AI · alternatives · 2026
24 alternatives to I built an open source multi-agent harness in Go
Hey HN. I built an AI agent harness over the past few months and I'm open sourcing it today. Some context on why. I've been building with Claude Code daily using this harness. It orchestrates multiple AI agents as a team, with a dashboard, chat, kanban board, the works. I used it to build a full SaaS product (MyUpMonitor, https://myupmonitor.com) in about 24 hours of focused coding. Then yesterday Anthropic announced Mythos and decided to keep it behind closed doors. Meanwhile I'm paying for Claude and I can't access their best model. I don't think that is nice at all... So I'm…
Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Prices are shown for the 3 we have checked on their own sites, 3 of them free or with a free tier.
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Harness by Autonomousfree tier, from $149/mo▲288Every coding agent, every machine, one command center.
6d ago · autonomous.ai · its alternatives →
- 2
HarnessRouter Community Editionfree tier, from $20/mo▲397Open-source unified interface for agent harnesses
Aug 2026 · harnessrouter.ai · its alternatives →
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Viberia▲146Hey HN, This is my take on the agent harness. Everything on an isometric map. Agents are grouped into "buildings" that run in a sequence or a loop; e.g., the CodeForge has an agent that writes a PRD, another one that implements, and a third that reviews. Everything is customizable, you build your own buildings/teams however you want. It's a Tauri app, really light (about 8x less energy than the closest competitor I benchmarked, so it actually runs from a coffee shop on battery). It's macOS only for now, but ping me if you are willing to test the Windows or Linux version. I've been…
May 2026 · getviberia.com · its alternatives →
- 4Agent 37▲401
Hey HN, I noticed there are 1,000+ MCP skills on GitHub with zero way for creators to charge for them. So I built Agent37. Selling Claude skills today means asking customers to download your skill, set up Claude Code on their laptops, configure MCP servers, and pray it works. No trial, no updates, often you're just handing over the source. Agent37 lets creators upload a skill, share a link, and anyone can try it instantly (no Claude account needed). Built-in Stripe, creators keep 80%. Looking for feedback on the approach. Would you use something like this?
Mar 2026 · agent37.com · its alternatives →
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AgentGrid▲77Hi HN, I’m Michael, I built AgentGrid with my friend Souren because we were tired of losing our coding sessions and couldn't keep track of what was actually being built across our many projects. Our approach was to use an infinite canvas desktop app for the TUIs we already know and love, mainly claude + codex. We drew inspiration from Figma and Railway. Overtime we added image nodes, notes, terminals, coding editors, source control, etc. I wasn't sure about it at first. It took me a month to give the first version Souren built a real try. What got me was an Apple System Update I've been…
Jul 2026 · agentgrid.sh · its alternatives →
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Hey HN! Wanted to show our open source agent harness called Gambit. If you’re not familiar, agent harnesses are sort of like an operating system for an agent... they handle tool calling, planning, context window management, and don’t require as much developer orchestration. Normally you might see an agent orchestration framework pipeline like: compute -> compute -> compute -> LLM -> compute -> compute -> LLM we invert this so with an agent harness, it’s more like: LLM -> LLM -> LLM -> compute -> LLM -> LLM -> compute -> LLM Essentially you describe each agent in either a self contained…
Jan 2026 · github.com · its alternatives →
- 7
Hi HN. I'm the founder of Phoenix Labs (ex TikTok, Applied AI) and we're open sourcing our internal tooling today which is like a toolchain / meta-harness for CLI agents useful for really scaling eng and creative work. We are a very small team who's building a very ambitious product so we had to find ways to squeeze every ounce of efficiency that we could get our hands on. Harness strengths of different models (Claude, GPTs) and CLI-harnesses (Claude Code, Codex), safe/robust browser integration to speed up UX/QA testing, teams cli to speed up security reviews and parallelize…
May 2026 · agents-cli.sh · its alternatives →
- 8
