# entwurf

`entwurf` is a garden-citizen dispatch substrate: a thin bridge that lets already-existing agent harnesses address one another by **garden id** without pretending to own each other's transcript, auth, or runtime.

![entwurf — a forged screwdriver for garden-citizen dispatch](docs/assets/entwurf-hero.jpg)

[![npm](https://img.shields.io/npm/v/@junghanacs/entwurf?logo=npm)](https://www.npmjs.com/package/@junghanacs/entwurf) · maintained by [junghanacs.com](https://junghanacs.com/)

npm package: <https://www.npmjs.com/package/@junghanacs/entwurf>

Legacy package: [`@junghanacs/pi-shell-acp`](https://www.npmjs.com/package/@junghanacs/pi-shell-acp). `entwurf` is its 0.12+ successor line: the same work renamed around the garden-citizen dispatch substrate rather than the pi adapter.

> **Repository shape.** This repo is **entwurf-core (v2 dispatch) + native-harness bridges + a pi adapter + an ACP plugin**. Pi is one supported harness adapter — important because it supplies control sockets and hosts the ACP plugin today — but it is not the project subject. Claude Code is shipped as a mailbox-backed meta-session; Antigravity (`agy`) is shipped as a native-push citizen with automatic `PreInvocation` birth, ambient garden-id status, and a managed MCP/permission install surface. Codex has a launch-mode-specific verified delivery probe documented in [DELIVERY.md](./DELIVERY.md), but no managed native-citizen install lane yet. The ACP plugin ships two backends through one adapter rail: Claude (the reference) and Snowflake Cortex Code (landed in 0.13.0 under the measured contract in [docs/acp-backend-rail.md](./docs/acp-backend-rail.md#cortex-code-audit-d1d10)).

```text
Claude Code / Codex / agy / pi
  → garden id
    → entwurf_v2
      → control-socket | spawn-bg resume | meta-mailbox | native-push
```

[`entwurf_v2`](#entwurf_v2--canonical-dispatch-verb) is the canonical dispatch surface over *existing* garden citizens — live control-socket send, spawn-bg resume, meta-mailbox enqueue, and native-push into a live Antigravity conversation. The meta-record is the sole address authority (#50 C4): a record-less control socket is refused as a `record-less-socket` diagnostic, never dispatched. The v1 entwurf verbs are gone. Fresh sibling minting is still a deferred lane; the non-Claude ACP lane is not — Snowflake Cortex Code landed as the second backend in 0.13.0.

**Garden id is deliberate vocabulary.** It is not a decorative synonym for session id, worker, delegate, or subagent. The unfamiliar word is a guard: each harness keeps its own identity and transcript, while `entwurf` supplies a narrow addressable surface between siblings.

**A narrow harness tool surface is discipline, not a missing feature.** When entwurf drives a backend the way pi taught — the ACP Claude session, a pi-native sibling — it runs without a sub-agent tool or a todo tool, on a narrow tool surface in auto-approve (`yolo`) mode (the ACP backend yolo-runs inside its isolated overlay). That restraint is the point: it keeps the one forged screwdriver from drifting into a second orchestrator, and keeps the operator's own driver — not a hidden agent swarm — the thing actually steering. See [AGENTS.md](./AGENTS.md) North Star.

**The ACP plugin is one ingress, not the boundary.** It re-enters as a pi provider/model on a host `--entwurf-control` session that is *already* a v2 socket-citizen; it does not mint its own socket / peers / citizen layer (see [AGENTS.md](./AGENTS.md) §ACP Plugin Boundary). No OAuth proxy, no subscription bypass, no CLI transcript scraping, no Claude Code emulation.

```text
pi --entwurf-control
  → entwurf ACP plugin
    → claude-agent-acp
      → Claude backend under the operator's local auth
```

**Native bridges reach beyond ACP transport.** A global `SessionStart` hook registers native Claude Code sessions as **garden-native meta-sessions** with a garden id, a mailbox, and a trusted sender marker. That makes an already-running Claude Code terminal addressable through `entwurf_v2` (the mailbox path), self-identifying through `entwurf_self`, and replyable by garden id — without turning pi into a second harness or importing Claude's transcript.

```text
native Claude Code
  → SessionStart hook
    → mailbox-backed meta-session <garden-id>
      → entwurf-bridge MCP
        → entwurf_self | entwurf_v2 | entwurf_inbox_read
```

Antigravity uses a separate shipped rail. Its `PreInvocation` hook births or re-attaches the conversation by native `conversationId`, writes a record-backed sender marker, and leaves delivery to the live native LS gRPC route. There is no mailbox or receiver marker on this rail: `entwurf_v2` probes the conversation and direct-injects with native-push.

```text
native Antigravity / agy
  → PreInvocation imprint → meta-session <garden-id>
  → entwurf-bridge MCP sender identity
  ↔ entwurf_v2 native-push
```

Claude's `install-meta-bridge` and agy's `install-agy-{bridge,statusline,hooks}` are distinct managed install surfaces because their lifecycle and delivery transports are genuinely different. Codex remains verified probe evidence, not a shipped managed native-citizen lane; see [DELIVERY.md](./DELIVERY.md).

