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Transloadit

The @uppy/transloadit plugin can be used to upload files directly to Transloadit for all kinds of processing, such as transcoding video, resizing images, zipping/unzipping, and much more.

When should I use it?​

tip

Not sure which uploader is best for you? Read “Choosing the uploader you need”.

Transloadit’s strength is versatility. By doing video, audio, images, documents, and more, you only need one vendor for all your file processing needs. The @uppy/transloadit plugin directly uploads to Transloadit so you only have to worry about creating a Template. Transloadit accepts the files, processes according to the instructions in the Template, and stores the results in storage of your choosing, such as a self-owned S3 bucket. The Transloadit plugin uses Tus under the hood so you don’t have to sacrifice reliable, resumable uploads.

You should use @uppy/transloadit if you don’t want to host your own Tus or Companion servers, (optionally) need file processing, and store it in the service (such as S3 or GCS) of your liking. All with minimal effort.

Install​

npm install @uppy/transloadit

Use​

A quick overview of the complete API.

import Uppy from '@uppy/core';
import Dashboard from '@uppy/dashboard';
import Transloadit from '@uppy/transloadit';

import '@uppy/core/dist/style.min.css';
import '@uppy/dashboard/dist/style.min.css';

const uppy = new Uppy()
	.use(Dashboard, { inline: true, target: 'body' })
	.use(Transloadit, {
		assemblyOptions: {
			params: {
				auth: { key: 'your-transloadit-key' },
				template_id: 'your-template-id',
			},
		},
	});
// Optionally listen to events
uppy.on('transloadit:assembly-created', (assembly, fileIDs) => {});
uppy.on('transloadit:upload', (file, assembly) => {});
uppy.on('transloadit:assembly-executing', (assembly) => {});
uppy.on('transloadit:result', (stepName, result, assembly) => {});
uppy.on('transloadit:complete', (assembly) => {});

Use with Companion​

note

All Transloadit plans come with a hosted version of Companion.

You can use this plugin together with Transloadit’s hosted Companion service to let your users import files from third party sources across the web. To do so each provider plugin must be configured with Transloadit’s Companion URLs:

import { COMPANION_URL, COMPANION_ALLOWED_HOSTS } from '@uppy/transloadit';
import Dropbox from '@uppy/dropbox';

uppy.use(Dropbox, {
	companionUrl: COMPANION_URL,
	companionAllowedHosts: COMPANION_ALLOWED_HOSTS,
});

This will already work. Transloadit’s OAuth applications are used to authenticate your users by default. Your users will be asked to provide Transloadit access to their files. Since your users are probably not aware of Transloadit, this may be confusing or decrease trust. You may also hit rate limits, because the OAuth application is shared between everyone using Transloadit.

To solve that, you can use your own OAuth keys with Transloadit’s hosted Companion servers by using Transloadit Template Credentials. Create a Template Credential on the Transloadit site. Select “Companion OAuth” for the service, and enter the key and secret for the provider you want to use. Then you can pass the name of the new credentials to that provider:

import { COMPANION_URL, COMPANION_ALLOWED_HOSTS } from '@uppy/transloadit';
import Dropbox from '@uppy/dropbox';

uppy.use(Dropbox, {
	companionUrl: COMPANION_URL,
	companionAllowedHosts: COMPANION_ALLOWED_HOSTS,
	companionKeysParams: {
		key: 'YOUR_TRANSLOADIT_API_KEY',
		credentialsName: 'my_companion_dropbox_creds',
	},
});

API​

Options​

id​

A unique identifier for this plugin (string, default: 'Transloadit').

service​

The Transloadit API URL to use (string, default: https://api2.transloadit.com).

The default will try to route traffic efficiently based on the location of your users. You could for instance set it to https://api2-us-east-1.transloadit.com if you need the traffic to stay inside a particular region.

limit​

Limit the amount of uploads going on at the same time (number, default: 20).

