Open Source, APIs, and the Rise of Agent-Led Growth

SubscribeSign in

Open Source, APIs, and the Rise of Agent-Led Growth<br>Open source helps agents discover and understand software. APIs help them use it. This report looks at four companies growing around that shift.

Hugo Santana<br>Jun 26, 2026

Share

For years, SaaS companies optimized growth around human users. Better onboarding, tuned interfaces, faster time to value. That still matters, but AI agents are changing how software gets discovered, recommended, and implemented.<br>Agents are not the buyer or the final decision-maker, yet. But they increasingly influence implementation and recommendation. They read docs, write code, call APIs, test integrations, debug errors, and connect tools together. This gives open-source and API-first companies a stronger distribution advantage.

Agents need software they can understand, test, and use. Open source gives them context. APIs, SDKs, and integrations give them a way to act. Freemium removes early friction.<br>Today, we are looking at four companies that show this pattern clearly: Supabase, Resend, PostHog, and n8n. They did not start by building for agents, but their open-source nature and API-first design made them unusually well suited for this shift.<br>Subscribe to The Applied Report to receive insights on AI Adoption

Subscribe

Supabase: The Backend Agents Can Reach For

Supabase is a strong example of how open-source, API-first infrastructure is becoming easier to adopt in the agent era. The product gives teams a hosted Postgres backend, authentication, storage, edge functions, realtime subscriptions, and generated APIs in one platform. For developers, this removes a lot of setup work. For AI agents, it creates a clear backend primitive they can understand, configure, and connect to an application.<br>The growth numbers are hard to ignore. From 1 million users to 10 million in two years.

In June 2026, Supabase raised $500 million at a $10 billion pre-money valuation, roughly doubling its valuation in eight months1.<br>The valuation is important, but the timing matters more. Supabase is growing during a period where more software is being created with AI assistance. Agents can help generate interfaces, prototypes, dashboards, and internal tools, and most of those products need a backend that works.<br>In the past year, database launches on Supabase have grown 600%. More than 60% of new databases are launched by some sort of AI tool .<br>Nearly 10 million developers build on Supabase today, more than doubling since our last fundraising announcement eight months ago. Growth is accelerating since January as Claude Code and Codex expand the number of people who can build.<br>Paul Copplestone,<br>CEO & Co-Founder, Supabase

✅ Applied uses Supabase for our living map of AI use cases, tools, vendors, and models.

Resend: Email as an API Primitive

Email is a basic infrastructure need for almost every product. Teams need welcome emails, login codes, receipts, notifications, alerts, and reports. Resend makes this easier by turning email into a developer-friendly API instead of a messy setup process.

Source.<br>This fits well with AI-assisted product creation. When an agent is helping build an app, email can be added as another product primitive, similar to a database or analytics library. The agent can read the docs, install the SDK, configure the API key, and generate the first implementation.<br>Resend is not fully open-source as a product, but its open-source surface is meaningful. React Email is open-source, and Resend maintains official open-source SDKs across several languages. That gives developers and agents public context to understand how the product works and how to implement it. This public surface has helped Resend stand out in AI search results.

Zeno Rocha@zenorocha

our OpenAI traffic 3x'd.

the cause: ChatGPT added branded links inside answers instead of burying them in citations.¹

but that's the small story.

Codex went from 600k to 5m weekly users.²

agents are choosing the stack now.

2:17 PM · Jun 4, 2026 · 154K Views

24 Replies · 19 Reposts · 349 Likes

The growth signal is extremely strong. Zeno Rocha shared a x10 growth in paying customers, from 9,000 in June 2025, to 92k in June 2026.<br>✅ Applied uses Resend for all our emails (except for the Substack reports).

PostHog: From Analytics to Product Feedback Loops

The company started with product analytics, but now covers web analytics, session replay, error tracking, feature flags, experiments, surveys, data warehouse, CDP, and an AI product assistant. The scope has expanded, but the core job is still clear. PostHog helps teams understand how users behave and what needs to improve.

In this ear, an agent can generate a landing page, build a dashboard, connect a database, or ship a small internal tool. Once that product is live, the team still needs to know what works, what breaks, where users drop off, and what should change next.<br>PostHog gives agent-built products a...