shopdb-flask/plugins/endpoints/AGENT-CONTRACT.md

Endpoint agent contract (C# build reference)

Companion to DESIGN-DECISIONS-agent.md. This is the concrete wire contract the future C# agent targets, derived from EndpointsPlugin.get_collector_schema() and the generic collector dispatcher in shopdb/core/api/collector.py. When the schema changes, update this file in the same change.

1. Transport

• Method/URL: POST {baseurl}/api/collector/endpoints
• Auth header: X-API-Key: <collector key> (Bearer token also accepted). The key is a UI-managed, endpoints-only service token minted from Settings -> Endpoint agent key (section 6). A bootstrap .env collector key still works until the first UI key is generated, then it is switched off (section 6). No querystring fallback.
• Body: application/json, a single flat object (NOT an array). One POST per report per endpoint.
• Identity field: hostname (required, case-insensitive).

2. Request payload

Only hostname is required. Every other field is optional; the server upserts only the keys that are present, so a lightweight report can omit inventory arrays. adopt is first-contact only.

{
  "hostname": "SHOP-PC-014",     // required, resolved to computers.hostname
  "adopt": true,                 // first run ONLY; delegates PC creation to computers plugin
  "loggedinuser": "j.smith",
  "serialnumber": "5CD1234ABC",  // adoption subset (forwarded to computers)
  "pctype": "CNC Controller",    // adoption subset
  "machinenumber": "12345",      // adoption subset; "" or "9999" == none
  "agentversion": "1.0.0",
  "trayversion": "1.0.0",            // file version of the interactive tray exe, omitted if no tray
  "lastboottime": "2025-01-14T06:12:00Z",   // ISO-8601 UTC
  "uptimeseconds": 86400,
  "idleseconds": 120,
  "cpupercent": 12.5,
  "memorypercent": 47.0,
  "services": [ /* opaque array, stored as JSON */ ],
  "ports": [ /* opaque array */ ],
  "interfaces": [
    {
      "alias": "Intel(R) Ethernet Connection",  // adapter description
      "ipv4": "10.20.30.40",                     // "" if none
      "mac": "AA:BB:CC:DD:EE:FF",
      "gateway": "10.20.30.1",                   // "" for the static machine-IPS NIC
      "subnet": "255.255.255.0",
      "dhcp": false
    }
  ],
  "scheduledtasks": [ /* opaque array */ ],
  "disks": [
	{
	  "drive": "C:",
	  "label": "OS",
	  "filesystem": "NTFS",
	  "sizebytes": 511000000000,
	  "freebytes": 128000000000,
	  "usedbytes": 383000000000,
	  "freepercent": 25.0            // precomputed; a threshold is a direct compare
	}
  ],
  "bios": { /* opaque object: vendor, version, release date */ },
  "memory": { /* opaque object: totalbytes, freebytes */ },
  "processor": { /* opaque object: name, cores, logicalprocessors, maxclockmhz */ },
  "osinfo": { /* opaque object: build, version, install date */ },
  "domain": "shopfloor.example.com",  // domain or workgroup membership
  "pendingreboot": false,             // omit when unknown; absent != false
  "usercontext": {                    // omitted entirely when nobody is signed in
	"netuse": [
	  {
		"localname": "Z:",
		"remotename": "\\\\fileserver\\programs",
		"status": "OK",
		"username": "SHOPFLOOR\\operator",
		"persistent": true
	  }
	],
	"userlisteners": [
	  { "localaddress": "0.0.0.0", "localport": 7878, "processid": 4512, "processname": "DncMain" }
	],
	"idleseconds": 45,
	"username": "operator",
	"collectedat": "2025-01-14T06:12:00Z"
  },
  "events": [
	{
	  "eventid": 6008,                        // required per item; non-catalog IDs are dropped, not errored
	  "eventrecordid": 184412,                // Windows record id; dedupe key, see notes
	  "eventchannel": "System",
	  "eventsource": "EventLog",
	  "eventtime": "2025-01-14T06:11:58Z",
	  "eventmessage": "The previous system shutdown was unexpected.",
	  "fields": { "any": "extra" }            // opaque object, stored as JSON
	}
  ]
}

