dev

A command for building and running an MCP server locally over HTTP. It can also connect the server to supported MCP clients such as Claude Code, Cursor, or Inspector.

In plain words
What is it for?
Use it to start a named server, choose its port, view live terminal logs, or start it already connected to an MCP client.
Why use it?
It avoids manually building the server, starting it, and registering it with a client during development.

Command

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/paiml/rust-mcp-sdk/dev
Clone the repo
git clone --depth 1 https://github.com/paiml/rust-mcp-sdk
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 374 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00374
Opus 5 $0.00000 $0.00187
Sonnet 5 $0.00000 $0.00075
Haiku 4.5 $0.00000 $0.00037

Measured 2d ago against content hash 15724ac6a2f7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

dev scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

cargo-pmcp/docs/commands/dev.md · 54 lines

What it actually says

cargo pmcp dev

Start a development server.

Usage

cargo pmcp dev --server <NAME> [OPTIONS]

Description

Builds and runs an MCP server with HTTP transport for local development. The server starts on http://0.0.0.0:<port> with live logs in the terminal.

If the server has a configured port in the workspace config, that port is used automatically (unless overridden with --port).

Options

Option Default Description
--server <NAME> (required) Name of the server to run
--port <PORT> 3000 Port to run the server on (overrides workspace config)
--connect <CLIENT> - Automatically connect to an MCP client (claude-code, cursor, inspector)

Examples

Start a server:

cargo pmcp dev --server calculator

Start on a custom port:

cargo pmcp dev --server calculator --port 8080

Start and connect to Claude Code in one step:

cargo pmcp dev --server calculator --connect claude-code

What It Does

  1. Builds the server binary (cargo build --bin {name}-server)
  2. Optionally runs connect to register with an MCP client
  3. Starts the server in the foreground with MCP_HTTP_PORT and RUST_LOG=info

Press Ctrl+C to stop the server.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 54 lines · 0 tokens per session scan A 15724ac6a2f7

Subscribe to this mod's changes

dev is a command published in the GitHub repository paiml/rust-mcp-sdk (53 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 374 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.