Meta Agent Schema

Meta-Agent Schema Skill

The format contract for agents, skills, and MCPs in glyph-compatible catalogs. Any agent that creates, validates, or modifies catalog entries should load this skill in full and follow it.

The same shape is also reflected in the open MetaAgents reference spec. glyph is the canonical implementation; that document is a related spec. Where the two differ, this skill (and the validators that ship with glyph) are authoritative.

Layout

A catalog has a flat three-bucket layout:

<catalog-root>/
  agents/<short-name>/AGENTS.md        (+ any sibling files)
  skills/<short-name>/SKILL.md         (+ scripts/, templates/, references/, hooks/, etc.)
  mcps/<namespace>_<short>.json

Rules:

• The folder name MUST equal frontmatter.name (kebab-case, lowercase [a-z0-9]+(-[a-z0-9]+)*, no /).
• All entries in a catalog typically share one scope: value (e.g. acme); the scope is per-catalog convention, not part of the schema itself. Different catalogs use different scopes.

Naming rules

scope and name are separate frontmatter fields. Do not write name: "<scope>/<short>" — glyph parses them independently.

Frontmatter — Skill (skills/<name>/SKILL.md)

---
name: my-skill                                  # kebab-case, matches folder
scope: acme                               # the catalog's scope
description: "What the skill does, one line."   # 1-1024 chars
version: 0.1.0                                  # 3-segment semver (bare or quoted)
prereqs: |                                      # OPTIONAL — keep short
  Requires: <one-line summary>. See `references/SETUP.md` for step-by-step setup.
dependencies:                                   # OPTIONAL
  skills:
    - "https://github.com/<owner>/<repo>/tree/<ref>/skills/<other-skill>"
  mcps:
    - "https://github.com/<owner>/<repo>/tree/<ref>/mcps/<file>.json"
---
# Skill body (markdown, verbatim — what the agent sees when this skill loads)

Required fields: name, scope, description, version.

Optional fields: prereqs, dependencies.skills, dependencies.mcps.

Field rules:

• description is one short sentence; the user sees it in install lists.
• version is mandatory and must be 3-segment semver; the parser accepts both 1.0.0 (bare) and "1.0.0" (quoted).
• prereqs is a YAML literal-block string. Keep it short — link to a sibling references/SETUP.md for the long version.
• dependencies.skills and dependencies.mcps are arrays of bare origin URI strings. Object form ({origin: ...}) is parsed but discouraged.
• Cross-catalog dependencies are allowed: any public GitHub repo URL of the form https://github.com/<owner>/<repo>/tree/<ref>/<path> works.

Frontmatter — Agent (agents/<name>/AGENTS.md)

Same shape as Skill, with one difference: agents reject prereqs.

---
name: my-agent
scope: acme
description: "What the agent does, one line."
version: 0.1.0
dependencies:
  skills:
    - "https://github.com/<owner>/<repo>/tree/<ref>/skills/git-pr"
  mcps:
    - "https://github.com/<owner>/<repo>/tree/<ref>/mcps/io.playwright_mcp.json"
---
# Agent body

Required fields: name, scope, description, version.

Optional fields: dependencies.skills, dependencies.mcps.

prereqs is rejected — if your agent needs setup steps, put them in the body as a ## Setup section.

Required body sections (agent)

Every AGENTS.md body must include the agent's actual instructions, conventionally under a ## Agent Playbook heading. Additional structural sections (e.g. ## Setup, ## Domain, ## Boundary, ## Write Access) are optional conventions individual agents or catalogs may adopt; they are not lint-enforced.

The display title above the frontmatter (# {Agent Name} Agent) is human-readable and may differ from the kebab-case name field.

Frontmatter / format — MCP (mcps/<namespace>_<short>.json)

{
  "_meta": {
    "name": "<namespace>/<short>"
  },
  "type": "stdio",
  "command": "...",
  "args": ["..."]
}

Required _meta.*:

• _meta.name is the MCP spec FQN. Reverse-DNS namespaces are preferred (io.playwright/mcp); single-segment vendor names (acme/cli, azure/mcp) are also OK.

Filename rule: the on-disk filename is <namespace>_<short>.json (replace / in the FQN with _). For example, the MCP whose _meta.name is io.playwright/mcp lives at mcps/io.playwright_mcp.json.

Other top-level fields (type, command, args, env, …) follow the MCP client-config convention. Other _meta.* keys (e.g. registry sub-objects) survive untouched on re-write.

Files MUST be pretty-printed with 2-space indent and a trailing newline.

MCP cross-platform rules

The MCP spec at modelcontextprotocol.io has no shell-style variable expansion: command is an executable name, args is an array of literal strings, env is an explicit map. Wrapping commands in bash -c "..." to get $HOME / $PATH expansion is a tempting workaround on POSIX that breaks Windows immediately (no bash on PATH; no POSIX env var names). Catalog MCP specs MUST be cross-platform.

The four rules:

1. command is a bare executable name — npx, node, python, uvx. Let the OS PATH resolve it (Windows ships npx.cmd shims for Node tooling; the same name works on every host). Do NOT hardcode bash, /usr/bin/..., or any other absolute interpreter.
2. No shell wrappers — ["bash", "-c", "..."] and friends are forbidden. If you need command composition, write a tiny node script inside your MCP project and call it directly.
3. args are literal strings — no $HOME, no ${VAR}, no ~/. The MCP server receives every arg verbatim.
4. For paths that can't be hardcoded, use placeholder substitution (see below). glyph resolves these at provision time, before the MCP child is spawned, so the path the server sees is already absolute and platform-correct.

