Verification engines

Engine overview

Engine	Technology	Key features
Math	SymPy + Decimal	Calculus, matrix ops, NPV/IRR, statistics
Logic	Z3 theorem prover	ForAll/Exists quantifiers, BitVectors, arrays
Reasoning	Multi-LLM + cache	Chain-of-thought validation, result caching
Stats	Wasm/Docker sandbox	Secure code execution with AST validation
Fact	TF-IDF + NLP	Semantic similarity, entity matching, citations
Graph	Knowledge graph	Triple verification (subject-predicate-object)
Code	Multi-lang AST	Python, JavaScript, Java, Go security analysis
SQL	SQLGlot AST	Complexity limits, cost estimation, schema validation
Taint	Data flow analysis	Trace untrusted inputs to sensitive sinks (e.g., `exec`, `os.system`, SQL queries)
Image	Deterministic + VLM	Metadata extraction, size verification, multi-VLM
Schema	Pydantic + Math	JSON structure + embedded calculation checks

Deterministic-first philosophy

All engines follow a deterministic-first approach:

Try deterministic methods first (100% reproducible)
Fall back to LLM only when necessary
Discount LLM confidence when used

# Example: fact verification is deterministic
result = client.verify_fact(
    claim="Paris is in France",
    context="Paris is the capital of France."
)
# Uses TF-IDF similarity + entity matching
# No LLM needed for most claims

See Determinism guarantee for the full engine classification and how to check if a response is SYMBOLIC or HEURISTIC.

Engine selection

QWED auto-detects the appropriate engine:

Content pattern	Detected engine
`2+2=4`, `sqrt(16)`, `derivative`	Math
`(AND ...)`, `ForAll`, `Exists`	Logic
`SELECT`, `INSERT`, `DROP`	SQL
````python`,` import`,` function`	Code
Claims with context	Fact
Image bytes + claim	Image

Or specify explicitly:

result = client.verify(query, type="math")

Engine documentation

Deterministic engines

Math engine — calculus, matrix, financial
Logic engine — quantifiers, theorem proving
Schema engine — JSON structure & math

Security engines

Code engine — multi-language security
SQL engine — complexity limits
Taint engine — data flow analysis

Data verification engines

Stats engine — Wasm sandbox execution
Fact engine — TF-IDF + citations
Graph engine — knowledge graph triples
Image engine — deterministic verification

Orchestration engines

Reasoning engine — multi-LLM validation
Consensus engine — parallel execution

Overview

Core Engines

Analysis Engines

Specialized Engines

Engine overview

Deterministic-first philosophy

Engine selection

Engine documentation

Deterministic engines

Security engines

Data verification engines

Orchestration engines

Overview

Core Engines

Analysis Engines

Specialized Engines

Documentation Index

​Engine overview

​Deterministic-first philosophy

​Engine selection

​Engine documentation

​Deterministic engines

​Security engines

​Data verification engines

​Orchestration engines

Engine overview

Deterministic-first philosophy

Engine selection

Engine documentation

Deterministic engines

Security engines

Data verification engines

Orchestration engines