> **Direction.** Inverse of [`pi-acp`](https://github.com/svkozak/pi-acp). `pi-acp` lets external ACP clients talk *to* pi; `entwurf` lets garden citizens talk across harness boundaries — with pi as one adapter, not the center.

## Concept primer

A few words that look unusual for a coding tool.

- **Entwurf** (기투, projection-of-self) — sibling sessions with their own runtime boundary. Not "delegate," not "worker," not "sub-agent." Spawn, resume, and live peer messaging are first-class.
- **Garden / garden id** — the garden is the shared address space where independent harness sessions become citizens without losing their own runtime or transcript. A garden id is the stable address of one such citizen (for pi, a garden-native session id like `YYYYMMDDTHHMMSS-<6hex>`; for native harnesses, a meta-session id minted from an authoritative lifecycle hook — Claude `SessionStart`, agy `PreInvocation`). It is not a worker name and not proof that pi owns the session. The same-looking id may name a live control socket, a dormant pi record, a mailbox-backed native session, or a native-push conversation, so callers discover facts with `entwurf_peers` and deliver with `entwurf_v2` instead of choosing a transport by hand.
- **Engraving** — optional short operator text delivered through each backend's native identity carrier. Not a giant hidden prompt, not a tool catalog.
- **MCP** — in this repo, MCP is just the transport by which ACP-backed sessions receive pi capabilities that native pi exposes directly as extensions. It is not a general MCP platform. Explicit `entwurfProvider.mcpServers` only; no ambient `~/.mcp.json` scanning, no automatic retrieval. The same `entwurf-bridge` entry can also be wired into another host's MCP catalog (Claude Code, Codex, Antigravity, …) when the operator chooses. `entwurf_self` returns an authoritative pi-session or trusted meta-session identity envelope; `entwurf_v2` requires an authoritative sender by default (#50 C4) — a plain external MCP host with no identity lane is refused unless the operator explicitly wires the documented anonymous hatch, and even then it is never replyable.
- **Session persistence** — re-attaches pi to the same remote ACP session. Does not hydrate backend transcripts into pi history.

## Install

`entwurf` is a neutral npm package first. Install the package with `npm` (or
`pnpm`/`yarn`) and then wire the harness you want to use. Pi is still the
adapter that hosts the ACP plugin and live control-socket surface, but the base
install is **not** `pi install npm:...` anymore.

The package exposes five bins:

- `entwurf` → `run.sh` (installer, checks, native-bridge doctors/installers)
- `entwurf-bridge` → the MCP stdio launcher (`mcp/entwurf-bridge/start.sh`)
- `entwurf-statusline` → the Claude Code statusline renderer (`scripts/meta-bridge-statusline.sh`)
- `entwurf-agy-statusline` → the Antigravity garden-id statusline renderer (`scripts/agy-statusline.sh`)
- `entwurf-agy-imprint` → the Antigravity `PreInvocation` birth/sender hook (`scripts/agy-imprint.sh`)

The bridge/renderers/hook use stable bin names so package upgrades do not bake versioned package-store paths into native-harness settings.

The bridge does not provide backend credentials, tokens, or subscription access,
and does not bypass any backend auth. Whatever the operator's local `claude` /
`codex` / `agy` / pi runtime already trusts is what entwurf can use.

### From npm — user/global install

```bash
npm install -g @junghanacs/entwurf

# wire a target project for the pi adapter / ACP plugin lane
cd /path/to/your-project
entwurf install .
entwurf check-bridge
```

This writes `.pi/settings.json` in the target project with the absolute path to
the installed `entwurf-bridge` launcher. It also links the target registry under
`~/.pi/agent/` for spawn-bg resume. The global install is the easiest path when
Claude Code's USER-scope MCP registration should work from every cwd.

### From npm — project-local install

```bash
cd /path/to/your-project
npm install --save-dev @junghanacs/entwurf

npx entwurf install .
npx entwurf check-bridge
```

For manual MCP registration from a project-local install, point the host at:

```text
/path/to/your-project/node_modules/.bin/entwurf-bridge
```

or at the package launcher directly:

```text
/path/to/your-project/node_modules/@junghanacs/entwurf/mcp/entwurf-bridge/start.sh
```

### From source — development clone

```bash
git clone https://github.com/junghan0611/entwurf ~/repos/gh/entwurf
cd ~/repos/gh/entwurf
pnpm install

./run.sh install /path/to/your-project
./run.sh check-bridge
```

A development clone runs the bridge source through Node's strip-types path;
an npm-installed package runs the prebuilt JS under `mcp/entwurf-bridge/dist/`
because Node refuses to strip `.ts` files under `node_modules`.

