GridZero - Capability Routing Grid (CRG)

Companion code to "Capability Routing Grid - From Decoupled Plugins to the Hardware Ceiling", Cyril Tissier's talk at CppCon 2026.

📖 GridZero User Manual

From decoupled plugins, to routing via geometry, to tensor-based dispatch, to heterogeneous execution beyond the CPU, this document explains the architectural principles behind GridZero and how they compose into a complete system.

Read the manual: doc/GridZero_User_Manual.md

The manual is organized as a progressive journey:

• 0. Hardware Affinity by Accident
• 1. Collaboration via Existence
• 2. Polymorphism via Capability
• 3. Routing via Geometry
• 4. Mutation via Residency
• 5. Beyond the CPU
• 6. Conclusion

This is not an API reference. This is the architectural journey behind GridZero.

Slides for the talk at CppCon2026

GridZero is a C++17 header-only toolkit for composing decoupled code across strictly segregated projects. NodeLink lets implementations register themselves - even across DLL boundaries - with no central registry and no Init() call; that alone is enough to build a plugin system, no routing tensor required. The capability router covers the other pole: bind behavior to model types through a flat tensor lookup instead of a vtable, and for a contract with no virtual methods that same lookup costs zero virtual calls and zero heap allocation - decoupled plugins to the hardware ceiling, as the talk title has it.

What is in this repository

This is the public tier of GridZero. It contains:

• crg_core - the complete routing engine (header-only, ~80 headers).
• Test stages - nine executable stages (00-08) that build up the framework layer by layer, plus the plugin_loadlibrary stage demonstrating manual-load plugins. Browse them directly in crg/tests/core_monolith/stages/.

There is no managed loader, no hot-reload pipeline, no JIT compiler, and no WASM backend target in this repository - those live in a separate protected tier.

Quick build

cmake -S gridzero -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
./build/crg/tests/core_monolith/Run_CoreMonolith_Tests
./build/crg/tests/plugin_loadlibrary/Run_PluginLoadLibrary_Tests

Requires a C++17 compiler. No external dependencies for crg_core.

The four layers

Layer	Headers	Concept
Discovery	crg/discovery/	NodeLink self-registration, plugin splice
Models	crg/models/, crg/core/	DenseID, domain, TypeHash
Capabilities	crg/capabilities/, crg/routing/	Tensor routing, DOD/Brain dispatch
Type erasure	crg/type_erasure/	ModelShell, Invoke/TryInvoke

See architecture.md for the full design rationale.

Test stages

Each stage is a self-contained .test.cpp + .md pair that introduces one concept, in crg/tests/core_monolith/stages/:

Stage	.md file	Concept
00	stage_00_nodelink.md	NodeLink auto-registration, Mutual Anonymity
01	stage_01_models.md	DenseID, ModelToken, domain
02	stage_02_brain_oop.md	Capability Brain, virtual, operator->(), TypeList model-set binding
03	stage_03_routing_1d.md	Contextual 1D axis, EnumTraits, routing is shape-agnostic
04	stage_04_routing_nd.md	N-D routing, branchless Horner
05	stage_05_dynamic_rules.md	EarlyExit dispatch cell, RuleContext
06	stage_06_shell_invoke.md	ModelShell, Invoke/TryInvoke, Cast<TModel>
07	stage_07_muscle_dod.md	Capability Muscle, single-Execute shape -> C-ABI slot
08	stage_08_ffi_trampoline.md	C-ABI proof: a foreign fn ptr fills the Muscle slot
plugin_loadlibrary	stage_plugin_loadlibrary.md	Manual-load plugin: LoadLibrary + CRG_Bootstrap

License

Apache License 2.0 - see LICENSE (added at publication time).