# Production builds

A deployable carries a small **build stamp**, not its manifest. The stamp
holds the build id, the commit, whether the tree was modified, the
compiler version, the deployable and the target. Every log event carries
it. Each fault site carries its `.jadpo` file and line as a constant, so
events already show `.jadpo` frames
([Errors point at the `.jadpo` line](errors-point-at-the-jadpo-line.md)).

- **The manifest is rebuilt, not shipped.** Builds are deterministic
  ([Tooling](tooling.md)), so `jadpo incident` builds the event's
  commit, checks that the build id matches, and caches the result.
  Nothing is uploaded or archived. `jadpo` fetches and runs the exact
  compiler version the stamp names, as `rustup` installs a pinned
  toolchain, so an old build can always be rebuilt.
- **No endpoint.** The deployed app reveals nothing about its structure.
  This also works for a worker with no HTTP surface.
- **Native and Wasm alike.** Nothing depends on debug information or
  unwinding: Rust Workers abort on panic with no stack, so the path comes
  from the runtime's own spans. On Workers the stamp is logged beside
  `CF_VERSION_METADATA`, so the platform's version and the Jadpo build can
  be joined.
- **Deploy only commits that stay in history**, on the default branch or
  a tag. A build from a modified tree is marked as such, and can be
  explained only from that exact tree.

`jadpo incident` isn't built yet ([What is built](records-and-manifest-built.md)).