Spanning

CI License: Apache 2.0

A Model Context Protocol server exposing the Spanning Cloud Backup API to Claude and other MCP clients.

What it does

Surface SaaS backup posture for your M365, Google Workspace, or Salesforce tenants directly to AI assistants — list backed-up users, inspect covered services, browse backup history, queue restores, and audit admin activity and license usage.

• Interactive backup status card (MCP Apps, SEP-1865): spanning_get_user renders as a read-only interactive card in MCP Apps hosts (Claude Desktop/web) showing the user's backup status, license state, last backup, and per-service coverage; neutral by default, brandable via window.__BRAND__ injection or MCP_BRAND_* env vars (MCP_BRAND_NAME, MCP_BRAND_LOGO_URL, MCP_BRAND_PRIMARY_COLOR, MCP_BRAND_ACCENT_COLOR, MCP_BRAND_BG, MCP_BRAND_TEXT). Plain-JSON behavior is unchanged in other hosts. Rebuild the embedded card with npm run build:ui after editing ui/.

Tools

Tool	Purpose
spanning_list_users	List backed-up users in the org
spanning_get_user	Fetch a single user's detail
spanning_list_services	List services covered for a user
spanning_list_backups	List backup runs for a user + service
spanning_queue_restore	Queue a restore (DESTRUCTIVE — requires confirmation)
spanning_get_restore_status	Check restore progress
spanning_list_audit_log	Admin audit log (date-range elicitation)
spanning_get_license_usage	Seats used vs purchased
spanning_status	Server status / health

Credentials

Copy .env.example and set the variables below. Leave CONDUIT_S2S_SECRET empty in the example. Never commit a real secret.

Local (env mode)

export SPANNING_PLATFORM="m365"        # or "gws" or "salesforce"
export SPANNING_ADMIN_EMAIL="..."
export SPANNING_API_TOKEN="..."

The stdio transport reads those variables and does not use CONDUIT_S2S_SECRET.

HTTP transport

CONDUIT_S2S_SECRET is required when MCP_TRANSPORT=http. If it is empty or a known placeholder (changeme, change-me, secret, placeholder, example, replace-me, replace-with-a-real-secret, your-secret, your-s2s-secret, s2s-secret), the process logs an error and exits non-zero. The secret value is never logged. Generate one with openssl rand -hex 32.

MCP_ALLOW_INSECURE_DEV=1 is local development only. It starts HTTP without CONDUIT_S2S_SECRET, logs a warning, does not check X-Gateway-S2S, and listens on 127.0.0.1 only. A non-loopback MCP_HTTP_HOST (including 0.0.0.0) is overridden to 127.0.0.1 and that override is logged. A known placeholder secret is still refused.

MCP_HTTP_HOST defaults to 127.0.0.1 when unset. A configured CONDUIT_S2S_SECRET honors MCP_HTTP_HOST. The container image sets MCP_HTTP_HOST=0.0.0.0 and AUTH_MODE=gateway.

X-Gateway-S2S

With a real CONDUIT_S2S_SECRET, every /mcp request must include X-Gateway-S2S. The check is verifyS2sHeader in src/s2s-verify.ts: the header value is t=<unix seconds>,v1=<hex>, where the hex is HMAC-SHA256 of the literal string t=<unix seconds> keyed with CONDUIT_S2S_SECRET (64 lowercase hex characters). The timestamp must be within 300 seconds of the server clock. A missing or invalid header is HTTP 401, before vendor credentials are read.

TS=$(date +%s)
SIG=$(printf 't=%s' "$TS" | openssl dgst -sha256 -hmac "$CONDUIT_S2S_SECRET" -hex | awk '{print $NF}')
curl -sS http://127.0.0.1:8080/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -H "X-Gateway-S2S: t=${TS},v1=${SIG}" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

Hosted (gateway mode)

AUTH_MODE=gateway (the Docker image and Compose default) requires all three headers on every /mcp request and does not fall back to SPANNING_* in the process environment:

• X-Spanning-Platform (required, one of m365 | gws | salesforce)
• X-Spanning-Admin-Email (required)
• X-Spanning-API-Token (required, secret)

A request missing any of those headers is HTTP 401. Add them to the signed curl above. The gateway Compose service does not set SPANNING_PLATFORM, SPANNING_ADMIN_EMAIL, or SPANNING_API_TOKEN.

/health stays unauthenticated and does not read credentials.

Single-tenant HTTP (AUTH_MODE=env)

/mcp still requires a valid X-Gateway-S2S header. Vendor credentials come from SPANNING_PLATFORM, SPANNING_ADMIN_EMAIL, and SPANNING_API_TOKEN. Pass those on that process. Do not add them to the gateway Compose service.

Variable	Required	Description
SPANNING_PLATFORM	stdio and AUTH_MODE=env	m365, gws, or salesforce
SPANNING_ADMIN_EMAIL	stdio and AUTH_MODE=env	Spanning admin account email
SPANNING_API_TOKEN	stdio and AUTH_MODE=env	Spanning API token
MCP_TRANSPORT	No	stdio (default) or http
AUTH_MODE	No	gateway (Docker image and Compose) or env. Gateway mode requires the X-Spanning-* headers and never falls back to SPANNING_*.
CONDUIT_S2S_SECRET	Yes for HTTP	Service-to-service HMAC secret. HTTP logs an error and exits non-zero when this is empty or a known placeholder. Compose will not start without it. Never commit a real value.
MCP_ALLOW_INSECURE_DEV	No	Set to 1 only for local development to start HTTP without CONDUIT_S2S_SECRET. Logs a warning, skips X-Gateway-S2S, and binds 127.0.0.1 only.
MCP_HTTP_HOST	No	Bind address when MCP_TRANSPORT=http. Defaults to 127.0.0.1. Honored when CONDUIT_S2S_SECRET is set. The container image sets 0.0.0.0.
MCP_HTTP_PORT	No	HTTP port. Defaults to 8080.

Run

npm install
npm run build
npm start                       # stdio

# HTTP refuses to start until CONDUIT_S2S_SECRET is a real secret
CONDUIT_S2S_SECRET="$(openssl rand -hex 32)" MCP_TRANSPORT=http npm start

# Local HTTP only, without a service-to-service secret (always binds 127.0.0.1)
MCP_TRANSPORT=http MCP_ALLOW_INSECURE_DEV=1 npm start

Docker

The image listens on 0.0.0.0 inside the container and defaults to AUTH_MODE=gateway. Publish the port on loopback and pass the S2S secret. In gateway mode, Spanning credentials arrive on each request as headers.

docker build --secret id=npmrc,src=$HOME/.npmrc -t spanning-mcp .
docker run --rm \
  -e CONDUIT_S2S_SECRET \
  -p 127.0.0.1:8080:8080 \
  spanning-mcp

Compose refuses to start when CONDUIT_S2S_SECRET is unset, sets AUTH_MODE=gateway, publishes 127.0.0.1:8080:8080, and does not inject static Spanning credentials:

CONDUIT_S2S_SECRET="$(openssl rand -hex 32)" docker compose up --build

The image build needs a GitHub Packages npmrc (docker build --secret id=npmrc,src=$HOME/.npmrc). Single-tenant HTTP still requires the S2S secret, then uses SPANNING_*:

docker run --rm \
  -e CONDUIT_S2S_SECRET \
  -e AUTH_MODE=env \
  -e SPANNING_PLATFORM=m365 \
  -e [email protected] \
  -e SPANNING_API_TOKEN \
  -p 127.0.0.1:8080:8080 \
  spanning-mcp

License

Apache 2.0 — see LICENSE.