### Pi adapter / ACP plugin lane

To use the `entwurf` provider inside pi, install a compatible pi binary
separately (`@earendil-works/pi-coding-agent >=0.83.0 <0.84`). Then point pi at
the npm-installed package or development clone:

```bash
# global npm install path
pi -e "$(npm root -g)/@junghanacs/entwurf" --list-models entwurf

# project-local install path
pi -e ./node_modules/@junghanacs/entwurf --list-models entwurf
```

For daily operator sessions, launch pi with `--entwurf-control` — no id
injection; the meta-record mints the garden address (see [Garden launcher](#garden-launcher)). Older pi
versions may silently miss the provider/extension surface, so treat the pi floor
as release-critical for the ACP/plugin lane. A host that only uses
`entwurf-bridge` from Claude Code / Codex / Antigravity does not need pi until it
tries an `owned-outcome` spawn-bg resume target.

### Native harness install and doctors

A plain MCP registration exposes the bridge tools; a **garden-native** session also
needs entwurf's lifecycle hook and identity marker. Use the managed installers rather
than editing native-harness state by hand:

```bash
# Claude Code (Linux-certified axis)
entwurf install-meta-bridge
entwurf doctor-meta-bridge

# Antigravity / agy
entwurf install-agy-bridge
entwurf install-agy-statusline
entwurf install-agy-hooks
entwurf doctor-agy-bridge
entwurf doctor-agy-statusline
entwurf doctor-agy-hooks
```

Claude Code uses the supported floor `>=2.1.217`; older versions silently discard the
exec-hook `args`, so install and doctor fail loud rather than falling back. After any
upgrade, rerun the installer for the native harness you use and restart its existing
processes. A claimed Claude host is certified only when a **new** session using the
installed artifact makes `doctor-meta-bridge` exit 0 with the live owner join.

Linux is the only currently certified Claude meta-bridge axis. New macOS wiring is
refused because the strict live-owner doctor depends on `/proc`; Darwin uninstall
remains available for legacy cleanup, and the neutral package itself has no `os`
restriction. Detailed diagnosis and clean-host steps live in
[docs/setup-clean-host.md](./docs/setup-clean-host.md).

The active citizen store is V3-only. A store that fails certification is never
silently migrated: quiesce the native sessions, run `entwurf meta-bridge-fresh-cut`,
then reinstall. The cut archives routing records only—never native transcripts or
external memory—and no runtime reads the archive. Exit meanings and the complete
operator contract are in [docs/fresh-cut-policy.md](./docs/fresh-cut-policy.md).

`entwurf check-bridge` proves the MCP surface boots without backend auth. A real ACP
turn requires `LIVE=1 entwurf smoke-acp-provider-live`; the full release protocol and
host evidence boundaries are [VERIFY.md](./VERIFY.md) and [BASELINE.md](./BASELINE.md).

> **Extension set — do not filter.** The ACP provider, `entwurf-control`, and
> `model-lock` extensions ship as one set. Disable the package as a whole rather than
> filtering individual entries into a partially wired state.

### Backend prerequisites

**Claude is the reference ACP backend.** The Claude ACP server package (`@agentclientprotocol/claude-agent-acp`, pinned with `@agentclientprotocol/sdk`) ships as a pinned `dependency` of `entwurf`; backend authentication still belongs to the operator's local `claude` CLI / runtime. Once the bridge is installed, the resolver picks the ACP server in this order:

1. **`CLAUDE_AGENT_ACP_COMMAND` env override** — explicit override for an alternative binary or a wrapper command.
2. **`require.resolve(...)` against the bundled package dependency** (`@agentclientprotocol/claude-agent-acp`). This is the default path; no extra global install needed.
3. **`PATH:claude-agent-acp` fallback** — used when the package resolution fails (e.g. a hand-edited `node_modules`).

The curated model registry exposes unprefixed Claude ids plus `cortex-` rows.
Codex is not an ACP backend or a shipped managed citizen lane: it has verified
native-delivery probe evidence, and the reserved 0.14.0 work must turn that evidence
into lifecycle, identity, installation, and doctors before calling it supported.

**Snowflake Cortex Code is the second ACP backend** (contract and audit:
[docs/acp-backend-rail.md](./docs/acp-backend-rail.md#cortex-code-audit-d1d10)). Curated ids are
`cortex-auto`, `cortex-claude-opus-5`, `cortex-claude-sonnet-5`, and
`cortex-openai-gpt-5.4`.

The operator supplies an authenticated `cortex` CLI and selects a connection with
`entwurfProvider.cortexConnection` or `ENTWURF_ACP_CORTEX_CONNECTION`. `CORTEX_HOME`
must be absent: the adapter refuses it because it would bypass the session-scoped
HOME containment. Explicit MCP servers are projected into the overlay-private
`cortex/mcp.json`; only the bridge receives the real operator HOME needed for the
garden store.

