truthchain 1.0.3

Python SDK for the TruthChain AI-validation API

TruthChain Python SDK

Validate AI / LLM outputs against any business rules in <100ms.
Catch hallucinations, schema violations, out-of-range values, and more — before they reach your users.

---

Installation

pip install truthchain

Requires Python 3.9+. The only dependency (httpx) is installed automatically.

---

Quick Start

from truthchain import signup, TruthChain

# One-time: create an account
result = signup(
    name="Acme Corp",
    email="[e-mail]",
    password="s3cretPW!",
    base_url="https://your-server.com",
)
API_KEY = result.api_key   # tc_live_...  — save this securely!

# Validate an AI output
client = TruthChain(api_key=API_KEY, base_url="https://your-server.com")

result = client.validate(
    output={"user_id": 12345, "hours": 8, "project_name": "Project-X"},
    rules=[
        {
            "type": "schema",
            "name": "structure",
            "schema": {
                "type": "object",
                "properties": {
                    "user_id":      {"type": "integer"},
                    "hours":        {"type": "number"},
                    "project_name": {"type": "string"},
                },
                "required": ["user_id", "hours", "project_name"],
            },
        },
        {
            "type": "range",
            "name": "hours_check",
            "field": "hours",
            "min": 0,
            "max": 24,
        },
    ],
    context={"auto_correct": True},
)

print(result.status)            # "passed" | "failed" | "warning"
print(result.is_valid)          # True / False
print(result.violations)        # list of Violation objects
print(result.corrected_output)  # auto-corrected dict (if auto_correct=True)
print(result.latency_ms)        # e.g. 12

---

Authentication

Sign up

from truthchain import signup

result = signup(
    name="Acme Corp",
    email="[e-mail]",
    password="s3cretPW!",
    tier="free",   # "free" | "startup" | "business" | "enterprise"
    base_url="https://your-server.com",
)
print(result.api_key)   # tc_live_...  � shown only once, save immediately

Login

from truthchain import login

auth = login("[e-mail]", "s3cretPW!", base_url="https://your-server.com")
client = TruthChain(api_key=auth.api_key, base_url="https://your-server.com")

---

Validation

result = client.validate(
    output={"score": 95, "label": "positive"},
    rules=[
        {"type": "range",    "name": "score_range",  "field": "score", "min": 0, "max": 100},
        {"type": "required", "name": "has_label",    "fields": ["label"]},
    ],
)

Rule types

Type	Required fields	Description
schema	schema (JSON Schema)	Structure & type validation
range	field, min, max	Numeric range check
pattern	field, pattern (regex)	Regex match
required	fields (list)	Presence check
reference	field, reference_type	External reference check

All rules accept an optional "severity": "error" (default) or "warning".

---

Async Usage

import asyncio
from truthchain import AsyncTruthChain

async def main():
    async with AsyncTruthChain(api_key="tc_live_...", base_url="https://your-server.com") as client:
        result = await client.validate(
            output={"score": 95},
            rules=[{"type": "range", "name": "score", "field": "score", "min": 0, "max": 100}],
        )
        print(result.status)

asyncio.run(main())

---

Error Handling

from truthchain.exceptions import (
    AuthenticationError,
    QuotaExceededError,
    RateLimitError,
    ValidationError,
    ServerError,
)

try:
    result = client.validate(output={}, rules=[])
except AuthenticationError:
    print("Invalid or revoked API key")
except QuotaExceededError:
    print("Monthly quota exhausted — upgrade your plan")
except RateLimitError as e:
    print(f"Rate limited — retry after {e.retry_after}s")
except ValidationError as e:
    print(f"Bad request: {e.message}")
except ServerError:
    print("Server error � try again later")

Error hierarchy:

TruthChainError
├── AuthenticationError   (401)
├── NotFoundError         (404)
├── ValidationError       (422)
├── RateLimitError        (429)
├── QuotaExceededError    (429 + quota)
├── ConflictError         (400 / 409)
└── ServerError           (5xx)

---

API Reference

TruthChain(api_key, base_url, timeout)

Parameter	Default	Description
api_key	—	Your tc_live_... API key
base_url	http://localhost:8000	TruthChain server URL
timeout	30.0	Request timeout in seconds

Supports context manager: with TruthChain(...) as client:.
AsyncTruthChain mirrors the same interface with async/await.

Methods

Method	Returns	Description
validate(output, rules, context)	ValidationResult	Validate AI output
get_analytics()	AnalyticsOverview	Analytics overview
get_validation_stats()	ValidationStats	Aggregated stats
get_subscription()	Subscription	Current plan & usage
get_plans()	List[BillingPlan]	Available plans
upgrade(tier)	Subscription	Change plan
list_api_keys()	List[APIKey]	List all keys
create_api_key(name)	APIKey	Create new key
rotate_api_key(key_id)	APIKey	Rotate key
revoke_api_key(key_id)	None	Revoke key

Top-level helpers

Function	Description
signup(name, email, password, tier, base_url)	Register new org
login(email, password, base_url)	Login, get fresh key

---

License

MIT © 2026 TruthChain