The future of software development with LLMs is here: Announcing Fixie’s Developer Preview and $17M in seed funding

Matt Welsh Blog


It’s pretty clear that 2023 is already shaping up to be the Year of AI. Large Language Models like ChatGPT are having a huge impact on the way we think about interacting with computers, and enabling all kinds of new use cases that would have been difficult to imagine just a few months ago.

Large Language Models, or LLMs, do much more than just autocomplete text — they are capable of interfacing with external APIs and data sources to solve problems and automate processes. The recently-announced ChatGPT Plugins feature allows companies to connect ChatGPT to their APIs. While an important first step, we believe companies are also looking for the ability to integrate any LLM (not just ChatGPT) into their own applications. This is where Fixie comes in.

The Fixie platform lets you build Agents that interact with external systems, data, and tools.

Fixie is a cloud-based platform for building, hosting, and scaling natural language agents that integrate with arbitrary tools, data sources, and APIs. Fixie can be used to automate business processes, build natural language understanding into existing products, answer questions about data hosted behind APIs, and more.

Today we’re excited to announce that we are launching the Fixie Developer Preview, enabling anyone to integrate LLMs into their own applications, data, and tools. We’re also announcing $17M in seed funding to accelerate our growth and power the next wave in innovation with AI.

The Fixie Developer Preview is live at, and you can get access to the open source SDK and example code on our GitHub Repo here!

Any business can now unlock the power of LLMs with Fixie

Fixie represents a foundational shift in building software, using LLMs as a computational engine. With Fixie, you wrap an existing data source or API in a little bit of code that hooks it up to a large language model of your choice. The resulting agent can then take English queries from end users, or even from other agents, and translate them into calls to that external system.

Fixie comes with over 30 agents built-in that provide access to a broad range of systems and tools, including databases, complex APIs such as GitHub, productivity tools like Google Calendar, and public data sources such as Web search and Twitter. The Fixie Agent SDK makes it super easy to build your own agents which can be deployed to the cloud in a single click.

Agents can be implemented in any programming language and hosted on any infrastructure, and each agent can use its own tailored LLM. Fixie supports popular models such as OpenAI’s GPT-4 out of the box, but agents can also use their own models or integrate with other commercial and open source models, such as AI21’s Jurassic-2, GPT-NeoX, or Cohere. Agents can also generate and process arbitrary media, for example, by generating images using Stable Diffusion and manipulating them in various ways. The Fixie platform runs in the cloud, handling the underlying LLM interactions, as well as details such as user identity, authentication, session management, storage, and configuration.

Companies can use Fixie for a wide range of use cases, including customer support, business automation, business intelligence, content generation, CRM automations, and more. We’re building solutions with customers to automate support ticket processing, enable custom chatbots that can query disparate data sources, and integrate generative AI into applicant tracking systems.

An example of how a customer service automation can be implemented with Fixie.

As an example, consider an enterprise that wants to integrate LLM capabilities into a customer support workflow. Using Fixie, the company can build agents that take in a customer ticket as input, and automate the process of looking up the customer’s order history, issuing a return label, and generating a draft reply to the ticket. Fixie provides the core platform and the company builds their own highly customized agents that integrate with the platform with extreme ease. Rather than using a vertically-integrated “customer ticket AI” product, using Fixie, the company can customize every aspect of the LLM integration with their own data and systems.

People often wonder how Fixie compares to ChatGPT Plugins. We’re a big fan of Plugins, and Fixie supports them in both directions: You can build a Fixie Agent that calls out to a ChatGPT Plugin, or build a ChatGPT Plugin that calls into a Fixie Agent! The big difference is that Fixie is about enabling enterprises to integrate LLMs into their own processes, data, and tools — rather than interfacing ChatGPT to their APIs. Fixie is model-agnostic, meaning it can be used with LLMs from any vendor, including open source models. Finally, Fixie agents are fully hosted in the cloud, making it easy to deploy new capabilities without managing any infrastructure on your own.

Our new funding allows us to support the pace of AI innovation

We’re also excited to share that we’ve raised $17M in seed funding, led by Redpoint, with participation from Madrona Venture Group, Zetta Venture Partners, SignalFire, Bloomberg Beta, and Kearny Jackson. Angel investors include current and former executives from companies like Google, Amazon, and Apple.

The Fixie team at our headquarters in Seattle.

Here’s what our lead investor at Redpoint has to say about Fixie:

“Existing LLMs are incredibly powerful and are only going to get more advanced, but the true magic comes from combining them with internal data and systems to dramatically improve the way businesses operate. That’s precisely what Fixie delivers. With world-class product, engineering, and AI experts at its helm, Fixie brings to life the promise of generative AI for companies in a way that’s never been possible before.”

— Erica Brescia, Managing Director, Redpoint

This seed round will allow us to scale up the team and continue expanding the reach of the Fixie platform. We’re hiring for multiple roles on our team in Seattle, including engineering, product, and developer relations. Check out our careers page for our open positions!

Fixie was founded by engineering and product leaders with experience building products used by billions of users at companies like Google, Apple, Shopify, and elsewhere. We’re on an incredible journey to rethink how software is built, and excited to see what you can build with the Fixie platform. Drop us a line if you’d like to learn more!



Matt Welsh Blog

AI and Systems hacker. Formerly at, OctoML, Google, Apple, Harvard CS prof. I like big models and I cannot lie.