`check-acp-cortex` runs in `pnpm check`. Real acceptance is deliberately on demand:

```bash
LIVE=1 ENTWURF_ACP_CORTEX_CONNECTION=<conn> entwurf smoke-acp-cortex-live
```

The aggregate Claude floor does not run this smoke, so silence is not a Cortex PASS.

### Emacs frontends

Works from terminals and from Emacs frontends that launch [pi-coding-agent](https://github.com/dnouri/pi-coding-agent).

<details>
<summary>Watch entwurf in Doom Emacs (1104×627 GIF, click to expand)</summary>

![entwurf in Doom Emacs](docs/assets/entwurf-doomemacs.gif)

</details>

For a dedicated agent socket, pass the socket name:

```elisp
(setq pi-coding-agent-extra-args
      '("--entwurf-control" "--emacs-agent-socket" "pi"))
```

The bridge exports the socket name to ACP children as `PI_EMACS_AGENT_SOCKET`, so skills call Emacs without hardcoding:

```bash
emacsclient -s "${PI_EMACS_AGENT_SOCKET:-server}" --eval '(...)'
```

## Settings

Reference shape lives in [`pi/settings.reference.json`](./pi/settings.reference.json). Minimum:

```json
{
  "compaction": { "enabled": false },
  "entwurfProvider": {
    "appendSystemPrompt": false,
    "settingSources": [],
    "strictMcpConfig": true,
    "showToolNotifications": true,
    "tools": ["Read", "Bash", "Edit", "Write"],
    "skillPlugins": [],
    "permissionAllow": ["Read(*)", "Bash(*)", "Edit(*)", "Write(*)", "mcp__*"],
    "mcpServers": {
      "entwurf-bridge": {
        "command": "/path/to/entwurf/mcp/entwurf-bridge/start.sh",
        "args": []
      }
    }
  }
}
```

`mcpServers` is the only ACP MCP injection path. In practice this repo is about the bundled `entwurf-bridge`, which carries pi capabilities into ACP-backed sessions — not about being a general MCP catalog. Invalid entries throw `McpServerConfigError` — broken tool state surfaces as broken tool state. `./run.sh install` writes the bundled `entwurf-bridge` entry and prunes the legacy bundled `session-bridge` entry from older installs.

`appendSystemPrompt: false` is intentional. Pi / AGENTS context rides the first-user augment; putting it into the Claude `_meta.systemPrompt` carrier can route OAuth sessions to metered "extra usage" billing.

**Which keys reach which backend.** `entwurfProvider` is one block for both backends, but its keys are not universal. `tools` / `permissionAllow` / `disallowedTools` / `settingSources` / `skillPlugins` / `appendSystemPrompt` are Claude's declaration surface: they do not shape a cortex session, which runs its own native tools and reaches MCP through the overlay-private `mcp.json` projection instead. They are not inert, though — the bridge still reads `tools` for its backend-invariant exclude-tools preflight and folds all of them into the config signature, so editing one still forces a fresh cortex session. `cortexConnection` is cortex-only. `mcpServers` is the one declaration surface that reaches both, each through its own transport. (`compaction` is a *top-level* pi key, not an `entwurfProvider` one — it is pi's own transcript policy and is not a backend knob at all; see §Compaction.) Unknown and retired keys are ignored rather than rejected, so a key aimed at the wrong backend fails silently: if a cortex session does not show the surface you configured, check that the key is one cortex actually consumes before suspecting the bridge.

### External MCP registration

`entwurf-bridge` can also be registered in a separate MCP-aware harness (Claude Code,
Codex CLI, Antigravity). Two shapes exist and they are not interchangeable:

- **plain external MCP host** — no garden meta-record or sender marker. It can read the
  surfaces, but `entwurf_v2` is **refused by default**: there is no authoritative sender.
- **garden-native session** — a trusted lifecycle hook minted a garden id, so it is
  addressable and replyable by that id.

```bash
claude mcp add --scope user entwurf-bridge entwurf-bridge
```

Per-harness registration (Claude Code `~/.mcp.json`, Codex `~/.codex/config.toml`, the
managed `install-agy-*` surfaces), the PATH/env boundary for GUI-launched MCP servers, the
anonymous-sender hatch, and the full external/meta-session semantics are in
[docs/external-mcp-host.md](./docs/external-mcp-host.md).
For the maintained multi-harness setup and skill/command packaging details, see `agent-config`. See also the MCP entry in [Concept primer](#concept-primer), the sender envelope contract in [AGENTS.md](./AGENTS.md), and [Custom skills](#custom-skills) for the in-pi ACP skill surface.

