Kettlelogic

A Model Context Protocol (MCP) server that exposes a Kettle Logic site's published content — whitepapers/playbooks ("insights") and industry pages — to any MCP-capable agent (Claude Desktop, IDEs, custom orchestrators).

It is a pure, read-only client of the public website: it fetches content live over HTTP and parses it with the Python standard library. No database, no API keys, no dependency on any backend cluster or LLM. The target site is configurable, so you can point it at your own deployment — or any site with the same shape — and see what it discovers.

Built on the official mcp Python SDK (FastMCP), speaking the standard stdio transport (and an optional streamable-http transport for container/Kubernetes deployment).

Engineering note: this repository doubles as a reference for how we build — hexagonal layering, fully-typed OO, dependency injection, and a suite of ratchets (see ARCHITECTURE.md) that enforce the rules in CI. pytest runs unit tests, real-stdio e2e tests, and the ratchets together.

---

What it exposes

Tools

Tool	Description
search_articles(query, limit=5)	Search insight articles by title / slug / description.
get_industry_overview(industry)	Plain-text overview extracted from an industry page.
list_articles()	JSON catalog of every insight article (title, slug, description).
list_industries()	JSON list of industries with guidance (name + slug).
get_article(slug)	A single insight article rendered as readable text.

Resources

URI	Description
kettlelogic://articles/manifest	JSON catalog of every insight article.
kettlelogic://industries/list	JSON list of industry pages discovered on the site.
kettlelogic://articles/{slug}	A single article rendered as readable text.

Discovery is live: articles from the site's /insights/ index, industries from its /llms.txt (falling back to crawling /industries/).

---

Install & run

pip install .            # Python >= 3.11; pulls in mcp + httpx
mcp-kettlelogic          # console script (stdio transport by default)

Normally an MCP client launches it. To explore interactively:

npx @modelcontextprotocol/inspector mcp-kettlelogic

Use it in an MCP client

{
  "mcpServers": {
    "kettlelogic": {
      "command": "mcp-kettlelogic",
      "env": { "KETTLELOGIC_BASE_URL": "https://kettlelogic.com" }
    }
  }
}

Or connect to the hosted server (no install)

A hardened instance runs live over streamable-HTTP — point any MCP client at it:

{
  "mcpServers": {
    "kettlelogic": { "url": "https://kettlelogic.com/mcp" }
  }
}

Publishing to the MCP registry

This server is listed in the public MCP registry as com.kettlelogic/mcp-kettlelogic (brand: kettlelogic, not a personal GitHub handle). server.json is the manifest — it advertises the hosted streamable-HTTP remote and validates against the 2025-12-11 schema.

The listing is claimed by HTTP domain ownership, not a GitHub login: the registry fetches https://kettlelogic.com/.well-known/mcp-registry-auth (a public-key challenge served by the marketing site — web/public/.well-known/mcp-registry-auth in the kettlelogic repo) and verifies a signature made with our Ed25519 private key.

Automated (on a self-hosted runner)

.github/workflows/publish-registry.yml publishes automatically on every GitHub Release (and via manual Run workflow). It runs on a self-hosted runner in our cluster (runs-on: [self-hosted, linux, cluster]) — chosen because GitHub-hosted minutes run out fast, and this way the publish costs zero quota and won't fail when the month is drained. That runner also mounts the signing key from an in-cluster Secret (/opt/mcp/key-hex), so the key never lives in GitHub Actions secrets.

So the normal flow is: bump version.py + server.json version → cut a GitHub Release → the registry updates itself.

Runner setup is one-time and lives in the private home repo: deployments/github-runner/ (README there). If the runner is down, re-run from the Actions tab, or use the local fallback below — it always works with no infra.

