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OB-1 vs Pi
Pi (pi.dev, earendil-works/pi) is an MIT-licensed terminal coding agent built on a unified multi-provider LLM API, and it is deliberately narrow: no subagents, no plan mode, no built-in permission system. It also is not a free path — you run /login or supply an API key before it answers. OB-1 starts with no key at all and adds parallel subagents, Fusion best-of-N, and a self-correction loop.
Choose OB-1 when you want a first token with no key, no account and no card, plus parallel read-only subagents and a verified best-of-N pass when a task deserves more compute.
Choose Pi when you already have provider keys, want a small MIT-licensed harness you can extend yourself, and consider a single-agent loop with no plan mode a feature rather than a gap.
| Question | OB-1 | Pi |
|---|---|---|
| Default route | Built-in keyless free-model router, or any OpenAI-compatible endpoint | /login with a supported provider, or your own API key |
| No-key start | Yes — keyless providers answer the first message | No — authentication is required before the first turn |
| License posture | Apache-2.0 CLI | MIT (earendil-works/pi) |
| Install | brew, curl installer, or npm @overbrilliant/ob1 | npm @earendil-works/pi-coding-agent |
| Provider choice | Built-in free router, OpenRouter, OpenAI, Gemini, Groq, Ollama, LM Studio, llama.cpp, vLLM, custom | Broad — a unified multi-provider LLM API covering OpenAI, Anthropic, Google and others |
| Multi-agent shape | Solo, Fusion best-of-N, verified escalation, read-only subagents | Single agent by design — subagents and plan mode are intentionally omitted |
| Memory | Inspectable local memory graph | Session state and context management, not a durable memory graph |
| Sandboxing | Seatbelt/bubblewrap modes plus permission controls | None built in — the docs recommend containerizing or sandboxing Pi yourself |
| Hosted tier | Optional prepaid credits at $9, $49, or $99 a month, hard-capped | None — you pay your chosen providers directly |
Practical read
- Pi's omissions are stated intent, not oversight: the project deliberately ships without subagents or a plan mode, and without a permission system, telling users to containerize instead. Judge it as a small, extensible harness rather than a batteries-included agent.
- The clearest practical difference is the first run. OB-1 answers with no key; Pi needs /login or an API key, so its cost floor is whatever your provider charges.
- Pi's multi-provider LLM API and self-extensible design are genuine strengths, and its packages are usable on their own if you are building your own agent rather than shopping for one.