Claude Code vs OpenCode | agentconfig.ing

Claude Code vs OpenCodeComparisonUpdated 2026-03-16

SUMMARY

Claude Code (CLI) uses markdown configuration while OpenCode (CLI) uses markdown. They differ on 2 of 11 compared features. Both tools provide AI-assisted development but take different approaches to project configuration.

FEATURE COMPARISON

Feature	Claude Code	OpenCode	Notes
Config format	markdown	markdown
Hierarchy support	✓	✓	Whether config files can be placed at multiple directory levels
Global config	✓	✓	User-wide configuration outside any project
Project config	✓	✓
Subdirectory scoping	✓	✓	Config files in subdirectories that apply only to that subtree
File inclusion / imports	✓	✗	Ability to include or reference other files from config
Ignore file	.claudeignore	✗
IDE integration	CLI	CLI
Schema / structure	Free-form (Markdown)	Free-form (Markdown)	Whether config uses structured schema or free-form content
Git committed	✓	✓	Whether primary config files are intended to be version-controlled
Encoding	UTF-8	UTF-8

FILE MAPPING

Purpose	Claude Code	OpenCode
Project instructions	CLAUDE.md	AGENTS.md
Settings / configuration	.claude/settings.json	opencode.json

SIDE-BY-SIDE CODE SAMPLES

Claude Code

CLAUDE.md

markdown

# Project Name

> TypeScript + React monorepo. Deployed on Vercel.

## Code Style

- TypeScript strict mode — no `any`, no `ts-ignore`
- Named exports only (no default exports)
- Prefer functional patterns: map/filter/reduce over for-loops
- Error handling: use Result<T, E> from `src/lib/result.ts`

## Architecture

- `src/routes/`   — Route handlers (thin layer, delegates to services)
- `src/services/`  — Business logic, one file per domain entity
- `src/db/`        — Drizzle ORM schema and query helpers
- `src/lib/`       — Shared utilities (logger, result type, validation)

## Commands

```bash
pnpm install          # Install dependencies
pnpm dev              # Start dev server (port 3000)
pnpm test             # Run Vitest suite
pnpm test:e2e         # Run Playwright tests
pnpm lint             # ESLint + Prettier check
pnpm db:migrate       # Run pending Drizzle migrations
```

## Git Conventions

- Conventional Commits: `feat:`, `fix:`, `chore:`, `docs:`
- Branch naming: `feat/short-description`, `fix/issue-number`
- Squash merge to main; delete branches after merge

## Notes

- The `src/legacy/` directory is being migrated. Do not add new code there.
- All dates are stored as UTC. Never use local time.

@docs/api-patterns.md
@docs/database-conventions.md

OpenCode

AGENTS.md

markdown

# Project Instructions

## Overview
This is a TypeScript monorepo using pnpm workspaces.

## Code Style
- Use strict TypeScript with no implicit any
- Prefer functional components with hooks
- All exports should be named (no default exports)

## Architecture
- /packages/core — shared business logic
- /packages/ui — React component library
- /apps/web — Next.js frontend

## Build & Test
Run tests with: pnpm test
Build all packages: pnpm build
All PRs must have >80% coverage on changed files.

## Conventions
- Use conventional commits (feat:, fix:, chore:)
- Prefer composition over inheritance
- See @docs/api-guidelines.md for API design patterns

KEY DIFFERENCES

1. File inclusion / imports

Claude Code: Supported. OpenCode: Not supported.

2. Ignore file

Claude Code: .claudeignore. OpenCode: Not supported.

WHICH SHOULD I USE?

Recommendation

Choose based on your IDE/CLI preference. If you use Claude Code, configure CLAUDE.md. If you use OpenCode, configure AGENTS.md. Many projects include config files for multiple tools so each team member can use their preferred editor.

PORTABILITY TIP

sync-instructions.sh

bash

# Maintain a single source of truth:
cp AI-INSTRUCTIONS.md CLAUDE.md
cp AI-INSTRUCTIONS.md .cursorrules
cp AI-INSTRUCTIONS.md AGENTS.md