Create a model

POST

/api/models

CURL *hnd = curl_easy_init();

curl_easy_setopt(hnd, CURLOPT_CUSTOMREQUEST, "POST");
curl_easy_setopt(hnd, CURLOPT_URL, "https://api.langparse.dev/api/models");

struct curl_slist *headers = NULL;
headers = curl_slist_append(headers, "X-Api-Key: <X-Api-Key>");
headers = curl_slist_append(headers, "Content-Type: application/json");
curl_easy_setopt(hnd, CURLOPT_HTTPHEADER, headers);

curl_easy_setopt(hnd, CURLOPT_POSTFIELDS, "{ \"name\": \"Invoice\", \"fields\": [ { \"title\": \"Invoice Number\", \"type\": \"text\", \"required\": true } ] }");

CURLcode ret = curl_easy_perform(hnd);

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
    Method = HttpMethod.Post,
    RequestUri = new Uri("https://api.langparse.dev/api/models"),
    Headers =
    {
        { "X-Api-Key", "<X-Api-Key>" },
    },
    Content = new StringContent("{ \"name\": \"Invoice\", \"fields\": [ { \"title\": \"Invoice Number\", \"type\": \"text\", \"required\": true } ] }")
    {
        Headers =
        {
            ContentType = new MediaTypeHeaderValue("application/json")
        }
    }
};
using (var response = await client.SendAsync(request))
{
    response.EnsureSuccessStatusCode();
    var body = await response.Content.ReadAsStringAsync();
    Console.WriteLine(body);
}

package main

import (
  "fmt"
  "strings"
  "net/http"
  "io"
)

func main() {

  url := "https://api.langparse.dev/api/models"

  payload := strings.NewReader("{ \"name\": \"Invoice\", \"fields\": [ { \"title\": \"Invoice Number\", \"type\": \"text\", \"required\": true } ] }")

  req, _ := http.NewRequest("POST", url, payload)

  req.Header.Add("X-Api-Key", "<X-Api-Key>")
  req.Header.Add("Content-Type", "application/json")

  res, _ := http.DefaultClient.Do(req)

  defer res.Body.Close()
  body, _ := io.ReadAll(res.Body)

  fmt.Println(res)
  fmt.Println(string(body))

}

HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://api.langparse.dev/api/models"))
    .header("X-Api-Key", "<X-Api-Key>")
    .header("Content-Type", "application/json")
    .method("POST", HttpRequest.BodyPublishers.ofString("{ \"name\": \"Invoice\", \"fields\": [ { \"title\": \"Invoice Number\", \"type\": \"text\", \"required\": true } ] }"))
    .build();
HttpResponse<String> response = HttpClient.newHttpClient().send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

OkHttpClient client = new OkHttpClient();

MediaType mediaType = MediaType.parse("application/json");
RequestBody body = RequestBody.create(mediaType, "{ \"name\": \"Invoice\", \"fields\": [ { \"title\": \"Invoice Number\", \"type\": \"text\", \"required\": true } ] }");
Request request = new Request.Builder()
  .url("https://api.langparse.dev/api/models")
  .post(body)
  .addHeader("X-Api-Key", "<X-Api-Key>")
  .addHeader("Content-Type", "application/json")
  .build();

Response response = client.newCall(request).execute();

import axios from 'axios';

const options = {
  method: 'POST',
  url: 'https://api.langparse.dev/api/models',
  headers: {'X-Api-Key': '<X-Api-Key>', 'Content-Type': 'application/json'},
  data: {
    name: 'Invoice',
    fields: [{title: 'Invoice Number', type: 'text', required: true}]
  }
};

try {
  const { data } = await axios.request(options);
  console.log(data);
} catch (error) {
  console.error(error);
}

const url = 'https://api.langparse.dev/api/models';
const options = {
  method: 'POST',
  headers: {'X-Api-Key': '<X-Api-Key>', 'Content-Type': 'application/json'},
  body: '{"name":"Invoice","fields":[{"title":"Invoice Number","type":"text","required":true}]}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}

val client = OkHttpClient()

val mediaType = MediaType.parse("application/json")
val body = RequestBody.create(mediaType, "{ \"name\": \"Invoice\", \"fields\": [ { \"title\": \"Invoice Number\", \"type\": \"text\", \"required\": true } ] }")
val request = Request.Builder()
  .url("https://api.langparse.dev/api/models")
  .post(body)
  .addHeader("X-Api-Key", "<X-Api-Key>")
  .addHeader("Content-Type", "application/json")
  .build()

val response = client.newCall(request).execute()

use serde_json::json;
use reqwest;

