Uploads

Upload File in Chunks

Send a file inline as small base64 chunks, assembled server-side. This exists for clients that can reach neither the S3 host nor the relay — prefer Initiate Upload everywhere else.

Omit upload_id on the first chunk; the response mints one to thread through the rest. Set is_last_part on the final chunk. Chunks may arrive out of order; the upload completes when every index from 0 to the last is present, and the response then carries file_url. Limits: 1 MiB decoded per chunk, 50 MiB per upload, 10,000 parts, and abandoned parts are discarded after an hour.

expected_decoded_bytes is the truncation guard: a mismatch rejects that chunk alone, so resend only that part_index.

POST

storage

upload

chunk

Upload File in Chunks

curl --request POST \
  --url https://api.modelrunner.run/storage/upload/chunk \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "part_index": 1,
  "is_last_part": true,
  "base64": "<string>",
  "file_name": "<string>",
  "expected_decoded_bytes": 2,
  "upload_id": "<string>",
  "content_type": "<string>",
  "sha256": "<string>",
  "file_sha256": "<string>"
}
'

import requests

url = "https://api.modelrunner.run/storage/upload/chunk"

payload = {
    "part_index": 1,
    "is_last_part": True,
    "base64": "<string>",
    "file_name": "<string>",
    "expected_decoded_bytes": 2,
    "upload_id": "<string>",
    "content_type": "<string>",
    "sha256": "<string>",
    "file_sha256": "<string>"
}
headers = {
    "Authorization": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    part_index: 1,
    is_last_part: true,
    base64: '<string>',
    file_name: '<string>',
    expected_decoded_bytes: 2,
    upload_id: '<string>',
    content_type: '<string>',
    sha256: '<string>',
    file_sha256: '<string>'
  })
};

fetch('https://api.modelrunner.run/storage/upload/chunk', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.modelrunner.run/storage/upload/chunk",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'part_index' => 1,
    'is_last_part' => true,
    'base64' => '<string>',
    'file_name' => '<string>',
    'expected_decoded_bytes' => 2,
    'upload_id' => '<string>',
    'content_type' => '<string>',
    'sha256' => '<string>',
    'file_sha256' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://api.modelrunner.run/storage/upload/chunk"

	payload := strings.NewReader("{\n  \"part_index\": 1,\n  \"is_last_part\": true,\n  \"base64\": \"<string>\",\n  \"file_name\": \"<string>\",\n  \"expected_decoded_bytes\": 2,\n  \"upload_id\": \"<string>\",\n  \"content_type\": \"<string>\",\n  \"sha256\": \"<string>\",\n  \"file_sha256\": \"<string>\"\n}")

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

	req.Header.Add("Authorization", "<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(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.modelrunner.run/storage/upload/chunk")
  .header("Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"part_index\": 1,\n  \"is_last_part\": true,\n  \"base64\": \"<string>\",\n  \"file_name\": \"<string>\",\n  \"expected_decoded_bytes\": 2,\n  \"upload_id\": \"<string>\",\n  \"content_type\": \"<string>\",\n  \"sha256\": \"<string>\",\n  \"file_sha256\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.modelrunner.run/storage/upload/chunk")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"part_index\": 1,\n  \"is_last_part\": true,\n  \"base64\": \"<string>\",\n  \"file_name\": \"<string>\",\n  \"expected_decoded_bytes\": 2,\n  \"upload_id\": \"<string>\",\n  \"content_type\": \"<string>\",\n  \"sha256\": \"<string>\",\n  \"file_sha256\": \"<string>\"\n}"

response = http.request(request)
puts response.read_body

{
  "upload_id": "<string>",
  "received_parts": [
    123
  ],
  "missing_parts": [
    123
  ],
  "file_url": "<string>"
}

{
  "error": "<string>",
  "request_id": "<string>"
}

{
  "error": "<string>",
  "request_id": "<string>"
}

Authorizations

Authorization

string

header

required

Use the format: Key modelrunner_key

Body

application/json

part_index

integer

required

Required range: x >= 0

is_last_part

boolean

required

Exactly one chunk may set this.

base64

string

required

This chunk's bytes, base64-encoded. ~32–48 KB per chunk works well.

file_name

string

required

expected_decoded_bytes

integer

required

Decoded byte length of this chunk.

