pr_01m47d15m3e54sn21z27rpy5n9/services/models/src/index.ts
| 1 | /** |
| 2 | * The model proxy: every model request a g1t sandbox makes comes through |
| 3 | * here, at `https://models.g1t.sh/anthropic`. |
| 4 | * |
| 5 | * A sandbox holds a token for its one run, never a key. The proxy looks the |
| 6 | * token up and forwards the request with the credentials for that run: |
| 7 | * g1t's AI Gateway when g1t pays, or the workspace's own Anthropic key or |
| 8 | * endpoint when the workspace does. So a sandbox that is tricked into |
| 9 | * printing its environment gives away a token that stops working when the |
| 10 | * run ends, and nothing of the workspace's. |
| 11 | * |
| 12 | * Responses stream through untouched. |
| 13 | */ |
| 14 | import { type ModelUpstream, type ServiceBinding, integrationsClient } from "@g1t/contracts"; |
| 15 | |
| 16 | import { type HostedRouting, presentedToken, upstreamRequest } from "./route"; |
| 17 | |
| 18 | interface Env extends HostedRouting { |
| 19 | INTEGRATIONS: ServiceBinding; |
| 20 | } |
| 21 | |
| 22 | /** How long a looked-up token is trusted before it is looked up again. */ |
| 23 | const REMEMBER_MS = 60_000; |
| 24 | const remembered = new Map<string, { upstream: ModelUpstream | null; until: number }>(); |
| 25 | |
| 26 | async function lookUp(env: Env, token: string): Promise<ModelUpstream | null> { |
| 27 | const now = Date.now(); |
| 28 | const hit = remembered.get(token); |
| 29 | if (hit && hit.until > now) return hit.upstream; |
| 30 | const upstream = await integrationsClient(env.INTEGRATIONS).modelUpstream(token); |
| 31 | if (remembered.size > 5_000) remembered.clear(); |
| 32 | remembered.set(token, { upstream, until: now + REMEMBER_MS }); |
| 33 | return upstream; |
| 34 | } |
| 35 | |
| 36 | /** An error in the shape Anthropic's API uses, which the harness understands. */ |
| 37 | function refuse(status: number, message: string): Response { |
| 38 | return Response.json( |
| 39 | { type: "error", error: { type: status === 401 ? "authentication_error" : "not_found_error", message } }, |
| 40 | { status }, |
| 41 | ); |
| 42 | } |
| 43 | |
| 44 | export default { |
| 45 | async fetch(request: Request, env: Env): Promise<Response> { |
| 46 | const url = new URL(request.url); |
| 47 | if (url.pathname === "/" || url.pathname === "") { |
| 48 | return new Response("g1t's model proxy, for g1t's sandboxes. See https://docs.g1t.sh/guides/models/\n"); |
| 49 | } |
| 50 | if (!url.pathname.startsWith("/anthropic/")) return refuse(404, "Requests go to /anthropic/v1/…."); |
| 51 | const token = presentedToken(request.headers); |
| 52 | if (!token?.startsWith("g1tm_")) return refuse(401, "This needs a g1t run's model token."); |
| 53 | const upstream = await lookUp(env, token); |
| 54 | if (!upstream) return refuse(401, "This run's model token has expired, or its model connection was removed."); |
| 55 | |
| 56 | const path = url.pathname.slice("/anthropic".length) + url.search; |
| 57 | const { url: target, headers } = upstreamRequest(upstream, env, path, request.headers); |
| 58 | return fetch(target, { |
| 59 | method: request.method, |
| 60 | headers, |
| 61 | body: request.method === "GET" || request.method === "HEAD" ? undefined : request.body, |
| 62 | }); |
| 63 | }, |
| 64 | } satisfies ExportedHandler<Env>; |