What is spline-mcp CLAUDE.md?

Project instructions for Spline MCP, a server that lets an agent manage objects, materials, events, and runtime state in Spline.design 3D scenes. They also describe the project's setup, commands, architecture, and health checks.

Use them when modifying, testing, formatting, type-checking, or starting the Spline MCP server.

They give the agent the repository context and the commands needed to develop and test it. This reduces guesswork about how the project is organised and run.

How lesleslie/spline-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to lesleslie/spline-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/lesleslie/spline-mcp/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/lesleslie/spline-mcp

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/lesleslie/spline-mcp/claude-md/github.svg)](https://agentmods.dev/instructions/lesleslie/spline-mcp/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/lesleslie/spline-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/lesleslie/spline-mcp/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/lesleslie/spline-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/lesleslie/spline-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,008 This file is loaded in full into every session.

When invoked 1,008 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.01008	$0.01008
Opus 5.5	$0.00403	$0.00403
Sonnet 5.5	$0.00202	$0.00202
Haiku 4.5	$0.00101	$0.00101

Measured 1mo ago against content hash 60bc552f0a71, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

spline-mcp CLAUDE.md 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 1mo 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.

CLAUDE.md · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

For a shorter, tool-neutral bootstrap document, start with AGENTS.md.

Project Overview

Spline MCP Server is a Model Context Protocol server for orchestrating Spline.design 3D scenes. It provides tools for managing 3D objects, materials, events, and runtime state. The spline-mcp component owns port 3052 (see spline_mcp/__init__.py DEFAULT_PORT).

Development Commands

Setup

uv venv
source .venv/bin/activate
uv pip install -e ".[dev]"

Testing

pytest
pytest --cov=spline_mcp --cov-report=html

Code Quality

ruff format spline_mcp/
ruff check spline_mcp/
mypy spline_mcp/

MCP Server

# Stdio mode
spline-mcp serve

# HTTP mode
spline-mcp serve --http --port 3052

# Health check
spline-mcp health

Architecture

spline_mcp/
├── __init__.py          # Package metadata
├── cli.py               # Typer CLI commands
├── config.py            # Oneiric-based configuration
├── server.py            # FastMCP application
├── client.py            # Spline API client (placeholder)
├── assets/              # Asset management
├── generators/          # Code generation (React, Vanilla, Next.js)
├── integrations/        # External integrations
└── tools/               # MCP tool definitions
    ├── __init__.py      # Tool registration helpers
    ├── generation.py    # Code generation tools (6)
    ├── assets.py        # Asset management tools (5)
    ├── helpers.py       # Utility tools (5)
    ├── integration.py   # Integration tools (6)
    └── docs.py          # Documentation tools (3)

Key Patterns

Oneiric Configuration

Settings loaded from:

Default values in SplineSettings
settings/spline-mcp.yaml
settings/local.yaml (gitignored)
Environment variables SPLINE_*

FastMCP Tool Registration

Tools are registered in dedicated modules:

def register_scene_tools(app: FastMCP) -> None:
    @app.tool()
    async def list_scenes() -> list[dict[str, Any]]:
        # Implementation

Read the full file on GitHub · 138 lines

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.

1mo ago Changed · -7 lines · -2 tokens per session 60bc552f0a71
2mo ago Changed aa71628ae430
2mo ago First seen · 145 lines · 1,010 tokens per session scan A 92dc4418df45

Subscribe to this mod's changes

spline-mcp CLAUDE.md is an instructions file published in the GitHub repository lesleslie/spline-mcp (4 stars, last pushed 1mo ago), licensed BSD-3-Clause. It adds 1,008 tokens to every session, about $0.0040 per session on Opus 5.5. 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 2026-08-31.

Building agents Creative and media

spline-mcp CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
spline-mcp CLAUDE.mdlesleslie/spline-mcp	Instructions file	4	1mo ago	BSD-3-Clause	A	1,008	Claude Code
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	today	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	today	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	275k	2d ago	MIT	A	4,313	Codex, OpenCode

spline-mcp: Instructions file for Claude Code