The OpenAI Cookbook is a short README wrapped around a registry of notebooks

OPENAI_API_KEY or a .env file, and nothing in the tree runs without it

The whole credential story is two sentences in the README and there is no third option. You need an OpenAI account and an associated API key, you set an environment variable called `OPENAI_API_KEY`, or, in most IDEs such as Visual Studio Code, you put a file at the root of your own repo containing this:

OPENAI_API_KEY=<your API key>

The notebooks pick that file up. What neither sentence addresses is cost or failure, and the consequence is that cloning this repository gives you a directory of programs that will each make billable network calls the moment you run them top to bottom. Several of the filenames suggest heavier work, including `Embedding_Wikipedia_articles_for_search.ipynb` and `Embedding_long_inputs.ipynb`, so the practical first step is to read the notebook and run it cell by cell rather than with Run All.

No releases and no tags, so nothing pins the API version a notebook was written against

The repository has no GitHub releases at all, and there is no version file in the tree either. The last push was 2026-11-02, but that date alone does not establish when an individual example was updated. That matters more here than in most code repositories, because a cookbook entry is a snapshot of somebody's request against a particular API shape at a particular time, so inspect the individual example and its history for the API shape it uses. The filenames show the exposure. `Build_a_coding_agent_with_GPT-5.1.ipynb` names one model generation outright. `Creating_slides_with_Assistants_API_and_DALL-E3.ipynb` names an image model. `Assistants_API_overview_python.ipynb` is named after an API surface rather than a task, which is the kind of entry that changes shape under you. The consequence for a reader is that staleness is silent: a notebook keeps opening, keeps running and keeps returning plausible output long after the endpoint it targets has moved, and may use an outdated API. Some Cookbook pages carry dates and archive notices, but readers should still check current API documentation before running an example.

registry.yaml, authors.yaml and articles/ make this an index, not a pile of notebooks

The top-level tree is what tells you what kind of project this is: `.codex/`, `.github/`, `.gitignore`, `AGENTS.md`, `CONTRIBUTING.md`, `LICENSE`, `README.md`, `articles/`, `authors.yaml`, `examples/`, `images/` and `registry.yaml`. Three of those files are metadata rather than content. By name, `registry.yaml` looks like an index of what exists, `authors.yaml` a record of authors, and `articles/` a home for articles. So the repository is structured as publishable content with machine-readable bookkeeping attached, and that is the reason the README can be short. It is also the reason the README's first line is a pointer: navigate at cookbook.openai.com. The practical consequence for anyone working offline or in an air-gapped environment is that the registry is the index, not the README, and if you are consuming this repository programmatically the `articles/`, `authors.yaml` and `registry.yaml` trio is where the structure lives rather than any single document.

Finding examples by task

The README has no table of contents for the examples. The files under `examples/` show examples grouped by task, while the OpenAI Cookbook site provides topic navigation and search. Embedding notebooks include `Classification_using_embeddings.ipynb`, `Clustering.ipynb`, `Clustering_for_transaction_classification.ipynb`, `Code_search_using_embeddings.ipynb`, `Customizing_embeddings.ipynb` and `Embedding_long_inputs.ipynb` among them. Fine-tuning gets its own group, including `Chat_finetuning_data_prep.ipynb`, `Fine_tuning_for_function_calling.ipynb`, `Fine_tuning_direct_preference_optimization_guide.ipynb` and `Fine-tuned_classification.ipynb`. Function calling appears both for a concrete task in `Function_calling_finding_nearby_places.ipynb` and for a whole specification in `Function_calling_with_an_OpenAPI_spec.ipynb`. Use the site navigation to find an entry, then check its date, any archive notice, and current API documentation before adapting it.

Most examples are Python, and the transfer to other languages is left to you

One sentence covers the language question: most code examples are written in Python, though the concepts can be applied in any language. The repository records Jupyter Notebook as its primary language, and the tree contains no JavaScript, Go, Rust, Java or C# directory. The second sentence is a promise the repository does not keep in any form, and there is nothing wrong with that, but it does move work onto the reader. If your stack is not Python, a notebook gives you the request shape, the parameter names and the order of operations, and you rewrite the transport yourself. The consequence is that the cookbook is most valuable to a Python reader and degrades into a specification document for everyone else, and the repository has no marker to tell you in advance which notebooks will survive the port.

AGENTS.md and .codex/ mean the repository is written to be read by a model too

Two entries in the top-level tree are unusual for a documentation repository. `AGENTS.md` is a file written for coding agents, and `.codex/` is a configuration directory for the same purpose. Alongside `CONTRIBUTING.md` and `.github/`, that means this repository carries instructions for three different audiences: a person cloning it, a person contributing to it, and an automated agent operating inside it. The consequence for a reader is that there is a file to read before the notebooks, and it is not the README. If you are about to hand this repository to an agent and let it modify examples, that agent is going to read `AGENTS.md` and act on it, so the rules for changing a notebook are written down somewhere you have not read yet. The other consequence is about scale: a tree with a registry file and agent instructions is built to grow without a human editing an index by hand, which is consistent with a site that presents the same content at cookbook.openai.com.

The README is 131 words and its first instruction is to leave the repository

Count what is actually in the README. A logo, a one-line pointer telling you to navigate at cookbook.openai.com, a paragraph about needing an account and an API key and setting `OPENAI_API_KEY`, one sentence about `.env` files, one sentence about Python, a link to related resources from around the web, and the words MIT License. Everything else, including what the collection covers and how the entries relate to each other, is on the site. This is a deliberate division of labour, and it has a cost that shows up in two places. The repository contains notebooks to browse locally, while the Cookbook site supplies topic navigation and search; examples do not necessarily form a prescribed course. And in a review, a change to a notebook is hard to assess, because the prose that would explain why the example looks the way it does may live on the site rather than next to the code. The README's licence section is just the words MIT License.

Editorial conclusion

Use the OpenAI Cookbook when you want a working starting point for one specific task, such as function calling against an OpenAPI spec or clustering embeddings for transaction classification, and you are willing to read the notebook before running it. Do not treat it as a library or a pinned reference, because there are no releases and no version manifest, so a notebook that names a particular model or API shape will rot without telling you. Before you rely on anything here, check the last commit date against the API version you are on, and expect to supply your own key and your own judgement about cost, since every cell that calls the API is a billable request and the notebooks run them by default.

Frequently asked questions

Official sources

1. Official documentation
2. Official README
3. Project repository