Placeholder substitution

Two placeholders are supported in any string field of an MCP spec (command, any element of args, any value of env, plus nested strings inside any custom object you put in the spec):

glyph substitutes both before writing .mcp.json to the workDir. The substituted paths use forward slashes regardless of host OS, so the same JSON value bytes ship to Windows and POSIX. A typo in a placeholder (${workspceDir}) is rejected at install time with a clear error — placeholders aren't silently passed through.

Pick ${sharedDir} over ${workspaceDir} only when the state genuinely belongs to the user account rather than the project — e.g. a model download cache or a global API token jar.

Example

{
  "_meta": {
    "name": "io.playwright/mcp"
  },
  "type": "stdio",
  "command": "npx",
  "args": [
    "-y",
    "@playwright/mcp@latest",
    "--headless",
    "--storage-state",
    "${workspaceDir}/.playwright/storage-state.json"
  ]
}

Origin URI grammar

Dependency origins (dependencies.skills, dependencies.mcps) are bare URI strings. Two schemes are accepted:

• https://github.com/<owner>/<repo>/tree/<ref>[/path] — recommended for shared catalog entries; supports any public GitHub repo
• file:<absolute-path> — local-only; never commit a file: origin

Runtime-agnostic file references in agent / skill bodies

Catalog content (the markdown body of AGENTS.md and SKILL.md) MUST NOT hardcode any specific runtime's on-disk layout. The same skill or agent body should work whether the runtime materialises files under .github/ (Copilot CLI), .claude/ (Claude Code), .gemini/ (Gemini CLI), .cursor/, .windsurf/, .codex/, or any other provider's per-project config directory. Each runtime owns the choice of where to put files; the body just refers to them logically.

When a skill needs to reference its own sibling files

Use the <SKILL_DIR> placeholder. The convention is established by the first-party sop and scientific-method skills:

# In a skill's SKILL.md body (or any reference file inside that skill):
cp <SKILL_DIR>/templates/plan.md .
cat <SKILL_DIR>/references/checklist.md

Document <SKILL_DIR> once, near where it first appears in the skill body — for example: > <SKILL_DIR> is the directory containing this SKILL.md. Resolve from your runtime context.

LLM-driven runtimes resolve the placeholder from runtime context — they know where THEIR provisioner puts skill files, the body doesn't need to.

When an agent needs to reference a dependency skill's files

Same pattern — refer to <SKILL_DIR> in the dependent skill, not a hardcoded path:

# In an agent body that depends on `agency-role-reference`:
cat <SKILL_DIR>/references/index.md   # in the dependent skill's body

Or, when the agent body is describing what to consult rather than executing a command, refer to the skill abstractly: "consult the agency-role-reference skill's references/index.md" — the LLM and its tools will locate it.

Antipatterns

The following patterns are forbidden in agent / skill bodies because they couple to one runtime's implementation:

These patterns should be caught during review of any catalog entry.

Rationale

Catalog content is fetched once and replayed against many runtimes / many users / many host environments. Anything that bakes one runtime's choices into the body causes silent breakage when:

• A user installs the same skill against a runtime that uses a different config dir (Copilot uses .github/, Claude Code uses .claude/, Gemini CLI uses .gemini/, etc.)
• A runtime team renames its materialisation layout (the __ flatten rule, the parent dir name, etc.)
• The user's catalog uses a different scope name than the one assumed by the hardcoded path

The <SKILL_DIR> placeholder + abstract references shift these decisions out of catalog content and into runtime concerns, where they belong.

CHANGELOG conventions

Every agent and skill ships a CHANGELOG.md next to its AGENTS.md / SKILL.md.

• Version headers use ## X.Y.Z (YYYY-MM-DD) format. Example: ## 1.2.0 (2026-04-17).
• Bump guidance:
  • patch (X.Y.Z+1) — bug fixes, typos, minor edits that don't change behavior or the public surface
  • minor (X.Y+1.0) — new features, behavioral additions, new optional dependencies
  • major (X+1.0.0) — breaking changes (rename, dropping a public dependency, removing a tool, semantic change to a workflow that downstream agents rely on)
• One version bump per PR per agent/skill — do not bump version multiple times within a single PR.
• Frontmatter version MUST match the latest entry in CHANGELOG.md.
• Sections that document past renames or breaking changes are provenance — do not delete them when later versions move on.

Submission flow (when publishing to a public catalog)

1. Fork the catalog repo, create a feat/add-<my-thing> (or other conventional-commit-prefixed) branch.
2. Add the new entry under the correct directory.
3. Verify locally — install via the glyph dashboard pointing at your fork's branch URL and exercise the entry.
4. git push and open a PR.
5. CI (when enabled) re-runs the upstream validators against every changed file.

References

Related surfaces:

• Open reference spec: metaagents-ai/metaagents — the open MetaAgents reference document. Useful as background; glyph and this skill are the canonical implementation for glyph-compatible catalogs.
• Runtime validators (deepest authority — what installs reject): the @glyphs-ai/catalog package in glyphs-ai/glyph. Where this skill's prose and the validators disagree, the validators are authoritative.