mail-address-semantics/SCOPE.md

# SCOPE

## One-liner

Reference implementation and spec workbench for Mail Address Semantics
(MAS), and the email building block for a future multimodal communication
framework. Contents: parser, statute discovery, pure policy, generator,
CLI, mail gateway, reference ticket service, a tested Postfix integration
profile, and the mode contract with an email side that works as master or
slave. It implements address spec v0.1.1 and v0.2 (final), and mode
contract v0.1 (draft). A second, independent implementation in
JavaScript (`impl/js/`) validates v0.2 and the master side of the mode
contract.

## Core Idea

Test whether ordinary email addresses can carry limited, parseable
semantics (opaque targets, `type=id` resources, `+` facets, `!`
interaction preferences) through real mail infrastructure, without
changing SMTP and without making addresses credentials or commands
(INTENT.md). The architectural boundary is fixed: the parser does no I/O,
policy is pure, only `mas_core/discovery.py` touches the network, and
delivery stays external.

## In Scope

- **Normative bundles.** `mas-v0.1-spec/` (v0.1.1 errata) and
  `mas-v0.2-spec/` (final 2026-10-19: stand-ins, destination transforms,
  `resource_id_case`). Spec changes go through
  `docs/spec-change-proposals.md`.
- **`impl/js/`.** The second implementation: parser, statute-aware rules,
  signing, outside master. Zero dependencies; `tests/test_js_impl.py` and
  the differential test `tests/test_differential.py` run it when Node is
  available.
- **`mas_core`.** Parser, model, statute validation and lint, exact-host
  discovery with explicit `inherits`, policy, and the generator with v0.2
  destination transforms.
- **`mas_conformance`.** Address, property, statute and v0.2
  statute-aware corpora, vendored unchanged from the bundles and checked
  for drift.
- **`mas` CLI.** `parse`, `explain`, `discover`, `compose`,
  `lint-statute`, `test`.
- **`mas_gateway`.** MTA `pipe` and provider-style `webhook` to a
  normalized HTTP event. It reads sender authentication only from trusted
  `Authentication-Results`.
- **Examples.** A static statute and the reference ticket service: create,
  correlate by address, closed lifecycle, quarantine, a DMARC-gated reply,
  and a lifetime send cap.
- **MTA integration.** `integrations/postfix/` (profile plus README),
  tested against a real Postfix by `experiments/postfix-probe/` and
  `tests/test_postfix_profile.py` (needs Docker). Exim: notes only
  (`integrations/exim/NOTES.md`).
- **Mode reference implementation** (INTENT.md, *Mode reference
  implementation*). `mas-modes-v0.1-spec/` is a language-neutral contract
  (handoffs, statuses, timeouts, master/slave roles, outside-master
  commands) with JSON schemas, including the gateway event, and
  conformance flows. `mas_modes/` holds the email side in both roles
  (master per resource type over the ticket service, or slave to an
  outside master that issues case ids), a scripted callback stub, a stub
  outside master and the flow runner. Email is the only real channel. See
  `docs/reuse-surface.md`.
- **Live test environment.** `deploy/railiance/`: the MX for
  `mas.coulomb.social`, with replies through Scaleway TEM capped at 300.
  It is temporary; MAS-WP-0007 retires it.

## Out of Scope

- Real non-email modes (telephony, chat, SMS, video), connectors to real
  CMS or ticketing products, and the multimodal framework itself. Other
  modes exist here only as contract-speaking test stubs.
- Further language implementations beyond `impl/js/`, and `impl/js/` as
  a published package.
- Postfix policy daemon, Exim profile (until there is demand), mail-client
  plugins and inspectors, browser extensions, a web composer.
- Central MAS registry, signed statutes, implicit parent-domain
  inheritance, production identity federation.
- P3 economic semantics: `$` and `^` stay reserved. Also payments,
  signatures and marketplaces.
- Application business logic in the gateway. Production ticketing. Sender
  policy beyond what the reference service needs to avoid backscatter.
- Irreversible operational actions (cluster teardown, key revocation,
  redeploys) without founder approval.

## Current State

- Status: active. The reference experiment (MAS-WP-0002) passed its
  decision gate on 2026-10-18; the findings are in
  `docs/experiment-review.md`.
- Finished: MAS-WP-0001 to 0006 and 0008 to 0013. That covers v0.2,
  which is final; the mode contract with authentication, one outbound
  path and harness-independent flows; and the second implementation. Postfix profile, v0.1.1
  errata, v0.2 draft, address composer, v0.2 conformance cases, and the
  mode contract with its reference implementation.
- Open: MAS-WP-0007 (retire the live MX; backlog, kept by decision) and
  MAS-WP-0014 (finalize mode contract v0.1; waits for an independent email
  side).
- v0.2 is final (founder, 2026-10-19, after MAS-WP-0009). Mode contract
  v0.1 stays a draft.
- P2 is decided: `!MODE` requests a handoff (founder, 2026-10-19; SCP-8,
  v0.2 §7.1). The mode contract v0.1 draft and the reference
  implementation are done (MAS-WP-0010); `mas test` runs the contract
  corpus.
- The live MX runs image `mas-live:v0.2-a95f848` (redeployed 2026-10-19)
  and is kept up by founder decision (MAS-WP-0007 stays in backlog).
  The deployment with MAS-WP-0012 (one outbound path) is recorded in
  MAS-WP-0007.
- Tests: `.venv/bin/pytest` runs 274 tests, offline apart from loopback
  fixtures, the Docker probe and Node for `impl/js/`. `mas test` runs
  four corpora: parser 64, statute 16, v0.2 statute-aware 33, mode
  contract 195. `cd impl/js && node --test` runs 85 more.
- Assessments: `history/` (latest: `2026-10-19T090725Z-scope-vs-intent.md`).

## Getting Oriented

- Start with: INTENT.md, then `docs/experiment-review.md` and
  `docs/reuse-surface.md`
- Agent instructions: AGENTS.md
- Workplans: workplans/