CoreStory vs Swimm

CoreStory

CoreStory targets large, old codebases that no single engineer fully understands any more, and its MCP and API hook gives coding agents real architectural context instead of only the files in view. A free Discover tier now lets an individual developer ingest a codebase and try it, but the Pro tier and every price are behind a sales conversation, so budgeting for team use means talking to the vendor first.

Pros

• +Persistent model of architecture, workflows and business rules instead of per-session context
• +Exposes that context to AI coding agents through MCP and an API
• +Generates diagrams, technical user stories and API specs directly from source
• +Free-forever Discover tier to test on a real codebase

Cons

• −No public prices; CIU usage is hard to estimate before a sales conversation
• −Free tier limits exports and sharing of generated documentation
• −The site shows mixed signals, with a waitlist page for a free individual plan alongside a live free-start sign-up

Swimm

Swimm is the rare documentation tool that treats old code as the source of truth instead of asking humans to describe it. If you are staring at a COBOL or .NET estate nobody understands, the flow maps and extracted business rules are the useful part. The catch is that it is no longer a tool you can simply buy: it is a staged engagement with engineers attached, and the self-serve documentation product it was known for is not what the site sells today.

Pros

• +Deterministic static analysis backs the AI output, so traces come from the code rather than a guess
• +Produces diagrams and flow maps, not only prose
• +Covers mainframe and COBOL alongside .NET and Java
• +Work is broken into fixed-price stages you can stop after

Cons

• −No pricing published anywhere on the site
• −Repositioned away from the continuous-documentation product it was known for
• −Aimed at large estates, which makes it overkill for a normal repository

Does CoreStory or Swimm have a free tier?

CoreStory has a free tier; Swimm prices on request.

Which has a public API, CoreStory or Swimm?

CoreStory ships a public API, as of our last verification. A public API for Swimm is not confirmed by us — check its developer docs before you plan an integration.