# Introduction
`bee-check` is a retrievability checker for [Ethereum Swarm](https://www.ethswarm.org/)
references — the Swarm analog of [check.ipfs.network](https://check.ipfs.network/).
You give it a 64-hex Swarm reference and one or more Bee API URLs;
it tells you whether the reference is retrievable through each Bee
node, how long retrieval took, which neighborhood each probe sits in
relative to the chunk, and — with `--per-chunk` — exactly which
chunks of the manifest are missing where.
It ships as two surfaces with identical capabilities:
- **`bee-check`** — a Rust CLI, installable from crates.io, ideal for
scripts, CI, and oncall workflows.
- **`bee-check-web`** — a static SPA at
[`ethswarm-tools.github.io/bee-check-web`](https://ethswarm-tools.github.io/bee-check-web/),
ideal for ad-hoc diagnostics and sharing a reproducible link with a
teammate.
Both speak the same `spec_version: 1` JSON report shape, so a probe
run on the CLI can be dropped onto the web page to visualize it (or
vice versa).
## Who is this for
- **Application developers** uploading to Swarm who want to confirm
their content is actually reachable from outside their own node.
- **Bee node operators** investigating "user X says they can't get
ref Y from my gateway" reports.
- **Researchers** measuring retrievability under different network
conditions or across different node fleets.
## What this book covers
- [Concepts](./concepts/index.md) — what "retrievable" actually means
in Swarm, how the stewardship probe differs from a `/bzz` download,
and what overlay / neighborhood / proximity-order numbers mean when
they show up in a report.
- [CLI guide](./cli/index.md) — install, every flag, output formats,
the re-seed flow.
- [Web UI guide](./web/index.md) — running the SPA against your own
Bee, dealing with CORS and HTTPS mixed-content, walking through the
results panel.
- [Cookbook](./cookbook/index.md) — worked scenarios: lost uploads,
feed references, re-seeding from an old batch, multi-region probes.
- [Reference](./reference/report-shape.md) — the JSON shape, exit
codes, and a feature-by-feature comparison to `check.ipfs.network`.
## Conventions used in this book
`code spans` are CLI flags, HTTP paths, or JSON keys.
> **Note** boxes flag subtle behaviors or footguns.
`bee-check`-the-CLI is referred to as just `bee-check`; the SPA is
always `bee-check-web` to avoid ambiguity.
## How to read it
If you've never used `bee-check` before, start with [Quick
start](./quick-start.md) and skim the first three Concepts pages —
that's enough to read a report. If you're triaging a specific
problem, jump to the [Cookbook](./cookbook/index.md).