Notes:

• adopt=true is sent ONLY by the installer's first run. Steady-state reports omit it (or send false). After adoption, an unknown hostname is a hard validation error again (DESIGN-DECISIONS-agent.md 1a).
• The adoption subset (serialnumber, pctype, machinenumber, plus loggedinuser) is forwarded to the computers collector so the newly created PC is not a bare shell. Send them on first contact.
• services/ports/interfaces/scheduledtasks are stored verbatim as JSON; the server does not validate their inner shape yet. Keep them stable so the UI can render them later. interfaces reports EVERY hardware NIC (not just the primary) so the gatewayless static NIC that links a PC to its machine's IPS is preserved (DESIGN-DECISIONS-agent.md 9.3); each entry is {alias, ipv4, mac, gateway, subnet, dhcp}.
• machinenumber is discovered on-box by the agent from the eDNC registry (HKLM\SOFTWARE\[WOW6432Node\]GE Aircraft Engines\DNC\General:MachineNo) or the UDC udc_settings_*.json (GeneralSettings.MachineNumber), in that order (DESIGN-DECISIONS-agent.md 9.4/9.5). "" or "9999" means none.
• eventrecordid is the Windows event record id: monotonic and unique within a channel on a machine. The agent uses it as a per-channel harvest watermark and the server enforces a unique index on (assetid, eventchannel, eventrecordid), so one real event is stored exactly once. It is nullable: an older agent omits it, and MySQL permits repeated NULLs in a unique index, so those reports keep the previous append behavior rather than failing ingest. Send it whenever the source record exposes one.
• disks/bios/memory/processor/osinfo/usercontext are stored verbatim as JSON snapshots on the endpoint state, newest-wins. domain and pendingreboot are scalar columns because the fleet view filters and alerts on them.
• OMITTING a key is not the same as sending an empty value. Every one of these fields is applied only when the key is PRESENT, so a report that omits it preserves the last-known value. Send null/[] only when you mean "this is genuinely empty now"; omit when you simply did not collect it this cycle.
• pendingreboot follows that rule strictly: omit it when the check failed. A literal false asserts the endpoint is confirmed NOT holding a reboot.
• usercontext is gathered by a probe the agent runs inside the signed-in user's session, because mapped drives, user-owned listeners and idle time do not exist in the agent's own LocalSystem session 0. It is omitted when no one is signed in, which is a normal unattended state, not a fault.
• ports carries LISTENING sockets only. The full connection table is available on demand via the network_connections command instead, because established connections churn constantly and would change every report for no diagnostic gain.

3. Response

Success (HTTP 200), ADR-006 envelope:

{
  "status": "ok",
  "action": "created",           // "created" first time, "updated" thereafter
  "assetid": 4821,
  "identityvalue": "SHOP-PC-014",
  "warnings": [
	"adopted new computer for hostname: 'SHOP-PC-014'"   // present only on adoption
  ]
}

Validation failure (HTTP 400) - e.g. unknown hostname with adopt absent:

{ "status": "error", "error": { "code": "VALIDATION_ERROR",
  "message": "could not resolve hostname to a computer: 'SHOP-PC-014'" } }

Agent handling: treat non-200 as retryable except a VALIDATION_ERROR that names an unresolved hostname on a NON-first-contact report - that means the PC was removed server-side; surface it, do not spin.

4. C# DTOs

Match the JSON keys EXACTLY (lowercase, no underscores) to satisfy the naming rule; use attributes so C# properties can stay PascalCase without a camelCase serializer changing the wire keys.

