DeepSeek

Lightweight, dependency-free, in-memory DeepSeek API fake. DeepSeek is OpenAI-compatible (POST /chat/completions, GET /models), so the openai SDK works against this fake. All generated content is deterministic — derived from a hash of the input. deepseek-reasoner additionally returns a reasoning_content field.

Default port: 4752

Quick start

import { DeepseekServer } from "./services/deepseek/src/server.js";

const server = new DeepseekServer(4752);
await server.start();
// ... run your app/tests ...
await server.stop();

Point the openai SDK at it via baseURL:

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: "sk-parlel",
  baseURL: "http://127.0.0.1:4752",
});

const completion = await client.chat.completions.create({
  model: "deepseek-chat",
  messages: [{ role: "user", content: "Hello DeepSeek" }],
});
// completion.choices[0].message.content => deterministic text

Implemented operations

All routes require an Authorization: Bearer <key> header (any non-empty bearer token is accepted). Both bare paths and an optional /v1 prefix are accepted. State is in-memory and ephemeral.

POST /chat/completions — chat completion. Supports stream: true (SSE ending with data: [DONE]). deepseek-reasoner returns a reasoning_content field and prompt-cache usage counters.
GET /models — list models (deepseek-chat, deepseek-reasoner).

Service & inspection operations (parlel extensions)

GET / — service metadata.
GET /health — health check ({ status: "ok" }).
POST /__parlel/reset — reset all in-memory state.
GET /__parlel/requests — list captured requests.
DELETE /__parlel/requests — clear the captured request log.

SDK usage example

from openai import OpenAI

client = OpenAI(api_key="sk-parlel", base_url="http://127.0.0.1:4752")
resp = client.chat.completions.create(
    model="deepseek-reasoner",
    messages=[{"role": "user", "content": "Solve this"}],
)
print(resp.choices[0].message.reasoning_content)
print(resp.choices[0].message.content)

Access via MCP / preview URL

HTTP services are auto-exposed at the Daytona preview URL. Send requests to the preview URL with the x-daytona-preview-token header. Set DEEPSEEK_BASE_URL to the preview URL.

Surface coverage

This emulator faithfully replicates the API surface most application code and agents exercise. Anything below the supported lines is either an intentional design choice for a fast, zero-cost local emulator (✓ By design) or a candidate for a future release (⟳ Roadmap) — never a silent inaccuracy.

Legend: ✅ fully supported · ◐ accepted (stored, not strictly enforced) · ✓ by design · ⟳ on the roadmap.

Feature	Status
`chat/completions` (+ streaming SSE)	✅ Supported
`reasoning_content` (`deepseek-reasoner`)	✅ Supported
`models` list	✅ Supported
Request inspection	✅ Supported (parlel extension)
Real model inference / quality	✓ By design — Deterministic stub output — repeatable assertions, no API spend
`tools` / function calling	◐ Accepted, not executed
Prompt-cache accounting	◐ Static counters, not real caching
Token counts	◐ Approximate word-based
Bearer-token validity / quota	✓ By design — Never throttles — local tests run at full speed, zero cost

Manifest

See services/deepseek/manifest.json:

name: deepseek, image: parlel/deepseek:1
port: 4752, protocol: http, healthcheck: /health, startup ≈ 100ms
env: DEEPSEEK_API_KEY, DEEPSEEK_BASE_URL

Configuration — `test.env`

Copy these into your test.env (used by the bridge sidecar flow). Tokens are Parlel's seeded test credentials — any non-empty value is accepted by the emulator, so you rarely need to change them. Swap in real credentials only when pointing at the live service in prod.env.

DEEPSEEK_API_KEY=sk-parlel
DEEPSEEK_BASE_URL=http://parlel-bridge:4752