---
model: claude-opus-5
service: claude
session: 7b9c97c4-fff7-4ac4-97fb-35720453308e
timestamp: 2026-08-13T00:11:02Z
git_ref: 27c34aebb615c30d4039fa399f4ce2766ed7ba2c
scope: code
substantive: true
raw_file: 20260813T001102Z_27c34aeb_prompt_io.raw.md
---

## Prompt

> draft hyper detailed implementation plans for [three]
> prospective new transport (tpt) backends for tractor's `.ipc`
> layer, from four GitHub issues: TIPC (gh #378) using built-in
> linux socket API w/ `trio` interfacing, leveraging TIPC's
> built-in discovery machinery; QUIC (gh #353) using the `iroh`
> lib, ideally with the py asyncio support (via ffi) rewritten
> for trio; wg (gh #482 and/or #443) with other shuttle-able
> tpts, using `pyroute2`, as much trio wrapping as possible
> where any other async support can be replaced.

With constraints: "be only slightly speculative"; realistic given
the linked info; the plans must be workable "by another
model/provider without much discrepancy on the design or lib
selections needed"; do it all in a new `/open-wkt` off main; and
be "as modular and modern-async-python-as-nearly-functional-style
as possible."

Key follow-up prompts that changed the design mid-session:

> wg requires binding a socket on both ends of the tunnel, the
> new support we added to `py-multiaddr` in their #108 enables
> declaring this in the maddr? […] so the
> `/ip4/10.0.0.1/udp/666/ip4/192.168.0.13/tcp/80` bullet example
> from #443 isn't correct for a wg tunnel maddr and would
> actually end up looking like,
> `/ip4/10.0.0.1/udp/666/wg/<pub-key>/ip4/192.168.0.13/tcp/80` no?

> right, we're likely going to need less `tuple`-formed
> `UnwrappedAddress` usage to make them all work and/or to extend
> the unwrapped form with a proto-str, likely the key from
> `multiaddrs` no?

> better encapsulating `UnwrappedAddress` for use externally is
> really way overdue; we should likely be encouraging (if not
> preventing unwrapped) wrapped addrs always much like other
> (std) libs, `ipaddress` comes to mind.

> so iirc netns mgmt becomes a lower-level runtime config-api
> rather then an actor-app-code API which can be dynamically
> changed once the actor is up ya?

## Response summary

A research-and-planning branch, `ng_tpts_planning` — **no runtime
code touched**. Five plan docs under `ai/tpt-backends/` plus a
corrected `wg` example set under `examples/multihost/wg_lan/`,
across 9 commits.

Three design conclusions came out of the planning that outlive
the branch:

1. **`wg` is a bindspace, not a `MsgTransport`.** The `/wg/`
   maddr segment is *infix*: bearer (underlay ip+udp
   `ListenPort`, bound by the kernel) → `/wg/u<key>` (an
   identity, bound by nothing) → overlay (the only part tractor
   binds). Verified empirically by installing
   `baudco/py-multiaddr@wg_support` (py-multiaddr#108) in a
   throwaway venv and round-tripping each candidate form; gh
   #482's original suffix form parses but is semantically
   inverted.
2. **Proto-key the `UnwrappedAddress` form**, spelled with the
   `multiaddr` protocol names, dispatched via
   `_address_types[addr[0]]`. Kills a whole collision class
   (TIPC's `(str, int)` ≡ `TCPAddress`; iroh's `(str, str)`
   swallowed by the UDS case) and is the recommended migration
   *before* any new backend lands.
3. **netns is a runtime/boot-time config API, not an app-code
   one** — `setns(2)` is per-thread and won't move
   already-created sockets, so there is deliberately no
   `await actor.enter_netns(...)`.

Also verified that `trio.SocketStream`/`SocketListener` are
address-family agnostic (no `AF_*` check anywhere), which is what
makes TIPC the cheapest of the three backends to add.

Four related issues were annotated with the results (#378, #353,
#482, #443); #443's body was rewritten to reflect the corrected
grammar, with no existing checkbox state changed.

## Files changed

- `ai/tpt-backends/00_shared_backend_contract.md` — normative
  backend duck-type contract, registration checklist, §1.1
  proto-key conclusion
- `ai/tpt-backends/01_tipc_backend.md` — TIPC plan; service
  addressing, `TIPC_TOP_SRV` push registry, instance-collision
  hazard, step-0 probe
- `ai/tpt-backends/02_quic_iroh_backend.md` — `iroh` plan;
  `uniffi`→`trio` bridge, listener/stream adapters, API-truth
  table
- `ai/tpt-backends/03_wg_tunnel_bindspace.md` — `wg`-as-bindspace
  plan; verified maddr grammar, 3-owner split, netns reality
- `ai/tpt-backends/README.md` — index
- `examples/multihost/wg_lan/wg_maddr.py` — frozen `msgspec`
  tunnelled addr + pure parse/render helpers; impure
  `verify_wg_peer()` kept separate
- `examples/multihost/wg_lan/host_a_srv.py` — host-A actor tree
- `examples/multihost/wg_lan/host_b_client.py` — host-B dialer
- `examples/multihost/wg_lan/README.md` — grammar, owner table,
  setup, "what changed vs #482"

## Human edits

Substantial human steering rather than post-hoc editing; the
corrections were applied by the model in-session after being
challenged:

- rejected an initial claim that `wg` has "nothing to bind at the
  tunnel layer" and supplied the correct composed maddr form,
  which forced a rewrite of plan 03 §3.2 and a retraction in the
  already-posted #443 comment
- rejected a supporting claim that `/ip4/../udp/443/quic-v1` was
  "also composed"
- directed the proto-key/`ipaddress`-discipline conclusion and
  the netns-as-runtime-config framing, both of which were then
  folded back into the docs
- chose the commit boundaries and authored all commits; ran every
  `git` mutation (commit, rebase, push) themselves

One model-initiated correction pre-publication: a self-review
downgraded two overconfident claims (the `uniffi`/asyncio thesis
and TIPC duplicate-binder behaviour) to explicitly-flagged
assumptions before the #353/#378 comments were posted.
