Add fast-jev-compaction extension — Jev System One compaction hook (session_before_compact): prunes stale tool calls/results, keeps user/assistant text verbatim

extensions/fast-jev-compaction/src/client.ts

@@ -0,0 +1,43 @@
+import { buildJevRequest, parseJevResponse } from './request.js';
+import type { JevAsker, JevQuestions, JevResponse, JevState } from './types.js';
+
+export interface JevClientOptions {
+  /** Defaults to `process.env.TYPESAFE_API_KEY`. */
+  apiKey?: string;
+  /** Defaults to `jev-latest`. */
+  model?: string;
+  /** Defaults to the System One endpoint. */
+  baseUrl?: string;
+  /** Defaults to the global `fetch`. */
+  fetch?: typeof fetch;
+}
+
+/** Asks Jev over HTTP with the global `fetch` (or an injected one). */
+export class JevClient implements JevAsker {
+  private readonly apiKey: string;
+  private readonly model: string | undefined;
+  private readonly baseUrl: string | undefined;
+  private readonly fetcher: typeof fetch;
+
+  constructor(options: JevClientOptions = {}) {
+    this.apiKey = options.apiKey ?? process.env.TYPESAFE_API_KEY ?? '';
+    this.model = options.model;
+    this.baseUrl = options.baseUrl;
+    this.fetcher = options.fetch ?? fetch;
+  }
+
+  async ask(state: JevState, questions: JevQuestions): Promise<JevResponse> {
+    if (!this.apiKey) throw new Error('TYPESAFE_API_KEY is not configured');
+    const request = buildJevRequest(
+      { apiKey: this.apiKey, model: this.model, baseUrl: this.baseUrl },
+      state,
+      questions,
+    );
+    const response = await this.fetcher(request.url, {
+      method: request.method,
+      headers: request.headers,
+      body: request.body,
+    });
+    return parseJevResponse(response.status, response.ok, await response.text());
+  }
+}