crestapps-core-mcp

crestapps-core-mcp is a skill for Claude Code, Codex from CrestApps/CrestApps.AgentSkills. It costs 27 tokens per session (625 once invoked), scanned A, original, MIT.

A software-development guide for registering CrestApps.Core as an MCP client or server in a C# application. MCP is a protocol for connecting an application to tools, prompts, and shared resources.

In plain words
What is it for?
Use it when adding CrestApps MCP support to consume remote servers or publish CrestApps tools, prompts, and resources through a C# MCP server.
Why use it?
It provides the required registration and transport setup instead of leaving you to assemble the integration from scattered configuration steps. It also distinguishes client setup from exposing an HTTP server.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it when adding CrestApps MCP support to consume remote servers or…

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Install with agentmods
npx agentmods add skills/crestapps/crestapps.agentskills/crestapps-core-mcp
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.

Any agent
npx skills add CrestApps/CrestApps.AgentSkills --skill crestapps-core-mcp
Clone the repo
git clone --depth 1 https://github.com/CrestApps/CrestApps.AgentSkills

Made for: Claude Code, Codex.

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.

agentmods badge for crestapps-core-mcp

README.md
[![agentmods](https://agentmods.dev/badge/skills/crestapps/crestapps.agentskills/crestapps-core-mcp.svg)](https://agentmods.dev/skills/crestapps/crestapps.agentskills/crestapps-core-mcp)
Your own site
<a href="https://agentmods.dev/skills/crestapps/crestapps.agentskills/crestapps-core-mcp"><img src="https://agentmods.dev/badge/skills/crestapps/crestapps.agentskills/crestapps-core-mcp.svg" alt="Measured on agentmods" height="20"></a>
Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 625 The whole file, excluding the scripts and references it only reads on demand.
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00027 $0.00625
Opus 5 $0.00014 $0.00313
Sonnet 5 $0.00005 $0.00125
Haiku 4.5 $0.00003 $0.00063

Measured 7d ago against content hash 9b1e8ec044d3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

crestapps-core-mcp 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 7d 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.

plugins/crestapps-core/skills/crestapps-core-mcp/SKILL.md · 70 lines

How it starts

The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CrestApps.Core MCP - Prompt Templates

Add MCP Support

Use CrestApps MCP client support to consume remote servers. Use the server support to expose CrestApps tools, prompts, and catalog-managed resources through an MCP C# SDK server.

AddMcpClient() registers the CrestApps client services with SSE and StdIO transport providers. AddMcpServer(...) registers CrestApps prompt and resource services, but an HTTP server also needs the MCP SDK server, its transport, and an endpoint mapping.

HTTP MCP Server

The following combines the CrestApps server services with the pinned MCP SDK HTTP transport. WithCrestAppsHandlers() supplies the CrestApps tool, prompt, and resource protocol handlers.

builder.Services.AddCrestAppsCore(crestApps => crestApps
    .AddAISuite(ai => ai
        .AddMcpServer(mcpServer => mcpServer
            .AddYesSqlStores())
    )
);

_ = builder.Services.AddMcpServer(options =>
{
    options.ServerInfo = new()
    {
        Name = "My MCP Server",
        Version = "1.0",
    };
})
.WithHttpTransport()
.WithCrestAppsHandlers();

var app = builder.Build();

app.MapMcp("mcp");

AddMcpServer(...) in the first registration is the CrestApps builder call. builder.Services.AddMcpServer() and app.MapMcp(...) are MCP SDK calls. Use both for an HTTP server. The server endpoint above is /mcp; apply authorization or other host middleware before exposing it publicly.

Client Registration

builder.Services.AddCrestAppsCore(crestApps => crestApps
    .AddAISuite(ai => ai
        .AddMcpClient(mcpClient => mcpClient
            .AddYesSqlStores())
    )
);

Use SSE transport for a remote HTTP MCP server. The default client registration also includes StdIO transport for a local process. Register only the connection and store features that the host needs.

Custom Resource Types

AddCoreAIMcpResourceType<THandler>() registers the type in McpOptions, registers the handler as scoped, and makes the handler available both through IEnumerable<IMcpResourceTypeHandler> and as a keyed service. The resource's Source selects that keyed handler at read time.

Read the full file on GitHub · 70 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.

  1. 7d ago First seen · 70 lines · 27 tokens per session scan A 9b1e8ec044d3

Subscribe to this mod's changes

crestapps-core-mcp is a skill published in the GitHub repository CrestApps/CrestApps.AgentSkills (13 stars, last pushed 9d ago), licensed MIT. It adds 27 tokens to every session and 625 once invoked, about $0.0001 per session on Opus 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 2026-08-30.

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