#5015 "Built-in host-agent playbooks make an MCP caller supply steward_url"
- run_playbook, create_schedule and set_alert_action fill a steward-builtin
playbook's steward_url when the caller leaves it out or empty, from
Settings → General → Public base URL, else the scheme and host the MCP
request arrived on — the same source the web actions use.
- run_playbook's reply names what it filled (filled_by_steward), and
get_playbook shows that value as the variable's default.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
MCP-4 of milestone 461 "MCP server: Steward as an LLM-inspectable,
LLM-operable hub". Twelve read-only viewer tools:
- get_overview: what is wrong now, ranked critical-then-oldest. Failing
monitors with their error and when the run of failures began, firing,
pending and still-breaching acknowledged alerts, TLS certificates expiring
within 14 days, agents that stopped reporting, hosts over the configured
CPU/memory/disk thresholds (Settings > Thresholds), failed Ansible runs in
the last 24h, and findings from enabled plugins through a new optional
`mcp_overview(db)` plugin hook. Each finding names the call that shows
its evidence.
- list_hosts, get_host, get_host_metrics
- list_monitors, get_monitor (HTTP header values and URL passwords are
redacted)
- list_alerts, get_alert_history, list_alert_rules, list_maintenance_windows
- query_metrics: the whole metric store, narrowed one argument at a time
(sources > resources > latest values > a series summary)
- list_audit_events
Shared shaping in steward/mcp/tools/_shape.py: UTC ISO times with age_s,
bounded lists that say when and how they were cut, series as
min/avg/max/p95/last plus a ≤60-point series, lookup by id or
case-insensitive name with a did-you-mean, and a range argument that
refuses an unknown key instead of reading it as 24h.
New core reads in steward/core/metric_series.py (sources and resources
via loose index scans, latest values via DISTINCT ON, series across the
raw/hourly-rollup seam). monitors/service.py gains monitor_states,
down_since and recent_failures; agent_overview_by_host now carries the
fullest disk and the last sample time.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Second step of milestone 461. An MCP client (Claude Code, Claude Desktop
via mcp-remote, Open WebUI) connects to /mcp with a personal API token.
- mcp>=2.2 (SDK v2 MCPServer). Mounted by wrapping app.asgi_app, so /mcp
never enters Quart's pipeline; stateless streamable HTTP so a redeploy
never strands a client on a session id the new process didn't issue.
- Auth: Authorization: Bearer stw_… resolves to a Caller (user +
effective role) in a ContextVar; 401 with WWW-Authenticate otherwise.
The web pipeline's database gate runs first, so a DB restart answers
503 instead of failing inside a tool.
- Registry, default-deny: register_tool(fn, role=, read_only=) is the only
door; role and read_only are required. Tools above the caller's role,
or from a disabled plugin, are neither listed nor callable. Undeclared
arguments are refused (not silently dropped); a tool's ValueError
reaches the agent as its reason; a DB failure mid-tool says so.
- Plugins contribute tools via an optional register_mcp_tools(register)
export, all-or-nothing, replaced on hot-reload. Documented in
docs/plugins/writing-a-plugin.md.
- First tool: whoami.
- Tests drive app.asgi_app directly (Quart's test client never reaches
/mcp); the integration test mints a real token against Postgres and
runs initialize → tools/list → whoami → revoke → 401.
Task #4966 "MCP-2 — /mcp transport".
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>