Message Broker known limits.

Known Message Broker unsupported behavior, route-level runtime boundaries, and review-required claim areas.

Current availability

Private Beta. Public beta is scheduled for October 5, 2026.

Audience

Use this page before designing broker integrations, writing migration guidance, or reviewing claims that mention Kafka, replication outcomes, auth posture, remote CLI behavior, or support boundaries.

Maturity Status

Controlled-Beta Routes

Controlled Beta

Stream, record, cursor, queue, audit, metrics, storage, and replication routes stay scoped to current controlled-beta references.

Verification Gaps

Verification Required

Kafka network compatibility, strict cross-site outcomes, identity-provider validation, and support wording remain review-bound.

Scope

Message Broker controlled-beta route families, configured auth modes, remote CLI and SDK transport limits, replication row boundaries, and Kafka-shaped prototype exclusions.

Prerequisites

Read the Message Broker route and auth compatibility matrix.
Use the HTTP reference and CLI/SDK reference for exact route and tooling behavior.

Current Limits

Message Broker known limits. current limits
Limit	Applies to	Runtime behavior	Next best path	Evidence
Kafka network listener	External Kafka clients and Kafka wire-protocol requests	There is no current Kafka network listener or external Kafka client smoke evidence. The Kafka-shaped adapter is a typed prototype, not a network endpoint.	Use the native HTTP routes, remote CLI management reads, or Rust SDK HTTP workflows documented for controlled-beta evaluation.	SMB-EVID-005, SMB-EVID-010
Replication outcomes	Cross-site durability, failover, target-environment outcomes, and topology promises	Replication status, poll, pause, resume, and target apply routes exist, but route responses alone do not prove topology outcomes.	Keep wording to route behavior and attach selected packet evidence before stronger claims.	SMB-EVID-005, SMB-EVID-008, SMB-EVID-010
Direct identity-provider validation	mTLS trust-file and trusted-header external auth modes	Protected route behavior depends on configured auth mode. External modes rely on a trusted upstream and do not prove broker-side identity-provider validation.	Use documented API-key, mTLS trust-file, or trusted-header mode wording and keep external identity claims in review.	SMB-EVID-005, SMB-EVID-008, SMB-EVID-010
Remote CLI data writes	Remote CLI over http:// targets	Remote CLI can call health, management inspection, and diagnostics routes over http:// targets; remote data writes and mTLS credentials are outside current CLI transport.	Use local CLI or documented HTTP routes for data workflows.	SMB-EVID-009, SMB-EVID-010

Unsupported Behavior

Message Broker known limits. unsupported behavior
Scenario	What happens	Recommended action
Connect an external Kafka client	No Kafka network listener is documented for the current broker.	Use native HTTP and SDK paths until a listener and client smoke evidence exist.
Treat replication status as failover proof	Status and target-apply responses are route-level evidence only.	Attach topology-specific operations evidence before publishing outcome wording.
Call protected routes without matching auth mode	Protected routes reject requests that do not satisfy the configured auth posture.	Use the HTTP reference for required permissions, headers, and mode-specific behavior.

Claims Requiring Review

Message Broker known limits. review-bound claims
Claim area	Required reviewer	Publication status
Kafka protocol compatibility	message-broker-product-sme and docs-qa-reviewer	Verification Required
Cross-site durability, recovery, or failover outcomes	operations-reviewer and message-broker-product-sme	Verification Required
Support, security, performance, or scale wording	support-reviewer, security-reviewer, and docs lead	Verification Required

Evidence

Message Broker known limits. evidence
Limit or unsupported behavior	Evidence	Status
Route and auth boundaries	DOCS-031, DOCS-040, SMB-EVID-008, and SMB-EVID-010	pending
CLI and SDK transport limits	DOCS-032 and SMB-EVID-009	pending
Message Broker limits page artifact	DOCS-042	pending

The evidence table summarizes the reviewed basis for each known limit without exposing internal source locations.

Limits

This page summarizes current Message Broker route, auth, CLI, SDK, replication, and Kafka boundaries.
Do not use route existence alone as evidence for cross-site or protocol outcomes.
Future protocol or replication claims need reviewer-accepted evidence before promotion.

Safe Next Steps

Available: DOCS-040
Compare route and auth scope
Use row status and evidence before relying on routes, auth, replication, CLI, SDK, or Kafka-shaped behavior.
Available: DOCS-031
Read HTTP reference
Check route permissions, errors, and limits for protected behavior.
Available
Review Message Broker evidence
Confirm source records before strengthening broker limits wording.