## Per-backend operating surface

The Claude ACP backend keeps its native model / API / tools; entwurf shapes only what enters from pi. Claude honors an explicit `CLAUDE_CONFIG_DIR` export when set by the operator.

**Claude** uses `_meta.systemPrompt` for the engraving carrier (kept short and pure — billing-safe; rich operator context rides the first user message instead, see [Context carriers](#context-carriers)) and `CLAUDE_CONFIG_DIR` for a whitelist overlay so auth/runtime entries stay available while operator memory, hooks, agents, history, local settings, and project memory remain hidden. The overlay writes an explicit empty `hooks: {}` because Claude SDK organic compaction needs the configured-empty shape; no operator hook definitions are inherited. The four-tool baseline (`Read`, `Bash`, `Edit`, `Write`) is enforced through `tools` + `permissionAllow`; `Skill` is added automatically when `skillPlugins` is non-empty. Operator context cap override: `ENTWURF_ACP_CLAUDE_CONTEXT=<int>`.

Codex is not an ACP backend here. Its native delivery probe remains separate from
the governed ACP adapter rail and does not yet constitute a managed garden citizen.

Antigravity is also not an ACP backend. It is a native-push citizen: `PreInvocation` supplies birth/sender identity, `entwurf_v2` probes and direct-injects replies into the live conversation, and no mailbox/receiver marker is involved.

entwurf owns **no** memory layer at all — the ACP plugin's boundary explicitly excludes a memory DB (see `AGENTS.md` §ACP Plugin Boundary), and no backend is a memory authority for another. What this overlay does is narrower: Claude's native memory layer is pinned off so operator memory, project state, and history never leak into an ACP session. Whatever semantic-memory / Denote tooling an operator runs is their own skill surface on whichever harness hosts it — deliberately kept out of the MCP bridge, and not a pi privilege.

## Smoke commands

```bash
pnpm check                              # full deterministic floor (all check-* gates, incl. check-acp-*)
./run.sh check-bridge                   # entwurf-bridge direct MCP smoke (no backend auth)
./run.sh smoke-agy-install-state        # agy MCP + exact permission ownership lifecycle (install/uninstall/doctor/inverse)
./run.sh smoke-agy-statusline-state     # agy ambient garden-id install surface
./run.sh smoke-agy-hooks-state          # agy PreInvocation birth hook
./run.sh check-agy-sender-identity      # record-backed pid/start-key sender identity

# source-maintainer only — qualification snapshots the git work surface, and both
# commands are source-contract gates rather than installed operator checks:
./run.sh check-agy-permission-matrix    # AGY permission contract space as a literal table (declared cells + stated exclusions)
./run.sh check-gate-qualification       # kill-proof: committed defect mutants must turn their gates red for the claimed reason

# agy LIVE acceptance — requires an already-running conversation:
LIVE=1 AGY_CONVERSATION_ID=<id> ./run.sh smoke-agy-native-push-live

# ACP plugin LIVE acceptance — need the operator's local Claude auth/credit:
LIVE=1 ./run.sh smoke-acp-socket-citizen-live   # turn-free socket citizenship (S1)
LIVE=1 ./run.sh smoke-acp-raw-turn-live         # pinned ACP pipe + raw 1 turn (S2a)
LIVE=1 ./run.sh smoke-acp-overlay-live          # config overlay + hooks:{} + tool meta (S2b)
LIVE=1 ./run.sh smoke-acp-provider-live         # real pi provider path + progress/L3 (S2c/S2f)
LIVE=1 ./run.sh smoke-acp-session-reuse-live    # process-scoped reuse + codeword recall (S2d)
LIVE=1 ./run.sh smoke-acp-carrier-augment-live  # augment delivery + empty-carrier billing clean (S2e-1)

LIVE=1 ./run.sh release-gate /tmp/scratch --cut # the single cut gate (MUST + BEHAVIOR; --cut refuses any MUST SKIP)
LIVE=1 ENTWURF_ACP_CORTEX_CONNECTION=<conn> ./run.sh smoke-acp-cortex-live  # Cortex is on-demand: the aggregate does not re-certify it
```

`pnpm check` already includes the two maintainer gates: the AGY permission contract
matrix and the full committed-mutant gate qualification run on every pass. A gate a
release touches must kill its known defect for the claimed `[QK:<claim>]` reason —
the descriptions above name what each smoke covers, and no check count is quality
evidence on its own. Gate qualification needs the git work surface, while the matrix
is the source permission-contract gate; both run from a clone, never as a post-install
operator step.

