agent register: surface structured hub failure reasons

Map the hub's structured `{detail: {reason}}` responses (invalid_key,
expired, revoked, already_consumed) and 429 rate-limits to actionable
CLI messages so users know to mint a fresh key from Settings → RIA
Agents instead of seeing a raw HTTPError.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ria_toolkit_oss/agent/cli.py

@@ -5,8 +5,11 @@ Subcommands:
 - ``ria-agent run [legacy args]`` — legacy long-poll NodeAgent (unchanged).
 - ``ria-agent stream`` — new WebSocket-based IQ streamer.
 - ``ria-agent detect`` — print SDR drivers whose modules import cleanly.
-- ``ria-agent register --hub URL --api-key KEY`` — register with the hub and
-  save credentials (and optional TX interlocks) to ``~/.ria/agent.json``.
+- ``ria-agent register --hub URL --api-key KEY`` — register with the hub
+  using a personal registration key (minted from **Settings → RIA Agents**
+  on the hub, shown once at mint time) and save credentials (and optional
+  TX interlocks) to ``~/.ria/agent.json``. The hub also accepts the legacy
+  shared ``[wac] API_KEY`` for back-compat, but that path is deprecated.
 
 Invoking ``ria-agent`` with no subcommand falls through to the legacy
 long-poll behavior for back-compatibility with existing deployments.
@@ -28,6 +31,57 @@ from .namegen import generate_agent_name
 _LEGACY_ALIASES = {"--hub", "--key", "--name", "--device", "--insecure", "--log-level", "--config"}
 
 
+REGISTRATION_REASON_MESSAGES = {
+    "invalid_key": (
+        "Registration key not recognized. Generate a fresh key from "
+        "Settings → RIA Agents on the hub."
+    ),
+    "expired": (
+        "This registration key has expired. Generate a new one from "
+        "Settings → RIA Agents on the hub."
+    ),
+    "revoked": (
+        "This registration key was revoked. Generate a new one from "
+        "Settings → RIA Agents on the hub."
+    ),
+    "already_consumed": (
+        "This single-use registration key has already been used. "
+        "Generate a new one, or mint a reusable key instead."
+    ),
+}
+
+
+def _explain_registration_failure(status: int, body: bytes) -> str:
+    """Return a human-readable explanation for a failed register call."""
+    try:
+        parsed = json.loads(body) if body else None
+    except ValueError:
+        parsed = None
+
+    if status == 429:
+        # 429 carries a plain string detail, never a reason code.
+        if isinstance(parsed, dict) and parsed.get("detail"):
+            detail = parsed["detail"]
+        else:
+            detail = body.decode("utf-8", "replace") or "rate limited"
+        return f"Registration rate-limited by the hub: {detail}"
+
+    if not isinstance(parsed, dict):
+        text = body.decode("utf-8", "replace")
+        return f"HTTP {status}: {text or 'no body'}"
+
+    detail = parsed.get("detail")
+    if isinstance(detail, dict):
+        reason = detail.get("reason")
+        if reason in REGISTRATION_REASON_MESSAGES:
+            return REGISTRATION_REASON_MESSAGES[reason]
+        if reason:
+            return f"Registration rejected ({reason})"
+    if isinstance(detail, str) and detail:
+        return f"Registration rejected: {detail}"
+    return f"HTTP {status}: {parsed}"
+
+
 def _cmd_detect(_args: argparse.Namespace) -> int:
     devices = available_devices()
     if not devices:
@@ -39,6 +93,7 @@ def _cmd_detect(_args: argparse.Namespace) -> int:
 
 
 def _cmd_register(args: argparse.Namespace) -> int:
+    import urllib.error
     import urllib.request
 
     hub_url = args.hub.rstrip("/")
@@ -56,6 +111,14 @@ def _cmd_register(args: argparse.Namespace) -> int:
     try:
         with urllib.request.urlopen(req) as resp:
             data = json.loads(resp.read())
+    except urllib.error.HTTPError as e:
+        try:
+            err_body = e.read()
+        except Exception:
+            err_body = b""
+        msg = _explain_registration_failure(e.code, err_body)
+        print(f"error: registration failed: {msg}", file=sys.stderr)
+        return 1
     except Exception as e:
         print(f"error: registration failed: {e}", file=sys.stderr)
         return 1
@@ -141,7 +204,16 @@ def main() -> None:
 
