File size: 8,950 Bytes
0e3d4b8 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 | """REST API Client — connect to external APIs and services.
Features:
- Generic REST client (GET, POST, PUT, DELETE)
- Authentication: API key, Bearer token, Basic auth, custom headers
- Request/response logging
- Rate limiting (configurable requests per second)
- Retry with exponential backoff
- Timeout handling
- JSON and raw response support
- Connection pooling (via urllib)
Uses only stdlib urllib — no external dependencies.
100% local: no data sent to any cloud service unless explicitly configured.
"""
from __future__ import annotations
import json
import logging
import time
import urllib.error
import urllib.request
from dataclasses import dataclass, field
from typing import Any
logger = logging.getLogger(__name__)
@dataclass
class APIConfig:
"""Configuration for an API connection."""
name: str
base_url: str
api_key: str = ""
auth_type: str = "api_key" # "api_key", "bearer", "basic", "none", "custom"
headers: dict[str, str] = field(default_factory=dict)
timeout_s: float = 30.0
max_retries: int = 3
rate_limit_s: float = 0.0 # min seconds between requests
retry_backoff: float = 1.5
@dataclass
class APIResponse:
"""Response from an API call."""
success: bool
status_code: int
data: Any = None
error: str = ""
elapsed_s: float = 0.0
url: str = ""
class RESTClient:
"""Generic REST API client with auth, retries, and rate limiting."""
def __init__(self, config: APIConfig) -> None:
self.config = config
self._last_request_time = 0.0
self._stats = {
"total_requests": 0,
"successful_requests": 0,
"failed_requests": 0,
"retries": 0,
"avg_response_time_s": 0.0,
}
def _build_headers(self, extra: dict[str, str] | None = None) -> dict[str, str]:
"""Build request headers with authentication."""
headers = dict(self.config.headers)
if extra:
headers.update(extra)
if self.config.auth_type == "api_key" and self.config.api_key:
headers["X-API-Key"] = self.config.api_key
elif self.config.auth_type == "bearer" and self.config.api_key:
headers["Authorization"] = f"Bearer {self.config.api_key}"
elif self.config.auth_type == "basic" and self.config.api_key:
import base64
headers["Authorization"] = f"Basic {base64.b64encode(self.config.api_key.encode()).decode()}"
return headers
def _rate_limit(self) -> None:
"""Enforce rate limiting."""
if self.config.rate_limit_s > 0:
elapsed = time.time() - self._last_request_time
if elapsed < self.config.rate_limit_s:
time.sleep(self.config.rate_limit_s - elapsed)
self._last_request_time = time.time()
def request(self, method: str, endpoint: str, data: dict | None = None,
params: dict | None = None, headers: dict | None = None) -> APIResponse:
"""Make an HTTP request.
Args:
method: GET, POST, PUT, DELETE
endpoint: API endpoint (appended to base_url)
data: request body (JSON)
params: query parameters
headers: extra headers
"""
url = self._build_url(endpoint, params)
body = json.dumps(data).encode() if data else None
req_headers = self._build_headers(headers)
if body:
req_headers["Content-Type"] = "application/json"
for attempt in range(self.config.max_retries + 1):
self._rate_limit()
t0 = time.time()
self._stats["total_requests"] += 1
try:
req = urllib.request.Request(url, data=body, method=method, headers=req_headers)
with urllib.request.urlopen(req, timeout=self.config.timeout_s) as resp:
raw = resp.read().decode()
elapsed = time.time() - t0
self._stats["successful_requests"] += 1
self._update_avg_time(elapsed)
try:
parsed = json.loads(raw)
except json.JSONDecodeError:
parsed = raw
return APIResponse(
success=True, status_code=resp.status,
data=parsed, elapsed_s=elapsed, url=url,
)
except urllib.error.HTTPError as e:
elapsed = time.time() - t0
error_body = ""
try:
error_body = e.read().decode()
except Exception:
pass
if attempt < self.config.max_retries and e.code >= 500:
self._stats["retries"] += 1
wait = self.config.retry_backoff ** (attempt + 1)
logger.warning("Retry %d/%d for %s (HTTP %d) after %.1fs",
attempt + 1, self.config.max_retries, url, e.code, wait)
time.sleep(wait)
continue
self._stats["failed_requests"] += 1
return APIResponse(
success=False, status_code=e.code,
error=f"HTTP {e.code}: {error_body[:200]}", elapsed_s=elapsed, url=url,
)
except Exception as e:
elapsed = time.time() - t0
if attempt < self.config.max_retries:
self._stats["retries"] += 1
wait = self.config.retry_backoff ** (attempt + 1)
logger.warning("Retry %d/%d for %s: %s", attempt + 1, self.config.max_retries, url, e)
time.sleep(wait)
continue
self._stats["failed_requests"] += 1
return APIResponse(
success=False, status_code=0,
error=str(e), elapsed_s=elapsed, url=url,
)
return APIResponse(success=False, status_code=0, error="Max retries exceeded", url=url)
def get(self, endpoint: str, params: dict | None = None) -> APIResponse:
return self.request("GET", endpoint, params=params)
def post(self, endpoint: str, data: dict | None = None) -> APIResponse:
return self.request("POST", endpoint, data=data)
def put(self, endpoint: str, data: dict | None = None) -> APIResponse:
return self.request("PUT", endpoint, data=data)
def delete(self, endpoint: str) -> APIResponse:
return self.request("DELETE", endpoint)
def _build_url(self, endpoint: str, params: dict | None = None) -> str:
url = f"{self.config.base_url.rstrip('/')}/{endpoint.lstrip('/')}"
if params:
import urllib.parse
query = urllib.parse.urlencode(params)
url = f"{url}?{query}"
return url
def _update_avg_time(self, elapsed: float) -> None:
total = self._stats["successful_requests"]
self._stats["avg_response_time_s"] = (
(self._stats["avg_response_time_s"] * (total - 1) + elapsed) / total
)
def get_stats(self) -> dict[str, Any]:
return {**self._stats, "name": self.config.name, "base_url": self.config.base_url}
class ConnectorRegistry:
"""Registry of named API connectors.
Allows the LLM to connect to multiple external services.
Connectors are registered with a name and can be called by the LLM
via tool calls: [TOOL: api_call("service_name", "GET", "/endpoint")]
"""
def __init__(self) -> None:
self._connectors: dict[str, RESTClient] = {}
self._stats = {"total_connectors": 0, "total_calls": 0}
def register(self, name: str, config: APIConfig) -> None:
"""Register a named API connector."""
config.name = name
client = RESTClient(config)
self._connectors[name] = client
self._stats["total_connectors"] += 1
logger.info("Registered API connector: %s → %s", name, config.base_url)
def get(self, name: str) -> RESTClient | None:
return self._connectors.get(name)
def call(self, name: str, method: str, endpoint: str,
data: dict | None = None, params: dict | None = None) -> APIResponse:
"""Call a registered connector."""
client = self._connectors.get(name)
if client is None:
return APIResponse(success=False, status_code=0, error=f"Connector '{name}' not found")
self._stats["total_calls"] += 1
return client.request(method, endpoint, data=data, params=params)
def list_connectors(self) -> list[dict[str, Any]]:
return [{"name": name, **client.get_stats()} for name, client in self._connectors.items()]
def get_stats(self) -> dict[str, Any]:
return {**self._stats, "connectors": {name: c.get_stats() for name, c in self._connectors.items()}}
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