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JSON to TOML API#

The JSON to TOML API converts a JSON file to TOML format with a single request to POST /v1/convert/json-to-toml. Upload a .json file via multipart form data and receive the converted TOML directly, or set direct_download=false to get metadata with a presigned download URL. JSON arrays are wrapped under an items key and scalar values under a value key, since TOML requires a top-level table.

Endpoint#

POST /v1/convert/json-to-toml

Content-Type: multipart/form-data

Accepted input: .json files (UTF-8 encoded)

Output format: .toml (application/toml)

Authentication#

Requires either a private API key or a JWT token from a public key.

X-API-Key: sk_your_private_key

Or:

Authorization: Bearer <jwt_token>

Request Parameters#

Parameter	Type	Required	Default	Description
`file`	file	Yes	--	The `.json` file to convert. Must be UTF-8 encoded. Must not contain `null` values.
`output_filename`	`string`	No	Input filename	Custom output filename. The `.toml` extension is added automatically.
`direct_download`	`boolean`	No	`true`	When `true`, returns raw TOML bytes. When `false`, returns metadata with a presigned download URL.

Conversion Rules#

JSON object passes through directly: json {"database": {"host": "localhost", "port": 5432}} Becomes: toml [database] host = "localhost" port = 5432
JSON array is wrapped under an items key (TOML requires a top-level table): json [1, 2, 3] Becomes: toml items = [1, 2, 3]
Scalar value is wrapped under a value key: json 42 Becomes: toml value = 42

Important: TOML does not support null values. If your JSON contains any null values, the conversion will fail with a 400 error. Remove or replace null values before converting.

Response#

Direct Download (`direct_download=true`, default)#

HTTP 200 OK
Content-Type: application/toml
Content-Disposition: inline; filename="config_20260405_123456789.toml"

Metadata Response (`direct_download=false`)#

{
    "presigned_url": "https://spaces.example.com/...",
    "object_key": "env/files/{project_id}/json-to-toml/config_20260405_123456789.toml",
    "filename": "config_20260405_123456789.toml",
    "file_size": 1234,
    "conversion_time_seconds": 0.03
}

Code Examples#

Python#

import requests

with open("config.json", "rb") as f:
    response = requests.post(
        "https://api.enconvert.com/v1/convert/json-to-toml",
        headers={"X-API-Key": "sk_your_private_key"},
        files={"file": ("config.json", f, "application/json")}
    )

with open("config.toml", "wb") as out:
    out.write(response.content)

Node.js#

const form = new FormData();
form.append("file", fs.createReadStream("config.json"));

const response = await fetch("https://api.enconvert.com/v1/convert/json-to-toml", {
    method: "POST",
    headers: { "X-API-Key": "sk_your_private_key" },
    body: form
});

const toml = await response.text();

PHP#

$ch = curl_init("https://api.enconvert.com/v1/convert/json-to-toml");
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => ["X-API-Key: sk_your_private_key"],
    CURLOPT_POSTFIELDS => ["file" => new CURLFile("config.json", "application/json")]
]);
$toml = curl_exec($ch);
curl_close($ch);

Go#

body := &bytes.Buffer{}
writer := multipart.NewWriter(body)
part, _ := writer.CreateFormFile("file", "config.json")
file, _ := os.Open("config.json")
io.Copy(part, file)
writer.Close()

req, _ := http.NewRequest("POST", "https://api.enconvert.com/v1/convert/json-to-toml", body)
req.Header.Set("Content-Type", writer.FormDataContentType())
req.Header.Set("X-API-Key", "sk_your_private_key")
resp, _ := http.DefaultClient.Do(req)

Error Responses#

Status	Condition
`400 Bad Request`	File is not a `.json` file
`400 Bad Request`	Invalid JSON content
`400 Bad Request`	JSON to TOML conversion failed (typically due to `null` values)
`401 Unauthorized`	Missing or invalid API key / JWT token
`402 Payment Required`	Monthly ops allowance exhausted
`413 Payload Too Large`	File exceeds plan's maximum file size

Limits#

Limit	Value
Max file size	Plan-dependent (Founding: 5 MB)
Input encoding	UTF-8 only
Null values	Not supported (TOML limitation)
Monthly conversions	Plan-dependent

Frequently asked questions#

How do I convert JSON to TOML with a REST API?#

Send a multipart/form-data POST request to POST /v1/convert/json-to-toml with your .json file in the file field, authenticating with an X-API-Key header or a JWT Authorization: Bearer token. By default the response body is the raw TOML bytes.

Why does my JSON to TOML conversion fail with a 400 error?#

TOML does not support null values, so any JSON containing null fails with a 400 Bad Request. A 400 is also returned when the upload is not a .json file or the JSON content is invalid.

Can I convert a JSON array or a scalar value to TOML?#

Yes. Because TOML requires a top-level table, a JSON array is wrapped under an items key and a scalar value is wrapped under a value key.

How do I get a download URL instead of the raw TOML file?#

Set direct_download=false in the request. The API then returns JSON metadata including a presigned_url, object_key, filename, file_size, and conversion_time_seconds.

What file size limit applies to JSON to TOML conversions?#

The maximum file size is plan-dependent (Founding plan: 5 MB). Files exceeding your plan's limit return 413 Payload Too Large.

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API Documentation