Normalizing Cognigy.AI Entity Extraction Outputs via REST API with Python

Normalizing Cognigy.AI Entity Extraction Outputs via REST API with Python

What You Will Build

  • A Python service that transforms raw Cognigy.AI entity extraction outputs into standardized canonical forms with synonym mappings, enforces schema constraints, and synchronizes updates via atomic PUT operations and webhooks.
  • This tutorial uses the Cognigy.AI v2 REST API for entity management, value normalization, and webhook configuration.
  • The implementation covers Python 3.9+ using httpx for HTTP operations, pydantic for strict schema validation, and structured logging for audit compliance.

Prerequisites

  • Authentication: Cognigy.AI API Key or Bearer Token with permissions equivalent to entities:read, entities:write, webhooks:manage
  • API Version: Cognigy.AI v2
  • Language/Runtime: Python 3.9 or higher
  • External Dependencies: httpx>=0.24.0, pydantic>=2.0.0, pydantic-settings>=2.0.0, python-dotenv>=1.0.0
  • Installation: pip install httpx pydantic pydantic-settings python-dotenv

Authentication Setup

Cognigy.AI secures API access via Bearer tokens. The following client initialization handles token injection, request timeouts, and automatic retry configuration for rate limiting.

import os
import httpx
from pydantic_settings import BaseSettings
from typing import Optional

class CognigySettings(BaseSettings):
    base_url: str
    api_token: str
    timeout_seconds: float = 15.0
    max_retries: int = 3

    class Config:
        env_file = ".env"
        case_sensitive = True

def create_cognigy_client(settings: CognigySettings) -> httpx.Client:
    """Initialize an authenticated HTTP client with retry logic for 429 responses."""
    transport = httpx.HTTPTransport(retries=settings.max_retries)
    client = httpx.Client(
        base_url=settings.base_url,
        transport=transport,
        timeout=settings.timeout_seconds,
        headers={
            "Authorization": f"Bearer {settings.api_token}",
            "Content-Type": "application/json",
            "Accept": "application/json"
        }
    )
    return client

Implementation

Step 1: Schema Validation & Payload Construction

Entity normalization requires strict validation against AI engine constraints. The following pipeline enforces regex boundaries, language locale verification, synonym matrix limits, and automatic case folding for canonical directives.

import re
import uuid
import time
import logging
from typing import List, Dict, Any
from pydantic import BaseModel, field_validator, ValidationError

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# AI Engine Constraints
MAX_ENTITY_VALUES = 5000
MAX_SYNONYMS_PER_VALUE = 20
CANONICAL_REGEX = re.compile(r"^[a-zA-Z0-9\s\-']{1,100}$")

class EntityValuePayload(BaseModel):
    id: Optional[str] = None
    text: str
    canonicalValue: str
    synonyms: List[str] = []

    @field_validator("canonicalValue")
    @classmethod
    def enforce_canonical_constraints(cls, v: str, info) -> str:
        # Automatic case folding trigger
        folded = v.strip().lower()
        if not CANONICAL_REGEX.match(folded):
            raise ValueError(f"Canonical value '{v}' violates regex boundary or length constraints.")
        return folded

    @field_validator("synonyms")
    @classmethod
    def validate_synonym_matrix(cls, v: List[str]) -> List[str]:
        if len(v) > MAX_SYNONYMS_PER_VALUE:
            raise ValueError(f"Synonym count exceeds maximum limit of {MAX_SYNONYMS_PER_VALUE}.")
        # Deduplicate and normalize synonyms
        normalized = list(dict.fromkeys([s.strip().lower() for s in v]))
        if len(normalized) != len(v):
            logger.warning("Duplicate synonyms detected. Deduplicating matrix.")
        return normalized

def construct_normalize_payload(
    entity_id: str,
    raw_extractions: List[Dict[str, Any]],
    target_locale: str
) -> Dict[str, Any]:
    """
    Constructs a normalized payload with entity type references, synonym matrix,
    and canonical directive. Validates against AI engine constraints.
    """
    # Locale verification pipeline
    locale_pattern = re.compile(r"^[a-z]{2}-[A-Z]{2}$")
    if not locale_pattern.match(target_locale):
        raise ValueError(f"Invalid language locale '{target_locale}'. Expected format: en-US")

    values = []
    for item in raw_extractions:
        try:
            payload_item = EntityValuePayload(
                id=item.get("id"),
                text=item["text"],
                canonicalValue=item["canonicalValue"],
                synonyms=item.get("synonyms", [])
            )
            values.append(payload_item.model_dump(exclude_none=True))
        except ValidationError as e:
            logger.error(f"Schema validation failed for extraction: {item['text']}. Details: {e.errors()}")
            raise

    if len(values) > MAX_ENTITY_VALUES:
        raise ValueError(f"Payload exceeds maximum mapping table limit of {MAX_ENTITY_VALUES}.")

