DeepSeek MCP Server

An MCP server for DeepSeek's current V4.1 Flash API: text and visual chat, the Responses API, FIM completion, Files API lifecycle operations, model discovery, balance checks, and bounded in-memory conversations.

Version 1.0.1 uses the stable MCP TypeScript SDK v2 and serves both the 2026-07-28 protocol and stateless legacy clients.

What's current

As of September 10, 2026:

• The canonical fast model is deepseek-flash, currently DeepSeek V4.1 Flash.
• deepseek-v4-flash and deepseek-v4-flash-vision-exp are temporary aliases

for deepseek-flash.

• DeepSeek announced that deepseek-v4-pro will begin serving V4.1 Flash on

September 14 until V4.1 Pro is released.

• V4.1 Flash accepts visual input through Chat Completions and Responses.
• The Files API supports upload, list, retrieve, and delete for reusable image

inputs.

• DeepSeek documents a 1M-token context window and up to 384K output tokens for

deepseek-flash.

“Multimodal” here means image understanding. This server does not generate images, video, or audio.

Tools

The server exposes eleven tools:

• chat_completion: text or visual Chat Completions, thinking controls,

function tools, JSON output, streaming aggregation, and optional conversation_id memory.

• create_response: stateless Responses API calls with text/images, reasoning

controls, function/custom tools, web search, structured output, and semantic streaming aggregation.

• completion: FIM completion through /beta/completions.
• list_models: live model discovery.
• get_user_balance: account availability and balances.
• upload_file: upload base64 JPEG, PNG, GIF, or WebP data and receive a

reusable DeepSeek file_id.

• list_files: list uploaded files with cursor, order, and purpose filters.
• retrieve_file: retrieve metadata for one file_id.
• delete_file: delete one uploaded file.
• reset_conversation: clear one local in-memory conversation.
• list_conversations: list local in-memory conversation IDs.

Every tool declares an MCP output schema and behavior annotations. Full provider payloads remain opt-in through include_raw_response=true.

Install

Node.js 20 or newer is required.

Run directly over stdio:

DEEPSEEK_API_KEY="REPLACE_WITH_DEEPSEEK_KEY" npx -y deepseek-mcp-server@1

Codex CLI:

codex mcp add deepseek --env DEEPSEEK_API_KEY="REPLACE_WITH_DEEPSEEK_KEY" -- npx -y deepseek-mcp-server@1

Claude Code:

claude mcp add deepseek --env DEEPSEEK_API_KEY="REPLACE_WITH_DEEPSEEK_KEY" -- npx -y deepseek-mcp-server@1

Example MCP client configuration:

{
  "mcpServers": {
    "deepseek": {
      "command": "npx",
      "args": ["-y", "deepseek-mcp-server@1"],
      "env": {
        "DEEPSEEK_API_KEY": "REPLACE_WITH_DEEPSEEK_KEY"
      }
    }
  }
}

Visual input

chat_completion accepts image URLs:

{
  "message": [
    { "type": "text", "text": "Describe this image." },
    {
      "type": "image_url",
      "image_url": {
        "url": "https://example.com/photo.png",
        "detail": "high"
      }
    }
  ]
}

It also accepts a supported base64 data URL without first uploading it:

{
  "message": [
    { "type": "text", "text": "What is shown here?" },
    {
      "type": "file",
      "file_data": "data:image/png;base64,iVBORw0KGgo...",
      "filename": "image.png"
    }
  ]
}

For reuse, call upload_file, then pass its returned ID:

{
  "filename": "diagram.png",
  "file_data": "iVBORw0KGgo...",
  "expires_after_seconds": 86400
}

{
  "message": [
    { "type": "text", "text": "Explain this diagram." },
    { "type": "file", "file_id": "file-api-..." }
  ]
}

The same uploaded file can be used with create_response:

{
  "input": [
    {
      "role": "user",
      "content": [
        { "type": "input_text", "text": "Read the image." },
        { "type": "input_image", "file_id": "file-api-..." }
      ]
    }
  ]
}

Supported image formats are JPEG, PNG, GIF, and WebP. Detail may be low, high, original, or auto.

