from __future__ import annotations import base64 import json import re from typing import Any import httpx from deepagents import create_deep_agent from langchain_core.messages import BaseMessage from langchain_core.tools import StructuredTool from langchain_openai import ChatOpenAI from pydantic import BaseModel, Field from a2a_pack import ( A2AAgent, ConsumerSetup, ConsumerSetupField, ConsumerSetupMissing, EgressPolicy, LLMProvisioning, Pricing, Resources, RunContext, skill, ) DEFAULT_BASE_URL = "https://tasks.a2acloud.io" OPERATIONS = json.loads("{\n \"create_task\": {\n \"description\": \"Create Task\",\n \"destructive\": true,\n \"method\": \"POST\",\n \"operation_id\": \"create_task\",\n \"parameters\": [],\n \"path\": \"/api/tasks\",\n \"request_body\": {\n \"$ref\": \"#/components/schemas/TaskCreate\"\n },\n \"security\": [\n {\n \"bearerAuth\": []\n },\n {\n \"apiKeyAuth\": []\n }\n ],\n \"skill_name\": \"create_task\",\n \"summary\": \"Create Task\",\n \"tags\": [\n \"Tasks\"\n ]\n },\n \"delete_task\": {\n \"description\": \"Delete Task\",\n \"destructive\": true,\n \"method\": \"DELETE\",\n \"operation_id\": \"delete_task\",\n \"parameters\": [\n {\n \"description\": \"\",\n \"in\": \"path\",\n \"name\": \"task_id\",\n \"required\": true,\n \"schema\": {\n \"title\": \"Task Id\",\n \"type\": \"string\"\n }\n }\n ],\n \"path\": \"/api/tasks/{task_id}\",\n \"request_body\": null,\n \"security\": [\n {\n \"bearerAuth\": []\n },\n {\n \"apiKeyAuth\": []\n }\n ],\n \"skill_name\": \"delete_task\",\n \"summary\": \"Delete Task\",\n \"tags\": [\n \"Tasks\"\n ]\n },\n \"get_task\": {\n \"description\": \"Get Task\",\n \"destructive\": false,\n \"method\": \"GET\",\n \"operation_id\": \"get_task\",\n \"parameters\": [\n {\n \"description\": \"\",\n \"in\": \"path\",\n \"name\": \"task_id\",\n \"required\": true,\n \"schema\": {\n \"title\": \"Task Id\",\n \"type\": \"string\"\n }\n }\n ],\n \"path\": \"/api/tasks/{task_id}\",\n \"request_body\": null,\n \"security\": [\n {\n \"bearerAuth\": []\n },\n {\n \"apiKeyAuth\": []\n }\n ],\n \"skill_name\": \"get_task\",\n \"summary\": \"Get Task\",\n \"tags\": [\n \"Tasks\"\n ]\n },\n \"get_tasks_health\": {\n \"description\": \"Healthz\",\n \"destructive\": false,\n \"method\": \"GET\",\n \"operation_id\": \"get_tasks_health\",\n \"parameters\": [],\n \"path\": \"/healthz\",\n \"request_body\": null,\n \"security\": null,\n \"skill_name\": \"get_tasks_health\",\n \"summary\": \"Healthz\",\n \"tags\": [\n \"Health\"\n ]\n },\n \"list_tasks\": {\n \"description\": \"List Tasks\",\n \"destructive\": false,\n \"method\": \"GET\",\n \"operation_id\": \"list_tasks\",\n \"parameters\": [\n {\n \"description\": \"\",\n \"in\": \"query\",\n \"name\": \"status\",\n \"required\": false,\n \"schema\": {\n \"anyOf\": [\n {\n \"enum\": [\n \"todo\",\n \"in_progress\",\n \"done\",\n \"canceled\"\n ],\n \"type\": \"string\"\n },\n {\n \"type\": \"null\"\n }\n ],\n \"title\": \"Status\"\n }\n },\n {\n \"description\": \"\",\n \"in\": \"query\",\n \"name\": \"q\",\n \"required\": false,\n \"schema\": {\n \"anyOf\": [\n {\n \"maxLength\": 120,\n \"minLength\": 1,\n \"type\": \"string\"\n },\n {\n \"type\": \"null\"\n }\n ],\n \"title\": \"Q\"\n }\n },\n {\n \"description\": \"\",\n \"in\": \"query\",\n \"name\": \"due_before\",\n \"required\": false,\n \"schema\": {\n \"anyOf\": [\n {\n \"format\": \"date-time\",\n \"type\": \"string\"\n },\n {\n \"type\": \"null\"\n }\n ],\n \"title\": \"Due Before\"\n }\n },\n {\n \"description\": \"\",\n \"in\": \"query\",\n \"name\": \"limit\",\n \"required\": false,\n \"schema\": {\n \"default\": 50,\n \"maximum\": 200,\n \"minimum\": 1,\n \"title\": \"Limit\",\n \"type\": \"integer\"\n }\n },\n {\n \"description\": \"\",\n \"in\": \"query\",\n \"name\": \"offset\",\n \"required\": false,\n \"schema\": {\n \"default\": 0,\n \"minimum\": 0,\n \"title\": \"Offset\",\n \"type\": \"integer\"\n }\n }\n ],\n \"path\": \"/api/tasks\",\n \"request_body\": null,\n \"security\": [\n {\n \"bearerAuth\": []\n },\n {\n \"apiKeyAuth\": []\n }\n ],\n \"skill_name\": \"list_tasks\",\n \"summary\": \"List Tasks\",\n \"tags\": [\n \"Tasks\"\n ]\n },\n \"update_task\": {\n \"description\": \"Update Task\",\n \"destructive\": true,\n \"method\": \"PATCH\",\n \"operation_id\": \"update_task\",\n \"parameters\": [\n {\n \"description\": \"\",\n \"in\": \"path\",\n \"name\": \"task_id\",\n \"required\": true,\n \"schema\": {\n \"title\": \"Task Id\",\n \"type\": \"string\"\n }\n }\n ],\n \"path\": \"/api/tasks/{task_id}\",\n \"request_body\": {\n \"$ref\": \"#/components/schemas/TaskUpdate\"\n },\n \"security\": [\n {\n \"bearerAuth\": []\n },\n {\n \"apiKeyAuth\": []\n }\n ],\n \"skill_name\": \"update_task\",\n \"summary\": \"Update Task\",\n \"tags\": [\n \"Tasks\"\n ]\n }\n}") ROOT_SECURITY = json.loads("[]") SECURITY_SCHEMES = json.loads("{\n \"apiKeyAuth\": {\n \"description\": \"Use the configured `TASKS_API_KEY` value.\",\n \"in\": \"header\",\n \"name\": \"x-api-key\",\n \"type\": \"apiKey\"\n },\n \"bearerAuth\": {\n \"description\": \"Use `Authorization: Bearer $TASKS_API_KEY`.\",\n \"scheme\": \"bearer\",\n \"type\": \"http\"\n }\n}") SECURITY_FIELDS = json.loads("{\n \"apiKeyAuth\": {\n \"field\": \"X_API_KEY\",\n \"kind\": \"apiKey\",\n \"location\": \"header\",\n \"name\": \"x-api-key\"\n },\n \"bearerAuth\": {\n \"field\": \"BEARERAUTH_TOKEN\",\n \"kind\": \"http\",\n \"scheme\": \"bearer\"\n }\n}") PATH_PARAMETER_RE = re.compile(r"{([^}/]+)}") class OperationInput(BaseModel): parameters: dict[str, Any] = Field( default_factory=dict, description="Path, query, header, and cookie parameters keyed by OpenAPI parameter name.", ) body: Any | None = Field(default=None, description="JSON request body, when the operation accepts one.") class TasksApi(A2AAgent): name = "tasks-api" description = "API-only service for tracking tasks in Postgres." version = "0.1.0" consumer_setup = ConsumerSetup.from_fields( ConsumerSetupField.config("OPENAPI_BASE_URL", label="API base URL", description="Override the default API server (https://tasks.a2acloud.io).", required=False, input_type="url"), ConsumerSetupField.secret("BEARERAUTH_TOKEN", label="bearerAuth bearer credential", description="Use `Authorization: Bearer $TASKS_API_KEY`.", required=True), ConsumerSetupField.secret("X_API_KEY", label="apiKeyAuth API key", description="Use the configured `TASKS_API_KEY` value.", required=True), ) llm_provisioning = LLMProvisioning.PLATFORM pricing = Pricing( price_per_call_usd=0.0, caller_pays_llm=False, notes="Uses a scoped platform LLM grant through ctx.llm.", ) resources = Resources(cpu="200m", memory="512Mi") egress = EgressPolicy( allow_hosts=('tasks.a2acloud.io',), deny_internet_by_default=True, ) tools_used = ("openapi", "deepagents") capabilities = { "openapi_auto_agent": { "operation_count": len(OPERATIONS), "default_base_url": DEFAULT_BASE_URL, "security_schemes": list(SECURITY_SCHEMES), } } @skill( name="auto", description="Use the OpenAPI service to complete a natural-language goal.", tags=("openapi", "auto"), timeout_seconds=180, ) async def auto(self, ctx: RunContext, goal: str) -> dict[str, Any]: creds = ctx.llm if not creds.api_key: return { "error": "llm_credentials_missing", "final": ( "LLM credentials were not available for this run. Hosted " "generated OpenAPI agents should receive a platform LLM grant." ), "messages": [], } model_kwargs: dict[str, Any] = { "model": creds.model, "base_url": creds.base_url, "api_key": creds.api_key, } if creds.temperature_mode != "omit" and creds.temperature is not None: model_kwargs["temperature"] = creds.temperature if creds.extra_body: model_kwargs["extra_body"] = dict(creds.extra_body) model = ChatOpenAI(**model_kwargs) graph = create_deep_agent( model=model, tools=self._operation_tools(ctx), system_prompt=self._system_prompt(), ) result = await graph.ainvoke({"messages": [{"role": "user", "content": goal}]}) messages = result.get("messages", []) if isinstance(result, dict) else [] final = _message_text(messages[-1]) if messages else