {
    "added_respondents": [
      {
        "respondent_id": "r3",
        "answers": {
          "name": "Grace"
        }
      }
    ],
    "removed_respondents": [
      {
        "respondent_id": "r1",
        "answers": {
          "name": "Ada"
        }
      }
    ],
    "changed_respondents": [],
    "unchanged_respondent_ids": [
      "r2"
    ],
    "counts": {
      "added": 1,
      "removed": 1,
      "changed": 0,
      "unchanged": 1,
      "respondents": 3
    }
  }
}

How to call it

MCP

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

{
  "id": "form-response-diff",
  "version": "1.0.0",
  "input": {
    "definition": {
      "fields": [
        {
          "id": "name",
          "label": "Name",
          "type": "string",
          "required": true
        }
      ]
    },
    "left": [
      {
        "respondent_id": "r1",
        "answers": {
          "name": "Ada"
        }
      },
      {
        "respondent_id": "r2",
        "answers": {
          "name": "Lin"
        }
      }
    ],
    "right": [
      {
        "respondent_id": "r2",
        "answers": {
          "name": "Lin"
        }
      },
      {
        "respondent_id": "r3",
        "answers": {
          "name": "Grace"
        }
      }
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/form-response-diff/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"definition":{"fields":[{"id":"name","label":"Name","type":"string","required":true}]},"left":[{"respondent_id":"r1","answers":{"name":"Ada"}},{"respondent_id":"r2","answers":{"name":"Lin"}}],"right":[{"respondent_id":"r2","answers":{"name":"Lin"}},{"respondent_id":"r3","answers":{"name":"Grace"}}]}'

The machine-readable contract is at /v1/tools/form-response-diff/versions/1.0.0.

CLI

node cli.mjs run form-response-diff 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Form answer diff: Diff two answer maps against one shared form definition.
• Form compare: Compare two filled form snapshots and return compact field and answer changes.
• Form definition diff: Diff two form definitions by stable field id, including choice lists and field order.
• Form response check: Report missing required answers, nulls, type failures, and choice failures.
• Form field map: Rename form fields with an explicit id map and reject collisions.