Stack Overflow used OpenAI’s Codex to accelerate development of its Stack Overflow for Agents product, producing a working implementation within weeks. Distribution through a ChatGPT plugin substantially increased signups and agent creation, with the company reporting up to tenfold growth in agent creation at peak.
Problem addressed and platform overview
Organizations often keep context and knowledge scattered across tools like Slack and Google Docs, making it hard for people and AI agents to find and use relevant information. Stack Overflow is building a knowledge intelligence platform to unify those sources and convert raw context into verified knowledge available where people and agents work. The platform routes tasks to different OpenAI models — GPT‑6 Astra and GPT‑6 Sol — based on the reasoning required and cost.
How the product was built
Stack Overflow for Agents began from a hypothesis and the work of two engineers using Codex. They provided Codex with a development environment and a plan, and iterated with it to build the product. According to Alex, this process produced a full-featured product within a few weeks, effectively amplifying the small team’s output.
For the broader enterprise offering, Stack Internal, connecting to all the systems where organizations store knowledge requires more human effort, but Codex has accelerated that work as well. Alex says Codex helped shorten time to market for the enterprise product from about a year to roughly three months. A concrete example is connector development: where connector builds previously took 3–6 weeks, Codex has enabled reductions to as little as 4 days, and the team recently built one connector in a single day.
Distribution via ChatGPT plugin and growth impact
To get Stack Overflow for Agents into users’ workflows, the team created a ChatGPT plugin that lets users discover and configure the product inside ChatGPT with fewer steps than a traditional Model Context Protocol (MCP) setup. Alex reports the plugin tripled registrations and accelerated agent creation; at one point the team observed up to a 10× increase in agent creation.
Automation, Decisions API, and knowledge sharing plans
Stack Overflow currently manages its own model routing and configuration. Alex said they are considering using the OpenAI Decisions API to automate parts of that work, which could save time and money and free engineering capacity to focus on product features rather than guardrails.
Separately, Stack Overflow is expanding its knowledge product to enable sharing of what individuals learn. To date the emphasis has been on ingesting information; the company is now working to close the loop so that insights gained in one‑to‑one sessions or outside engineering teams can be propagated across the organization. Alex framed this goal as ensuring that as individuals learn, the rest of the organization learns with them, aiming to build a product that supports the full knowledge life cycle.
Conclusion
Using Codex for development and a ChatGPT plugin for distribution, Stack Overflow has both sped up product development and driven substantial growth in agent creation. The company is exploring further automation via OpenAI’s APIs and enhancing knowledge-sharing capabilities to provide broader organizational value.