Setting this to 0 means no limit on concurrent uploads, but we recommend a value between 5 and 20. This option is passed through to the @uppy/tus plugin, which this plugin uses internally.

assemblyOptions​

Configure the Assembly Instructions, the fields to send along to the assembly, and authentication (object | function, default: null).

The object you can pass or return from a function has this structure:

{
  params: {
    auth: { key: 'key-from-transloadit' },
    template_id: 'id-from-transloadit',
    steps: {
      // Overruling Template at runtime
    },
    notify_url: 'https://your-domain.com/assembly-status',
  },
  signature: 'generated-signature',
  fields: {
    // Dynamic or static fields to send along
  },
}
  • params is used to authenticate with Transloadit and using your desired template.
    • auth.key (required) is your authentication key which you can find on the “Credentials” page of your account.
    • template_id (required) is the unique identifier to use the right template from your account.
    • steps (optional) can be used to overrule Templates at runtime. A typical use case might be changing the storage path on the fly based on the session user id. For most use cases, we recommend to let your Templates handle dynamic cases (they can accept fields and execute arbitrary JavaScript as well), and not pass in steps from a browser. The template editor also has extra validations and context.
    • notify_url (optional) is a pingback with the assembly status as JSON. For instance, if you don’t want to block the user experience by letting them wait for your template to complete with waitForEncoding, but you do want to want to asynchrounously have an update, you can provide an URL which will be “pinged” with the assembly status.
  • signature (optional, but recommended) is a cryptographic signature to provide further trust in unstrusted environments. Refer to “Signature Authentication” for more information.
  • fields (optional) can be used to to send along key/value pairs, which can be used dynamically in your template.
Examples

As a function

A custom assemblyOptions() option should return an object or a promise for an object.

uppy.use(Transloadit, {
	assemblyOptions(file) {
		return {
			params: {
				auth: { key: 'TRANSLOADIT_AUTH_KEY_HERE' },
				template_id: 'xyz',
			},
			fields: {
				caption: file.meta.caption,
			},
		};
	},
});

The ${fields.caption} variable will be available in the Assembly spawned from Template xyz. You can use this to dynamically watermark images for example.

assemblyOptions() may also return a Promise, so it could retrieve signed Assembly parameters from a server. For example, assuming an endpoint /transloadit-params that responds with a JSON object with { params, signature } properties:

uppy.use(Transloadit, {
	async assemblyOptions(file) {
		const res = await fetch('/transloadit-params');
		return response.json();
	},
});

As an object

If you don’t need to change anything dynamically, you can also pass an object directly.

uppy.use(Transloadit, {
	assemblyOptions: {
		params: { auth: { key: 'transloadit-key' } },
	},
});

Use with @uppy/form

Combine the assemblyOptions() option with the Form plugin to pass user input from a <form> to a Transloadit Assembly:

// This will add form field values to each file's `.meta` object:
uppy.use(Form, { getMetaFromForm: true });
uppy.use(Transloadit, {
	getAssemblyOptions(file) {
		return {
			params: {
				/* ... */
			},
			// Pass through the fields you need:
			fields: {
				message: file.meta.message,
			},
		};
	},
});
caution

When you go to production always make sure to set the signature. Not using Signature Authentication can be a security risk. Signature Authentication is a security measure that can prevent outsiders from tampering with your Assembly Instructions. While Signature Authentication is not implemented (yet), we recommend to disable allow_steps_override in your Templates to avoid outsiders being able to pass in any Instructions and storage targets on your behalf.

waitForEncoding​

Wait for the template to finish, rather than only the upload, before marking the upload complete (boolean, default: false).

  • When false, the Assemblies will complete (or error) in the background but Uppy won’t know or care about it. You may have to let Transloadit ping you via a notify_url and asynchronously inform your user (email, in-app notification).
  • When true, the Transloadit plugin waits for Assemblies to complete before the files are marked as completed. This means users have to wait for a potentially long time, depending on how complicated your Assembly instructions are. But, you can receive the final status and transcoding results on the client side with less effort.

