1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
/**
* Shell — HTTP transport layer (effects injected at the edges).
*
* streamChat: POST /chat, returns an async iterable of AgentEvents.
* fetchModels: GET /models, returns the ModelsResponse.
*
* The fetchImpl dependency is injected (outermost edge mock allowed).
*/
import type { AgentEvent, ChatRequest, ModelsResponse } from "@dispatch/transport-contract";
import { splitNdjsonLines } from "./ndjson.js";
interface FetchDeps {
readonly fetchImpl: typeof fetch;
}
interface StreamChatOpts {
readonly server: string;
readonly request: ChatRequest;
}
export async function streamChat(
deps: FetchDeps,
opts: StreamChatOpts,
): Promise<{ conversationId: string | null; events: AsyncIterable<AgentEvent> }> {
const url = `${opts.server}/chat`;
const res = await deps.fetchImpl(url, {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify(opts.request),
});
if (!res.ok) {
const body = await res.text();
throw new Error(`POST /chat failed with status ${res.status}: ${body}`);
}
const conversationId = res.headers.get("X-Conversation-Id");
if (!res.body) {
throw new Error("POST /chat returned no body");
}
const events = readNdjsonStream(res.body);
return { conversationId, events };
}
async function* readNdjsonStream(body: ReadableStream<Uint8Array>): AsyncIterable<AgentEvent> {
const reader = body.getReader();
const decoder = new TextDecoder();
let buffer = "";
try {
while (true) {
const { done, value } = await reader.read();
if (done) break;
buffer += decoder.decode(value, { stream: true });
const { lines, rest } = splitNdjsonLines(buffer);
buffer = rest;
for (const line of lines) {
yield JSON.parse(line) as AgentEvent;
}
}
if (buffer.length > 0) {
yield JSON.parse(buffer) as AgentEvent;
}
} finally {
reader.releaseLock();
}
}
interface FetchModelsOpts {
readonly server: string;
}
export async function fetchModels(deps: FetchDeps, opts: FetchModelsOpts): Promise<ModelsResponse> {
const url = `${opts.server}/models`;
const res = await deps.fetchImpl(url);
if (!res.ok) {
const body = await res.text();
throw new Error(`GET /models failed with status ${res.status}: ${body}`);
}
return (await res.json()) as ModelsResponse;
}
|
