config-and-mcp

config-and-mcp is a cursor rule for Cursor from themoah/klag. It costs 0 tokens per session (411 once invoked), scanned A, original, Apache-2.0.

Configuration rules and an optional MCP interface for Klag, a service that reports Kafka consumer-group lag. MCP lets an AI client call defined tools to read that information.

In plain words
What is it for?
Use it to map environment variables to Kafka settings, configure metrics and feature toggles, and expose read-only tools for listing groups, finding lag, and diagnosing consumer issues.
Why use it?
It gives configuration values a clear precedence and lets an AI client inspect a stored metrics snapshot without querying Kafka directly.

Cursor rule for Cursor

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 rules/themoah/klag/config-and-mcp
Clone the repo
git clone --depth 1 https://github.com/themoah/klag

Made for: Cursor.

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 config-and-mcp

README.md
[![agentmods](https://agentmods.dev/badge/rules/themoah/klag/config-and-mcp.svg)](https://agentmods.dev/rules/themoah/klag/config-and-mcp)
Your own site
<a href="https://agentmods.dev/rules/themoah/klag/config-and-mcp"><img src="https://agentmods.dev/badge/rules/themoah/klag/config-and-mcp.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 411 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 5.1 $0.00000 $0.00411
Opus 5 $0.00000 $0.00205
Sonnet 5 $0.00000 $0.00082
Haiku 4.5 $0.00000 $0.00041

Measured yesterday against content hash 9c3994f80394, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

config-and-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 yesterday.

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.

.cursor/rules/config-and-mcp.mdc · 38 lines

What it actually says

Configuration

Common env vars

Variable Default Notes
KAFKA_BOOTSTRAP_SERVERS localhost:9092
HTTP_PORT 8888
METRICS_REPORTER none prometheus, datadog, otlp
METRICS_INTERVAL_MS 60000
METRICS_GROUP_FILTER * glob include
METRICS_GROUP_EXCLUDE (empty) glob exclude
KLAG_CONFIG_FILE external application.properties

Any KAFKA_X_Y_Z env maps to kafka.x.y.z for AdminClient. Precedence: classpath props < external file < env.

Feature toggles: HOT_PARTITION_*, TIME_LAG_*, COMMIT_FRESHNESS_*, ISR_ENABLED, DATA_SKEW_ENABLED (default false), CONSUMER_MEMBER_LABELS_ENABLED.

MCP (opt-in)

  • MCP_ENABLED=false by default; requires METRICS_REPORTER set (snapshot from metrics cycle)
  • Read-only; serves in-memory snapshot — never queries Kafka directly
  • Tools: list_consumer_groups, get_consumer_group_lag, find_lagging_groups, diagnose
  • Auth: MCP_AUTH_TOKENAuthorization: Bearer <token>

OTLP

HTTP only (port 4318). OTEL_* vars or Klag overrides (OTLP_ENDPOINT, OTLP_HEADERS, etc.). See CLAUDE.md for full list.

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. yesterday Changed 9c3994f80394
  2. 6d ago First seen · 38 lines · 0 tokens per session scan A 6fb6a8ef156b

Subscribe to this mod's changes

config-and-mcp is a cursor rule published in the GitHub repository themoah/klag (82 stars, last pushed 5d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 411 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.