result return { "final": final, "messages": [_message_to_dict(message) for message in messages[-8:]], } @skill( name="get_tasks_health", description="GET /healthz - Healthz", tags=('Health',), timeout_seconds=60, ) async def get_tasks_health( self, ctx: RunContext, parameters: dict[str, Any] | None = None, body: Any | None = None, ) -> dict[str, Any]: return await self._request( ctx, "get_tasks_health", parameters=parameters or {}, body=body, ) @skill( name="list_tasks", description="GET /api/tasks - List Tasks", tags=('Tasks',), timeout_seconds=60, ) async def list_tasks( self, ctx: RunContext, parameters: dict[str, Any] | None = None, body: Any | None = None, ) -> dict[str, Any]: return await self._request( ctx, "list_tasks", parameters=parameters or {}, body=body, ) @skill( name="create_task", description="POST /api/tasks - Create Task", tags=('Tasks',), timeout_seconds=120, ) async def create_task( self, ctx: RunContext, parameters: dict[str, Any] | None = None, body: Any | None = None, ) -> dict[str, Any]: return await self._request( ctx, "create_task", parameters=parameters or {}, body=body, ) @skill( name="get_task", description="GET /api/tasks/{task_id} - Get Task", tags=('Tasks',), timeout_seconds=60, ) async def get_task( self, ctx: RunContext, parameters: dict[str, Any] | None = None, body: Any | None = None, ) -> dict[str, Any]: return await self._request( ctx, "get_task", parameters=parameters or {}, body=body, ) @skill( name="update_task", description="PATCH /api/tasks/{task_id} - Update Task", tags=('Tasks',), timeout_seconds=120, ) async def update_task( self, ctx: RunContext, parameters: dict[str, Any] | None = None, body: Any | None = None, ) -> dict[str, Any]: return await self._request( ctx, "update_task", parameters=parameters or {}, body=body, ) @skill( name="delete_task", description="DELETE /api/tasks/{task_id} - Delete Task", tags=('Tasks',), timeout_seconds=120, ) async def delete_task( self, ctx: RunContext, parameters: dict[str, Any] | None = None, body: Any | None = None, ) -> dict[str, Any]: return await self._request( ctx, "delete_task", parameters=parameters or {}, body=body, ) def _operation_tools(self, ctx: RunContext) -> list[StructuredTool]: tools: list[StructuredTool] = [] for operation_id, operation in OPERATIONS.items(): async def call( parameters: dict[str, Any] | None = None, body: Any | None = None, *, _operation_id: str = operation_id, ) -> dict[str, Any]: return await self._request( ctx, _operation_id, parameters=parameters or {}, body=body, ) tools.append( StructuredTool.from_function( coroutine=call, name=operation["skill_name"], description=self._tool_description(operation), args_schema=OperationInput, ) ) return tools def _system_prompt(self) -> str: lines = [ "You operate an API through generated OpenAPI tools.", "Call tools to get real results. Do not invent API responses.", "For write, update, or delete operations, explain the intended action before calling the tool.", "If an operation reports missing consumer setup, tell the user which setup field is required.", "", "Available operations:", ] for operation in OPERATIONS.values(): marker = "WRITE" if operation.get("destructive") else "READ" lines.append( f"- {operation['skill_name']}: {marker} {operation['method']} {operation['path']} — {operation['summary']}" ) return "\n".join(lines) def _tool_description(self, operation: dict[str, Any]) -> str: parts = [ f"{operation['method']} {operation['path']}", str(operation.get("description") or operation.get("summary") or ""), ] if operation.get("parameters"): parts.append( "Parameters: " + ", ".join( f"{p['name']} in {p['in']}{' required' if p.get('required') else ''}" for p in operation["parameters"] ) ) if operation.get("request_body") is not None: parts.append("Accepts a JSON request body.") return "\n".join(part for part in parts if part) async def _request( self, ctx: RunContext, operation_id: str, *, parameters: dict[str, Any], body: Any | None, ) -> dict[str, Any]: operation = OPERATIONS[operation_id] base_url = str(ctx.consumer_config("OPENAPI_BASE_URL", DEFAULT_BASE_URL) or DEFAULT_BASE_URL).rstrip("/") url, query, headers = self._request_parts(ctx, operation, parameters) request_kwargs: dict[str, Any] = { "params": query, "headers": headers, } if body is not None: request_kwargs["json"] = body async with httpx.AsyncClient(timeout=60.0, follow_redirects=True) as client: response = await client.request( operation["method"], f"{base_url}{url}", **request_kwargs, ) content_type = response.headers.get("content-type", "") try: payload: Any = response.json() if "json" in content_type else response.text except ValueError: payload = response.text if response.status_code >= 400: return { "ok": False, "status_code": response.status_code, "operation_id": operation_id, "error": payload, } return { "ok": True, "status_code": response.status_code, "operation_id": operation_id, "result": payload, } def _request_parts( self, ctx: RunContext, operation: dict[str, Any], parameters: dict[str, Any], ) -> tuple[str, dict[str, Any], dict[str, str]]: path = operation["path"] query: dict[str, Any] = {} headers: dict[str, str] = {} cookies: dict[str, Any] = {} for param in operation.get("parameters") or []: name = param["name"] if name not in parameters: if param.get("required"): raise ValueError(f"missing required parameter {name!r}") continue value = parameters[name] location = param["in"] if location == "path": path = path.replace("{" + name + "}", str(value)) elif location == "query": query[name] = value elif location == "header": headers[name] = str(value) elif location == "cookie": cookies[name] = value unresolved = PATH_PARAMETER_RE.findall(path) if unresolved: missing = ", ".join(sorted(set(unresolved))) raise ValueError("missing required path parameter(s): " + missing) if cookies: headers["cookie"] = "; ".join(f"{key}={value}" for key, value in cookies.items()) auth_headers, auth_query = self._auth_for_operation(ctx, operation) headers.update(auth_headers) query.update(auth_query) return path, query, headers def _auth_for_operation(self, ctx: RunContext, operation: dict[str, Any]) -> tuple[dict[str, str], dict[str, Any]]: requirements = operation.get("security") if requirements is None: requirements = ROOT_SECURITY if requirements == []: return {}, {} missing: list[str] = [] for requirement in requirements or []: if not isinstance(requirement, dict) or not requirement: return {}, {} headers: dict[str, str] = {} query: dict[str, Any] = {} ok = True for scheme_name in requirement: mapping = SECURITY_FIELDS.get(scheme_name) or {} secret_name = mapping.get("field") value = _consumer_secret_optional(ctx, secret_name) if secret_name else "" if not value: ok = False if secret_name: missing.append(secret_name) continue kind = mapping.get("kind") if kind == "apiKey": prefix = mapping.get("prefix") or "" sent_value = f"{prefix}{value}" if mapping.get("location") == "query": query[mapping.get("name") or scheme_name] = sent_value else: headers[mapping.get("name") or scheme_name] = sent_value elif kind in {"http", "oauth2"}: scheme = mapping.get("scheme") or "Bearer" if scheme.lower() == "basic": token = base64.b64encode(value.encode("utf-8")).decode("ascii") headers["authorization"] = f"Basic {token}" else: headers["authorization"] = f"{scheme} {value}" else: ok = False if ok: return headers, query if missing: raise ConsumerSetupMissing( "operation requires consumer setup secret(s): " + ", ".join(sorted(set(missing))) ) return {}, {} def _consumer_secret_optional(ctx: RunContext, name: str | None) -> str: if not name: return "" try: return ctx.consumer_secret(name) except ConsumerSetupMissing: return "" def _message_text(message: Any) -> Any: content = getattr(message, "content", message) return content def _message_to_dict(message: Any) -> dict[str, Any]: if isinstance(message, BaseMessage): return message.model_dump(mode="json") if hasattr(message, "model_dump"): return message.model_dump(mode="json") if isinstance(message, dict): return message return {"content": str(message)} agent = TasksApi()