     p_reg = sub.add_parser("register", help="Register agent with RIA Hub and save credentials")
     p_reg.add_argument("--hub", required=True, help="RIA Hub URL (e.g. http://whitehorse:3005)")
-    p_reg.add_argument("--api-key", dest="api_key", required=True, help="Hub API key")
+    p_reg.add_argument(
+        "--api-key",
+        dest="api_key",
+        required=True,
+        help=(
+            "Personal registration key from the RIA Agents page on the hub "
+            "(format: ria_reg_...). Shown once when generated; save it then. "
+            "The legacy shared API key is also accepted but deprecated."
+        ),
+    )
     p_reg.add_argument("--name", default=None, help="Human-friendly agent name")
     p_reg.add_argument("--insecure", action="store_true", help="Skip TLS verification")
     p_reg.add_argument(

tests/agent/test_cli_register_errors.py

@@ -0,0 +1,95 @@
+"""Structured error reporting for `ria-agent register` (T2)."""
+
+from __future__ import annotations
+
+import json
+import sys
+import urllib.error
+from io import BytesIO
+from unittest.mock import patch
+
+import pytest
+
+from ria_toolkit_oss.agent import cli as agent_cli
+
+
+def _structured(reason: str) -> bytes:
+    return json.dumps({"detail": {"reason": reason}}).encode()
+
+
+@pytest.mark.parametrize(
+    "reason",
+    ["invalid_key", "expired", "revoked", "already_consumed"],
+)
+def test_explain_maps_known_reasons(reason):
+    msg = agent_cli._explain_registration_failure(403, _structured(reason))
+    assert msg == agent_cli.REGISTRATION_REASON_MESSAGES[reason]
+
+
+def test_explain_unknown_reason_falls_through_with_code():
+    msg = agent_cli._explain_registration_failure(403, _structured("brand_new_thing"))
+    assert "brand_new_thing" in msg
+    assert "rejected" in msg.lower()
+
+
+def test_explain_string_detail():
+    body = json.dumps({"detail": "Forbidden"}).encode()
+    msg = agent_cli._explain_registration_failure(403, body)
+    assert msg == "Registration rejected: Forbidden"
+
+
+def test_explain_429_with_string_detail():
+    body = json.dumps({"detail": "Too many attempts; try again shortly"}).encode()
+    msg = agent_cli._explain_registration_failure(429, body)
+    assert "rate-limited" in msg
+    assert "Too many attempts" in msg
+
+
+def test_explain_429_with_no_body():
+    msg = agent_cli._explain_registration_failure(429, b"")
+    assert "rate-limited" in msg
+
+
+def test_explain_malformed_json():
+    msg = agent_cli._explain_registration_failure(500, b"<html>boom</html>")
+    assert msg.startswith("HTTP 500")
+    assert "boom" in msg
+
+
+def test_explain_empty_body():
+    msg = agent_cli._explain_registration_failure(502, b"")
+    assert msg == "HTTP 502: no body"
+
+
+def _http_error(status: int, body: bytes) -> urllib.error.HTTPError:
+    return urllib.error.HTTPError(
+        url="http://hub/screens/agents/register",
+        code=status,
+        msg="",
+        hdrs=None,  # type: ignore[arg-type]
+        fp=BytesIO(body),
+    )
+
+
+def test_register_surfaces_reason_on_http_error(tmp_path, capsys):
+    cfg_path = tmp_path / "agent.json"
+    err = _http_error(403, _structured("revoked"))
+
+    with (
+        patch.dict("os.environ", {"RIA_AGENT_CONFIG": str(cfg_path)}, clear=False),
+        patch("urllib.request.urlopen", side_effect=err),
+        patch.object(
+            sys,
+            "argv",
+            ["ria-agent", "register", "--hub", "http://hub:3005", "--api-key", "ria_reg_x"],
+        ),
+    ):
+        with pytest.raises(SystemExit) as exc:
+            agent_cli.main()
+
+    assert exc.value.code == 1
+    captured = capsys.readouterr()
+    assert "revoked" in captured.err.lower()
+    assert "Settings → RIA Agents" in captured.err
+    # Config must NOT be written on failure.
+    assert not cfg_path.exists()