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 agentmods add instructions/mctar/mcp-nb/claude-mdgit clone --depth 1 https://github.com/mctar/mcp-nbWrote 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/instructions/mctar/mcp-nb/claude-md)<a href="https://agentmods.dev/instructions/mctar/mcp-nb/claude-md"><img src="https://agentmods.dev/badge/instructions/mctar/mcp-nb/claude-md.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 | $0.00938 | $0.00938 |
| Opus 5 | $0.00469 | $0.00469 |
| Sonnet 5 | $0.00188 | $0.00188 |
| Haiku 4.5 | $0.00094 | $0.00094 |
Grade A, and why
mcp-nb 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 4d 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 — 73 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.
What this is
An MCP (Model Context Protocol) server that gives AI agents access to Norges Bank's open data API. Covers exchange rates, policy rate, government debt, money market data, bank liquidity, and the Regional Network survey. Built by Gervi Labs alongside MCP servers for SSB and FHI.
Running
pip install -r requirements.txt
python server.py
Or with Docker:
docker compose up
Server runs on port 8007 (streamable HTTP). No auth required on either side.
There are no tests in this project.
Architecture
Framework: FastMCP | Transport: streamable HTTP on port 8007 | Upstream: Norges Bank SDMX 2.1 REST API at https://data.norges-bank.no/api/
Data flow
server.py creates a FastMCP instance and registers tools/prompts from tools.py and entry_prompt.py using mcp.tool()() / mcp.prompt()(). Tools call NorgesBankClient (in client.py), which makes HTTP requests to the SDMX API. Config constants and currency aliases live in config.py.
Import pattern
All internal imports use a try/except pattern (from .module falling back to from module) so the code works both as a package and when run directly with python server.py.
Tool design
Progressive discovery pattern: discover (nb_list_dataflows) -> explore (nb_get_dataflow_structure) -> query (nb_get_data). Two convenience wrappers (nb_get_exchange_rate, nb_get_policy_rate) handle the most common use cases. nb_get_api_status is a health check.
All tools return human-readable pipe-separated text tables, not raw SDMX JSON. The SDMX-JSON parsing in _parse_sdmx_json_data decodes positional indices (series keys like "0:1:0:0" and observation keys like "0") into dimension labels and dates. Output is capped at 500 rows.
Currency resolution
nb_get_exchange_rate accepts ISO codes or common names ("dollar", "euro", "pound"). Aliases are in the CURRENCY_ALIASES dict in config.py. Resolution: lowercase input -> alias lookup -> fallback to 3-letter uppercase as ISO code.
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.
- 4d ago First seen · 73 lines · 938 tokens per session scan A 4d438c98eacf
mcp-nb CLAUDE.md is an instructions file published in the GitHub repository mctar/mcp-nb (0 stars, last pushed 5mo ago), licensed MIT. It adds 938 tokens to every session, about $0.0047 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 2026-08-31.
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