fable

fable-5-anything

Portable prompt governance for adapting useful Claude Fable 5 style behaviors to non-Claude agent runtimes — without copying Claude-specific identity, tools, paths, or product assumptions. fable installs a model-neutral behavioral constitution into the charters and skills your hosts already load.

Dispatch moved to hopper-plugin. fable used to also assemble and dispatch handoffs (the former "Mode 2"). That capability now lives in hopper-plugin, a vendor-neutral background dispatcher. Governance reaches hopper-dispatched vendors either via the AGENTS.md/CLAUDE.md charter fable installs, or via hopper's opt-in GOVERNANCE.md overlay (which references fable's portable core).

Install (one command)

Zero-clone, straight from GitHub source (no clone, no npm publish needed). fable has no runtime dependencies, so npx just fetches and runs it:

npx -y github:surebeli/fable-5-anything governance --project <your-project>

This inlines the full portable core into your project's AGENTS.md + CLAUDE.md, so every host that auto-loads those charter files (opencode, Codex, Claude Code, Grok, Copilot) follows the constitution. Use --project . for the current directory.

Any governance command works the same way, e.g.:

npx -y github:surebeli/fable-5-anything kimi setup --project .          # Kimi loads skills, not charter markdown
npx -y github:surebeli/fable-5-anything codex setup --project . --apply # charter + read-only fable MCP server
npx -y github:surebeli/fable-5-anything runtime --list                  # read-only introspection

From a clone (for development)

git clone https://github.com/surebeli/fable-5-anything
cd fable-5-anything
node bin/fable.js governance --project <your-project>

Commands

Every command is governance-delivery — it installs or wires fable's constitution into a host (inlined into AGENTS.md/CLAUDE.md, written as a Kimi skill, wired into opencode.json, or exposed read-only via MCP). None of them dispatch, run, or execute tasks: the former dispatch/executor commands (init, install, build-prompt, smoke, run, doctor) were removed, and background dispatch now lives in hopper-plugin.

Command	Description
fable governance --project <dir>	Inline the full portable core into AGENTS.md + CLAUDE.md (host-agnostic).
fable charter sync --project <dir>	Seed/refresh the fable block in the charter files.
fable runtime [<name>]	Show how fable overlays governance onto a runtime.
`fable codex	copilot
fable kimi setup	Seed charter + write the fable Kimi skill.
fable opencode setup	Slim charter + portable core wired into opencode.json instructions.
fable mcp-server	Start the fable MCP server (read-only fable_runtime).
fable --version	Print the version.

Use as a Claude Code plugin (optional)

fable also ships a Claude Code plugin manifest (.claude-plugin/), so you can install it as a marketplace and drive governance from slash commands:

• Add the marketplace: surebeli/fable-5-anything (once pushed to GitHub), or a local path to a clone (./path/to/fable-5-anything).
• Then use /fable:governance (inline the constitution into this repo), /fable:setup <codex|kimi|copilot|grok|opencode> (wire a specific host), or /fable:runtime (read-only introspection).

The plugin only wraps the governance CLI — it adds no dispatch.

Strategy

Use a shared behavior core plus thin runtime adapters.

• prompts/portable-agent-core.md is the model-neutral constitution.
• adapters/*.md adds runtime-specific execution facts.
• prompts/claude-fable-5-exclusions.md lists Claude-specific material that must not be migrated into the portable core.
• tests/smoke-checklist.md defines minimum governance validation before an adapter is used.

The core owns principles. Adapters own mechanics. If an adapter conflicts with the core, the core wins.

Runtimes

fable does not replace most vendor system prompts. Claude Code is special: a user can replace the system prompt with --system-prompt-file. For opencode, Kimi, Codex, Copilot, and opaque hosts, fable overlays project governance on top of the host's authoritative system prompt — it never tells the model to ignore host rules.