Upload safety boundary

upload_file accepts raw base64 or a supported image data URL. It deliberately does not accept local file paths and does not fetch arbitrary URLs on the server. Decoded uploads are limited to 64 MiB, and the bytes are signature-checked before upload. Uploaded data is stored by DeepSeek under your account; use an expiry or delete_file when it should not persist. Expiry must be between 3,600 and 2,592,000 seconds.

Streamable HTTP

Run a local HTTP endpoint:

DEEPSEEK_API_KEY="REPLACE_WITH_DEEPSEEK_KEY" \
MCP_TRANSPORT=streamable-http \
MCP_HTTP_HOST=127.0.0.1 \
MCP_HTTP_PORT=3001 \
npx -y deepseek-mcp-server@1

The endpoint defaults to http://127.0.0.1:3001/mcp.

For browser clients, set an exact comma-separated origin allowlist:

MCP_HTTP_ALLOWED_ORIGINS=https://app.example.com,http://localhost:3000

Requests that include an Origin header are rejected with 403 unless the origin is allowlisted. Native clients that omit Origin are unaffected.

Hosted endpoint

A separately deployed endpoint is available at https://deepseek-mcp.ragweld.com/mcp using Authorization: Bearer <token>. The hosted deployment has its own release cycle and may lag the npm/GitHub release; inspect tools/list before relying on a newly added tool.

Environment

Required:

DEEPSEEK_API_KEY=your-api-key

Optional:

DEEPSEEK_BASE_URL=https://api.deepseek.com
DEEPSEEK_REQUEST_TIMEOUT_MS=120000
DEEPSEEK_DEFAULT_MODEL=deepseek-flash
MCP_TRANSPORT=stdio
MCP_HTTP_HOST=127.0.0.1
MCP_HTTP_PORT=3001
MCP_HTTP_PATH=/mcp
MCP_HTTP_ALLOWED_ORIGINS=https://app.example.com,http://localhost:3000
CONVERSATION_MAX_MESSAGES=200

CONVERSATION_MAX_MESSAGES bounds the total messages retained in the process-local conversation store. Restarting the process clears this store.

MCP compatibility

• Built on @modelcontextprotocol/server, @modelcontextprotocol/node, and

@modelcontextprotocol/client 2.0.

• Streamable HTTP negotiates MCP 2026-07-28 and falls back to stateless

2025-era handling for older clients.

• Stdio chooses the protocol era from the opening exchange and pins one server

instance for that connection.

• Static discovery/list results carry one-hour public cache hints; dynamic

resource lists, runtime data, live account data, and conversations remain private and short-lived or uncached.

• Explicit conversation_id memory is application state and works independently

of transport session state.

Migrating from 0.6.0

• The default model changed from deepseek-v4-flash to deepseek-flash.
• The MCP SDK moved from the monolithic v1 package to the split v2 packages.
• MCP_HTTP_STATEFUL_SESSION was removed. HTTP protocol handling is now

per-request/stateless; use conversation_id for retained chat context.

• Four Files API tools and visual inputs were added.
• Existing tool names and include_raw_response behavior remain compatible.

Development and verification

npm ci
npm run build
npm test
npm pack --dry-run

Credentialed smoke tests:

DEEPSEEK_API_KEY="REPLACE_WITH_DEEPSEEK_KEY" npm run test:live
DEEPSEEK_MCP_AUTH_TOKEN="REPLACE_WITH_TOKEN" npm run test:remote

The live smoke covers model listing, balance, text chat, thinking streaming, Responses, FIM, visual input, and a Files upload/retrieve/list/delete lifecycle with cleanup.

Registry identity

• MCP Registry: io.github.DMontgomery40/deepseek
• npm: deepseek-mcp-server@1.0.1
• OCI: docker.io/dmontgomery40/deepseek-mcp-server:0.5.0 is the last

published image and does not contain the 1.0.1 feature set.

Official references

• DeepSeek V4.1 Flash announcement
• DeepSeek pricing and model limits
• DeepSeek visual input guide
• DeepSeek Files API guide
• DeepSeek Chat Completions
• DeepSeek Responses API
• MCP 2026-07-28 specification