What FireMQ does not support

FireMQ aims to be honest about its gaps. If something you need is missing, open an issue on GitHub.

Not supported

Feature	Notes
Clustering and replication	FireMQ runs on one node. Leader-follower replication is on the roadmap.
Quorum queue semantics	`x-queue-type: quorum` is accepted and creates a durable classic queue. Delivery limits (`x-delivery-limit`) and replication are not implemented.
Streams	`x-queue-type: stream` is rejected. Streams are on the roadmap.
MQTT, STOMP, AMQP 1.0	Only AMQP 0-9-1 and the FireMQ protocol. MQTT is on the roadmap.
Plugins	No plugin system. Plugin exchange types (`x-delayed-message`, `x-consistent-hash`, `x-random`) are rejected with `COMMAND_INVALID`.
Federation and shovel	Not supported.
LDAP, OAuth 2, x509 client authentication	Only username and password (PLAIN, AMQPLAIN).
Topic permissions	Only configure, write and read permissions per vhost.
`immediate` publishing	Closes the connection with 540, as in RabbitMQ 3.x.
`channel.flow` with `active=false`	Rejected with 540, as in RabbitMQ.
`basic.recover` with `requeue=false`	Rejected with 540, as in RabbitMQ.
`prefetch_size` (byte-based prefetch)	Rejected with 540, as in RabbitMQ.
Consumer priorities (`x-priority` on consumers)	Accepted and ignored.
Direct reply-to (`amq.rabbitmq.reply-to`)	Not supported; use a temporary exclusive queue.
Vhost and user limits, operator policies, parameters	Not supported.
HTTPS on the management listener	Use a TLS-terminating proxy.
Management API statistics history	Rates are current only; there is no sampling history or `?lengths_age`.

Everything else in RabbitMQ's core AMQP 0-9-1 model works, including:

exchanges: direct, fanout, topic and headers (x-match all, any, all-with-x and any-with-x), exchange-to-exchange bindings, alternate exchanges, internal and auto-delete exchanges
queues: durable, exclusive, auto-delete, server-named, x-message-ttl, per-message expiration, x-expires, x-max-length, x-max-length-bytes, x-overflow (drop-head, reject-publish, reject-publish-dlx), x-dead-letter-exchange, x-dead-letter-routing-key with x-death headers, x-max-priority, x-single-active-consumer
consuming: prefetch per consumer and per channel (global), acks, nacks and rejects with requeue, basic.get, basic.recover, consumer cancel notifications
publishing: publisher confirms, mandatory returns, transactions (tx.select, tx.commit, tx.rollback)
policies, vhosts, users, permissions, definitions import and export, memory and disk alarms with connection.blocked