Required range: x >= 1

upload_id

string

Omit on the first chunk; echo the minted value on every later chunk.

content_type

string

Defaults to application/octet-stream.

sha256

string

Optional hex SHA-256 of this chunk's decoded bytes.

file_sha256

string

Optional hex SHA-256 of the whole assembled file, checked at completion.

Response

Chunk stored, or upload completed.

upload_id

string

received_parts

integer[]

Indices held so far.

missing_parts

integer[]

Present once the final part has been seen and gaps remain.

file_url

string

Present only on the chunk that completes the upload.

Upload File in Chunks

curl --request POST \
  --url https://api.modelrunner.run/storage/upload/chunk \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "part_index": 1,
  "is_last_part": true,
  "base64": "<string>",
  "file_name": "<string>",
  "expected_decoded_bytes": 2,
  "upload_id": "<string>",
  "content_type": "<string>",
  "sha256": "<string>",
  "file_sha256": "<string>"
}
'

import requests

url = "https://api.modelrunner.run/storage/upload/chunk"

payload = {
    "part_index": 1,
    "is_last_part": True,
    "base64": "<string>",
    "file_name": "<string>",
    "expected_decoded_bytes": 2,
    "upload_id": "<string>",
    "content_type": "<string>",
    "sha256": "<string>",
    "file_sha256": "<string>"
}
headers = {
    "Authorization": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    part_index: 1,
    is_last_part: true,
    base64: '<string>',
    file_name: '<string>',
    expected_decoded_bytes: 2,
    upload_id: '<string>',
    content_type: '<string>',
    sha256: '<string>',
    file_sha256: '<string>'
  })
};

fetch('https://api.modelrunner.run/storage/upload/chunk', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.modelrunner.run/storage/upload/chunk",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'part_index' => 1,
    'is_last_part' => true,
    'base64' => '<string>',
    'file_name' => '<string>',
    'expected_decoded_bytes' => 2,
    'upload_id' => '<string>',
    'content_type' => '<string>',
    'sha256' => '<string>',
    'file_sha256' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://api.modelrunner.run/storage/upload/chunk"

	payload := strings.NewReader("{\n  \"part_index\": 1,\n  \"is_last_part\": true,\n  \"base64\": \"<string>\",\n  \"file_name\": \"<string>\",\n  \"expected_decoded_bytes\": 2,\n  \"upload_id\": \"<string>\",\n  \"content_type\": \"<string>\",\n  \"sha256\": \"<string>\",\n  \"file_sha256\": \"<string>\"\n}")

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

	req.Header.Add("Authorization", "<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(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.modelrunner.run/storage/upload/chunk")
  .header("Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"part_index\": 1,\n  \"is_last_part\": true,\n  \"base64\": \"<string>\",\n  \"file_name\": \"<string>\",\n  \"expected_decoded_bytes\": 2,\n  \"upload_id\": \"<string>\",\n  \"content_type\": \"<string>\",\n  \"sha256\": \"<string>\",\n  \"file_sha256\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.modelrunner.run/storage/upload/chunk")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"part_index\": 1,\n  \"is_last_part\": true,\n  \"base64\": \"<string>\",\n  \"file_name\": \"<string>\",\n  \"expected_decoded_bytes\": 2,\n  \"upload_id\": \"<string>\",\n  \"content_type\": \"<string>\",\n  \"sha256\": \"<string>\",\n  \"file_sha256\": \"<string>\"\n}"

response = http.request(request)
puts response.read_body

{
  "upload_id": "<string>",
  "received_parts": [
    123
  ],
  "missing_parts": [
    123
  ],
  "file_url": "<string>"
}

{
  "error": "<string>",
  "request_id": "<string>"
}

{
  "error": "<string>",
  "request_id": "<string>"
}

API documentation

Queue API

Platform APIs

Upload File in Chunks

Authorizations

Body

Response