Manual

If you ever need to publish by hand:

# 1. Get the CLI (prebuilt binary from the registry releases)
curl -L https://github.com/modelcontextprotocol/registry/releases/latest/download/mcp-publisher_linux_amd64.tar.gz | tar xz mcp-publisher

# 2. From the repo root (where server.json lives):
./mcp-publisher validate
./mcp-publisher login http --domain kettlelogic.com \
  --private-key "$(openssl pkey -in .secrets/mcp-registry-key.pem -outform DER | tail -c 32 | xxd -p -c 64)"
./mcp-publisher publish

Keys & recovery & rotation

The Ed25519 key authorizes publishing under the com.kettlelogic namespace. It exists in three places (the private key is intentionally NOT in git):

1. Local — .secrets/mcp-registry-key.pem (gitignored). Convenience for manual publishes.
2. Cluster — Secret mcp-registry-key (key key-hex) in the github-runner namespace. This is what the auto-publish runner uses, and the canonical backup.
3. Public half — served at https://kettlelogic.com/.well-known/mcp-registry-auth (committed in the kettlelogic repo as web/public/.well-known/mcp-registry-auth).

Lost the local .pem? Recover the signing key (as hex) straight from the cluster — publishing only needs the hex, not the pem file:

KEY_HEX="$(kubectl -n github-runner get secret mcp-registry-key -o jsonpath='{.data.key-hex}' | base64 -d)"
./mcp-publisher login http --domain kettlelogic.com --private-key "$KEY_HEX"
./mcp-publisher publish

Rotate (if the key is ever exposed):

openssl genpkey -algorithm Ed25519 -out .secrets/mcp-registry-key.pem   # new key
PUB="$(openssl pkey -in .secrets/mcp-registry-key.pem -pubout -outform DER | tail -c 32 | base64)"
# 1. update the served challenge (in the kettlelogic repo) + redeploy the site:
echo "v=MCPv1; k=ed25519; p=$PUB" > ../kettlelogic/web/public/.well-known/mcp-registry-auth
# 2. update the cluster Secret the runner uses:
kubectl -n github-runner delete secret mcp-registry-key
kubectl -n github-runner create secret generic mcp-registry-key \
  --from-literal=key-hex="$(openssl pkey -in .secrets/mcp-registry-key.pem -outform DER | tail -c 32 | xxd -p -c 64)"
# 3. re-publish (new key must be live at the well-known URL first).

Versions are immutable in the registry — you can't re-publish an existing version; bump version.py + server.json first.

Configure

Env var	Default	Purpose
KETTLELOGIC_BASE_URL	https://kettlelogic.com	Target site to read. Point it at your own.
KETTLELOGIC_TRANSPORT	stdio	stdio (local clients) or streamable-http (network/k8s).
KETTLELOGIC_HTTP_HOST / KETTLELOGIC_HTTP_PORT	0.0.0.0 / 8080	Bind for the http transport.
KETTLELOGIC_METRICS_PORT	(unset)	If set, serve Prometheus metrics at /metrics.
KETTLELOGIC_LOG_LEVEL	INFO	Log level. Logs go to stderr (stdout is the MCP channel).
KETTLELOGIC_CACHE_TTL_SECONDS / KETTLELOGIC_MAX_ARTICLES / KETTLELOGIC_FETCH_CONCURRENCY / KETTLELOGIC_OVERVIEW_MAX_CHARS	see constants.py	Tuning.

Containers & Kubernetes

For network deployment the server runs the streamable-http transport.

docker compose -f deploy/docker/docker-compose.yaml up --build

Kubernetes manifests live in deploy/k8s/ (Deployment with 2 replicas, readiness/liveness probes, resource bounds, non-root + read-only root FS, ClusterIP Service, ConfigMap). Apply with:

kubectl apply -k deploy/k8s

Observability

• Logging — structured logs to stderr: operation start/finish + durations, fetch results, cache hits/misses, errors. Set KETTLELOGIC_LOG_LEVEL.
• Metrics — Prometheus /metrics (set KETTLELOGIC_METRICS_PORT): mcp_operations_total, mcp_errors_total, mcp_http_fetches_total, mcp_http_errors_total, mcp_cache_total{result}, mcp_op_duration_seconds.

Develop & test

pip install -e ".[dev]"
ruff check src tests        # lint + import order
mypy                        # type check (disallow-untyped-defs)
pytest                      # unit + e2e + ratchets, coverage gate (fail-under 90%)

Coverage runs ~99%. See ARCHITECTURE.md for layering, the request flow, and the full list of ratchets.

License

MIT — see LICENSE.