# Caching, Retries, and Failure Semantics

## GET lifecycle

1. Build full URL from `baseUrl`, `path`, and query params.
2. Check cache by full URL.
3. Fetch with auth headers and timeout on cache miss.
4. Retry network errors, timeout errors, `429`, and `5xx`.
5. Parse JSON.
6. Throw `SocialhoseError` for unsupported non-OK responses.
7. Store successful parsed response in cache.

## POST lifecycle

1. Build URL.
2. Fetch JSON body with auth headers and timeout.
3. Retry network errors, timeout errors, `429`, and `5xx`.
4. Parse JSON.
5. Return `{ status, data }`.
6. Never cache.

## Retry policy

Defaults:

```ts
retries: 3,
retryDelayMs: (attempt) => 400 * 2 ** attempt + Math.random() * 200,
timeoutMs: 8_000,
```

Retries apply to transient conditions only:

- network failures
- SDK timeout/abort failures
- `429 Too Many Requests`
- `5xx` server errors

Retries do not apply to normal client errors such as `400`, `401`, `403`, and `404`.

## Cache contract

```ts
interface Cache {
  get(key: string): Promise<unknown | undefined>;
  set(key: string, value: unknown, ttlMs: number): Promise<void>;
  delete(key: string): Promise<void>;
}
```

The cache key is the full request URL. `ttlMs` is in milliseconds and comes from `cacheTtlMs` or per-request `revalidateSeconds`.

## Redis-style cache example

```ts
import { SocialhoseClient, type Cache } from '@socialhose/api';

class RedisJsonCache implements Cache {
  constructor(private redis: {
    get(k: string): Promise<string | null>;
    set(k: string, v: string, mode: 'PX', ttl: number): Promise<unknown>;
    del(k: string): Promise<unknown>;
  }) {}

  async get(key: string) {
    const value = await this.redis.get(key);
    return value == null ? undefined : JSON.parse(value);
  }

  async set(key: string, value: unknown, ttlMs: number) {
    if (ttlMs <= 0) return;
    await this.redis.set(key, JSON.stringify(value), 'PX', ttlMs);
  }

  async delete(key: string) {
    await this.redis.del(key);
  }
}

const socialhose = new SocialhoseClient({
  apiKey: process.env.SOCIALHOSE_API_KEY!,
  cache: new RedisJsonCache(redis),
});
```

## Method failure semantics

Campaign, analytics, mention, and list methods:

- Throw `SocialhoseError` after retry exhaustion or unsupported non-OK responses.
- Return normalized arrays when the API wraps arrays in properties such as `series`, `platforms`, or `keywords`.

`inviteMailingListMember()`:

- `201 + status: invited` -> `outcome: 'invited'`.
- `409` -> `outcome: 'already'`.
- Unexpected success/conflict shapes -> `outcome: 'error'`.
- Other non-OK statuses throw.

Entity methods:

- `getEntityBrief()` throws if the mention search fails.
- `getEntityStats()` requires the initial brief but treats later subrequests as best-effort.
- `getEntityBriefs()` skips failed terms and returns successful entries.