    return {
        "entityId": entity_id,
        "locale": target_locale,
        "values": values
    }

Step 2: Atomic PUT Operations & Duplicate Prevention

Cognigy.AI supports atomic replacement of entity values via PUT /api/v2/entities/{entityId}/values. This step fetches existing values to prevent duplicate records during scaling, applies the normalized payload, and handles HTTP errors explicitly.

def fetch_existing_values(client: httpx.Client, entity_id: str) -> List[Dict[str, Any]]:
    """Fetch current entity values with pagination support to prevent duplicate records."""
    all_values = []
    page = 1
    limit = 1000
    
    while True:
        response = client.get(
            f"/api/v2/entities/{entity_id}/values",
            params={"page": page, "limit": limit}
        )
        response.raise_for_status()
        
        data = response.json()
        values = data.get("values", [])
        all_values.extend(values)
        
        # Pagination check
        if len(values) < limit:
            break
        page += 1
        
    return all_values

def atomic_put_normalize(client: httpx.Client, payload: Dict[str, Any]) -> Dict[str, Any]:
    """
    Executes an atomic PUT operation to replace entity values.
    Includes format verification and automatic retry for 429 rate limits.
    """
    entity_id = payload["entityId"]
    endpoint = f"/api/v2/entities/{entity_id}/values"
    
    start_time = time.perf_counter()
    try:
        response = client.put(endpoint, json={"values": payload["values"]})
        latency_ms = (time.perf_counter() - start_time) * 1000
        
        if response.status_code == 200:
            logger.info(f"Normalization successful. Latency: {latency_ms:.2f}ms")
            return {"status": "success", "latency_ms": latency_ms, "response": response.json()}
        elif response.status_code == 409:
            logger.warning("Conflict detected. Entity values may be locked or concurrently modified.")
            return {"status": "conflict", "message": "Entity update conflict"}
        else:
            response.raise_for_status()
    except httpx.HTTPStatusError as e:
        if e.response.status_code == 429:
            logger.warning("Rate limit exceeded. Retry logic engaged by transport layer.")
            return {"status": "rate_limited", "message": "429 Too Many Requests"}
        elif e.response.status_code == 400:
            logger.error(f"Bad Request: {e.response.text}")
            return {"status": "validation_error", "message": e.response.text}
        else:
            logger.error(f"Unexpected HTTP error: {e.response.status_code}")
            raise

Step 3: Webhook Synchronization & Audit Logging

External master data managers require synchronous alignment. This step registers a webhook for entity normalization events, tracks standardization success rates, and generates structured audit logs for AI governance.

import json
from datetime import datetime, timezone

class NormalizationAuditor:
    def __init__(self):
        self.success_count = 0
        self.failure_count = 0
        self.total_latency = 0.0

    def record_event(self, event_type: str, latency_ms: float, success: bool, payload_hash: str):
        audit_entry = {
            "timestamp": datetime.now(timezone.utc).isoformat(),
            "event": event_type,
            "latency_ms": latency_ms,
            "success": success,
            "payload_hash": payload_hash,
            "success_rate": f"{(self.success_count / max(1, self.success_count + self.failure_count)) * 100:.2f}%"
        }
        logger.info(f"AUDIT_LOG: {json.dumps(audit_entry)}")
        if success:
            self.success_count += 1
        else:
            self.failure_count += 1
        self.total_latency += latency_ms

def sync_webhook(client: httpx.Client, webhook_url: str, entity_id: str, event_payload: Dict[str, Any]):
    """Synchronize normalizing events with external master data managers."""
    webhook_endpoint = f"{webhook_url}/entity-normalized"
    sync_payload = {
        "source": "cognigy-ai-normalizer",
        "entityId": entity_id,
        "normalized_at": datetime.now(timezone.utc).isoformat(),
        "data": event_payload
    }
    
    try:
        external_client = httpx.Client(timeout=10.0)
        resp = external_client.post(webhook_endpoint, json=sync_payload)
        if resp.status_code == 200:
            logger.info("External master data manager synchronized successfully.")
        else:
            logger.warning(f"Webhook sync returned status {resp.status_code}. Payload may require manual reconciliation.")
    except Exception as e:
        logger.error(f"Webhook synchronization failed: {e}")

Complete Working Example

The following script combines authentication, validation, atomic updates, webhook synchronization, and audit tracking into a single executable module. Replace environment variables with your Cognigy.AI credentials before execution.

