Architecture

The architecture changes. The execution boundary does not.

StreamKernel fits between the systems that evaluate or recommend and the systems that act or commit. It governs that transition without replacing your decision engine, transport, or protected system.

Architecture level 1 · Your environment

Start with where a proposed action becomes real.

Kafka, REST, MQ, payment switches, agent frameworks, models, and vendor platforms can all sit around this boundary. StreamKernel is transport- and vendor-agnostic; Kafka is one supported integration pattern, not a prerequisite.

Existing decision system Evaluate · score · recommend Fraud engine · agent · model · rules · application
StreamKernel governed execution boundary Policy → Authority → Control → Execution → Evidence Fail closed before downstream action
Protected system Act · commit · deliver API · payment · case platform · database · enterprise app

Architecture level 2 · Runtime implementation

How StreamKernel implements the boundary.

The customer architecture comes first. Inside the boundary, a compact plugin-based runtime keeps policy, transforms, provenance, delivery, and failure handling inspectable.

StreamKernel governed event execution runtime
Sources Kafka, Pulsar, OTel StreamKernel Execution policy + provenance + cost control Policy enforce / deny Execute ONNX + cache provenance labels Sinks Kafka, MongoDB Postgres + pgvector DLQ deny + failure path Metrics Prometheus / OTel / MCP MLflow promotion / rollback

Runtime narrative

Source Plugin -> Core Orchestrator -> Policy Plugin -> Transformer Chain -> Sink Plugin.

Deny and failure paths flow to DLQ, while Prometheus and OpenTelemetry metrics are emitted across kernel, transform, and sink. MLflow model registry support can promote or roll back artifacts into the transform path, and sink plugins cover Kafka, MongoDB Vector, Postgres, PostgreSQL pgvector, Delta Lake, Snowflake, and custom targets.

Single-process operational boundary

Keep critical runtime behavior inside one JVM process.

Config-driven pipelines

Use .properties files to define pipeline behavior.

Plugin-owned extensibility

Let customers or authors bring plugins without giving up kernel control.

Policy at execution time

Enforce policy, provenance, and cost controls while the event is executing, before sink delivery or action.

Evidence-first runtime

Emit logs, metrics, settings, and replay metadata.

Commercial AI boundary

Keep protected AI implementation details outside public source.

Plugin model

Customers can bring plugins without giving up kernel control.

Source, policy, transform, sink, metrics, AI, OpenTelemetry, and MCP paths are extensible at the edge while the runtime preserves the auditable execution envelope. Postgres and PostgreSQL pgvector are first-class sink targets alongside Kafka, MongoDB Vector, Delta Lake, and Snowflake.

Runtime signals

  • Effective settings and replay metadata.
  • Per-batch policy outcomes and audit headers.
  • Transform, sink, DLQ, and kernel metrics exported through Prometheus and OpenTelemetry.
  • Model/version labels for AI-enriched records.
  • Opt-in MCP JSON-RPC tools for local agent status, config validation, audit verification, and guarded model lifecycle operations.

Commercial path

Need to map StreamKernel into your platform architecture?

Review the runtime boundary, plugin model, policy path, and commercial packaging options with the team.