When this is enabled, you can listen for the transloadit:result and transloadit:complete events.

waitForMetadata​

Wait for Transloadit’s backend to catch early errors, not the entire Assembly to complete. (boolean, default: false)

When set to true, the Transloadit plugin waits for Transloadit’s backend to extract metadata from all the uploaded files. This is mostly handy if you want to have a quick user experience (so your users don’t necessarily need to wait for all the encoding to complete), but you do want to let users know about some types of errors that can be caught early on, like file format issues.

You you can listen for the transloadit:upload event when this or waitForEncoding is enabled.

importFromUploadURLs​

Allow another plugin to upload files, and then import those files into the Transloadit Assembly (boolean, default: false).

When enabling this option, Transloadit will not configure the Tus plugin to upload to Transloadit. Instead, a separate upload plugin must be used. Once the upload completes, the Transloadit plugin adds the uploaded file to the Assembly.

For example, to upload files to an S3 bucket and then transcode them:

uppy.use(AwsS3, {
	getUploadParameters(file) {
		return {
			/* upload parameters */
		};
	},
});
uppy.use(Transloadit, {
	importFromUploadURLs: true,
	assemblyOptions: {
		params: {
			auth: { key: 'YOUR_API_KEY' },
			template_id: 'YOUR_TEMPLATE_ID',
		},
	},
});

Tranloadit will download the files and expose them to your Template as :original, as if they were directly uploaded from the Uppy client.

note

For this to work, the upload plugin must assign a publicly accessible uploadURL property to the uploaded file object. The Tus and S3 plugins both do this automatically, but you must configure your S3 bucket to have publicly readable objects. For the XHRUpload plugin, you may have to specify a custom getResponseData function.

alwaysRunAssembly​

Always create and run an Assembly when uppy.upload() is called, even if no files were selected (boolean, default: false).

This allows running Assemblies that do not receive files, but instead use a robot like /s3/import to download the files from elsewhere, for example, for a bulk transcoding job.

locale​

export default {
	strings: {
		// Shown while Assemblies are being created for an upload.
		creatingAssembly: 'Preparing upload...',
		// Shown if an Assembly could not be created.
		creatingAssemblyFailed: 'Transloadit: Could not create Assembly',
		// Shown after uploads have succeeded, but when the Assembly is still executing.
		// This only shows if `waitForMetadata` or `waitForEncoding` was enabled.
		encoding: 'Encoding...',
	},
};
Deprecated options

These options have been deprecated in favor of assemblyOptions, which we now recommend for all use cases. You can still use these options, but they will be removed in the next major version.

getAssemblyOptions​

This function behaves the same as passing a function to assemblyOptions.

params​

The Assembly parameters to use for the upload (object, default: null) See the Transloadit documentation on Assembly Instructions for further information.

The auth.key Assembly parameter is required. You can also use the steps or template_id options here as described in the Transloadit documentation.

uppy.use(Transloadit, {
	params: {
		auth: { key: 'YOUR_TRANSLOADIT_KEY' },
		steps: {
			encode: {
				robot: '/video/encode',
				use: {
					steps: [':original'],
					fields: ['file_input_field2'],
				},
				preset: 'iphone',
			},
		},
	},
});

signature​

An optional signature for the Assembly parameters. See the Transloadit documentation on Signature Authentication for further information.

If a signature is provided, params should be a JSON string instead of a JavaScript object, as otherwise the generated JSON in the browser may be different from the JSON string that was used to generate the signature.

fields​

An object of form fields to send along to the Assembly. Keys are field names, and values are field values. See also the Transloadit documentation on Form Fields In Instructions.

uppy.use(Transloadit, {
	// ...
	fields: {
		message: 'This is a form field',
	},
});

You can also pass an array of field names to send global or file metadata along to the Assembly. Global metadata is set using the meta option in the Uppy constructor, or using the setMeta method. File metadata is set using the setFileMeta method. The Form plugin also sets global metadata based on the values of <input />s in the form, providing a handy way to use values from HTML form fields:

uppy.use(Form, { target: 'form#upload-form', getMetaFromForm: true });
uppy.use(Transloadit, {
	fields: ['field_name', 'other_field_name'],
	params: {
		/* ... */
	},
});

Form fields can also be computed dynamically using custom logic, by using the getAssemblyOptions(file) option.

