# MoonMQ AMQP 0-9-1 Core Profile

This document is the compatibility contract for the first release. It is narrower than the entire RabbitMQ feature set and will be expanded only through a recorded design change.

## Current implemented surface

| Area | Methods / behavior |
| --- | --- |
| Framing | protocol header, method/header/body/heartbeat envelopes, `0xCE` terminator, exact-size and bounded frame validation |
| Primitives | network-byte-order `u16`/`u32`/`u64`, UTF-8 short strings, bounded arbitrary-byte long strings, exact-width and malformed-input checks |
| Methods | typed connection/channel handshake, exchange/queue topology, Basic QoS/consume/get/deliver/publish/return/ack/reject/cancel methods with field validation |
| Content | Basic class content properties, header property flags, and bounded multi-frame body assembly with exact declared-size checks |
| Broker | in-memory default/direct/fanout/topic routing, named/generated queues, push/pull delivery, prefetch, ack/reject/requeue, cancellation cleanup, exchange delete, queue unbind, idle queue delete, and owner-scoped batch acknowledgement |
| Session | portable handshake, channel lifecycle, exchange/queue declare/delete/bind/unbind, publish/content assembly, get, consume/deliver, cancel, single/multiple ack, reject, and heartbeat translation to the embedded Broker |
| Transport | native-only bounded TCP adapter on `moonbitlang/async/socket`; portable embedded/session use remains available on all targets |

## Deferred profile expansion

External-client interoperability remains a planned follow-up slice. The native adapter is covered by fragmented-stream and real local TCP handshake tests; this is not yet a claim of complete RabbitMQ client compatibility.

## Explicit non-goals

AMQP 1.0 and 0-10, persistence/recovery, replication, clustering, transactions, publisher confirms, alternate exchanges, dead-lettering, priorities, plugins, TLS, authentication/ACL, and full RabbitMQ extension compatibility are not first-release promises.

## Session limitations

- `exchange.delete` removes a named exchange and its bindings. `if-unused` rejects exchanges that still have bindings. The built-in default exchange cannot be deleted.
- `queue.unbind` removes an exact queue/exchange/routing-key binding. Its arguments table must be empty.
- `queue.delete` honors `if-unused` and `if-empty`, returns the ready-message count, and removes bindings. It is supported only when the queue has no active consumers and no unsettled deliveries. Deleting an active queue is explicitly unsupported, even when `if-unused` is false, because the portable session/native transport boundary has no cross-session consumer-cancel or delivery-invalidation notification mechanism.
- `basic.ack(multiple=true)` acknowledges only outstanding deliveries on the current channel; tag zero acknowledges all outstanding deliveries on that channel. The Broker validates the owner-scoped tag set before changing state and resumes prefetch-limited dispatch afterward.

The native profile currently accepts only `PLAIN`/`guest`/`guest` on virtual host `/`; it is a local demonstration policy, not a general authentication system. Negotiated channel and frame limits are bounded and applied to session validation and response body fragmentation. Basic content properties and the source exchange are preserved through Broker delivery and returned content frames.

## Interoperability position

The wire codec aims to be spec-driven and bounds-checked. Interoperability claims will be limited to the methods and content properties covered by tests. The embedded demo is the default verification path and requires no external broker.