Install for six harnesses

On many teams one developer uses Claude Code, another uses Cursor, and a CI job runs Codex. Each harness wants the same agent (subagent) in a different folder and format. palm writes all six from one command, records every file in one lock, and tells you what each harness could not take.

When you finish, the agent exists once per harness format and the skill twice:

Folder.agents/
- Folderskills/
  - Foldersdk-helper/
    …
Folder.claude/
- Folderagents/
  - agent-sdk-verifier-py.md
- Folderskills/
  - Foldersdk-helper/
    …
Folder.codex/
- Folderagents/
  - agent-sdk-verifier-py.toml
Folder.cursor/
- Folderagents/
  - agent-sdk-verifier-py.md
Folder.gemini/
- Folderagents/
  - agent-sdk-verifier-py.md
Folder.github/
- Folderagents/
  - agent-sdk-verifier-py.agent.md
Folder.opencode/
- Folderagents/
  - agent-sdk-verifier-py.md
palm.lock.yaml
palm.yaml

The skill appears twice because Claude Code reads .claude/skills, which Cursor reads too, and the other four share .agents/skills. The sessions on this page ran against palm’s fixture that mirrors anthropics/claude-plugins-official.

Before you start

The project is a git repository.
You accept that the Gemini CLI and OpenCode placements are unverified. They follow each harness’s documentation and source, checked on 2026-09-28, and have not run against a live CLI in palm’s tests yet.

Steps

Declare all six targets.

palm init --target claude,codex,copilot,cursor,gemini,opencode

Install the agent and the skill it uses.

palm install anthropics/claude-plugins-official agent-sdk-verifier-py sdk-helper

$ palm install anthropics/claude-plugins-official agent-sdk-verifier-py sdk-helper
i agent agent-sdk-verifier-py preloads mcp context7, not installed: palm install anthropics/claude-plugins-official mcp:context7
i ref main saved to palm.yaml; edit ref: to pin a tag
+ skill  sdk-helper              .agents/skills/sdk-helper/, .claude/skills/sdk-helper/   2 files   from anthropics/claude-plugins-official main
    claude gets its own copy in .claude/skills
    cursor reads .claude/skills; no second copy
+ agent  agent-sdk-verifier-py   .claude/agents/agent-sdk-verifier-py.md, .codex/agents/agent-sdk-verifier-py.toml +4   6 files   from anthropics/claude-plugins-official main
    .codex/agents/agent-sdk-verifier-py.toml: dropped model (sonnet), tools, skills, mcpServers, color (not supported by Codex)
    .github/agents/agent-sdk-verifier-py.agent.md: dropped model (sonnet), tools: Bash(python -m pytest:*) restriction (all of execute), mcpServers, skills, color (not supported by GitHub Copilot)
    .cursor/agents/agent-sdk-verifier-py.md: dropped model (sonnet), tools, skills, mcpServers, color (not supported by Cursor)
    .gemini/agents/agent-sdk-verifier-py.md: dropped model (sonnet), tools: Bash(python -m pytest:*) restriction (all of run_shell_command), skills, color (not supported by Gemini CLI)
    .opencode/agents/agent-sdk-verifier-py.md: dropped model (sonnet), color (green), tools: Bash(python -m pytest:*) restriction (all of bash), skills (not supported by OpenCode)
2 installed. Commit palm.yaml, palm.lock.yaml, .claude/, .codex/, .cursor/, .gemini/, .github/, .opencode/ and .agents/ together.

Each i line names what one harness has no place for, such as a model field for Codex or an argument restriction for Copilot. palm records the same notes in the lock, and palm describe agent-sdk-verifier-py shows them later.

Compare the formats palm wrote.

$ cat .claude/agents/agent-sdk-verifier-py.md
---
name: agent-sdk-verifier-py
description: "Use this agent to verify a Python Agent SDK app. Examples: <example>Context: user created an app</example>"
model: sonnet
tools: Read, Grep, Glob, Bash(python -m pytest:*)
skills:
  - sdk-helper
mcpServers:
  - context7
color: green
---

You are a Python Agent SDK application verifier.
$ cat .codex/agents/agent-sdk-verifier-py.toml
name = "agent-sdk-verifier-py"
description = "Use this agent to verify a Python Agent SDK app. Examples: <example>Context: user created an app</example>"
developer_instructions = """
You are a Python Agent SDK application verifier.
"""
$ cat .github/agents/agent-sdk-verifier-py.agent.md
---
name: agent-sdk-verifier-py
description: "Use this agent to verify a Python Agent SDK app. Examples: <example>Context: user created an app</example>"
tools:
  - read
  - search
  - execute
  - context7/*
---

You are a Python Agent SDK application verifier.

