# beachcomber Node.js SDK
Node.js/TypeScript client for the [beachcomber](https://github.com/NavistAu/beachcomber) shell state daemon.
**No external runtime dependencies** — pure Node.js stdlib (`net`, `fs`, `os`, `path`).
## Requirements
- Node.js 18+
- A running `comb` daemon
## Installation
```sh
npm install beachcomber
```
## Quick Start
```typescript
import { Client } from 'beachcomber';
const client = new Client();
const result = await client.get('git.branch', '/path/to/repo');
if (result.isHit) {
console.log(result.getString()); // e.g. "main"
console.log(result.ageMs); // e.g. 1234
console.log(result.stale); // false
}
```
## API
### `Client`
```typescript
const client = new Client();
const client = new Client({ socketPath: '/custom/path' });
const client = new Client({ socketPath: '/custom/path', timeoutMs: 2000 });
```
#### `client.get(key, path?)`
Read a cached value.
```typescript
const result = await client.get('git.branch', '/some/repo');
const result = await client.get('hostname'); // global provider, no path needed
const result = await client.get('git', '/some/repo'); // full provider (returns object)
```
Returns a `CombResult`.
#### `client.poke(key, path?)`
Force the daemon to recompute a provider.
```typescript
await client.poke('git', '/some/repo');
```
#### `client.list()`
List available providers.
```typescript
const providers = await client.list();
// [{ name: 'git', global: false, fields: ['branch', 'dirty', ...] }, ...]
```
#### `client.status()`
Return daemon status information.
```typescript
const status = await client.status();
```
#### `client.session()`
Open a persistent connection. More efficient when querying multiple keys
in sequence (one TCP round-trip per query instead of one connection per
query).
```typescript
const session = await client.session();
await session.setContext('/some/repo'); // optional — sets default path
const branch = await session.get('git.branch');
const dirty = await session.get('git.dirty');
await session.poke('git');
session.close();
```
### `CombResult`
| `isHit` | `boolean` | `true` when the cache had a value |
| `isMiss` | `boolean` | `true` when the cache had no value |
| `data` | `unknown` | Raw data (undefined on miss) |
| `ageMs` | `number` | Cache age in milliseconds (0 on miss) |
| `stale` | `boolean` | Whether the value is stale (false on miss) |
| `getString(field?)` | `string \| undefined` | Data as a string; picks a named field from object results |
| `getNumber(field?)` | `number \| undefined` | Data as a number |
| `getBool(field?)` | `boolean \| undefined` | Data as a boolean |
For full provider queries (e.g. `key = "git"`), the data is an object.
Use the `field` argument to pick a field:
```typescript
const result = await client.get('git', '/repo');
result.getString('branch'); // "main"
result.getBool('dirty'); // false
```
### Errors
| `DaemonNotRunning` | Socket does not exist or connection was refused |
| `ServerError` | Daemon responded with `{"ok":false,"error":"..."}` |
| `ParseError` | Response was not valid JSON or not an object |
All extend `CombError` which extends `Error`.
## Socket discovery
The socket path is resolved in this order:
1. `$XDG_RUNTIME_DIR/beachcomber/sock`
2. `$TMPDIR/beachcomber-<uid>/sock`
3. `<os.tmpdir()>/beachcomber-<uid>/sock`
Override with the `socketPath` option.
## Development
```sh
npm install
npm run build # compile to dist/
npm test # run tests with node:test
```