Why Ratify

Every agent framework tells you how to run an agent. Almost none let you declare what it must and must not do — and enforce that consistently across frameworks.

The 2025–2026 "agent contracts" wave (relari agent-contracts, agentcontract/spec, AgentAssert/ABC, ToolGate, FORGE) each nailed one slice: resource governance, or tool-level pre/postconditions, or policy enforcement, or behavioral invariants. Ratify unifies them into one declarative object and adds the two things production teams actually need:

Plus: parameterizable templates (one contract → many scenarios), composition (reuse a base policy everywhere), probabilistic satisfaction ((p, δ, k) — run a judge k times, require a pass rate), pathconditions (constrain the trajectory, not just the output), and budget conservation (a delegated child budget can never exceed its parent).

Ratify has zero required dependencies, is strictly typed, and is hermetically testable — the LLM judge is a pluggable protocol, so the whole test suite runs offline.

Install

pip install ratify-agents            # core, zero deps
pip install "ratify-agents[schema]"  # + JSON-Schema checks
pip install "ratify-agents[openai]"  # + OpenAI judge adapter

60-second example

import ratify
from ratify import checks, Scope, Lifecycle

# 1. Declare a contract — a reusable template with a parameter.
support = (
    ratify.Contract("support-reply", version="1.0")
    .param("brand", type=str)
    # HARD: deterministic, runs on the output, no LLM needed
    .hard("no-pii", "Must not leak an email address.",
          scope=Scope.OUTPUT, check=checks.excludes("@"))
    .hard("bounded", "Reply is at most 600 chars.",
          scope=Scope.OUTPUT, check=checks.max_length(600))
    # JUDGE: fuzzy, an LLM scores the natural-language criterion
    .judge("on-brand", "The reply mentions {brand} and stays positive.",
           scope=Scope.BEHAVIORAL, threshold=0.6)
    # TRAJECTORY: a "pathcondition" on how the agent worked
    .hard("used-kb", "Must consult the knowledge base before answering.",
          scope=Scope.TRAJECTORY, check=checks.used_tool("search_kb"))
)

# 2. Specialize the same template for a specific client.
acme = support.bind(brand="Acme")

# 3. Enforce it live around your agent.
from ratify import KeywordJudge  # deterministic stand-in; swap for a real model
judge = KeywordJudge(required=["Acme"])

@ratify.guard(acme, judge=judge)
def agent(question: str) -> str:
    return "Thanks for reaching out to Acme — happy to help!"

print(agent("How do I reset my password?"))

If a blocking clause fails, ContractViolation is raised with a full report; switch to mode="monitor" to log instead of raise.

Three ways to enforce

# a) Offline verification (CI, eval harnesses, replaying traces)
report = ratify.evaluate(acme, output=answer, trajectory=traj, judge=judge)
assert report.passed, report.summary()

# b) Decorator (function-style agents)
@ratify.guard(acme, judge=judge, mode="monitor")
def my_agent(q): ...

# c) Context manager (imperative loops)
with ratify.guarded(acme, prompt, judge=judge) as box:
    box.record(agent.run(prompt), trajectory=traj)

Probabilistic satisfaction — (p, δ, k)

LLM judgments are noisy. A clause can require that a criterion hold across k samples:

contract.judge(
    "grounded", "Every claim is supported by the retrieved context.",
    scope=Scope.OUTPUT,
    threshold=0.7,   # a single judgment "passes" at score ≥ 0.7
    samples=5,       # k: run the judge 5 times
    pass_rate=0.8,   # p: at least 4/5 must pass
)

Budget conservation for multi-agent delegation

from ratify import ResourceBudget

root = ResourceBudget(tokens=100_000, cost_usd=5.0, label="orchestrator")
worker = root.child(label="researcher", tokens=40_000)   # ✅ fits
root.child(label="rogue", tokens=200_000)                # ❌ BudgetExceeded

A child budget that would exceed the parent's remaining headroom is rejected at creation — runaway spend becomes structurally impossible, not merely discouraged.

Integrations

The generic adapter ratifies any callable(input) -> output, so it works with every framework today:

from ratify.adapters import wrap
safe_agent = wrap(my_agent.run, contract, judge=judge)

Framework guides (LangChain / LangGraph, CrewAI, AutoGen, OpenAI Agents SDK, Pydantic-AI, Anthropic + MCP) with copy-paste snippets live in docs/INTEGRATION.md.

Documentation

• Integration guide — per-framework wiring
• Concepts — the scope × enforcement × lifecycle model, prior art, and design rationale
• examples/ — runnable end-to-end scripts

Status & honesty

0.1.0, beta. The core engine, checks, judge protocol, resources, trajectory, and the generic adapter are fully unit-tested (see tests/, run pytest). Framework-specific adapters are provided as documented, import-light patterns; those requiring a third-party package are labeled as such and are not exercised in the default hermetic test run. Contributions and real-world reports welcome.

License

MIT © 2026 Duc Nguyen