Mac Anderson

Work

Work

What Mac Anderson builds and has built. Oxagen, Stella, Arena, the Context Graph Protocol, his career from Fonteva to Oxagen, and his GitHub activity.

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Updated October 8, 2026

GitHub activity

Updated October 9, 2026
Contributions since 26 Feb 2026
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Contributions in all of 2025
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Mac Anderson is the founder and CEO of Oxagen, and its principal engineer and architect. He is also the creator of Stella, Arena, and the Context Graph Protocol. Before Oxagen he co-founded Fonteva, which Togetherwork acquired in 2021, and founded inTown Technologies.

Oxagen#

Oxagen is workforce management for autonomous agents. You give each agent its own identity. You set its authority, budget, tools, and skills in one mandate. For actions routed through Oxagen, the agent asks, a rule your team wrote answers, and Oxagen records the answer with its cost. A mandate has four parts:

  • Access: the identity the agent acts as, and what it may request.
  • Budget and rules: what it may spend, and the rules it works under.
  • Equipment: the tools, skills, and business context it may use.
  • Record: what each governed run read, changed, and cost, and which rule answered each request.

Oxagen does not run agents. It wraps the ones teams already use, such as Claude Code and Codex, through hooks installed beside the agent and a gateway for model calls.

Stella#

Stella is a fast, model-agnostic terminal coding agent written in Rust. You bring your own model key. Its definition of done is a witness test: a test that fails on the old code and passes on the new code. Its core is one loop with five tools, and everything else is a plugin. On Terminal-Bench 2.1 on 31 July 2026, with both agents on the same GLM model, Stella solved 58 of 89 tasks and Claude Code solved 44. Stella is open source under the AGPL. Install it with brew install oxageninc/stella/stella, and read the docs at stella.oxagen.sh.

Arena#

Arena (source) runs your coding agent head to head against Claude Code, Gemini, and other agents, with regression checks that keep it improving instead of drifting.

Context Graph Protocol#

The Context Graph Protocol (CGP) is an open specification for representing, exchanging, and accounting for an agent's context as a typed graph of frames instead of loose text. It ships with JSON schemas, a conformance suite, and SDKs for TypeScript, Python, and Go.

Other open source#

  • stella-lang: a programming language written by AI agents for AI agents.
  • token-tax-meter: measures what each model actually bills for the same sentence in six languages.
  • rainforest: a proving ground. A supply-chain app specified in markdown and issues, built on its own by Stella.
  • arena-bench: a loop-integrity benchmark for coding agents, with kill-and-resume chaos tests and execution-trace checks.

Career#

  • 2026 to now. Oxagen, founder and CEO. Mac founded Oxagen in 2026 and is its principal engineer and architect. He builds the agent control plane, Stella, and the Context Graph Protocol.
  • 2024 to 2026. The Unnatural Group, director of AI and machine learning engineering. In Los Angeles he built the firm's AI and machine learning team and its trading systems, including LSTM pricing models and retrieval over a Neo4j knowledge graph.
  • 2021 to 2024. inTown Technologies, founder and CTO. In Washington, DC, he built software for city governments, including a multi-agent LLM system that answers residents' requests.
  • 2010 to 2021. Fonteva, co-founder and CTO. Mac co-founded Fonteva in 2010 with Jerry Huskins and Paul Lundy. Fonteva built membership, events, and commerce software for associations, native to Salesforce. As CTO he built the engineering team and the platform. In 2017 Fonteva's revenue grew 71% to $12.8 million, and it had more than 100 employees. The Washington Business Journal ranked it 24th among the region's fastest-growing companies in 2018, and the U.S. Small Business Administration named it Small Business Exporter of the Year for the Washington area. Togetherwork acquired Fonteva in February 2021.
  • Before 2010. Wipro, senior technical architect. He led architecture for enterprise Salesforce Service Cloud implementations.

Talks#

  • Dreamforce 2014: "Design Patterns Every ISV Needs to Know," with Andrey Volosevich of Salesforce and Ross Belmont of Appiphony.