WAMP Compliance

Which parts of the WAMP specification Bondy Connect implements, and where it departs from it.

Each table has two status columns. Announced is what Bondy states in the roles of its WELCOME message, which is what a client library reads to decide which features to use. Implemented is what the router actually does. The two disagree in a few places; the notes say which.

Basic Profile

Transports and serialization

Feature	Implemented	Notes
WebSocket transport	Yes
RawSocket transport (TCP and TLS)	Yes	Also over a Unix domain socket listener.
HTTP long-poll transport	Yes	JSON only. See WAMP HTTP Transports.
HTTP Server-Sent Events transport	Yes	JSON only. Bondy-specific; not part of the specification.
Batched WebSocket transport	No	Bondy accepts the batched subprotocols (wamp.2.json.batched and others) during the WebSocket handshake, but cannot decode their messages, so the session fails on the first message. Do not use them.
JSON serialization	Yes	WebSocket subprotocol wamp.2.json; RawSocket serializer 1.
MessagePack serialization	Yes	WebSocket subprotocol wamp.2.msgpack; RawSocket serializer 2.
CBOR serialization	Yes	WebSocket subprotocol wamp.2.cbor; RawSocket serializer 3.
Erlang term serialization	Yes	Bondy-specific. WebSocket subprotocol wamp.2.erl; RawSocket serializer set by wamp.serializers.erl.
BERT serialization	No	Refused on every transport, because its decoder can create atoms before the session authenticates.

See Serialization for how each serializer maps WAMP types.

Sessions and messages

Feature	Implemented	Notes
One session per transport connection	Yes	wamp.connection_lifetime accepts only session.
Closing the session and connection on a protocol error	Yes	See Protocol errors.
Validation of URIs and custom attribute keys	Yes
Agent identification	Yes

Publish/Subscribe

Feature	Implemented	Notes
Event ordering between a publisher and a subscriber	Partial	See NC1.
One subscription, and one subscription ID, shared by every subscriber to a topic	No	See NC2.

Routed RPC

Feature	Implemented	Notes
One registration, and one registration ID, shared by every callee of a procedure	No	See NC3.

Advanced Profile

Authentication

Authentication method	Implemented	Notes
anonymous	Yes	Controlled by security.allow_anonymous_user.
ticket	Yes	A ticket issued by Bondy. Supports Single Sign-on across realms.
wampcra	Yes
wamp-scram	Yes
cryptosign	Yes
cookie	Yes	Transport-level, for the HTTP transports.
trust	Yes	Bondy-specific. Accepts an existing authid without credentials; restrict it with sources.
password	Yes	Bondy-specific. Sends the password in clear text; use it only over TLS.
oauth2	Yes	Bondy-specific.
tls	No	Listed by Bondy, but has no implementation; a session that requests it is refused.

Publish/Subscribe

Feature	Announced	Implemented	Notes
Subscriber black- and whitelisting	Yes	Yes	Bondy filters on exclude and eligible (session IDs), and on exclude_authid, exclude_authrole, eligible_authid and eligible_authrole, for every subscription match policy and for retained events. An empty eligible list delivers the event to no subscriber.
Publisher exclusion	Yes	Yes	exclude_me defaults to true.
Publisher identification	Yes	Yes	disclose_me defaults to true, so the publisher's session ID is disclosed unless it opts out.
Pattern-based subscription	Yes	Yes
Event retention	Yes	Yes	See message retention.
Payload passthru mode	Yes	Yes
Session meta API	Yes	Partial	See Session meta API.
Subscription meta API	Yes	Partial	Bondy implements the wamp.subscription.* procedures and publishes the on_subscribe and on_unsubscribe events. Bondy does not publish on_create or on_delete; see NC4.
Topic reflection	Yes	Yes	The wamp.reflection.topic.* procedures.
Publication trust levels	No	No
Sharded subscription	No	No
Event history	No	No
Subscription revocation	No	No