using System.Text.Json.Serialization;

public sealed class EndpointReport
{
	[JsonPropertyName("hostname")]      public string Hostname { get; set; } = "";
	[JsonPropertyName("adopt")]         public bool? Adopt { get; set; }
	[JsonPropertyName("loggedinuser")]  public string? LoggedInUser { get; set; }
	[JsonPropertyName("serialnumber")]  public string? SerialNumber { get; set; }
	[JsonPropertyName("pctype")]        public string? PcType { get; set; }
	[JsonPropertyName("machinenumber")] public string? MachineNumber { get; set; }
	[JsonPropertyName("agentversion")]  public string? AgentVersion { get; set; }
	[JsonPropertyName("trayversion")]   public string? TrayVersion { get; set; }
	[JsonPropertyName("lastboottime")]  public DateTimeOffset? LastBootTime { get; set; }
	[JsonPropertyName("uptimeseconds")] public long? UptimeSeconds { get; set; }
	[JsonPropertyName("idleseconds")]   public long? IdleSeconds { get; set; }
	[JsonPropertyName("cpupercent")]    public double? CpuPercent { get; set; }
	[JsonPropertyName("memorypercent")] public double? MemoryPercent { get; set; }
	[JsonPropertyName("services")]      public object[]? Services { get; set; }
	[JsonPropertyName("ports")]         public object[]? Ports { get; set; }
	[JsonPropertyName("interfaces")]    public object[]? Interfaces { get; set; }
	[JsonPropertyName("scheduledtasks")]public object[]? ScheduledTasks { get; set; }
	[JsonPropertyName("disks")]         public object[]? Disks { get; set; }
	[JsonPropertyName("bios")]          public object? Bios { get; set; }
	[JsonPropertyName("memory")]        public object? Memory { get; set; }
	[JsonPropertyName("processor")]     public object? Processor { get; set; }
	[JsonPropertyName("osinfo")]        public object? OsInfo { get; set; }
	[JsonPropertyName("domain")]        public string? Domain { get; set; }
	[JsonPropertyName("pendingreboot")] public bool? PendingReboot { get; set; }
	[JsonPropertyName("usercontext")]   public object? UserContext { get; set; }
	[JsonPropertyName("applications")]  public object[]? Applications { get; set; }
	[JsonPropertyName("events")]        public EndpointEventRecord[]? Events { get; set; }
}

public sealed class EndpointEventRecord
{
	[JsonPropertyName("eventid")]       public int EventId { get; set; }
	[JsonPropertyName("eventrecordid")]  public long? EventRecordId { get; set; }
	[JsonPropertyName("eventchannel")]  public string? EventChannel { get; set; }
	[JsonPropertyName("eventsource")]  public string? EventSource { get; set; }
	[JsonPropertyName("eventtime")]    public DateTimeOffset? EventTime { get; set; }
	[JsonPropertyName("eventmessage")] public string? EventMessage { get; set; }
	[JsonPropertyName("fields")]       public Dictionary<string, object>? Fields { get; set; }
}

public sealed class CollectorResponse
{
	[JsonPropertyName("status")]        public string Status { get; set; } = "";
	[JsonPropertyName("action")]        public string? Action { get; set; }
	[JsonPropertyName("assetid")]       public int? AssetId { get; set; }
	[JsonPropertyName("identityvalue")] public string? IdentityValue { get; set; }
	[JsonPropertyName("warnings")]      public string[]? Warnings { get; set; }
}

Serializer settings: DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull so omitted fields are not sent (server upserts only present keys). Send UTC ISO-8601.

5. "Build site agent" settings flow (build cadence)

Goal: an operator in ShopDB Settings produces an instance-locked .exe that knows its server URL and its collector key, needing no manual config on the client.

1. Settings -> "Build site agent": operator picks/creates a collector-scoped managed token (the same token accepted by X-API-Key on /api/collector/endpoints). This binds the build to one ShopDB instance.
2. Server stamps a small config (base URL + token + reporting cadence) into the agent build artifact. Instance-locked = the token only works against that server, and the server can revoke it to kill a leaked build.
3. First run on a client:
   • Collect the ShopDB PowerShell asset-collector data set (minus the CSV emit): hostname, logged-in user, serial number, pc type, machine number, boot time, plus the curated event tail.
   • POST once with adopt=true. The endpoints plugin delegates PC creation to the computers collector, then writes the first EndpointState in the same commit. The endpoint appears in the Fleet UI immediately - no second call, no separate enrollment endpoint.
4. Subsequent runs POST on the configured cadence with adopt omitted; strict hostname resolution applies from then on.

