Power users
Substrate, not defaults - maximum extensibility for people with opinions about every layer of the stack.
Some users don’t want defaults at all - they want building blocks. This slot is for them, and this window handed its gold medallist the best vindication a philosophy can get.
Why Pi takes gold
Pi is basically in a class of its own when it comes to high-quality primitives with ultimate customisability. It’s essentially a ‘build your perfect harness’ pack with ready-to-place blocks: a system prompt under a thousand tokens, a four-tool core, runtime self-extension in TypeScript, lazy-loading skills, session trees that let you branch a conversation from any earlier point, and bring-your-own-key across 20+ providers. Nothing hidden, nothing injected, everything legible.
That last part stopped being abstract this summer. Pi’s founding thesis is that vendor harnesses inject hidden context you can’t see - and then a vendor harness was caught doing exactly that, encoding covert fingerprints into its own system prompts for months. You don’t often get to watch a design philosophy collect its receipts in real time.
Extremely cool, and extremely powerful - with two honest caveats. There’s no permission system: extensions run with full system access and the docs tell you to containerise, so do. And it’s deliberately minimal in ways some power users will find limiting - no MCP, no subagents, by design. Above all: be careful not to get lost in the sauce. The classic Pi failure mode is spending more hours perfecting the harness than the harness ever saves you.
The runners-up
Codex earns silver as the power-user pick that stays practical: open source top to bottom, deeply customisable, first to most features, and with enough surface area (plugins, multi-agent controls, background execution) to absorb serious tinkering without demanding it.
Claude Code takes bronze on the depth of its primitive surface - skills, hooks, subagents, agent teams, worktree isolation, an SDK - the richest set of official building blocks anywhere, inside a vendor-controlled frame you can’t fully see through. Maximum capability, partial legibility. Know the trade you’re making.
The DIY frontier, for completeness: the community’s honest secret is that a coding agent is a few hundred lines in a loop, and rolling your own teaches you more than any framework readme. Hermes Agent is where those people end up when they tire of maintaining their own (‘I came back and Hermes was way ahead… so I abandoned mine’). And treat GitHub stars as marketing, not adoption - the community’s verdict on this window’s most-starred harness was brutal on exactly that distinction.
What to do now
If you have opinions about every layer and experience with tools of this shape: try Pi, time-box the setup week, and containerise it. If you’re not sure you’re the target user, you aren’t yet - Claude Code or Codex will make you faster this week, not next quarter.