Kilo, an open source coding agent, bets on subscriptions that reward sustained usage
CEO: "We believe in being transparent about costs and not locking people into a single model or vendor."
Welcome to Forkable’s COSS Corner column, where I profile startups and key figures from the commercial open source software (COSS) space.
In this edition, I check in with Scott Breitenother, CEO of Kilo Code, an open source AI coding agent that has introduced a new “momentum”-based subscription designed for AI-heavy development.
Kilo Pass reflects a growing tension in open source monetization, as AI-native projects introduce real, usage-based costs—from hosted inference to long-running agents—that don’t map cleanly onto flat subscriptions or traditional open core models. Kilo’s approach is to surface those economics directly, rather than hide them behind limits or access rules which ultimately shape how developers are able to use these tools.
“We didn’t want to play games with behavior,” Breitenother told me. “Limits and throttling usually feel random and frustrating, especially when they interrupt you mid-flow.”
Read the story in full below.
Kilo Pass comes to pass
How do you price an AI coding tool when every keystroke has a real, recurring cost? That’s the million-token question Kilo Code is striving to answer with the launch of Kilo Pass, a new “momentum”-based subscription designed for regular, sustained use of AI in software development.
To rewind just a little, commercial open source startups (COSS) have long struggled with a familiar financial tension: how to build sustainable businesses around software that is, by design, freely available. The standard playbook typically revolves around things like hosted services, support contracts, or enterprise features layered on top of an “open core.” While there are pros and cons to these approaches, they all share a common characteristic: running the open source software itself typically does not impose significant, ongoing costs on the project’s developers, because execution happens on the user’s own infrastructure.
The rapid rise of AI adds a distinct economic wrinkle to that problem. Unlike traditional open source software, AI-powered tools carry direct, recurring costs every time they are used, driven by model inference that consumes GPU compute and electricity, and is typically metered in tokens—the units of text that AI model providers charge for processing. As developers increasingly rely on AI for longer-running tasks and autonomous agents, those costs scale with usage, but not always in ways developers can easily see or predict. For open source–aligned companies, this creates a dilemma: how to stay open and predictable without drifting toward limits, lock-ins, or licensing changes as usage grows.
It’s against this backdrop that Kilo Code, an open source AI coding agent, has launched Kilo Pass, a new subscription model built around what the company calls “momentum-based” usage. Rather than bundling AI access behind flat “unlimited” plans, Kilo converts subscription payments into non-expiring balances that developers spend directly on AI model usage, priced at the providers’ published rates, with additional bonus credits tied to sustained use.
The launch reflects a view that early pricing models across the AI coding landscape were misaligned with how these tools would actually be used in practice. Fixed monthly plans were simple to market, but they left little room for the sharp increases in compute demand that come with more frequent, longer-running AI-assisted workflows.
“A lot of AI coding tools started with flat subscriptions because everyone hoped model costs would drop fast enough to make unlimited use sustainable,” Kilo Code CEO Scott Breitenother explained to Forkable over email. “In reality, per-user usage scaled, and while the price of a specific model trends down over time, the cost of frontier models has remained stable.”
As those economics became harder to ignore, many products opted for incremental guardrails — adding caps, throttles, or slowdowns to rein in usage without revisiting the underlying pricing model.
And so Kilo’s approach speaks to a broader shift in how developers are responding to usage limits, model lock-ins, and opaque pricing as AI tools become more central to their work.
“That concern is valid, and we’re seeing it play out in real time,” Breitenother said. “Developers are pushing back on tools that combine limits with lock-in and unclear pricing.”
By way of example, Claude Code, Anthropic’s AI coding product, has become a recent flashpoint for developer frustration around limits and lock-in. While Anthropic offers higher-tier subscriptions aimed at power users, it recently restricted access to its Opus model when used through third-party tools.
As a result, developers paying for Claude’s higher-end plans could no longer use those benefits inside external coding environments such as OpenCode, Cursor, or Windsurf, and were instead confined to Anthropic’s own product surface. For many, that change underscored concerns that pricing and access controls were being used less to manage infrastructure costs, and more to shape where and how AI tools could be used.
