ConfigFrontmatterError when parsing Claude Code SKILL.md with 'arguments' field

[corrius]

Bug Description

OpenCode crashes with ConfigFrontmatterError when it discovers Claude Code skills that contain the arguments field in their YAML frontmatter.

Environment

• OpenCode version: 1.1.20
• OS: Linux (Arch Linux 6.18.3)
• Claude Code skills location: ~/.claude/skills/

Error Message

ConfigFrontmatterError: ConfigFrontmatterError
  data:
    path: "/home/user/.claude/skills/aws-sso/SKILL.md",
    message: "Failed to parse YAML frontmatter: incomplete explicit mapping pair; a key node is missed; or followed by a non-tabulated empty line at line 9, column 52"

Steps to Reproduce

1. Have Claude Code installed with custom skills in ~/.claude/skills/
2. Skills contain YAML frontmatter with arguments field (standard Claude Code format)
3. Run opencode in any directory
4. OpenCode crashes immediately with the frontmatter error

Example SKILL.md That Causes the Error

---
name: aws-sso
description: Login to AWS SSO using Chrome browser automation
user_invocable: true
invocation_syntax: "/aws-sso [profile]"
model: haiku
arguments:
  - name: profile
    description: AWS profile to login with (default: adri-dev)
    required: false
---

# AWS SSO Login Skill
...

Expected Behavior

OpenCode should either:

1. Gracefully skip skills with unrecognized frontmatter fields
2. Support Claude Code's arguments syntax for compatibility
3. Provide a way to exclude directories from skill discovery

Related Issues

• Skill discovery doesn't match Claude Code's skills/ directory structure #6177 - Skill discovery directory structure mismatch
• Does opencode actually support finding skills at .claude/skills? #6266 - Does opencode actually support finding skills at .claude/skills?
• [FEATURE]: Support discovering Global Claude skills #6400 - Support discovering Global Claude skills

Workaround

Currently none - the only option is to rename/move the ~/.claude/skills/ directory which breaks Claude Code.

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Crash on SKILL.md files with non-OpenCode frontmatter schema #7575: Crash on SKILL.md files with non-OpenCode frontmatter schema - This is the closest match, addressing the exact same problem of OpenCode crashing when encountering Claude Code SKILL.md files with different frontmatter schemas
• YAML parsing errors in skills/agents cause TUI crashes #8047: YAML parsing errors in skills/agents cause TUI crashes - Covers the same YAML parsing failure behavior when discovering SKILL.md files
• opencode scans claude code's SKILL files and sometimes failed to parse YAML #7022: opencode scans claude code's SKILL files and sometimes failed to parse YAML - Also addresses OpenCode scanning Claude Code's SKILL files and failing to parse YAML

Feel free to ignore if none of these address your specific case.

[corrius]

Closing as duplicate of #7575 which describes the same ConfigFrontmatterError when parsing Claude Code SKILL.md files.