#[tokio::main]
pub async fn main() {
    let url = "https://api.langparse.dev/api/models";

    let payload = json!({
        "name": "Invoice",
        "fields": (
            json!({
                "title": "Invoice Number",
                "type": "text",
                "required": true
            })
        )
    });

    let mut headers = reqwest::header::HeaderMap::new();
    headers.insert("X-Api-Key", "<X-Api-Key>".parse().unwrap());
    headers.insert("Content-Type", "application/json".parse().unwrap());

    let client = reqwest::Client::new();
    let response = client.post(url)
        .headers(headers)
        .json(&payload)
        .send()
        .await;

    let results = response.unwrap()
        .json::<serde_json::Value>()
        .await
        .unwrap();

    dbg!(results);
}

curl --request POST \
  --url https://api.langparse.dev/api/models \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <X-Api-Key>' \
  --data '{ "name": "Invoice", "fields": [ { "title": "Invoice Number", "type": "text", "required": true } ] }'

wget --quiet \
  --method POST \
  --header 'X-Api-Key: <X-Api-Key>' \
  --header 'Content-Type: application/json' \
  --body-data '{ "name": "Invoice", "fields": [ { "title": "Invoice Number", "type": "text", "required": true } ] }' \
  --output-document \
  - https://api.langparse.dev/api/models

Create a model — a named extraction schema. fields define what to pull (text / number / date / boolean / select / list / object); list and object fields nest their own children. Optionally attach an extraction strategy, a validation rule, and outputTags.

Authorizations

apiKey
bearerAuth

Request Body^required

application/json

object

name

required

string

slug

Friendly, URL-safe key (unique per org). Auto-derived from the name when omitted; editable. Usable in place of the model id.

string

fields

Array<object>

object

title

required

string

name

Output JSON key. Any style (kept verbatim); snake_case is derived from title when omitted.

string

type

required

string

Allowed values: text number date boolean select list object image synthesize

required

boolean

multiple

List: repeated rows (default true). object: array of objects (default false).

boolean

transform

Per-field JS (value, doc) => newValue.

string

validators

Validator ids to run on the value — built-in (e.g. iban, nzbn, abn, vat_eu, aba_routing, iso_date) or a custom val_…. A failure flags the document for review.

Array<string>

children

Array<object> recursive

rule

Document validation JS (doc, ctx) => void.

string

enhance

Enhance scan-like pages (deskew / denoise / contrast / crop) before extraction. Digital PDFs are untouched.

boolean

reconcile

Totals reconciliation — flag when total ≠ sum of the items list’s amount field.

object

total

Top-level number field holding the document total.

string

items

Top-level list field holding the line items.

string

amount

Field within each list row holding the line amount.

string

tolerance

Absolute rounding tolerance (default 0.01).

number

outputTags

Array<object>

An S3 object tag projected from parsed data. Use ${data.field}, ${dest.uri/bucket/key} or literals.

object

name

required

string

expression

required

string

toSource

Tag the original source file (S3 sources).

boolean

toDestination

Tag the delivered output object.

boolean

strategy

{ kind: single|consensus, extractors: […], judge? }

object

key

additional properties

any

Example

{
  "name": "Invoice",
  "fields": [
    {
      "title": "Invoice Number",
      "type": "text",
      "required": true
    }
  ]
}

Responses

200

The created model.

application/json

object

data

required

A model (schema + strategy + output tags). Own key id; slug is a friendly, unique-per-org handle accepted anywhere the id is.

object

key

additional properties

any

Example

{
  "data": {
    "id": "mdl_inv01",
    "slug": "invoice",
    "name": "Invoice",
    "description": "Supplier invoices with line items, taxes and totals.",
    "fieldCount": 12,
    "fieldPreview": [
      "Invoice Number",
      "Invoice Date",
      "Total"
    ],
    "strategy": "single",
    "features": [],
    "coverUrl": null,
    "updatedAt": "2026-07-07T04:50:26.659Z",
    "fields": []
  }
}

401

Missing or invalid API key.

application/json

Error response. statusCode mirrors the HTTP status; statusMessage is human-readable.

object

statusCode

integer

statusMessage

string

Example

{
  "statusCode": 404,
  "statusMessage": "Document not found"
}

Create a model

Authorizations

Request Bodyrequired

Example

Responses

200

Example

401

Example

Request Body^required