# AGENTS.md
## Project purpose
Casper devnet launcher in Rust. It is heavily influenced by the NCTL workflow but targets smart contract developers and CI, with a single command to start a local devnet and a self-managed process lifecycle.
## Core workflows
- `casper-devnet assets add <path>`: install a local `.tar.gz` bundle into the assets store.
- `casper-devnet assets pull [--target] [--force]`: download bundles from the latest GitHub release, verify `.sha512`, compare `manifest.json`, update local assets, and write `assets/latest` with the release tag.
- `casper-devnet assets list`: list installed protocol versions (newest first).
- `casper-devnet start [--protocol-version <ver>]`: start devnet. Defaults to newest bundle version. Logs “resuming…” if assets already exist and `--force-setup` is not used.
## Assets layout
- Platform data dir (via `directories` crate):
- `.../assets/` stores bundles: `v{version}/...`
- `.../networks/<network>/...` stores runtime assets
- Bundle contents (required):
- `vX.Y.Z/bin/casper-node`
- `vX.Y.Z/bin/casper-sidecar`
- `vX.Y.Z/chainspec.toml`
- `vX.Y.Z/node-config.toml`
- `vX.Y.Z/sidecar-config.toml`
- `vX.Y.Z/manifest.json` (used to compare updates)
## State persistence
- Runtime state is stored at `networks/<network>/state.json`.
- JSON uses `time::serde::rfc3339` for `OffsetDateTime` timestamps.
## Process control
- casper-node runs via the embedded launcher state machine.
- casper-sidecar runs as a tokio child process.
- Signals are sent directly to PIDs (no process groups).
## Logging and SSE
- SSE logs are timestamp-prefixed (no node id).
- Child `RUST_LOG` is set from `--loglevel` (default `info`).
- Node config logging format uses `--node-log-format` (default `json`).
## Non-goals and removals
- No external `casper-node-launcher` binary.
- No `--hash`/trusted hash support.
- No `--chainspec-path` / `--config-path` overrides.
- No URLs for `assets add` (local files only).
## Key files
- `src/assets.rs`: bundle handling, asset generation, hashes
- `src/cli.rs`: CLI flows and UX
- `src/process.rs`: process lifecycle
- `src/node_launcher.rs` + `src/node_launcher/`: embedded launcher logic
## Conventions
- Use `tokio::fs` for IO and `spawn_blocking` for CPU/TOML operations.
- Prefer concise user-facing logs.
- Default target for assets is the build target (from `build.rs`).
- Keep `README.md` updated with CLI defaults/flags whenever code changes.