#!/usr/bin/env python3
import os
import httpx
import logging
from typing import Dict, Any, List
from pydantic_settings import BaseSettings

# Import components from previous steps
# (In production, these would be imported from separate modules)
# Re-declaring core logic here for a single copy-pasteable file

import re
import uuid
import time
import json
from datetime import datetime, timezone
from pydantic import BaseModel, field_validator, ValidationError

logging.basicConfig(level=logging.INFO, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s")
logger = logging.getLogger(__name__)

MAX_ENTITY_VALUES = 5000
MAX_SYNONYMS_PER_VALUE = 20
CANONICAL_REGEX = re.compile(r"^[a-zA-Z0-9\s\-']{1,100}$")

class EntityValuePayload(BaseModel):
    id: str | None = None
    text: str
    canonicalValue: str
    synonyms: List[str] = []

    @field_validator("canonicalValue")
    @classmethod
    def enforce_canonical_constraints(cls, v: str, info) -> str:
        folded = v.strip().lower()
        if not CANONICAL_REGEX.match(folded):
            raise ValueError(f"Canonical value '{v}' violates regex boundary or length constraints.")
        return folded

    @field_validator("synonyms")
    @classmethod
    def validate_synonym_matrix(cls, v: List[str]) -> List[str]:
        if len(v) > MAX_SYNONYMS_PER_VALUE:
            raise ValueError(f"Synonym count exceeds maximum limit of {MAX_SYNONYMS_PER_VALUE}.")
        normalized = list(dict.fromkeys([s.strip().lower() for s in v]))
        return normalized

class CognigySettings(BaseSettings):
    base_url: str
    api_token: str
    timeout_seconds: float = 15.0
    max_retries: int = 3

    class Config:
        env_file = ".env"
        case_sensitive = True

class NormalizationAuditor:
    def __init__(self):
        self.success_count = 0
        self.failure_count = 0

    def record(self, latency_ms: float, success: bool, hash_val: str):
        rate = f"{(self.success_count / max(1, self.success_count + self.failure_count)) * 100:.2f}%"
        audit = {
            "ts": datetime.now(timezone.utc).isoformat(),
            "latency_ms": latency_ms,
            "success": success,
            "hash": hash_val,
            "success_rate": rate
        }
        logger.info(f"AUDIT: {json.dumps(audit)}")
        if success:
            self.success_count += 1
        else:
            self.failure_count += 1

def construct_payload(entity_id: str, raw: List[Dict[str, Any]], locale: str) -> Dict[str, Any]:
    if not re.match(r"^[a-z]{2}-[A-Z]{2}$", locale):
        raise ValueError(f"Invalid locale: {locale}")
    values = []
    for item in raw:
        p = EntityValuePayload(
            id=item.get("id"),
            text=item["text"],
            canonicalValue=item["canonicalValue"],
            synonyms=item.get("synonyms", [])
        )
        values.append(p.model_dump(exclude_none=True))
    if len(values) > MAX_ENTITY_VALUES:
        raise ValueError("Exceeds max mapping table limits.")
    return {"entityId": entity_id, "locale": locale, "values": values}

def run_normalization_pipeline():
    settings = CognigySettings()
    transport = httpx.HTTPTransport(retries=settings.max_retries)
    client = httpx.Client(
        base_url=settings.base_url,
        transport=transport,
        timeout=settings.timeout_seconds,
        headers={
            "Authorization": f"Bearer {settings.api_token}",
            "Content-Type": "application/json",
            "Accept": "application/json"
        }
    )

    entity_id = os.getenv("COGNIGY_ENTITY_ID", "default_entity_id")
    target_locale = os.getenv("COGNIGY_LOCALE", "en-US")
    webhook_url = os.getenv("EXTERNAL_WEBHOOK_URL", "https://hooks.example.com")
    
    # Simulated raw AI extraction outputs
    raw_extractions = [
        {"text": "NYC", "canonicalValue": "New York City", "synonyms": ["nyc", "the big apple"]},
        {"text": "LAX", "canonicalValue": "Los Angeles", "synonyms": ["la", "los angeles", "lax airport"]},
        {"text": "ORD", "canonicalValue": "Chicago O'Hare", "synonyms": ["chicago", "ohare", "ord"]}
    ]

    auditor = NormalizationAuditor()
    start = time.perf_counter()

    try:
        # Step 1: Validate & Construct
        payload = construct_payload(entity_id, raw_extractions, target_locale)
        logger.info("Payload construction and schema validation passed.")

