jev-mcp

中文 | English

中文

MCP server + CLI，把 TypeSafe 的 Jev（System One 模型）开放给 AI agent 调用。Agent 调用 jev_ask，传入 state 和类型化问题， 拿回结构化判断——无文本生成、无需解析。

这是一个薄桥接：只做请求校验，转发到 POST https://api.typesafe.ai/v1/systemone，再把答案原样返回。 问题的设计由调用方负责（见 TypeSafe 文档）。

工具

jev_ask

针对一段 state 回答类型化问题。所有问题并行、基于同一 state 求值， 答案按你起的 question id 返回。

问题类型：

• noul —— 是否判断。返回 noul（0–1，yes 的概率）。可用 criteria: {true, false} 定义两种结果的含义。

• choice —— 从 1–255 个命名选项中单选。返回 choice、 probabilities（和为 1）、confidence。

• score —— 在你定义的 2–10 级量表上打分。返回 score（可落在两级 之间）、legend、probabilities、confidence。

示例：

{
  "state": "Help! My payouts have been failing for 3 days.",
  "questions": {
    "is_urgent": { "type": "noul", "instructions": "Does this convey urgency?" },
    "department": {
      "type": "choice",
      "instructions": "Which team should handle this?",
      "criteria": { "billing": "Payments, invoicing, refunds", "technical": "Bugs, outages, integrations" }
    }
  }
}

jev_models

列出当前 API key 可用的模型名/别名，供 jev_ask 的 model 参数使用。无参数。

安装

npm install -g @iixingchen/jev-mcp
# 或从源码运行：node src/server.js

需要 Node.js 20+。

授权

环境变量 TYPESAFE_API_KEY（到 console.typesafe.ai 创建）。也接受 CHECK_AI_CLI_TYPESAFE_API_KEY 作为回退。无 key 时 server 拒绝启动，且 key 永不写入日志。

接入你的 agent

Claude Code（claude mcp add，或 .mcp.json）：

claude mcp add jev-mcp --env TYPESAFE_API_KEY=$TYPESAFE_API_KEY -- node /path/to/jev-mcp/src/server.js

Codex（~/.codex/config.toml）：

[mcp_servers.jev-mcp]
command = "node"
args = ["/path/to/jev-mcp/src/server.js"]
env = { "TYPESAFE_API_KEY" = "..." }

Gemini CLI（~/.gemini/settings.json）：

{
  "mcpServers": {
    "jev-mcp": {
      "command": "node",
      "args": ["/path/to/jev-mcp/src/server.js"],
      "env": { "TYPESAFE_API_KEY": "..." }
    }
  }
}

任何兼容 MCP 的客户端都一样：stdio 传输，node /path/to/jev-mcp/src/server.js， key 放环境变量。

CLI

export TYPESAFE_API_KEY=...
jev-ask request.json
cat request.json | jev-ask
jev-ask --model jev-1.13.0 request.json

请求格式：{"state": ..., "model": "jev-latest", "questions": {...}}， 答案 JSON 输出到 stdout。

测试

export TYPESAFE_API_KEY=...
npm test   # MCP stdio 冒烟测试，含真实 jev_ask + jev_models 调用

说明

• 计费只按输入 token（$0.042/Mtok），输出免费；客户端侧已做 state 上限以控制成本。

• Jev 英文最强；其他语言请在自己的数据上验证，并用 confidence 决定自动执行还是转人工。

• 每个问题只问一个原子判断；宽泛的判断拆成多个原子问题，答案在代码里组合。

Related MCP server: askjev

English

MCP server + CLI exposing TypeSafe Jev (a System One model) to AI agents. Agents call jev_ask with a state and typed questions; they get back structured judgments — no text generation, no parsing.

This is a thin bridge: it validates the request shape, forwards it to POST https://api.typesafe.ai/v1/systemone, and returns the answers. Question design stays with the caller (see the TypeSafe docs).

Tools

jev_ask

Answer typed questions about a state. All questions run in parallel against the same state; answers come back under your question ids.

Question types:

• noul — yes/no. Returns noul 0–1 (probability of yes). Optional criteria: {true, false} to define the outcomes.

• choice — pick one of 1–255 named options. Returns choice, probabilities (sums to 1), confidence.

• score — position on your 2–10 level rubric. Returns score (can land between levels), legend, probabilities, confidence.

Example:

{
  "state": "Help! My payouts have been failing for 3 days.",
  "questions": {
    "is_urgent": { "type": "noul", "instructions": "Does this convey urgency?" },
    "department": {
      "type": "choice",
      "instructions": "Which team should handle this?",
      "criteria": { "billing": "Payments, invoicing, refunds", "technical": "Bugs, outages, integrations" }
    }
  }
}

jev_models

Lists the model names/aliases this API key can use in jev_ask's model field. No parameters.

Install

npm install -g @iixingchen/jev-mcp
# or run from source: node src/server.js

Node.js 20+ required.

Auth

Set TYPESAFE_API_KEY in the environment (create one at console.typesafe.ai). CHECK_AI_CLI_TYPESAFE_API_KEY is accepted as a fallback. The server refuses to start without a key and never logs it.

Connect your agent

Claude Code (claude mcp add, or .mcp.json):

claude mcp add jev-mcp --env TYPESAFE_API_KEY=$TYPESAFE_API_KEY -- node /path/to/jev-mcp/src/server.js

Codex (~/.codex/config.toml):

[mcp_servers.jev-mcp]
command = "node"
args = ["/path/to/jev-mcp/src/server.js"]
env = { "TYPESAFE_API_KEY" = "..." }

Gemini CLI (~/.gemini/settings.json):

{
  "mcpServers": {
    "jev-mcp": {
      "command": "node",
      "args": ["/path/to/jev-mcp/src/server.js"],
      "env": { "TYPESAFE_API_KEY": "..." }
    }
  }
}

Any MCP-compatible client works the same way: stdio transport, node /path/to/jev-mcp/src/server.js, key in the environment.

CLI

export TYPESAFE_API_KEY=...
jev-ask request.json
cat request.json | jev-ask
jev-ask --model jev-1.13.0 request.json

Request shape: {"state": ..., "model": "jev-latest", "questions": {...}}. Response JSON goes to stdout.

Test

export TYPESAFE_API_KEY=...
npm test   # MCP stdio smoke test incl. live jev_ask + jev_models calls

Notes

• Billing is per input token only ($0.042/Mtok); output tokens are free. State is capped client-side to bound cost.

• Jev is strongest in English; validate on your own data for other languages, and use confidence to decide when to act vs. escalate.

• Ask one atomic judgment per question; decompose broad judgments and combine answers in code.

License

MIT — same as the official @typesafe-ai/sdk and @modelcontextprotocol/sdk. See LICENSE.