Static exports​

COMPANION_URL​

The main endpoint for Transloadit’s hosted companions. You can use this constant in remote provider options, like so:

import Dropbox from '@uppy/dropbox';
import { COMPANION_URL } from '@uppy/transloadit';

uppy.use(Dropbox, {
	companionUrl: COMPANION_URL,
});

When using COMPANION_URL, you should also configure companionAllowedHosts.

The value of this constant is https://api2.transloadit.com/companion. If you are using a custom service option, you should also set a custom host option in your provider plugins, by taking a Transloadit API url and appending /companion:

uppy.use(Dropbox, {
	companionUrl: 'https://api2-us-east-1.transloadit.com/companion',
});

COMPANION_ALLOWED_HOSTS​

A RegExp pattern matching Transloadit’s hosted companion endpoints. The pattern is used in remote provider companionAllowedHosts options, to make sure that third party authentication messages cannot be faked by an attacker’s page but can only originate from Transloadit’s servers.

Use it whenever you use companionUrl: COMPANION_URL, like so:

import Dropbox from '@uppy/dropbox';
import { COMPANION_ALLOWED_HOSTS } from '@uppy/transloadit';

uppy.use(Dropbox, {
	companionAllowedHosts: COMPANION_ALLOWED_HOSTS,
});

The value of this constant covers all Transloadit’s Companion servers, so it does not need to be changed if you are using a custom service option. But, if you are not using the Transloadit Companion servers at *.transloadit.com, make sure to set the companionAllowedHosts option to something that matches what you do use.

Events​

transloadit:assembly-created​

Fired when an Assembly is created.

Parameters

  • assembly - The initial Assembly Status.
  • fileIDs - The IDs of the files that will be uploaded to this Assembly.
uppy.on('transloadit:assembly-created', (assembly, fileIDs) => {
	console.group('Created', assembly.assembly_id, 'for files:');
	for (const id of fileIDs) {
		console.log(uppy.getFile(id).name);
	}
	console.groupEnd();
});

transloadit:upload​

Fired when Transloadit has received an upload. Requires waitForMetadata to be set.

Parameters

  • file - The Transloadit file object that was uploaded.
  • assembly - The Assembly Status of the Assembly to which the file was uploaded.

transloadit:assembly-executing​

Fired when Transloadit has received all uploads, and is executing the Assembly.

Parameters

transloadit:result​

Fired when a result came in from an Assembly. Requires waitForEncoding to be set.

Parameters

  • stepName - The name of the Assembly step that generated this result.
  • result - The result object from Transloadit. This result object has one more property, namely localId. This is the ID of the file in Uppy’s local state, and can be used with uppy.getFile(id).
  • assembly - The Assembly Status of the Assembly that generated this result.
uppy.on('transloadit:result', (stepName, result) => {
	const file = uppy.getFile(result.localId);
	document.body.appendChild(html`
		<div>
			<h2>From ${file.name}</h2>
			<a href=${result.ssl_url}> View </a>
		</div>
	`);
});

transloadit:complete​

Fired when an Assembly completed. Requires waitForEncoding to be set.

Parameters

uppy.on('transloadit:complete', (assembly) => {
	// Could do something fun with this!
	console.log(assembly.results);
});

Frequently Asked Questions​

Accessing the assembly when an error occurred​

If an error occurs when an Assembly has already started, you can find the Assembly Status on the error object’s assembly property.

uppy.on('error', (error) => {
	if (error.assembly) {
		console.log(`Assembly ID ${error.assembly.assembly_id} failed!`);
		console.log(error.assembly);
	}
});

Assembly behavior when Uppy is closed​

When integrating @uppy/transloadit with @uppy/dashboard, closing the dashboard will result in continuing assemblies on the server. When the user manually cancels the upload any running assemblies will be cancelled.