I've been running Claude Code and Codex together every day. At some point I figured out you can use tmux to let them talk to each other, so I started doing that. Once they could coordinate, I kept adding more agents. Before long I had a whole team working together. But any time I rebooted my machine, the whole thing was gone. Not just the tabs. The way they were wired up, what each one was doing, all of it. Nothing I'd found treats your agent setup as a topology, as something with a shape you can save and bring back. So I built OpenRig, a multi-agent harness. A harness wraps a model. A "rig"…
Apr 2026 · github.com · its alternatives →
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Hey HN! We are building HarnessRouter, a canonical API for running Codex, Claude Code, Hermes, and other managed agent harnesses as your product backend. Before building HarnessRouter, I used to build our own agent harness for our products. I tried LangGraph, agent SDKs from different vendors, pydantic, LLM tool use / function call, and so on. It's a very heavy lifting engineering effort, and I am disappointed about the agent deliveries compared to what Codex, CC can deliver. That changed my mindset. The frontier labs and famous open source communities are already putting so much…
Aug 2026 · github.com · its alternatives →
- 10
Repo guardrails for reliable AI coding agents
May 2026 · baskduf.github.io · its alternatives →
- 11IM
Hey HN, I’m Chris, a solo dev in Melbourne AU. For the past month I've been spending my after work hours building AgentVisa. I'm both excited (and admittedly nervous) to be sharing it with you all today. I've been spending a lot of time thinking about the future of AI agents and the more I experimented, the more I realized I was building on a fragile foundation. How do we build trust into these systems? How do we know what our agents are doing, and who gave them permission? My long-term vision is to give developers an "Agent Atlas" - a clear map of their agentic workforce, showing where…
2025 · agentvisa.dev · its alternatives →
- 12
I've been experimenting with ways to increase AI adoption for non-technical people. Basically, all companies are pushing for AI because it's all over the news and they feel left behind but most people have no clue where to start. I think 90% of people (ie non coders) are sufficiently well served by using cowork instead of claude code or something similar. If we can get people from sales, customer support, marketing, etc to collaborate with skills and cowork to form a company brain, I think it's gold. So I think there's opportunity for the community to share skills that work well for 1000s of…
Jun 2026 · claudinho.xyz · its alternatives →
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We were spending a lot of time re-writing the same primitives in projects we were doing getting claude + codex + other harnesses communicating in real time. Many other projects forced us into using their framework or harness or into a specific stack. So we open sourced an SDK that acts as the messaging layer without the rest of it. Still early, but we've been working on it and found it useful.
Jun 2026 · github.com · its alternatives →
- 15
This weekend I built a multi-agent coding system which, quite unexpectedly, beat Claude Code on Stanford's Terminal Bench! The architecture is straightforward, consisting of an orchestrator agent that deploys explorer & coder subagents to complete complex terminal based tasks, utilising an intelligent context sharing mechanism along the way which makes it all work. The repo has a lot of technical details, and all the code and prompts for you to play around with if you'd like! I had a lot of fun making this, I hope you have fun reading the README, using it yourself, or even extending it! As…
2025 · github.com · its alternatives →
- 16
We built meta-agent: an open-source library that automatically and continuously improves agent harnesses from production traces. Point it at an existing agent, a stream of unlabeled production traces, and a small labeled holdout set. An LLM judge scores unlabeled production traces as they stream. A proposer reads failed traces and writes one targeted harness update at a time, such as changes to prompts, hooks, tools, or subagents. The update is kept only if it improves holdout accuracy. On tau-bench v3 airline, meta-agent improved holdout accuracy from 67% to 87%. We open-sourced meta-agent.…
Apr 2026 · github.com · its alternatives →
- 17AA
Hi HN, Even the smartest AI coding agents stall when the fix isn’t in their training data. AgruSeek runs an agentic search loop across ~30 M developer sources to dig up solutions normal web search misses. REAL‑WORLD USES • Found an undocumented `--runtime‑bypass` flag (buried in a 2017 gist) • Pulled actual Claude Code pricing from forum anecdotes - no “contact us” paywalls • Traced a race condition by cross‑linking five issue trackers across forks WHY POST NOW We’ve abused AgruSeek internally for three weeks; we’d love outside stress tests. Access is free (limited seats for Beta, no…