Harness	File	What palm changes
Claude Code	`.claude/agents/<name>.md`	nothing for a Claude Code agent; from another format, keys Claude Code does not define are dropped with a note
Codex	`.codex/agents/<name>.toml`	TOML with `name`, `description` and `developer_instructions`
GitHub Copilot	`.github/agents/<name>.agent.md`	Copilot tool names such as `read` and `execute`, MCP servers as `context7/*`
Cursor	`.cursor/agents/<name>.md`	`readonly: true` only when no tool in the list writes files or runs commands
Gemini CLI	`.gemini/agents/<name>.md`	strict frontmatter with `kind: local` and Gemini tool names
OpenCode	`.opencode/agents/<name>.md`	`mode: subagent` and a `permission` map that denies what the tool list leaves out

Install kinds that some harnesses cannot hold.

palm install anthropics/claude-plugins-official new-sdk-app
palm install anthropics/claude-plugins-official hook:agent-sdk-dev --dry-run

$ palm install anthropics/claude-plugins-official new-sdk-app
i ref main saved to palm.yaml; edit ref: to pin a tag
+ skill  new-sdk-app   .agents/skills/new-sdk-app/, .claude/skills/new-sdk-app/   2 files   from anthropics/claude-plugins-official main
    from command new-sdk-app.md: installed as a skill, which a harness may also load on its own when it looks relevant
    claude gets its own copy in .claude/skills
    cursor reads .claude/skills; no second copy
1 installed. Commit palm.yaml, palm.lock.yaml, .agents/ and .claude/ together.
$ palm install anthropics/claude-plugins-official hook:agent-sdk-dev --dry-run
This install adds 1 program that will run on your machine.

  1. hook agent-sdk-dev  from anthropics/claude-plugins-official  (commit bc94689, main, 2026-09-28)
     PreToolUse  Write|Edit  CLAUDE_PLUGIN_ROOT="$CLAUDE_PROJECT_DIR"/.palm/assets/anthropics__claude-plugins-official/agent-sdk-dev/plugins/agent-sdk-dev python3 "$CLAUDE_PROJECT_DIR"/.palm/assets/anthropics__claude-plugins-official/agent-sdk-dev/plugins/agent-sdk-dev/hooks/guard.py
       cursor: CURSOR_PLUGIN_ROOT="$CURSOR_PROJECT_DIR"/.palm/assets/anthropics__claude-plugins-official/agent-sdk-dev/plugins/agent-sdk-dev CLAUDE_PLUGIN_ROOT="$CURSOR_PROJECT_DIR"/.palm/assets/anthropics__claude-plugins-official/agent-sdk-dev/plugins/agent-sdk-dev python3 "$CURSOR_PROJECT_DIR"/.palm/assets/anthropics__claude-plugins-official/agent-sdk-dev/plugins/agent-sdk-dev/hooks/guard.py
     targets: claude (.claude/settings.json), codex (.codex/hooks.json), copilot (.github/hooks/agent-sdk-dev.json), cursor (.cursor/hooks.json), gemini (.gemini/settings.json)
     skipped: opencode (OpenCode hooks are JS plugins; hook agent-sdk-dev not installed)
     scripts: 2 files, 321 B  ->  .palm/assets/anthropics__claude-plugins-official/agent-sdk-dev/  (committed with your repo)
       plugins/agent-sdk-dev/hooks/guard.py  644   12 B  sha256:3a66aebd
       ... 1 more  (--review shows every script)

palm never runs this itself. If you say yes, its hash goes into palm.lock.yaml,
so teammates and CI install it without being asked; any change asks again.
+ would install  hook  agent-sdk-dev   .github/hooks/agent-sdk-dev.json, .palm/assets/anthropics__claude-plugins-official/agent-sdk-dev/plugins/agent-sdk-dev/ +4   3 files +4 merged   from anthropics/claude-plugins-official main
    OpenCode hooks are JS plugins; hook agent-sdk-dev not installed
    opencode: skipped
dry run: 1 would install; nothing written.

The command file installs as a skill everywhere, with a note about $ARGUMENTS. A harness without skill commands loses the /new-sdk-app call, and the note says so too. The hook lands in five harnesses. OpenCode has no declarative hooks, so palm skips it there and says so.

These are the combinations palm skips.

Kind	Harness	Scope	Why
hook	OpenCode	both	OpenCode hooks are JavaScript plugins
hook with a matcher that has arguments, such as `Bash(git commit*)`	GitHub Copilot	both	Copilot matchers cannot hold arguments
instruction	Cursor	global	Cursor keeps user rules in its settings

An on-request or manual rule is not skipped in Claude Code and OpenCode, but installs always-on there until 0.3, with a notice per rule.

palm describe target <target> prints where each kind goes for one harness, skips included.

palm describe target opencode

One entity, one carrier

Several harnesses read the same files, and palm keeps each entity loaded once per harness. With claude and cursor, a skill lives only in .claude/skills, because Cursor reads it there. Codex reads instructions from AGENTS.md, which Cursor, OpenCode and Copilot also read. palm 0.2 still writes Cursor’s own .cursor/rules file too, and palm check warns about that double load. palm 0.3 records one carrier per harness and drops the second copy. The skill copies palm chose above never warn, because palm check uses the same facts as the install.

Check the result

palm describe agent-sdk-verifier-py
palm check

palm describe lists the file each target received and every note palm recorded.

Next steps

Share a team baseline, so every developer gets the same six harnesses.
The targets matrix lists every path for every kind.
Why native files per harness explains the design.