Streaming Agents
Run LLM-powered agents on your Kafka streams — process each record with a model and tools, validate against a schema, and write results back to a topic
A streaming agent is a Streamkap resource type alongside sources, destinations, pipelines, and transforms. It reads records from a Kafka topic, runs each one through an LLM (optionally calling tools), validates the result against a schema you declare, and writes the output to another topic. Records it can’t process are routed to a dead-letter topic.
Agents are independent of sources and destinations. They bind to a Kafka topic, whichever way that topic was produced: by a source connector, a transform, another agent, or your own producer. Use them to classify, enrich, redact, or summarize streaming records in real time without hand-building a Kafka consumer and an LLM loop.
How It Works
- An agent consumes records from one input Kafka topic.
- For each record, it calls your chosen LLM with your system prompt and the record as input.
- If the agent has tools, the model can call them and feed the results back to itself, looping until it produces a final answer (up to a maximum number of steps).
- The response is validated against your optional output schema and written to the output topic.
- Records that can’t be processed — schema mismatch, tool failure, or unparseable output — are routed to a dead-letter topic (
dlq.<output-topic>).
Every LLM and tool call runs on your own credentials — you bring an LLM connection (your provider API key), and all model usage is billed by your provider. Where available, Streamkap also provides managed default connections (an LLM and a vector store) so you can try your first agent without any keys — they’re for quick tests, not production data. See Streamkap Default Connections.
Where to Find It
Streaming Agents is a project-level feature. Open Agentic (Beta) in the project sidebar to reach it. The section is organized into tabs:
| Tab | What it’s for |
|---|---|
| Overview | Fleet health, recent activity, and a setup checklist for your first agent |
| Agents | Create, deploy, and manage agents — see Build an Agent and Manage Agents |
| Knowledge Bases | Streaming embedding pipelines for retrieval — see Knowledge Bases |
| Observability | Traces, tool calls, and logs — see Observability |
| Connections | Shared LLM, MCP, HTTP, and vector store credentials — see Connections |
| Query Playground | Ad-hoc SQL over your Kafka topics to inspect data before building an agent — see Query Playground |
Key Concepts
- Agent — a deployed job that processes one input topic. Agents come in two shapes, selected automatically from whether you add tools:
- Workflow — no tools; a single LLM pass per record (classify, summarize, redact).
- ReAct — one or more tools; the model reasons, calls a tool, feeds the result back, and repeats until it produces an answer.
- Connection — a saved, encrypted credential shared across every agent in your organization: an LLM provider, an external MCP server, an HTTP endpoint, or a vector store. See Connections.
- Tool — something the model can call during a run: an HTTP request, a Script (JavaScript or Python), an External MCP server, or Streamkap MCP (the agent operating your Streamkap platform).
- Knowledge Base — a streaming pipeline that embeds a Kafka topic into a vector store so agents can retrieve from live data. See Knowledge Bases.
- Memory — optional short-term (time-boxed) and long-term (vector store) context carried across records.
- Dead-letter topic (DLQ) — where unprocessable records land, derived as
dlq.<output-topic>.
Permissions
Access is controlled by two permissions on your Streamkap roles:
| Permission | Grants |
|---|---|
read:agents |
View the Agentic section, agents, knowledge bases, observability traces and tool calls, and connections (secrets stay masked) |
write:agents |
Create, edit, deploy, and manage agents and knowledge bases; save connections; view logs; run knowledge base retrieval |
The sidebar entry is hidden if you don’t have read:agents. Read-only users can view the screens but write actions are disabled. If you don’t see the feature or an action, ask an admin for the appropriate permission.
Limits
| Limit | Value |
|---|---|
| Input topics per agent | 1 |
| Knowledge bases attached per agent | 10 |
| Max reasoning steps (ReAct) | 25 |
| Custom instructions | 8,000 characters |
| Filter SQL | 4,000 characters |
| Config versions retained | 50 per agent |
| Preview run | 15 seconds, one record |
Next Steps
Connections
Set up the LLM, MCP, HTTP, and vector store credentials agents use.
Build an Agent
Walk through the deploy wizard, preview a run, and go live.
Manage Agents
Lifecycle, savepoints and offsets, config history, and the DLQ.
Knowledge Bases
Stream a topic into a vector store for retrieval.
Observability
Traces, tool calls, logs, and the query playground.