:PROPERTIES:
:ID:       7a060b36-36db-4eb7-b8cc-844bd6ac9d36
:CREATED:  [2026-05-22 Thu]
:END:
#+title: OpenCode — AI Coding Agent
#+filetags: :passepartout:strategy:competitive:opencode:

TypeScript/Bun. anomalyco/opencode, 163K★. The dominant open-source coding agent by adoption. Bun runtime, Effect-TS functional core, Solid.js TUI, Turborepo monorepo.

Architecture: Dual LLM runtime — default AI SDK (streamText/generateText) + opt-in native Effect-Schema runtime with 4-axis route decomposition (Protocol/Endpoint/Auth/Framing). 30+ provider plugins. Agent workflow DSL with plan/build agent switching. Agent Communication Protocol (ACP) for inter-agent messaging. Subagents inherit permission boundaries from parent. 18+ built-in tools + custom tools from config. Effect-TS ScopedCache per-project state management.

Safety model: Explicitly documents not sandboxing the agent. Permission system is rule-based (glob matching, actions: allow/ask/deny) and exists as a UX feature, not security isolation. Built-in agents have carefully scoped defaults. Permission rules inherited by subagents.

Data model: SQLite via Drizzle ORM with bun:sqlite or better-sqlite3. Key tables: SessionTable, MessageTable, PartTable. Project model stores worktree, VCS, sandbox config. Config is JSON-chain with remote config fetch.

Self-modification: Agent.generate() interface lets the LLM create new agent definitions — the system grows its own subagent roster. Skills system loads domain-specific knowledge packs dynamically.

Verification: None.

Key gap vs Passepartout: No deterministic safety architecture, no knowledge graph, no Org-mode, no verification/proof system, no neurosymbolic architecture. The permission system is explicitly labeled not security isolation — it's UX, not a gate stack.

See the full [[id:3aa22300-2f25-57b0-8787-9f199cc978b1][competitive analysis]] for the landscape view and comparison.