2025 · agruseek.com · its alternatives →
- 18
We've built the first General AI Agent that works seamlessly across multiple AI platforms, e.g. ChatGPT, Claude, Cursor, and more. Try it today at no cost (no API credits needed), and join our waitlist for Flow, our visual designer that lets you customize it or build your own agent using just natural language—no coding required. #Why we made this We built this after experiencing firsthand the frustration of designing AI agents that require coding or the use of platforms with steep learning curves, only to find ourselves tied to these solutions. Our team spent months in stealth developing a…
2025 · orkestralai.com · its alternatives →
- 19
Around 3 months ago, we were thinking why none of the iPhone apps running an LLM are built as a full harness (as in inference + agentic loop + context management + tools + MCP servers and etc.). It became more interesting when we noticed even the new Siri is not fully on device (and not available in EU for that matter). Having built a few agentic products around a custom harness in the past, we thought this shouldn't be that hard. well, we underestimated how "dumb" a 4B model can be, especially when it comes to tool calling. :D We tried 8 different models and we settled on Qwen 3.5 4B and we…
Aug 2026 · orvena.app · its alternatives →
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I love Claude Code but got tired of having nothing to do while I waited for sessions to finish, and managing multiple sessions on the command line was getting annoying and I kept losing track of the tabs. I originally built a quick and dirty version of this for my own use, but decided to polish it up and make it open source. The idea is that you should be able to do all your agentic coding without leaving the tool or needing to go back to a traditional IDE. You can view the diffs, run your program, and merge your changes back. I support OSX and Linux right now, but could add Windows support…
2025 · github.com · its alternatives →
- 21
I’ve spent the last 2.5 months building a product that runs LLM-powered code reviews on my pull requests — and I just launched it. The tool is built specifically for solo developers. You install it on your repo, trigger a scan by creating a pull request, and it leaves structured review comments using OpenAI under the hood. Funnily enough, I used the dev version of this app to review its own pull requests while building it. It helped me spot bugs, simplify structure, and keep quality high — all with minimal need for another human in the loop. Things I want to try out in the next months : -…
2025 · codii.dev · its alternatives →
- 22
We wanted to build a development environment that can make you a better agentic engineer, not a tool that makes money when you waste tokens. A tool where you can swap models between turns, edit the context, and see every agent action. To do it, we had to build our own harness. Free to use. We don't sell inference, so bring your own key. The sore spot is Claude subscriptions. We can't support them because of Anthropic's terms. The app runs on your machine, and your data never touches our servers. We've been building Voidleap Code using Voidleap Code since January. We didn't rush to launch,…
Aug 2026 · voidleap.com · its alternatives →
- 23
Hi HN, I built VAEN (an open source CLI) because I kept running into a boring problem with AI coding-agent workflows: the setup becomes useful, but then it is hard to move. A good, useful agentic harness consists of more than just instructions: skills, mcp servers and more. There should be a better way to share those than just .MD files, and that is why I created VAEN. What works: create a yaml, run the CLI commands as per the repo, and get a .agent file that you can share and extract. Think of how awesome it could be if anyone could use a very useful agentic harness, and share it with one…
May 2026 · github.com · its alternatives →
- 24
Hi HN, I built AgenTank. It is a small game where an AI agent writes the logic for your tank. You watch it fight, give strategic feedback, let the agent update the tank code, and send it back into battle. I have run 1,000+ battles on my own tank and spent about $200 in Claude credits improving it. The part I enjoy most is not just winning, but watching the tank make visible mistakes, thinking of a better strategy, and seeing whether Claude can turn that into better code.
May 2026 · agentank.ai · its alternatives →
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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →