A little demonstration of how to provide a filename when uploading a file to a vector store using the OpenAI Assistants API.

main.go

package main

import (
	"bytes"
	"context"
	"io"

	"github.com/openai/openai-go"
)

func main() {
	client := openai.NewClient()

	s := "This is just random context"

	file, err := client.Files.New(context.TODO(), openai.FileNewParams{
		// IMPORTANT
		File:    openai.FileParam(io.Reader(bytes.NewBuffer([]byte(s))), "context.txt", "text/plain"),
		Purpose: openai.F(openai.FilePurposeAssistants),
	})
	if err != nil {
		panic(err)
	}
	vs, err := client.Beta.VectorStores.New(context.TODO(), openai.BetaVectorStoreNewParams{
		Name:    openai.F(" Vector Store"),
		FileIDs: openai.F([]string{file.ID}),
	})
	if err != nil {
		panic(err)
	}
	_, err = client.Beta.Assistants.New(context.TODO(), openai.BetaAssistantNewParams{
		Model:        openai.F(openai.ChatModelGPT4o),
		Name:         openai.F("Random Assistant"),
		Instructions: openai.F("You're a helpful assistant."),
		Tools: openai.F([]openai.AssistantToolUnionParam{openai.FileSearchToolParam{
			Type: openai.F(openai.FileSearchToolTypeFileSearch),
		}}),
		ToolResources: openai.F(openai.BetaAssistantNewParamsToolResources{
			FileSearch: openai.F(openai.BetaAssistantNewParamsToolResourcesFileSearch{
				VectorStoreIDs: openai.F([]string{vs.ID}),
			}),
		}),
	})
	if err != nil {
		panic(err)
	}
}