Cloudflareのエンジニアが、ユーザーが欠けている機能を生成するウェブアプリを提案

Why it matters

LLMs can write niche features on demand, but the larger opportunity belongs to platforms that can run that code safely inside products holding real customer data.

Jeremy Morrell, a principal engineer at Cloudflare, wants web applications to let users generate the features that product teams will never have time to build.

Y Combinator が X に

In an essay published August 18, Morrell lays out a model for web software built around a stable, accountable core and controlled extension points. A user could describe a specialized workflow in plain English, have an LLM write the necessary code, and run it inside a sandbox managed by the host application.

その構造はよく知られたプロダクト上の問題に対応している。ソフトウェアチームは最も多くの顧客にサービスを提供する機能を優先する。需要曲線の下の方にある要求は待たされるか、手作業のままで残るか、あるいは決して実装されない。要求されるすべての機能を追加すれば、最終的にインターフェースは無関係な何千人ものユーザーの蓄積された好みを背負うことになる。

Morrell の提案は、そのようなユーザーに別の選択肢を与える：アプリケーションに不足している部分を作ってくれるよう依頼することだ。

His examples are deliberately ordinary. A read-it-later service could send every saved article longer than 4,000 words to an e-reader. A research tool could find new papers in a narrow field each week and add summaries. A user could have an agent repair a parser that consistently mishandles one publication.

それぞれのリクエストは広範なプロダクトロードマップに載せるにはあまりに個別的だ。しかし、それらを合わせると大きな未対応需要のクラスを形成する。

A platform engineer follows the problem down the stack

Morrell worked at Heroku from 2019 to 2024, where he owned the Node.js language experience and later led an observability team, and joined Cloudflare in November 2024. Earlier, he worked as a frontend engineer at Facebook and Recurly. He studied computational and applied mathematics at Rice University.

その経歴は、彼のエッセイがコード生成を称賛する時間をあまり割かず、モデルがコードを生成した後に何が起きるかを詳しく検討している理由を説明している。難しい問題はデプロイ、権限、リソース制限、デバッグ、テナント分離に関わる。

Morrell の提案は、生成されたコードを制御された境界内に留めつつ有用な動作をさせられるランタイムを前提としている。ホストアプリケーションは拡張に対してアクセス、信頼性、および公開されるデータの責任を保持することになる。

A June 2026 security study found recurring vulnerabilities in applications produced through natural-language coding, including exposed secrets, unfiltered input and placeholder logic. Better models and prompts reduced problems in the researchers' testing without eliminating the underlying risks.

Pi shows what self-extending software looks like

Morrell points to Pi as his clearest working example. Pi is an open-source terminal coding-agent harness published under Earendil Works. It exposes hooks for tools, commands, events and its terminal interface. Users can ask Pi to write a TypeScript extension, reload it during a session and package the result for others.

Pi の設計は機能をコアへの恒久的追加ではなくオプションのモジュールとして扱う。その構造により、すべての拡張が公式機能になることを要求せずにユーザーがソフトウェアをカスタマイズできる。

OpenCode is moving in a similar direction with an internal plugin architecture. These projects currently expect users to be comfortable running code locally, inspecting permissions and accepting the risks that follow. Morrell's larger opportunity lies outside that technical audience.

会計士、医師、弁護士、サポートスタッフは非常に特化したワークフローを持っているかもしれないが、任意のローカルコードを管理することを合理的に期待することはできない。彼らに届くには、ホストアプリケーションがセキュリティと運用の負担を引き受ける必要がある。

That is the gap Pete Koomen, the Optimizely co-founder who is now a Y Combinator general partner, described under the label "Small Software." In a July 22 post, Y Combinator argued that agents had made personal tools easier to create while deployment, security and sharing remained considerably harder.

Morrell moves that argument inside existing products. Instead of asking every user to create and operate a separate application, a SaaS provider could supply the trusted data, interface and runtime, then let generated extensions handle the peculiar last mile.

Cloudflare has an infrastructure reason to like the thesis

Morrell identifies Cloudflare Dynamic Workers as a particularly good fit for the model he describes. The system is one possible way to execute runtime-supplied code within a controlled boundary.

Cloudflare also has a concrete demonstration in Cloudflare OS, an open-source AI productivity environment originally developed for use inside Cloudflare. Its documentation describes an agent chat interface, sandboxed development for small personal applications called Gadgets, and a security framework called Gatekeepers that applies guardrails to agents and applications.

このプロジェクトは Morrell が述べる動作の初期バージョンを提供しているが、彼のエッセイはその考えを Cloudflare のロードマップというより広いプロダクトアーキテクチャとして提示している。

The feature backlog becomes a runtime problem

LLMs could remove much of the authoring burden, while serverless runtimes, V8 isolates, microVMs and WebAssembly reduce the cost of executing user code. The hard work shifts toward defining safe extension points and deciding what the host application will permit.

創業者にとって、それはプロダクト判断を変える。小さな顧客セグメントからの要求は、もはや恒久的なメニュー項目やサポート対象外のWebhookにならなくてよい。それはユーザーが生成しアプリケーションが監督する範囲を限定した拡張になり得る。

The tradeoff remains substantial. Every extension point expands the security model, creates support obligations and introduces behavior the original product team did not write. A stable core still needs clear limits, audit trails and a way to disable failing code. LLMs make customization cheaper; they do not make the host less accountable.

Morrell's bet is that the economics have moved far enough to justify taking on that work. If he is right, the next generation of SaaS products will ship fewer assumptions about how every customer should work. Their most important feature may be a safe place for users to build the rest.