“Kilo Pass is designed to go the opposite direction – we believe in being transparent about costs, not locking people into a single model or vendor, never throttling usage, and avoiding confusing credit systems,” Breitenother continued. “You can use a wide range of models, you pay true pass-through pricing, and the value in the pass comes from bonus credits, not restrictions.”
The path to Kilo Pass
Kilo launched some nine months back, courtesy of a founding team that includes GitLab co-founder and former CEO Sid Sijbrandij. Breitenother joined as CEO in September after the founding CEO stepped aside for personal reasons, and shortly after raised $8 million in seed funding.
At its core, Kilo Code is a multi-model coding environment designed to work across the IDE, command-line interface, and cloud-based agents. The project’s agent framework is open source, while model inference — the act of running AI models — is commercial, with developers paying for usage.
Until now, Kilo has charged developers directly for AI usage on a pay-as-you-go basis, with teams paying separately for team or collaboration features, and the option to bring their own API keys or run inference on their own infrastructure.
With Kilo Pass, the company is formalizing that usage-based approach into a recurring subscription, responding to growing frustration with how AI coding tools manage heavy usage behind the scenes, especially through pricing and access rules that shape day-to-day use.
“We didn’t want to play games with ‘behaviour’,” Breitenother said. “Limits and throttling usually feel random and frustrating, especially when they interrupt you mid-flow. Our principle from the start has been simple: don’t throttle people.”
Kilo Pass is offered as a monthly or annual subscription that adds money directly to a developer’s Kilo balance, which is then used to pay for AI model usage at providers’ list rates. Monthly plans are priced at $19, $49, or $199, with the subscription balance never expiring. On top of that balance, subscribers receive monthly bonus credits, which provide additional usage but expire at the end of each month.
Importantly, Kilo Pass doesn’t mark up model pricing or introduce usage controls. Instead, it’s structured to reward longer-term commitment, giving Kilo more predictable revenue while leaving developers in control of how they use the software.
“They’re [bonus credits] designed to reward people who are actively building, not to encourage stockpiling,” Breitenother explained. “The longer you stay subscribed, the higher your boost percentage becomes, up to a cap.”
Annual plans, on the other hand, cost the equivalent of twelve months paid upfront, but come with a key difference: subscribers receive a flat 50% bonus in boost credits each month, rather than gradually building toward that level over time.
In both cases, the bonus credits expire monthly, while the underlying paid balance remains available indefinitely.
When open source economics meets the reality of AI
Kilo’s move comes at a time when the broader open source ecosystem is grappling with how AI is reshaping sustainability. Just last week, the team behind Tailwind CSS – a widely used open source framework for styling web applications – cut the majority of its engineering staff after a reported drop in developer traffic. The project’s creator linked this in part to AI tools intermediating access to developer documentation, reducing direct traffic to the project’s site and their ability to convert developers to paid plans.
The episode underscored how AI is reshaping the relationship between open source projects and their users, altering where value is captured. In Tailwind’s case, AI tools increasingly sit between developers and documentation, weakening a key conversion path that had supported commercial products. Elsewhere, including at Kilo, the pressure shows up differently — through real, ongoing infrastructure costs tied directly to usage.
Against that backdrop, Kilo’s bet is that pricing models themselves need to evolve to reflect the real costs AI introduces, without undermining developer trust or openness. It also points to a broader tension now facing open source–aligned companies, as rising infrastructure costs collide with expectations of predictability and long-term sustainability.
Indeed, for Breitenother, Kilo Pass is perhaps as much about avoiding future trade-offs as solving today’s problems.
“A lot of licensing pressure comes from the same place,” he said. “Costs spike, pricing no longer matches reality, and companies reach for stronger control levers. Sometimes that shows up as throttling. Sometimes it’s lock-in. Sometimes it turns into licensing changes.”
If pricing can better reflect real usage, he argues, that pressure eases. “Kilo Pass is our attempt to prove you can keep trust high, keep the product open, and still support heavy real-world usage in a sustainable way.”