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.
npx skills add CrestApps/CrestApps.AgentSkills --skill crestapps-core-mcpgit clone --depth 1 https://github.com/CrestApps/CrestApps.AgentSkillsWrote 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.
[](https://agentmods.dev/skills/crestapps/crestapps.agentskills/crestapps-core-mcp)<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>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 | $0.00027 | $0.00625 |
| Opus 5 | $0.00014 | $0.00313 |
| Sonnet 5 | $0.00005 | $0.00125 |
| Haiku 4.5 | $0.00003 | $0.00063 |
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.
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.
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.
- 7d ago First seen · 70 lines · 27 tokens per session scan A 9b1e8ec044d3
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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