fix: update hermes_cli/web_server.py for agent card discovery

agent/agent_card.py

@@ -0,0 +1,135 @@
+"""
+Agent Card — A2A-compliant agent discovery.
+Part of #843: fix: implement A2A agent card for fleet discovery (#819)
+
+Provides metadata about the agent's identity, capabilities, and installed skills
+for discovery by other agents in the fleet.
+"""
+
+import json
+import logging
+import os
+from dataclasses import asdict, dataclass, field
+from pathlib import Path
+from typing import Any, Dict, List, Optional
+
+from hermes_cli import __version__
+from hermes_cli.config import load_config, get_hermes_home
+from agent.skill_utils import (
+    iter_skill_index_files,
+    parse_frontmatter,
+    get_all_skills_dirs,
+    get_disabled_skill_names,
+    skill_matches_platform
+)
+
+logger = logging.getLogger(__name__)
+
+@dataclass
+class AgentSkill:
+    id: str
+    name: str
+    description: str = ""
+    version: str = "1.0.0"
+
+@dataclass
+class AgentCapabilities:
+    streaming: bool = True
+    tools: bool = True
+    vision: bool = False
+    reasoning: bool = False
+
+@dataclass
+class AgentCard:
+    name: str
+    description: str
+    url: str
+    version: str = __version__
+    capabilities: AgentCapabilities = field(default_factory=AgentCapabilities)
+    skills: List[AgentSkill] = field(default_factory=list)
+    defaultInputModes: List[str] = field(default_factory=lambda: ["text/plain"])
+    defaultOutputModes: List[str] = field(default_factory=lambda: ["text/plain"])
+
+def _load_skills() -> List[AgentSkill]:
+    """Scan all enabled skills and return metadata."""
+    skills = []
+    disabled = get_disabled_skill_names()
+    
+    for skills_dir in get_all_skills_dirs():
+        if not skills_dir.is_dir():
+            continue
+        for skill_file in iter_skill_index_files(skills_dir, "SKILL.md"):
+            try:
+                raw = skill_file.read_text(encoding="utf-8")
+                frontmatter, _ = parse_frontmatter(raw)
+            except Exception:
+                continue
+
+            skill_name = frontmatter.get("name") or skill_file.parent.name
+            if str(skill_name) in disabled:
+                continue
+            if not skill_matches_platform(frontmatter):
+                continue
+
+            skills.append(AgentSkill(
+                id=str(skill_name),
+                name=str(frontmatter.get("name", skill_name)),
+                description=str(frontmatter.get("description", "")),
+                version=str(frontmatter.get("version", "1.0.0"))
+            ))
+    return skills
+
+def build_agent_card() -> AgentCard:
+    """Build the agent card from current configuration and environment."""
+    config = load_config()
+    
+    # Identity
+    name = os.environ.get("HERMES_AGENT_NAME") or config.get("agent", {}).get("name") or "hermes"
+    description = os.environ.get("HERMES_AGENT_DESCRIPTION") or config.get("agent", {}).get("description") or "Sovereign AI agent"
+    
+    # URL - try to determine from environment or config
+    port = os.environ.get("HERMES_WEB_PORT") or "9119"
+    host = os.environ.get("HERMES_WEB_HOST") or "localhost"
+    url = f"http://{host}:{port}"
+    
+    # Capabilities
+    # In a real scenario, we'd check model metadata for vision/reasoning
+    capabilities = AgentCapabilities(
+        streaming=True,
+        tools=True,
+        vision=False, # Default to false unless we can confirm
+        reasoning=False
+    )
+    
+    # Skills
+    skills = _load_skills()
+    
+    return AgentCard(
+        name=name,
+        description=description,
+        url=url,
+        version=__version__,
+        capabilities=capabilities,
+        skills=skills
+    )
+
+def get_agent_card_json() -> str:
+    """Return the agent card as a JSON string."""
+    try:
+        card = build_agent_card()
+        return json.dumps(asdict(card), indent=2)
+    except Exception as e:
+        logger.error(f"Failed to build agent card: {e}")
+        # Minimal fallback card
+        fallback = {
+            "name": "hermes",
+            "description": "Sovereign AI agent (fallback)",
+            "version": __version__,
+            "error": str(e)
+        }
+        return json.dumps(fallback, indent=2)
+
+def validate_agent_card(card_data: Dict[str, Any]) -> bool:
+    """Check if the card data complies with the A2A schema."""
+    required = ["name", "description", "url", "version"]
+    return all(k in card_data for k in required)

hermes_cli/web_server.py

@@ -45,6 +45,7 @@ from hermes_cli.config import (
     redact_key,
 )
 from gateway.status import get_running_pid, read_runtime_status
+from agent.agent_card import get_agent_card_json
 
 try:
     from fastapi import FastAPI, HTTPException, Request
@@ -96,6 +97,9 @@ _PUBLIC_API_PATHS: frozenset = frozenset({
     "/api/config/defaults",
     "/api/config/schema",
     "/api/model/info",
+    "/api/agent-card",
+    "/agent-card.json",
+    "/.well-known/agent-card.json",
 })
 
 
@@ -360,6 +364,14 @@ def _probe_gateway_health() -> tuple[bool, dict | None]:
     return False, None
 
 
+@app.get("/api/agent-card")
+@app.get("/agent-card.json")
+@app.get("/.well-known/agent-card.json")
+async def get_agent_card():
+    """Return the A2A agent card for fleet discovery."""
+    return JSONResponse(content=json.loads(get_agent_card_json()))
+
+
 @app.get("/api/status")
 async def get_status():
     current_ver, latest_ver = check_config_version()