summarizer-agent

Summarizer Agent

This is the worker-only example in the set.

It demonstrates the smallest useful @kalamdb/consumer runConsumer() flow:

1. a row lands in blog.blogs
2. KalamDB routes the change into blog.summarizer
3. the worker consumes the topic
4. the worker writes summary back into the same row
5. failures are stored in blog.summary_failures

There is no model dependency here. The summarizer is deterministic so the example is easy to read and the test is stable.

Use change.data as the blog row inside onChange(). This example routes changes from blog.blogs, which is a SHARED table in setup.sql, so change.user is expected to be undefined here.

Quick start

1. Make sure KalamDB is running on http://127.0.0.1:2900.
2. Run npm install.
3. Run npm run setup.
4. Run npm run start.

Test it

Run npm test.

The integration test starts the agent, inserts a blog row, and waits until the summary field is written back by the worker.

Files worth reading

• src/agent.ts: full worker logic
• setup.sql: schema and topic route
• tests/summarizer.integration.test.ts: end-to-end verification