InputLayer

Streaming reasoning layer for AI systems.

Store facts. Define rules. InputLayer derives the conclusions, keeps them current as data changes, and explains every result with a proof tree. Combine recursive reasoning with vector search in a single query. Open source.

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Quick Example

Connecting flights - define direct routes as facts, let InputLayer derive all reachable destinations:

// Facts: direct flight routes
+direct_flight[("New York", "London"), ("London", "Paris"), ("Paris", "Tokyo"), ("Tokyo", "Sydney")]

// Rules: you can reach a destination directly, or through connections
+can_reach(A, B) <- direct_flight(A, B)
+can_reach(A, C) <- direct_flight(A, B), can_reach(B, C)

// Query: where can you fly from New York?
?can_reach("New York", Dest)

┌────────────┬──────────┐
│ New York   │ Dest     │
├────────────┼──────────┤
│ "New York" │ "London" │
│ "New York" │ "Paris"  │
│ "New York" │ "Tokyo"  │
│ "New York" │ "Sydney" │
└────────────┴──────────┘
4 rows

Four facts, two rules, and the engine derived every reachable destination - including connections through intermediate cities.

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What Makes It Different

Rules + vector search in one query

A shopper asks for printer ink. In embedding space, every ink cartridge looks the same. But only specific models fit their printer - that's a structured fact, not a similarity score. InputLayer evaluates compatibility rules and ranks by cosine distance in a single query.

Correct conclusion retraction

An entity is cleared from a sanctions list. Every flag derived through it retracts - but only if no second ownership path still supports it. InputLayer tracks every derivation path independently and only retracts when all paths are gone.

Incremental updates

One fact changes in a 2,000-node graph with 400,000 derived relationships. InputLayer updates only the affected derivations in 6.83ms. Full recompute: 11.3 seconds. 1,652x faster.

Provenance

Run .why on any result and get a structured proof tree showing which facts and which rules produced it. Run .why_not to see exactly which condition blocked a derivation.

.why ?can_reach("New York", "Sydney")
// [rule] can_reach (clause 1): can_reach(A, C) <- direct_flight(A, B), can_reach(B, C)
//   [base] direct_flight("New York", "London")
//   [rule] can_reach (clause 1): ...
//     [base] direct_flight("London", "Paris")
//     [rule] can_reach (clause 1): ...
//       [base] direct_flight("Paris", "Tokyo")
//       [rule] can_reach (clause 0): can_reach(A, B) <- direct_flight(A, B)
//         [base] direct_flight("Tokyo", "Sydney")

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Get Started

# Docker
docker run -p 8080:8080 ghcr.io/inputlayer/inputlayer

# Or build from source
git clone https://github.com/inputlayer/inputlayer.git
cd inputlayer
cargo build --release
./target/release/inputlayer-server --port 8080

Open http://localhost:8080 for the interactive GUI, or connect via WebSocket at ws://localhost:8080/ws.

If you know SQL, the query language takes about 10 minutes to learn. See the Quick Start Guide.

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SDKs

Python:

pip install inputlayer

from inputlayer import InputLayer

async with InputLayer() as il:
    kg = il.knowledge_graph("default")
    result = await kg.query(CanReach)

TypeScript:

npm install inputlayer-js

See Python SDK docs and TypeScript SDK docs.

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Use Cases

• Financial Risk - Trace ownership chains to any depth for sanctions screening. Correct retraction handles the diamond problem.
• Conversational Commerce - Compatibility rules + vector similarity in one query. The wrong cartridge never gets recommended.
• Manufacturing - Multi-hop dependency chains from training records to production line availability, updated in milliseconds.
• Supply Chain - A port closes and every affected supplier, order, and SLA penalty is identified across the graph.
• Agentic AI - Agent memory as a knowledge graph with .why proof trees for every conclusion.

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Built On

Differential Dataflow by Frank McSherry. Incremental computation engine written in Rust. Single binary, no external dependencies.

Documentation

• Quick Start
• Core Concepts
• Explainability (.why / .why_not)
• Vector Search
• Recursion
• Python SDK
• TypeScript SDK
• WebSocket API Docs

Contributing

See CONTRIBUTING.

License

Apache 2.0 + Commons Clause. Open source for non-commercial use. Commercial use requires a separate license - see COMMERCIAL_LICENSE.md.