Open item (from DESIGN-DECISIONS-agent.md 1a): whether adopt stays a per-report flag or is promoted to a site setting (strict vs self-adopting fleet). Default proposed: agent sends adopt=true on first run only.

6. UI-managed agent key (kill switch)

The endpoint agent authenticates with a single UI-managed key scoped to ONLY collector.ingest.endpoints, so rotating or revoking it stops all endpoint-agent traffic without affecting the computers or geenforce collectors.

• Settings -> Endpoint agent key (admin only) generates the key. The full secret is shown ONCE at generation and stored only as a hash afterwards; configure it as the agent X-API-Key.
• Generating a key is a hard cutover: any previous endpoint key is revoked in the same request, and the bootstrap .env fallback for endpoints is switched off (plugin.endpoints.envkeyfallback -> false), so the managed key becomes the sole credential.
• Regenerate to rotate (old key dies immediately). Revoke to stop all endpoint-agent reporting until a new key is generated - the kill switch for a leaked agent.
• Backend: GET/POST /api/endpoints/agentkey, POST /api/endpoints/agentkey/regenerate, DELETE /api/endpoints/agentkey. These use the mint_service_token/list_service_tokens/revoke_service_tokens contract helpers (shopdb.api, contract 0.22.0).

The bootstrap .env key (COLLECTOR_API_KEY[_ENDPOINTS]) remains only as a first-run path before a UI key exists; it cannot be the runtime kill switch because container env is injected at boot and cannot be rotated live.

7. Command channel (WebUI -> agent)

The WebUI can send an endpoint an ALLOWLISTED command (never an arbitrary command string). Delivery is agent-initiated long-poll, so shop-floor PCs open no inbound port: the agent makes an outbound request the server holds open until a command is queued, runs it locally, and posts the result back. All three routes reuse the same endpoints collector key (section 6) via X-API-Key, so the command channel shares the kill switch and adds no second secret.

Allowlisted actions (server source of truth: plugins/endpoints/commands.py):

• mtconnect_start - run the MTConnect UDC agent start script (C:\ProgramData\UDC\MTConnect_UDC\Agent\run.bat).
• mtconnect_stop - stop the running MTConnect UDC agent process.
• mtconnect_status - report whether the MTConnect UDC agent is running.
• network_connections - return the full TCP connection table with owning process ids and names. Read-only diagnostic. The result is capped at 500 connections with a truncated flag in detail, because an oversized payload rejected by the server returns nothing at all and a partial answer is more useful than a failed one. Standard reports carry listening ports only.

7.1 Claim the next command (long-poll)

GET {baseurl}/api/endpoints/commands/next?hostname=<hostname>

• Auth: X-API-Key (endpoints collector key).
• The server holds the request open up to ~25s. If a command is queued it is atomically claimed (marked running) and returned; only one poll ever claims a given command.
• Command queued (HTTP 200):

{ "status": "ok", "data": { "endpointcommandid": 91, "action": "mtconnect_start" } }

• Nothing queued within the hold window: HTTP 204 (no body). Re-poll.

7.2 Report a command result

POST {baseurl}/api/endpoints/commands/<endpointcommandid>/result

• Auth: X-API-Key (endpoints collector key).
• Body:

{
  "succeeded": true,               // required; false marks the command failed
  "message": "MTConnect started",  // short summary, optional (<= 2000 chars)
  "mtconnectrunning": true,        // optional; observed run state after the action
  "detail": { "any": "extra" }     // optional structured detail, stored as JSON
}

• When mtconnectrunning is present the server caches it on the endpoint's EndpointState (mtconnectrunning + mtconnectcheckedat) so the WebUI toggle shows a real state between polls. Every mtconnect_* action SHOULD probe and report the resulting run state so the toggle never lies.

7.3 Enqueue (WebUI side, for reference)

POST /api/endpoints/<assetid>/commands with { "action": "mtconnect_start" }, gated by user JWT + endpoints.command. Only one command may be in flight per endpoint (a second enqueue returns HTTP 409 until the first finalizes).