Hey folks! I hope this is the right place to ask about this.
I have a workflow where I use a custom trained ChatGPT model to process PDF transcripts. The AI extracts specific data and creates 3 output files that I then download and upload to Google Drive. After that, Zapier picks up these files using a folder trigger and handles the remaining steps.
The problem is I want to eliminate the manual file handling part to make everything fully automated.
I tried using Zapier’s OpenAI integration, but it doesn’t work as well as my trained model. No matter how I adjust the prompts or switch between different models in Zapier, the results are not accurate enough. I even tried copying my custom GPT’s configuration but it still doesn’t match the quality. Unfortunately, Zapier doesn’t support connecting to specific custom GPTs yet.
My last idea was using browser automation tools like Selenium or similar options, but that means keeping a computer running 24/7 which defeats the purpose of having a cloud-based automation.
I really want to keep using my trained ChatGPT because it’s incredibly good at understanding the data format I work with.
Am I missing any other approaches? Any ideas would be super helpful!
have you thought about using the openai api directly? set up a basic server to call your custom gpt model through it, then send results to zapier. might be worth checking if chatgpt plus allows access to custom gpts now.
Had the same issue last year with document automation. Here’s what worked for me: use the ChatGPT API with assistants that handle file uploads and custom instructions. Create an assistant through the API with detailed system prompts that copy your custom GPT’s behavior, then feed it PDFs directly. Spend time dialing in the system message and examples until output quality matches your custom model. Try different temperature settings and use gpt-4 if you’re not already. Another option - set up a simple Node.js script on a cheap VPS that processes files through OpenAI’s API, then hits your Zapier workflow via webhook once files land in Google Drive.
Hit this exact problem recently. Custom GPTs can’t be accessed through regular API endpoints, so yeah - trying to replicate it in Zapier feels impossible. Here’s what worked for me: reverse-engineer your custom GPT by testing the same inputs in both places, then keep tweaking the API version until it matches. Export training conversations from your custom GPT and throw those into your API calls as examples. Most people don’t realize how much the system message structure actually matters. Another option - build a quick Python script on Google Cloud Functions or similar. It processes PDFs through OpenAI’s API with your refined prompts, spits out results, and hits your Zapier workflow via webhooks. Costs almost nothing when you’re not using it and scales automatically. The serverless route gets you automation without dealing with infrastructure. You can keep tweaking prompts until they match your custom model’s accuracy.
Power Automate’s worth checking out too - their AI Builder connects nicely with OpenAI models and handles file processing way better than Zapier. Plus you get much more control over fine-tuning your prompts.
Try Make.com (used to be Integromat) instead of Zapier. Make handles OpenAI integrations way better and deals with complex API calls without the headaches. Or set up a webhook that grabs your PDF data, runs it through OpenAI with your prompts, then dumps everything straight into Google Drive. No more downloading and re-uploading stuff. I’ve done this with AWS Lambda and Google Cloud Functions - they sit there doing nothing until you need them, costs almost zero for occasional jobs. Just nail down your prompts and tweak the API temperature/model settings until it performs like your custom GPT.
Had this exact problem a few months ago with contract processing. Traditional automation platforms are way too rigid for complex AI workflows.
You need something that handles the full pipeline without forcing preset integrations. I switched to Latenode and it fixed everything.
Latenode lets you build workflows that process PDFs through OpenAI’s API with custom prompts that replicate your trained model. Use their HTTP modules for direct API calls with your exact specs - system messages, temperature settings, everything.
Here’s what’s great: it handles file processing, API calls, conditional logic, and Google Drive uploads in one workflow. No manual steps, no computer running 24/7, no downloading/reuploading files.
I built a pipeline that watches for new PDFs, processes them through OpenAI with custom instructions, generates multiple outputs, and drops everything into the right Drive folders. Runs in the cloud and triggers automatically.
The visual workflow builder shows exactly what happens at each step. You can add error handling and retry logic that Zapier can’t handle well.