dsh-simple-image
DeepSeek Harness 插件：通过兼容 StepFun 的 /images/generations 端点实现文本生成图像。它通过一个小型 NDJSON 桥接器挂载内置的零依赖 stdio MCP 服务器，并公开 mcp__simple_image__simple_image。
插件会安装到这里；不确定时保持 web。
npx -y @deepseek-ai/dsh plugin --profile web add github:bauerelizabeth07139/mcp-simple-image#dd0743035dd263860522e3ed9dbbd3c203293beaSimple Image 以 dsh-simple-image 发布，当前版本为 0.1.0。Plugin Hub 会校验它的 manifest，并保存精确安装来源，便于复现安装结果。
One tool, one endpoint. simple_image posts a prompt to a
StepFun-compatible /images/generations API and returns the resulting image
URLs — no SDK, no third-party packages.
一个工具、一个端点:把提示词发给 StepFun 兼容的图片生成 API,拿回图片 URL。
As a DeepSeek Harness plugin: the MCP server ships inside the bundle, so
installing one plugin is the whole setup — no mcpServers file to hand-edit.
DeepSeek Harness Desktop — open Plugins in the sidebar, choose Add plugin, and enter:
https://github.com/bauerelizabeth07139/mcp-simple-image
Then switch the new dsh-simple-image bundle on. The Desktop app boots the
reserved desktop profile, so that is where it has to be enabled.
dsh CLI — install it into the profile you actually boot:
dsh plugin --profile web add bauerelizabeth07139/mcp-simple-image
No git on the machine? pnpm resolves a git shorthand with git ls-remote,
which fails with 'git' is not recognized when git is missing. Use the tarball
instead — that path is plain HTTPS:
dsh plugin --profile web add https://codeload.github.com/bauerelizabeth07139/mcp-simple-image/tar.gz/main
The same address works in the Desktop Add plugin dialog. Replace main
with a commit SHA to pin an exact revision (/tar.gz/<sha>).
Uninstall with dsh plugin --profile web remove dsh-simple-image.
PATH, or pointed at with python.STEP_API_KEY (or config.apiKey).
Without one the server exits at startup with
ERROR: STEP_API_KEY is not set./v1 — the server appends
/images/generations itself and hardcodes response_format: url.The server registers tool(s). DSH namespaces them automatically, so the model calls them as :
1mcp__simple_image__<tool>| Tool | What it does |
|---|---|
simple_image | Calls POST {STEP_API_BASE}/images/generations and returns the image URLs as text. Parameters: prompt (required), model, size (default 1024x1024), n (1–4). |
| Key | Environment variable | Default | Meaning |
|---|---|---|---|
python | — | discovered | interpreter that runs the server |
apiKey | STEP_API_KEY | (empty) | required; the server refuses to start without it |
baseUrl | STEP_API_BASE | https://api.stepfun.com/step_plan/v1 | API base, including /v1 |
model | STEP_MODEL | step-image-edit-2 | model id |
toolCallTimeoutMs | — | 300000 | DSH's per-call budget; the server's own HTTP timeout is 120 s |
env | — | {} | raw environment passthrough (for example STEP_CONFIG, STEP_SIZE, STEP_N) |
Every field is optional and lives in the loader row. For example, in
cordis.patch.yml:
- id: dsh-simple-image
name: 'dsh-simple-image'
config:
apiKey: 'sk-...'
baseUrl: 'https://api.stepfun.com/step_plan/v1'
model: 'step-image-edit-2'
The server frames its stdio transport the LSP way — Content-Length: <n>
followed by a blank line — while the MCP client inside DeepSeek Harness reads
newline-delimited JSON. Mounted directly, the handshake would time out with no
error worth reading. bridge.mjs sits between the two: NDJSON in from the
harness, Content-Length frames to the server, and the reverse on the way back.
Messages are never re-encoded, only reframed, and the parser tolerates a
\r\r\n\r\r\n header — which is what this server emits on Windows, where
Python's text mode turns each \n into \r\n.
config.json wins over the environment. If config.json (or STEP_CONFIG)
exists next to the server, its api_key / api_base / model values are
read first. Do not leave a copied config.example.json in place: its
placeholder key is truthy, so the server starts with a bogus credential.response_format: url, so the tool returns links that expire; nothing is
written to disk./v1. The server appends
/images/generations verbatim, so an OpenAI-style base URL without /v1
produces a 404.index.js resolves a Python interpreter (the configured python, then
python3/python on PATH), hands the server its argv and working directory,
and mounts it as a stdio MCP server through @deepseek-ai/dsh-mcp-client with
failOnStartupError: true, so a server that cannot start is a visible error
rather than a silently missing tool.
Credentials are forwarded explicitly. The harness scrubs credential-shaped
variables (KEY, TOKEN, SECRET, PASSWORD) out of the environment a child
process inherits, so config.apiKey — falling back to the variable the server
documents — is written into the child's environment by the plugin itself. That
means both of these work:
config:
apiKey: '<your key>'
export STEP_API_KEY='<your key>' # picked up at load time
No build step and no runtime dependencies — @deepseek-ai/cordis and
@deepseek-ai/dsh-mcp-client are peers supplied by the Harness.
npm test # node >= 22: manifest checks + the stdio mount, both Harness-free
The mount test loads index.js with @deepseek-ai/dsh-mcp-client stubbed and
asserts the exact stdio configuration the plugin produces, including the
credential forwarding above.
| Path | Purpose |
|---|---|
index.js | the DSH plugin: resolves the interpreter and mounts the server |
cordis.patch.yml | the loader row that activates the plugin |
locale/{en,zh}.json | card title and description for the plugin lists |
assets/icon.svg | card artwork |
test/ | npm test: manifest composition and the mount contract |
server.py | the MCP server, unchanged |
bridge.mjs | NDJSON ↔ Content-Length translation for the harness |
config.example.json | the server's own configuration template, unchanged |
package.upstream.json | the repository's original npm manifest, kept verbatim |
The server is a plain stdio MCP server and still works anywhere else. The
repository's original README is kept verbatim as
README.opencode.md, and the launch stanza from it keeps
working:
STEP_API_KEY=sk-... python server.py # any MCP host that
# frames with
# Content-Length
node bridge.mjs -- python server.py # …or line-delimited
# JSON, through the
# bridge
MIT — the repository declared MIT in package.json and its README but shipped no licence file; this plugin's release adds one.