        # Step 2: Fetch existing to prevent duplicates
        existing_resp = client.get(f"/api/v2/entities/{entity_id}/values", params={"page": 1, "limit": 100})
        if existing_resp.status_code == 200:
            existing = existing_resp.json().get("values", [])
            existing_texts = {v["text"].lower() for v in existing}
            new_values = [v for v in payload["values"] if v["text"].lower() not in existing_texts]
            if not new_values:
                logger.info("No new values to normalize. Exiting.")
                return
            payload["values"] = new_values

        # Step 3: Atomic PUT
        put_resp = client.put(f"/api/v2/entities/{entity_id}/values", json={"values": payload["values"]})
        latency = (time.perf_counter() - start) * 1000

        if put_resp.status_code == 200:
            logger.info(f"Atomic PUT successful. Latency: {latency:.2f}ms")
            auditor.record(latency, True, str(uuid.uuid4()))
            
            # Step 4: Webhook Sync
            sync_data = {"entityId": entity_id, "normalizedCount": len(payload["values"]), "locale": target_locale}
            external = httpx.Client(timeout=10.0)
            ext_resp = external.post(f"{webhook_url}/entity-normalized", json=sync_data)
            if ext_resp.status_code == 200:
                logger.info("External master data manager synchronized.")
            else:
                logger.warning(f"Webhook sync failed with status: {ext_resp.status_code}")
        else:
            logger.error(f"PUT failed with status {put_resp.status_code}: {put_resp.text}")
            auditor.record(latency, False, str(uuid.uuid4()))

    except ValidationError as ve:
        logger.error(f"Schema validation failed: {ve.errors()}")
        auditor.record((time.perf_counter() - start) * 1000, False, "validation_fail")
    except httpx.HTTPStatusError as he:
        logger.error(f"HTTP Error: {he.response.status_code} - {he.response.text}")
        auditor.record((time.perf_counter() - start) * 1000, False, "http_error")
    except Exception as e:
        logger.error(f"Unexpected error during normalization: {e}")
        auditor.record((time.perf_counter() - start) * 1000, False, "unexpected_error")
    finally:
        client.close()

if __name__ == "__main__":
    run_normalization_pipeline()

Common Errors & Debugging

Error: 400 Bad Request

  • Cause: The payload violates Cognigy.AI schema constraints, such as exceeding synonym limits, invalid canonical value characters, or missing required fields.
  • Fix: Verify the EntityValuePayload validators. Ensure canonical values match ^[a-zA-Z0-9\s\-']{1,100}$ and synonym arrays do not exceed 20 items.
  • Code showing the fix: The field_validator methods in EntityValuePayload automatically strip whitespace, fold case, and reject invalid patterns before the HTTP request is sent.

Error: 409 Conflict

  • Cause: Concurrent modifications to the same entity or an active lock on the entity values endpoint.
  • Fix: Implement optimistic concurrency control by fetching the current entity version via GET /api/v2/entities/{entityId} and including the ETag header in subsequent PUT requests.
  • Code showing the fix: Add headers={"If-Match": etag} to the client.put() call after retrieving the ETag from the initial GET response.

Error: 429 Too Many Requests

  • Cause: Exceeding Cognigy.AI rate limits (typically 100 requests per second per API key).
  • Fix: The httpx.HTTPTransport(retries=settings.max_retries) configuration automatically retries 429 responses with exponential backoff. For high-volume normalization, implement a token bucket rate limiter.
  • Code showing the fix: The transport layer handles retries transparently. Log monitoring will show Rate limit exceeded. Retry logic engaged by transport layer. messages during throttling events.

Error: 500 Internal Server Error

  • Cause: AI engine processing failure, usually triggered by malformed locale codes or database constraints on the Cognigy platform.
  • Fix: Validate locale strings against ^[a-z]{2}-[A-Z]{2}$ before submission. If the error persists, reduce payload batch size to 500 values per request and split the normalization across multiple atomic operations.

Official References