Multipart subpart headers for sticker creation require too specific content-type

[MinnDevelopment]

When creating a sticker using the Create Guild Sticker endpoint, you have to specify an exact media-type for the image you use, ie. image/png and application/json. Discord should be able to determine the type automatically, just like they do for image attachments.

For image attachments with the Create Message endpoint, you can get away with setting the content-type to just application/octet-stream, and discord automatically determines the image type from the data.

Additionally, it seems that payload_json does not work for this endpoint, as I get 400 response when I send my metadata as a json subpart.

[gidsola]

This endpoint does not use json_payload form key.
The docs indicate the 4 required keys to use in the formdata.
Also, all images have thier type included. Not a big thing to pass the type.

form.append('name', `${params.data.options[1]?.value}`);
form.append('desc', `${params.data.options[3]?.value}`);
form.append('tags', `${params.data.options[2]?.value}`);
form.append('file', new Blob([newBuffer], { type: `${type}` }), `${sticker.filename}`);

[gidsola]

This should help:
toBase64 gets an image from url, in this case the url from the attachment I used.
Returns a string simliar to: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAH4AAACACAYAAADN
I split off the content and create a buffer. <Buffer 89 50 4e 47 0d 0a 1a 0a 00 00 00 0d 49 48 44 52 00 00 00 7e 00 00 00 80 0
This buffer matches what you would get from reading a file using FS. (file contents)
The buffer then gets put to the blob with its type. ( type = sticker.content_type; )
I used sticker.content_type as the attachment upload has this info ready for use. (sticker being the attachment uploaded)
The resize not always needed as Discord resizes static assets automatically but it did correct some image issues I was having.
The interactions stuff is just extra I used for the slash command.

async execute(params) {
        await params.api.discord.interactions.callback.defer(params, { ephemeral: true });

        const { toBase64 } = require('../../../../../src/api/resources/functions');
        const sharp = require("sharp");
        const { Blob } = require('node:buffer');
        const form = new (require('undici').FormData);
        const axios = require('axios');

        try {
            let sticker = params.data?.resolved?.attachments?.[params.data.options[0]?.value];
            if (sticker) {
                console.log('sticker', sticker);
                const
                    file = (await toBase64(sticker.url)),
                    type = sticker.content_type;

                // PNG
                if (type == 'image/png') {
                    const content = file.split(',')[1],
                        buffer = Buffer.from(content, 'base64'),
                        newBuffer = (await resizePNG(buffer));

                    try {
                        form.append('name', `${params.data.options[1]?.value}`);
                        form.append('desc', `${params.data.options[3]?.value}`);
                        form.append('tags', `${params.data.options[2]?.value}`);
                        form.append('file', new Blob([newBuffer], { type: `${type}` }), `${sticker.filename}`);

                        console.log('form out', form);

                        let ax;
                        console.log('Request Attempt:', ax =
                            await axios({
                                method: `post`,
                                url: `https://discord.com/api/v10/guilds/${params.guild_id}/stickers`,
                                data: form,
                                headers: { 'Content-Type': 'multipart/form-data', 'Authorization': `Bot TOKEN_HERE` }
                            })
                        );

                        await params.api.discord.interactions.followup.create(params, {
                            ephemeral: true,
                            channel_id: `${params.channel_id}`,
                            content: `${JSON.stringify(ax.data)}`
                        });

                    } catch (e) {
                        console.log('error:', e);
                        await params.api.discord.interactions.followup.create(params, {
                            ephemeral: true,
                            channel_id: `${params.channel_id}`,
                            content: `${e}`
                        });
                    }
                } // END PNG
            }
        } catch (e) {
            console.log(e);
            await params.api.discord.interactions.followup.create(params, {
                ephemeral: true,
                channel_id: `${params.channel_id}`,
                content: `${e}`,

            });
        };

        /**
         * @function resizePNG resizes a PNG to 320px x 320px as required by Discord to use as a sticker.
         * @param {Buffer} buffer 
         * @returns {Promise<Buffer | undefined>}
         */
        async function resizePNG(buffer) {
            try {
                return await sharp(buffer).resize({
                    width: 320,
                    height: 320
                })
                    .png()
                    .toBuffer();
            } catch (e) {
                console.log('There was an error while re-sizing, Error:', e);
                return undefined;
            };
        };
    }

[Rapptz]

Hey, just so you know this discussion is for a feature request to the API. It is not a question on how to do something.

[gidsola]

It seemed as if the request was an understanding on how to achieve results.