docs: add AGENTS.md with a prompt to get the viewer running

AGENTS.md

@@ -0,0 +1,55 @@
+# Agent guide
+
+Instructions for coding agents asked to run or integrate Hyper. Human readers
+should start with [README.md](README.md).
+
+## Run the viewer
+
+Requires [uv](https://docs.astral.sh/uv/getting-started/installation/) on PATH.
+No repository checkout and no Rust toolchain:
+
+```sh
+uvx --python 3.12 --from hypergraph-viz-viewer hyper
+uvx --python 3.12 --from hypergraph-viz-viewer hyper dataset.hif.json
+```
+
+`--from` is required. `hypergraph-viz` supplies the Python API and ships no
+executable; `hypergraph-viz-viewer` supplies the `hyper` command.
+
+Accepted inputs are [HIF](docs/HIF.md) and native `hypergraph.v1` JSON, detected
+automatically. `--projection bipartite|clique|star` and `--watch` are available;
+see the [viewer guide](docs/VIEWER.md).
+
+## Check before you run it
+
+- **The viewer opens a native window on the machine running the command.** It is
+  not a notebook widget, and a remote host or container cannot display on the
+  user's laptop. Without a desktop session and working graphics drivers, report
+  that constraint rather than retrying the launch.
+- Prebuilt wheels cover Linux x86_64 (glibc 2.28+), macOS arm64/x86_64 (11.0+),
+  and Windows x86_64. Other platforms build from source and need Rust 1.89+.
+- `hyper --help` and `hyper --version` parse arguments before opening a window,
+  so they are safe to run headless to confirm the install.
+
+## Use the Python API
+
+For interchange and validation, which need no desktop:
+
+```sh
+uv add hypergraph-viz
+```
+
+Add the viewer only when a window is actually wanted, with
+`uv add "hypergraph-viz[viewer]"`. The API alone has no Bevy dependency. See the
+[Python and HIF guide](docs/HIF.md).
+
+## Work in this checkout
+
+```sh
+cargo run --locked --release -- fixtures/sample.json   # native viewer
+cargo run --locked -p hyper-viz --example project_scene # headless, no window
+```
+
+The first release build can take several minutes.
+[CONTRIBUTING.md](CONTRIBUTING.md) is authoritative for the test, clippy, fmt,
+and Python checks a change must pass, and for what belongs in this repository.

README.md

@@ -16,6 +16,22 @@ groups, and explore neighborhoods with search, picking, and lasso selection.
 
 ## Try the viewer
 
+<details>
+<summary>Ask a coding agent to run it</summary>
+
+Paste this prompt into an agent working on your machine:
+
+```text
+Read https://github.com/atomicstrata/hyper/blob/main/AGENTS.md and open Hyper's
+built-in demo. Install uv first if it is not on PATH. Do not clone the
+repository or install Rust.
+```
+
+[AGENTS.md](AGENTS.md) carries the commands, the platform matrix, and the
+desktop-session constraint, so the agent does not have to infer them.
+
+</details>
+
 Install [uv](https://docs.astral.sh/uv/getting-started/installation/), then open
 the built-in coauthorship demo: