FabledScribe/plugin/PACKAGING.md

Packaging Scribe for an agent client

This is the maintainer contract for shipping Scribe into an agent client: what every client package shares, what each one adds, and where a new client's files go. It follows from decision #4027 (milestone 410): the server orients, the skills hold the depth, and a client adapter only times delivery and says what that one client needs said.

Claude Code is the only client built today. The layout below is kept so adding another one means adding files, not moving or rewriting any.

Shared by every client package

Piece	Where	What it is
The skills	plugin/skills/*/SKILL.md	Agent Skills (the open SKILL.md format). They state every Scribe reflex in full and name no client. tests/test_guidance_ownership.py fails if a skill names a particular client, or references anything outside its own folder. Every client package ships this folder verbatim.
The MCP server	<base URL>/mcp	HTTP, Authorization: Bearer <fmcp_ key>. Its _INSTRUCTIONS is a client-neutral orientation — the workflow across tools (≤1,600 chars, #4389); each tool's description carries its contract; in-band responses (placement, report_back, systems_hint, the duplicate gate, the guessed-id refusal) fire in every client.
The adapter API	<base URL>/api/plugin/*	Plain GET endpoints any client's hooks can call with the same key (read scope is enough): context (live session state), retrieve (rules, preferences and notes for a message), prior-art (records and shape-ledger hints for code being written), tool-rules (rules for a command about to run), report-check (records a completion-report check and returns the reason for a block), processes (stored Processes to expose as skills).
The API key	Scribe → Settings → API Keys	One fmcp_ key per install. Read scope for hooks; write scope for the MCP tools.

Added by each client

Piece	What it holds	Rule of thumb
A manifest	Name, version, how to reach the MCP server with the key, where the skills and hooks are	Only that client's format.
Hooks	Scripts in that client's hook format that call the adapter API at the right moment and print what comes back	Timing and transport only. A hook may print status lines (unconfigured, unreachable, running version) and pointers; guidance text comes from the server or the adapter's own static text.
Commands	That client's command wrappers, e.g. a process sync	Optional.
Adapter static text	What only that client needs said: its local memory files, its compaction command, its commands	Never a copy of a skill or of _INSTRUCTIONS. The loss guard and ownership registry in tests/test_guidance_ownership.py cover it.

The worked example: Claude Code

File	Role
.claude-plugin/plugin.json	Manifest: mcpServers.scribe (HTTP, Authorization: Bearer ${user_config.api_token}), userConfig for the base URL and key, version (minted, never hand-edited; see README).
../.claude-plugin/marketplace.json (repo root)	The marketplace entry pointing at ./plugin.
hooks/hooks.json	Wires the scripts to Claude Code events.
hooks/scribe_session_context.sh	SessionStart: adapter static text + running version + GET /api/plugin/context; a reload banner after compaction.
hooks/scribe_autoinject.sh	UserPromptSubmit: GET /api/plugin/retrieve for the message.
hooks/scribe_prior_art.sh	PreToolUse on editor writes: GET /api/plugin/prior-art.
hooks/scribe_after_write.sh	PostToolUse on shell commands: the same check for code written through the shell.
hooks/scribe_tool_rules.sh	PreToolUse on shell commands: GET /api/plugin/tool-rules.
hooks/scribe_moment.sh	PreToolUse on every tool: the rules mounted on the moments the call reaches, POST /api/plugin/moment; skips tools GET /api/plugin/moment-tools says reach nothing mounted, and Scribe's own (their responses carry moment_rules).
hooks/scribe_report_check.sh	Stop: when the turn closed a task, checks the reply for the completion sections and reports to GET /api/plugin/report-check; blocks once, with the reason the server returns.
hooks/scribe_shape_check.sh	Stop: sends the definitions the turn wrote (the write hooks' <sid>.written.ids ledger) to GET /api/plugin/shape-check; blocks once, with the reason the server returns, so the agent judges what it built.
hooks/scribe_sync_processes.sh + commands/sync.md	GET /api/plugin/processes → ~/.claude/skills/scribe-proc-* stubs; /scribe:sync on demand.
hooks/scribe_defs.sh	Shared shell helpers: config, dedup ledgers, outage line.
hooks/scribe_static_context.md	The adapter static text.

Hook config arrives as CLAUDE_PLUGIN_OPTION_API_ENDPOINT / CLAUDE_PLUGIN_OPTION_API_TOKEN (uppercased by Claude Code, #2198), with SCRIBE_URL / SCRIBE_TOKEN as an override.

How other clients would map

Researched, not tested (spike #4023, September 2026). Re-check each client's current docs before building.

• Agent Plugins 1.0 (Codex, Cursor, GitHub Copilot / VS Code, Kiro, ChatGPT): a root plugin.json, a skills/ folder, and an mcp.json. That is the same plugin/skills/ plus two small files. Hooks, commands and rules are not part of v1; each client adds its own under a reverse-domain directory (e.g. com.<client>/) that other clients ignore.
• Gemini CLI: gemini-extension.json configuring the MCP server, a context file, and bundled skills.
• Client-native formats also exist (.codex-plugin/, .cursor-plugin/) where a client wants more than the shared standard carries.
• Claude Code does not read Agent Plugins: only .claude-plugin/plugin.json.

Open questions for whoever builds the second package

1. Passing the key to the MCP server. Claude Code substitutes ${user_config.api_token} into the header. Agent Plugins' mcp.json and Gemini's extension config have their own variable and secret handling. Decide per client, and keep the key out of files that get committed.
2. Coexistence in one folder. Whether a root plugin.json (Agent Plugins) beside .claude-plugin/plugin.json changes how Claude Code loads the plugin is untested. Test it before shipping both from plugin/, or give the second client its own package directory that reuses plugin/skills/.
3. Hook parity. Other clients' hook events differ and are partly implemented. Map each Scribe hook to the nearest event, and where none exists, leave that timing to the in-band server responses rather than writing a copy of the guidance.
4. Process skills. The Claude Code sync writes ~/.claude/skills. Another client needs its own skills location, or the MCP skills extension (SEP-2640) once a client supports it.