## Custom skills

Claude sessions accept custom skills through `skillPlugins` — an array of absolute paths to directories matching the Claude Agent SDK plugin layout:

```
<your-plugin-root>/
├── .claude-plugin/
│   └── plugin.json
└── skills/
    └── <skill-name>/
        └── SKILL.md
```

A self-contained example lives at [`pi/skill-plugin-example/`](./pi/skill-plugin-example/). Put plugin roots anywhere on disk except under `~/.pi/agent/` (pi's internal cache).

```json
{
  "entwurfProvider": {
    "skillPlugins": ["/absolute/path/to/your-plugin-root"]
  }
}
```

`Skill` is auto-added to `tools` and `Skill(*)` to `permissionAllow` whenever `skillPlugins` is non-empty. Each entry is validated at settings parse time and throws when the path is missing, not absolute, not a directory, or missing `.claude-plugin/plugin.json`. The Claude session does not start until the violation is fixed. The bridge does not validate `plugin.json` contents or `SKILL.md` bodies — that is the Claude Agent SDK's contract.

To verify, start a fresh Claude session and ask the model to list its skills; the names declared in your `SKILL.md` frontmatter should appear among the visible skills. The operator-driven version of this check is `Q-SKILL-CALLABLE` in [VERIFY.md](./VERIFY.md).

`skillPlugins` is a Claude-backend-only install surface. Codex exposes skills through native `~/.codex/skills/` passthrough.

For a real consumer arranging many skills, see [agent-config](https://github.com/junghan0611/agent-config).

## Entwurf orchestration

**Entwurf is one dispatch capability with native-pi and MCP surfaces.** Native pi exposes it directly as extension tools; ACP-backed and external native-harness sessions reach it through `entwurf-bridge`. The purpose is not to invent a different sub-agent system, but to preserve the same sibling-based model across harnesses.

A sibling has its own runtime boundary and its own provider/model identity — not a worker, delegate, or sub-agent. Minting a brand-new sibling from nothing is a deferred v2 lane (`spawn-fresh`); today every transport targets an *existing* garden citizen. `entwurf_v2` routes from rail-specific liveness + intent: live pi fire-and-forget → control socket; dormant pi owned-outcome → spawn-bg resume; active self-fetch → meta-mailbox; probe-alive agy → native-push. A **control-socket-domain** dispatch takes the per-target lock — both the live send and the dormant cell's spawn-bg resume; mailbox and native-push use their own deliverability evidence and remain lock-free.

A two-pane recording covers the surface end-to-end — sibling resume, cross-process MCP dispatch across a different cwd, and a live peer greeting:

<details>
<summary>Watch (2131×1142 GIF, click to expand)</summary>

![entwurf demo](./docs/assets/entwurf-entwurf.gif)

</details>

Live peer messaging carries a sender envelope `{ sessionId, agentId, cwd, timestamp, origin?, replyable? }`; `entwurf_self` returns that authoritative envelope for the current pi session or trusted meta-session. Plain external MCP hosts are non-replyable. A garden-native meta-session carries a trusted `meta-session` envelope, but **`replyable` is a fact its own rail decides, not a consequence of being trusted** — a self-fetch citizen needs a live armed receiver, a native-push citizen needs an alive adapter probe, and a pi session needs its control socket. `entwurf_self` also reports which rail a meta-session reply would ride, because a native-push citizen has no mailbox to name. `wants_reply` is an etiquette marker rendered as a `(wants reply)` badge — not a transport contract, no wait, no polling. **v2 never gates on it:** a `wants_reply` from an external/non-replyable caller is passed through and surfaced honestly beside that sender's `replyable: false`, not rejected — the decider routes on target + intent, never on sender replyability. (The retired v1 `entwurf_send` did reject it; that behaviour went with the verb.)

In ACP-backed and external native-harness sessions, `entwurf-bridge` exposes five tools: `entwurf_v2`, `entwurf_peers`, `entwurf_self`, `entwurf_inbox_read`, and the explicit/manual `entwurf_register_native` fallback. Native pi exposes the shared capability directly through the extension surface (`entwurf_v2`, `entwurf_peers` tools; the socket-scan `/entwurf-sessions` command is gone — #50 C4). **For garden-id delivery/reply use `entwurf_v2`** — the canonical surface that classifies the target and routes to live-pi / dormant-resume / Claude-Code-meta-mailbox / Antigravity-native-push. Fresh sibling creation from nothing is a deferred lane. (The v1 verbs `entwurf` / `entwurf_resume` / `entwurf_send` are gone.) Garden-native operator commands require `--entwurf-control`. There is no spawn target allowlist — the target registry is gone (#50 C3): `entwurf_v2` resumes an already-identified record-backed citizen, never a model tuple from a file.

