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Documentation Index

Fetch the complete documentation index at: https://docs.pentagon.run/llms.txt

Use this file to discover all available pages before exploring further.

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Agent Runtimes

Every Pentagon agent runs on top of a coding-agent CLI installed on your Mac. Pentagon supports two runtimes today: Claude Code (Anthropic) and Codex (OpenAI). You can install one or both, and you can pick which one each agent uses.

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Why two runtimes?

Different models are good at different things. Picking the runtime per agent lets you:
  • Use Claude for one agent and Codex for another — same canvas, same team
  • Match the model to the work (long-context reasoning, tool use, coding speed, cost)
  • Avoid being locked into a single vendor’s pricing or availability

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Installing a runtime

You install the CLI yourself — Pentagon doesn’t ship the binaries. From a terminal: 
# Claude Code
curl -fsSL https://claude.ai/install.sh | bash
claude        # sign in

# Codex
# Install via the official Codex distribution, then:
codex login   # sign in
Pentagon detects both CLIs on launch and again whenever you open the Create Agent screen — so a newly-installed CLI shows up immediately.

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Picking a runtime for an agent

The runtime is determined by the model you select for the agent. Each model in Pentagon’s model picker is tagged with its runtime:
  • Claude Opus / Sonnet / Haiku → runs on Claude Code
  • GPT-5 family → runs on Codex
When you change the model in the agent’s Settings → About section (or at creation time), Pentagon switches the runtime automatically. There’s no separate runtime toggle.

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Checking what’s available

Open Settings and look for the runtime section. Pentagon shows the status of each CLI:
  • Ready — installed and signed in
  • Missing — not installed yet
  • Sign in — installed but not authenticated
  • Optional — you already have the other one, so this is fine to skip
You need Git and at least one runtime ready to spawn local agents. The first-run setup flow checks this before letting you create your first agent.

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How agents run

Agents run on your Mac — Pentagon spawns a local CLI process for each turn. Each agent uses its own clone of your repo (on its own git branch) so they don’t step on each other.

Next: Spawning Agents

Build your first agent.