T81 Foundation

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Deterministic, governed runtime stack for auditable computing.

T81 is a deterministic compilation and execution pipeline (T81Lang -> TISC -> HanoiVM). It prioritizes auditability, policy enforcement (Axion), and reproducibility over raw hardware speed.

Note on Floating Point Determinism: T81Float transcendental functions (sin, cos, tan, log, exp, sqrt) are now implemented via a deterministic software-defined backend (dmath) and are guaranteed bit-exact across platforms. T81Float division and inverse/hyperbolic trigonometric functions (asin, sinh, etc.) may still rely on host-platform behavior in non-strict modes. Strict bit-exact determinism is guaranteed for T81Int, T81BigInt, T81Fraction (canonical), and core T81Float operations.

⚡ 30-Second Evaluation

Verify the claims yourself in 4 steps:

1. Build & Run Hello World

   cmake -S . -B build -DCMAKE_BUILD_TYPE=Release && cmake --build build --parallel
   ./build/t81 compile examples/hello_world.t81 -o hello.tisc
   ./build/t81 run hello.tisc

2. Run Determinism Gate

   # Verify cross-architecture reproducibility hash
   python3 scripts/ci/t81lang_repro_gate.py --t81-bin build/t81 --check

3. Run a VM Demo

   ./build/t81_demo

4. Inspect a Trace Artifact

   ./build/t81 trace show trace.txt

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🚫 Non-Goals

To save your time, here is what T81 is NOT:

• NOT a hardware accelerator: T81 does not claim ternary hardware speedups. This is a software runtime for deterministic correctness.
• NOT a general-purpose replacement: T81 focuses on high-stakes, auditable logic, not replacing C++ or Python for general tasks.
• NOT "fast and loose": If a performance optimization breaks trace determinism, T81 rejects it.

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❓ Why This Exists

Modern runtimes trade reproducibility for speed. T81 inverts this: Auditability is the primary constraint.

This is enforced via a strict architectural boundary between the Language/Compiler and the Execution Runtime, governed by explicit contracts.

View Architectural Boundary Diagram | View Runtime Contract

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📚 Document Authority Map

Document	Purpose	Authority Scope
STATUS.md	What is true today	Operational Truth
ROADMAP.md	Forward plan	Strategic
VERSIONING.md	Compatibility rules	Normative
spec/	Behavioral definition	Normative
docs/EVIDENCE.md	Proof of claims	Verification

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🤝 Compatibility Guarantees

• Stable: T81Lang Syntax, TISC Binary Format, HanoiVM Execution Semantics.
• Experimental: JIT Compilation, Distributed Tensor Ops.
• SemVer: T81 follows Semantic Versioning. Breaking changes to Stable components increment the Major version.

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🖥️ Supported Platforms

Platform	Compiler	Status
Linux (x86_64)	Clang 18+, GCC 14+	✅ Determinism Gate
Linux (ARM64)	Clang 18+	✅ Determinism Gate
macOS (ARM64)	Apple Clang	✅ Supported

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Quick Start (Full)

git clone https://github.com/t81dev/t81-foundation.git
cd t81-foundation
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build --parallel
ctest --test-dir build --output-on-failure

Single-threaded safe mode:

cmake --build build --parallel 1
ctest --test-dir build --output-on-failure -j1

CLI Surface

Common workflows:

# Compile / run
t81 compile examples/hello_world.t81 -o build/hello.tisc
t81 run build/hello.tisc

# Inspect / debug
t81 disasm build/hello.tisc
t81 debug build/hello.tisc

# Diagnostics / reproducibility
t81 check examples/hello_world.t81
t81 repro-hash tests/fixtures/t81lang_determinism

# Trace workflows
t81 trace show trace.txt
t81 trace diff trace_a.txt trace_b.txt
t81 trace replay build/hello.tisc trace.txt

Model tooling:

t81 weights import model.safetensors -o model.t81w
t81 weights info model.t81w
t81 weights quantize model.safetensors --to-gguf model.gguf

See full command help:

t81 help

Repository Map

• include/t81/: public API headers
• src/: frontend, TISC, VM, Axion, CanonFS, CLI implementation
• tests/: conformance, determinism, VM/e2e, property slices
• docs/: guides, status, benchmarks, runtime boundary docs
• spec/: normative semantics and governance inputs
• examples/: runnable samples and demos

Runtime Boundary

T81 uses an explicit runtime boundary contract:

• Marker: contracts/runtime-contract.json
• Boundary policy: docs/runtime-semantics-boundary.md

Further Reading

• ARCHITECTURE.md
• docs/system-integration.md
• ANALYSIS.md
• CHANGELOG.md
• docs/research-guide.md
• docs/ai-quickstart.md

License

This repository is licensed under MIT (see LICENSE).