### `entwurf_v2` — canonical dispatch verb

`entwurf_v2` / `runEntwurfV2` is the canonical v2 dispatch verb over **existing** garden targets — record-backed citizens only (#50 C4: the record is the sole address authority; a record-less control socket rejects pre-probe as `record-less-socket`, a diagnostic state, never a delivery target). You give a target garden id plus an intent (`fire-and-forget` or `owned-outcome`); one decider reads the target's liveness as a fact and picks the transport from a frozen table keyed on **both** the target's state **and** the intent — never on state alone — then reports one outcome under the v2 lock policy. A **control-socket-domain** dispatch takes a per-target lock — the live control-socket send and the dormant cell's spawn-bg resume alike, even though spawn-bg is a separate relaunch transport; mailbox and native-push are lock-free, with deliverability guarded by their own receiver/probe evidence:

| target state | intent | transport |
|---|---|---|
| live pi | fire-and-forget | control-socket send |
| live pi | owned-outcome | **reject** (a live peer is not an owned spawn target) |
| dormant pi | owned-outcome | spawn-bg resume (a real `pi --entwurf-control` child) |
| dormant pi | fire-and-forget | **reject** (`dormant-fire-forget-unsupported`) |
| active self-fetch receiver | fire-and-forget | meta-mailbox enqueue + doorbell |
| inactive / terminated self-fetch receiver | fire-and-forget | **reject** (`mailbox-undeliverable` — no `.msg`, no doorbell) |
| self-fetch | owned-outcome | **reject** (no owned result over a mailbox) |
| live native-push conversation | fire-and-forget | native-push direct injection |
| dead / indeterminate native-push conversation | fire-and-forget | **reject** (`native-push-target-dead` / `native-push-probe-indeterminate`) |
| native-push | owned-outcome | **reject** (`native-push-no-resume-authority`) |
| record-less control socket (no meta-record) | any | **reject** (`record-less-socket` — pre-probe; diagnostic state, #50 C4) |

**`entwurf_v2` is the canonical surface for garden-id delivery.** When you have a garden id and want to reach whoever it names — message, reply, or hand-off — `entwurf_v2` is the one surface that reads whether the target is live pi, dormant pi, mailbox-backed Claude Code, or native-push Antigravity and routes correctly; *when unsure which transport, use `entwurf_v2`*. This prevents callers from guessing a rail from the shape of an id.

What v2 provides is a **deterministic dispatch substrate** that moves the "which transport?" decision out of the fallible caller/model and into the decider, with transport-appropriate locking and an honest reject (no `✓ delivered`, no `.msg` garbage) when a target cannot receive. What it does **not** do is **fresh sibling creation** — minting a brand-new sibling from a provider/model/prompt is a deferred lane (the `dormant pi → spawn-bg resume` row above resumes an *already-identified* citizen, it does not mint one). The meta-mailbox row requires an **active** self-fetch receiver; native-push requires a record-backed, probe-alive native conversation and never borrows mailbox state. Claude↔Claude / Claude tmux-live transport is a later lane (the contract enum names `tmux-live` but no production path executes it).

A live pi target is *reached* over its control socket, but the socket is dispatch-internal transport, never identity (#50 C4). A control socket that no meta-record claims — a pre-record-era resident, an unreadable store, or a stale/planted file — is refused for **every** intent as `record-less-socket`, and the reject names the fix (restart the resident so `session_start` births its record, or quiesce and run the fresh-cut). `entwurf_peers` reports the same state as an aggregated `record-less-socket` diagnostic rather than a peer row.

> **Direction.** An Entwurf core (peer identity / garden id / inbox / liveness / dispatch / replyability / evidence) could later extract into its own repo with per-backend plugins; today this repo holds the v2 core + meta-bridge + ACP plugin together. ACP is one plugin, not the boundary — rationale: [#38](https://github.com/junghan0611/entwurf/issues/38).

### Garden launcher

A `--entwurf-control` session needs **no special launcher** (#50 C2): pi mints its own session id (a `uuidv7` is normal), and `session_start` attaches the session to its meta-record — the record mints the garden id, keys the control socket on it, and `PI_SESSION_ID` carries that garden address to every MCP child. The old `--session-id "$(run.sh new-session-id)"` injection contract (and the header-id guard it fed) is gone; `run.sh new-session-id` survives only as the garden-id generator the record layer itself uses. Launch is simply:

```bash
pi --entwurf-control
```

**Resuming an existing garden session.** Addressing is record-only: `entwurf_v2` with `intent: owned-outcome` resumes a dormant record-backed citizen via spawn-bg (`--session <transcriptPath>` under the hood, resolved from the record — never a header scan). Operators re-opening a session by hand use pi's own `--session` picker; the reopened session re-attaches to the same record (same garden id) at `session_start`.

**Starting a new session in-process — pi's own `/new`.** Since the #50 C2 cut there is nothing to replace it with: `/new`, `/fork`, `/clone` and RPC session replacement are pi's again. The replacement session fires `session_start`, which upserts its own meta-record and rebinds the control socket to that record's garden id; the old socket is dropped. pi's session id (a uuidv7) is recorded as the citizen's `nativeSessionId` and is never an address. Gate: `run.sh smoke-resident-garden-guard` REPLACEMENT section (0-token RPC E2E).

## Context carriers

System / developer carriers and rich pi context are separate.