Routed RPC

Feature	Announced	Implemented	Notes
Call timeout	Yes	Yes
Call canceling	Yes	Yes	Granted only to a session that announces it. Bondy sends INTERRUPT only to a callee that announced call_canceling; for any other callee, kill and killnowait act as skip.
Caller identification	Yes	Yes	The caller's session ID is disclosed unless both the callee's disclose_caller and the caller's disclose_me are false.
Pattern-based registration	Yes	Yes
Shared registration	Yes	Yes	Invocation policies single, roundrobin, random, first and last. When sessions on one node register a procedure with single concurrently, exactly one registration succeeds.
Progressive call results	Yes	Yes	Granted only to a session that announces it. Bondy asks a callee for progressive results only when the callee also announced call_canceling; any other callee settles the call with one final YIELD. See Dealer.
Progressive calls	Yes	Yes	Granted only to a session that announces it. Bondy routes a progressive call only to a callee that announced both progressive_call_invocations and call_canceling.
Payload passthru mode	Yes	Yes
Registration meta API	Yes	Partial	Bondy publishes on_register and on_unregister, but not on_create or on_delete. See NC4.
Session meta API	Yes	Partial	See Session meta API.
Procedure reflection	Yes	Yes	The wamp.reflection.procedure.* and wamp.reflection.error.* procedures.
Call trust levels	No	No
Call reroute	No	No
Sharded registration	No	No
Registration revocation	No	No
Testament meta API	No	No

Session meta API

Bondy announces the session meta API on both the broker and dealer roles, and implements part of it:

• wamp.session.get is implemented.
• The wamp.session.on_join and wamp.session.on_leave events are published.
• wamp.session.count, wamp.session.list, wamp.session.kill, wamp.session.kill_all, wamp.session.kill_by_authid and wamp.session.kill_by_authrole are not implemented, and fail with wamp.error.no_such_procedure.

Protocol errors

The table lists how the router replies to a message that it cannot accept. An ABORT closes the session and the connection.

Message	Reply
A frame that does not decode: invalid JSON, malformed CBOR or MessagePack, a truncated frame, or bytes after the end of the message	ABORT with reason wamp.error.protocol_violation
A frame whose payload (Arguments or ArgumentsKw) does not decode, or does not complete the message	ABORT with reason wamp.error.protocol_violation
A frame that is not a WAMP array, or whose shape matches no WAMP message	ABORT with reason wamp.error.protocol_violation
A request or session ID that is not an integer from 0 to 2^53	ABORT with reason wamp.error.protocol_violation
A field of the wrong WAMP type, such as a Details or Options that is not a dictionary, or a URI that is not a string	ABORT with reason wamp.error.protocol_violation
An option or detail with an invalid value, such as a HELLO with no roles	ABORT with reason wamp.error.protocol_violation
Over the erl serialization, a term outside the WAMP data model, such as a tuple or an improper list	ABORT with reason wamp.error.protocol_violation
A URI that is not valid under wamp.uri.strictness	ERROR with wamp.error.invalid_uri. The session stays open.

Bondy checks that the payload of every JSON and CBOR message decodes when the message arrives. A malformed payload therefore aborts the sender's session and never reaches a receiver.

Non-compliance cases

Bondy Connect is a distributed router built for continuous availability. Its nodes do not coordinate through consensus. The cases below are where the specification assumes a single router, or coordination between routers, that Bondy does not provide.

NC1

Requirement — ordering of events. If a subscriber is subscribed to two topics and a publisher publishes one event to each, the subscriber receives them in publication order. A SUBSCRIBED reply reaches the subscriber before any EVENT for that subscription.

Behaviour. When the publisher and the subscriber are connected to the same node, Bondy delivers events in order. When they are connected to different nodes, Bondy does not guarantee the order.

NC2

Requirement — shared subscriptions. A subscription is created when the first client subscribes to a topic, and every later subscriber to the same topic receives the same subscription ID.

Behaviour. Each subscriber gets its own subscription, with its own ID, even for the same topic. Sharing one subscription between subscribers on different nodes would require the nodes to agree on it, which needs coordination Bondy does not use.

NC3

Requirement — shared registrations. A registration is created when the first callee registers a procedure, and every later callee of the same procedure receives the same registration ID.

Behaviour. Each callee gets its own registration, with its own ID, even for the same procedure. The reason is the same as for NC2.

NC4

Requirement — creation and deletion meta events. The router publishes wamp.registration.on_create when a procedure gets its first registration, and wamp.registration.on_delete when it loses its last. The subscription meta API defines wamp.subscription.on_create and wamp.subscription.on_delete in the same way.

Behaviour. Bondy does not publish these four events. A cluster cannot decide which registration or subscription is the first or the last for a URI without coordinating its nodes. Each node would announce its own, and a subscriber would see a URI deleted while other nodes still serve it. Bondy publishes on_register, on_unregister, on_subscribe and on_unsubscribe for each registration and subscription instead. A client that needs to know whether a URI has registrations or subscriptions calls the wamp.registration.* or wamp.subscription.* meta procedures.