g1t/services/models/src/index.ts
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| Integrations: your own model provider, alerts that open issues, tickets agents read | 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: | |
| Models per workspace: several providers, routed by kind of work | 7 | * g1t's AI Gateway when g1t pays, or one of the workspace's own providers |
| 8 | * when it does. A provider that speaks OpenAI's API gets the request | |
| 9 | * translated, and its answer translated back. So a sandbox that is tricked | |
| 10 | * into printing its environment gives away a token that stops working when | |
| 11 | * the run ends, and nothing of the workspace's. | |
| Integrations: your own model provider, alerts that open issues, tickets agents read | 12 | * |
| Models per workspace: several providers, routed by kind of work | 13 | * Responses stream through. |
| Integrations: your own model provider, alerts that open issues, tickets agents read | 14 | */ |
| 15 | import { type ModelUpstream, type ServiceBinding, integrationsClient } from "@g1t/contracts"; | |
| 16 | ||
| Models per workspace: several providers, routed by kind of work | 17 | import { type AnthropicRequest, StreamTranslator, errorFromChat, estimateTokens, fromChat, toChat } from "./openai"; |
| Integrations: your own model provider, alerts that open issues, tickets agents read | 18 | import { type HostedRouting, presentedToken, upstreamRequest } from "./route"; |
| 19 | ||
| 20 | interface Env extends HostedRouting { | |
| 21 | INTEGRATIONS: ServiceBinding; | |
| 22 | } | |
| 23 | ||
| 24 | /** How long a looked-up token is trusted before it is looked up again. */ | |
| 25 | const REMEMBER_MS = 60_000; | |
| 26 | const remembered = new Map<string, { upstream: ModelUpstream | null; until: number }>(); | |
| 27 | ||
| 28 | async function lookUp(env: Env, token: string): Promise<ModelUpstream | null> { | |
| 29 | const now = Date.now(); | |
| 30 | const hit = remembered.get(token); | |
| 31 | if (hit && hit.until > now) return hit.upstream; | |
| 32 | const upstream = await integrationsClient(env.INTEGRATIONS).modelUpstream(token); | |
| 33 | if (remembered.size > 5_000) remembered.clear(); | |
| 34 | remembered.set(token, { upstream, until: now + REMEMBER_MS }); | |
| 35 | return upstream; | |
| 36 | } | |
| 37 | ||
| 38 | /** An error in the shape Anthropic's API uses, which the harness understands. */ | |
| 39 | function refuse(status: number, message: string): Response { | |
| 40 | return Response.json( | |
| 41 | { type: "error", error: { type: status === 401 ? "authentication_error" : "not_found_error", message } }, | |
| 42 | { status }, | |
| 43 | ); | |
| 44 | } | |
| 45 | ||
| Models per workspace: several providers, routed by kind of work | 46 | /** Sends an Anthropic request to a provider that speaks OpenAI's API. */ |
| 47 | async function viaChat(upstream: ModelUpstream, path: string, request: Request): Promise<Response> { | |
| 48 | const body = (await request.json()) as AnthropicRequest; | |
| 49 | const model = upstream.model ?? body.model ?? ""; | |
| 50 | if (path.startsWith("/v1/messages/count_tokens")) { | |
| 51 | return Response.json({ input_tokens: estimateTokens(body) }); | |
| 52 | } | |
| 53 | if (!path.startsWith("/v1/messages")) return refuse(404, `${path} has no counterpart at this provider.`); | |
| 54 | ||
| 55 | const headers = new Headers({ "content-type": "application/json" }); | |
| Model providers: gateway tokens for endpoints, tidier rows, and the docs | 56 | if (upstream.gatewayToken) headers.set("cf-aig-authorization", `Bearer ${upstream.gatewayToken}`); |
| Models per workspace: several providers, routed by kind of work | 57 | if (upstream.apiKey) { |