The carrier holds an optional short operator engraving; empty or missing is fine. The runtime default is the bundled `pi-extensions/lib/acp/prompts/engraving.md` (the `# Engraving Here` placeholder, pinned non-empty by a gate); [`prompts/engraving.md`](./prompts/engraving.md) is a documented sample you copy and point the runtime at with `ENTWURF_ACP_ENGRAVING_PATH=/path/to/alt.md`. Template variables: `{{backend}}`, `{{mcp_servers}}`. Do not put AGENTS.md, bridge narrative, or tool catalogs here — large Claude carriers can route OAuth sessions to metered "extra usage" billing.

Your file's own leading and trailing whitespace is trimmed, and the loader then opens the carrier with one blank line. That boundary is not cosmetic: the Claude Agent SDK prefixes its own fixed identity sentence and concatenates the carrier onto it with nothing in between, so without it the engraving's first line reads as the tail of the SDK's sentence (measured 2026-07-31 as `You are a Claude agent, built on Anthropic's Claude Agent SDK.# Engraving Here`). Do not try to supply the boundary from inside the markdown — it is trimmed away before it reaches the wire.

Bridge identity, pi context, `~/AGENTS.md`, `cwd/AGENTS.md`, and date/cwd ride a one-shot first-user prepend (`pi-context-augment.ts`). Entwurf prompts already carry `cwd/AGENTS.md` inside `<project-context ...>`; the augment removes that duplicate. The augment describes capabilities, but the **actual callable schema remains source of truth** — `read` vs `Read` vs `exec_command`, MCP only when schema-visible.

## Compaction policy

**entwurf does not implement compaction.** When a backend compacts natively, the pi session and mapping survive that. The bridge exposes no backend-specific compaction knobs; operators who need to alter a backend's auto-compaction configure that backend through its own native interface. Do not rely on a pi-side JSONL summary to reduce a backend transcript — it does not.

The footer uses ACP `usage_update.used / size` (backend prompt/tools/cache/session included) with `[entwurf:usage]` diagnostics. Near limit, choose a visible action: clear, open a new session with a different model, or let the backend compact on its own.

## What this repo owns, and does not

Owns: provider registration (`entwurf/...`), ACP subprocess lifecycle + `resume > load > new`, prompt forwarding + ACP event mapping, the bridge surface that exposes pi capabilities such as entwurf to ACP-backed sessions, pi-facing MCP injection via `entwurfProvider.mcpServers`, and bridge-local cleanup and diagnostics.

Does not: reconstruct full history, hydrate backend transcripts into pi history, emulate Claude Code or Codex, run broad multi-agent orchestration (entwurf is narrow, registry-gated, identity-locked), or run a second session model competing with pi.

Only `pi:<sessionId>` mappings are persisted (`~/.pi/agent/cache/entwurf/sessions/`) — enough to re-attach pi to the same remote ACP session, never enough to act as a second harness. Backend stores (`~/.claude/`, `~/.codex/`) are interoperability side effects, not authority.

This repo also doubles as the maintainer's working laboratory for agent-harness boundaries — new workflow patterns (e.g. Mitsein over MCP) land here first as low-level instruments, before crystallizing into invariants or graduating into more polished surfaces elsewhere.

## Verification surfaces

- **[VERIFY.md](./VERIFY.md)** — agent-driven. One ACP-bridged identity runs the script against another and records what it sees. Carries the Evidence Levels L0–L5 rung ladder and the Claims Ledger so each claim is parked at the rung it has actually reached, and owns the deterministic-floor kill-proof protocol (gate qualification and its `[QK:<claim>]` coordinates).
- **[BASELINE.md](./BASELINE.md)** — operator-driven. The maintainer runs the interview directly (no agent in the verifier seat) and the result is recorded.
- **[DELIVERY.md](./DELIVERY.md)** — capability-coordinate. The cross-harness yardstick for one question: can an already-running native session receive an async message without pretending pi owns the backend transcript? Records the per-backend async-delivery level (`D0–D8`) each harness actually reaches instead of collapsing into works/doesn't.

VERIFY + BASELINE are the verification pair — use both; either one alone leaves a blind spot the other closes. DELIVERY sits on the orthogonal delivery-capability axis.

## References

- File map + code-level invariants: [AGENTS.md](./AGENTS.md)
- Current priority + open decisions: [NEXT.md](https://github.com/junghan0611/entwurf/blob/main/NEXT.md)
- Release record: [CHANGELOG.md](./CHANGELOG.md)
- [xenodium/agent-shell](https://github.com/xenodium/agent-shell) — Emacs ACP client, `resume > load > new` idea origin
- [agentclientprotocol/claude-agent-acp](https://github.com/agentclientprotocol/claude-agent-acp) — canonical ACP server for Claude Code
- [agent-config](https://github.com/junghan0611/agent-config) — real consumer repo

## License

MIT