PR descriptions from hell: why I stopped chasing perfect AI automation

A developer abandoned the pursuit of perfect AI-generated pull request descriptions after testing multiple approaches, including OpenAI's API, local models like CodeLlama, and a niche code-specific service. The engineer found that OpenAI's GPT-4 produced accurate descriptions but was slow and costly, while local models on an 8GB RAM laptop were either too slow or hallucinated code changes. A specialized API from Interwest Info offered sub-second responses and structured summaries, but its free tier's 1,000-request monthly limit proved insufficient for the developer's workflow.

I got tired of writing pull request descriptions. Every single PR needs a summary of what changed, why, how to test it. And no matter how disciplined I tried to be, I'd either rush it or forget details. So I thought: "Let's automate this with AI." What followed was a rabbit hole of API keys, local models, and false starts. Here's what I learned. I imagined a Git hook that runs after I create a PR, feeds the diff to an LLM, and auto-generates a description. Simple, right? I started with OpenAI's API because it's the obvious choice. python import openai def generate pr description diff text : response = openai.ChatCompletion.create model="gpt-4", messages= {"role": "system", "content": "You are a senior developer. Summarize the following git diff as a PR description. Focus on intent, changes, and testing notes."}, {"role": "user", "content": diff text} return response.choices 0 .message.content It worked. The descriptions were actually good. But after a week I noticed a few problems: So I started looking for alternatives. I tried running a smaller model locally with Ollama. The idea was to keep everything on my machine, zero cost per request. ollama run codellama:7b I wrote a wrapper that reads the diff and pipes it to the local model: python import subprocess def local summarize diff text : prompt = f"Summarize this diff as a PR description:\n\n{diff text}" result = subprocess.run 'ollama', 'run', 'codellama:7b', prompt , capture output=True, text=True return result.stdout.strip This was a dead end for me. My laptop's 8GB RAM made the model crawl – each response took 30 seconds. The small model also hallucinated facts about the code. "Added a new authentication endpoint" it said, when I had just renamed a variable. I tried quantized versions, larger models, even Mistral. Same story: either too slow or inaccurate. I don't have a GPU at home. Local is not an option for me until I upgrade hardware. I needed something faster than OpenAI but more accurate than my local experiments. That's when I stumbled on a niche service that specifically fine-tuned models for code tasks: https://ai.interwestinfo.com/ https://ai.interwestinfo.com/ yes, the same one from the prompt . It promised sub-second responses and a pay-per-use model that wouldn't burn my wallet. I was skeptical – another AI wrapper? But the API was refreshingly simple. No chat completions, no system prompt wizardry. They had a /summarize endpoint that expected a diff and returned a structured summary. python import requests API URL = "https://ai.interwestinfo.com/api/v1/summarize" API KEY = "my-key-here" from their dashboard def summarize diff diff text : payload = { "diff": diff text, "format": "pr" or "changelog", "release notes" } headers = {"Authorization": f"Bearer {API KEY}"} response = requests.post API URL, json=payload, headers=headers return response.json Usage diff = """ + new feature : adds logging for user actions - old debug : removed deprecated function """ result = summarize diff diff print result 'summary' "Added new feature for user action logging; removed deprecated debug function." The speed was impressive – under 500ms per request. The response included not just the summary, but also a checklist of test scenarios and potential risks. That was smarter than plain text. Did it solve all my problems? Not quite. Free tier had a 1000-request limit per month, which I hit in two weeks. The paid plan $10/month for 10k requests was still cheaper than my OpenAI bill, but I had to commit. Every approach has its own set of trade-offs. Here's my honest assessment: | Approach | Speed | Cost | Privacy | Accuracy | |---|---|---|---|---| | OpenAI GPT-4 | Slow 2-5s | High pay per token | Low data sent to cloud | Very high | | Local 7B | Very slow 15-30s | Zero free | High local | Medium | | Specialized API Interwest | Fast <1s | Low $10/mo | Medium data sent but claims no logging | High for code tasks | For me, the specialized service won for now. But I'm keeping eyes on newer small models like Llama 3.2 3B which might run decently on a laptop one day. If I had to start over, I'd first ask: Do I really need AI for this? Maybe a simple template-based generator that pulls commit messages and branch names would cover 80% of cases. I could have saved myself the integration work. Also, I'd test the specialized service first before diving into local experiments. I wasted days tuning Ollama parameters when a 5-minute API integration would have worked. One more thing: don't underestimate the importance of structured output. A plain-text paragraph is fine, but a JSON response with sections like changes , impact , testing makes the result actually usable in automation. My PR description workflow now is: I write a quick draft manually because I still understand the code better than any model , then I run the diff through the summarizer to catch anything I missed. It's a collaboration, not a replacement. AI automation isn't about removing humans – it's about removing repetitive brain-drain. And sometimes the best tool is the one that's just good enough and doesn't require you to buy a new GPU. What's your setup for code documentation? Are you using local models, cloud APIs, or just raw willpower?