| 58 | if (upstream.authHeader === "x-api-key") headers.set("x-api-key", upstream.apiKey); | |
| 59 | else headers.set("authorization", `Bearer ${upstream.apiKey}`); | |
| 60 | } | |
| 61 | const answer = await fetch(`${(upstream.baseUrl ?? "").replace(/\/+$/, "")}/chat/completions`, { | |
| 62 | method: "POST", | |
| 63 | headers, | |
| 64 | body: JSON.stringify(toChat(body, model, { official: upstream.official })), | |
| 65 | }); | |
| 66 | if (!answer.ok) { | |
| 67 | return Response.json(errorFromChat(answer.status, await answer.text()), { status: answer.status }); | |
| 68 | } | |
| 69 | if (!body.stream) return Response.json(fromChat((await answer.json()) as Record<string, unknown>, model)); | |
| 70 | ||
| 71 | const translator = new StreamTranslator(model); | |
| 72 | const decoder = new TextDecoder(); | |
| 73 | const encoder = new TextEncoder(); | |
| 74 | const translated = answer.body!.pipeThrough( | |
| 75 | new TransformStream<Uint8Array, Uint8Array>({ | |
| 76 | transform(chunk, controller) { | |
| 77 | const out = translator.push(decoder.decode(chunk, { stream: true })); | |
| 78 | if (out) controller.enqueue(encoder.encode(out)); | |
| 79 | }, | |
| 80 | flush(controller) { | |
| 81 | const out = translator.push(decoder.decode()) + translator.finish(); | |
| 82 | if (out) controller.enqueue(encoder.encode(out)); | |
| 83 | }, | |
| 84 | }), | |
| 85 | ); | |
| 86 | return new Response(translated, { | |
| 87 | headers: { "content-type": "text/event-stream", "cache-control": "no-cache" }, | |
| 88 | }); | |
| 89 | } | |
| 90 | ||
| Integrations: your own model provider, alerts that open issues, tickets agents read | 91 | export default { |
| 92 | async fetch(request: Request, env: Env): Promise<Response> { | |
| 93 | const url = new URL(request.url); | |
| 94 | if (url.pathname === "/" || url.pathname === "") { | |
| 95 | return new Response("g1t's model proxy, for g1t's sandboxes. See https://docs.g1t.sh/guides/models/\n"); | |
| 96 | } | |
| 97 | if (!url.pathname.startsWith("/anthropic/")) return refuse(404, "Requests go to /anthropic/v1/…."); | |
| 98 | const token = presentedToken(request.headers); | |
| 99 | if (!token?.startsWith("g1tm_")) return refuse(401, "This needs a g1t run's model token."); | |
| 100 | const upstream = await lookUp(env, token); | |
| 101 | if (!upstream) return refuse(401, "This run's model token has expired, or its model connection was removed."); | |
| 102 | ||
| 103 | const path = url.pathname.slice("/anthropic".length) + url.search; | |
| Models per workspace: several providers, routed by kind of work | 104 | if (upstream.api === "openai") return viaChat(upstream, path, request); |
| 105 | ||
| Integrations: your own model provider, alerts that open issues, tickets agents read | 106 | const { url: target, headers } = upstreamRequest(upstream, env, path, request.headers); |
| Models per workspace: several providers, routed by kind of work | 107 | // A route that names a model gets it for every request of the run, |
| 108 | // including the harness's small background ones. | |
| 109 | let body: BodyInit | null = request.method === "GET" || request.method === "HEAD" ? null : request.body; | |
| 110 | if (upstream.model && body && path.startsWith("/v1/messages")) { | |
| 111 | const parsed = (await request.json()) as Record<string, unknown>; | |
| 112 | body = JSON.stringify({ ...parsed, model: upstream.model }); | |
| 113 | headers.delete("content-length"); | |
| 114 | } | |
| 115 | return fetch(target, { method: request.method, headers, body }); | |
| Integrations: your own model provider, alerts that open issues, tickets agents read | 116 | }, |
| 117 | } satisfies ExportedHandler<Env>; |