Add Binding Feature

Add a Binding Feature

Companion Guidance

Use karpathy-guidelines alongside this skill for implementation or review

work. Keep changes scoped, surface assumptions, and define focused validation

before editing.

Use this skill when a change affects the public runtime surface and must stay in

parity across the Rust core, FFI, and one or more bindings.

Do not use this skill for:

• Internal-only core refactors with no public API change
• Binding-local bug fixes that do not change shared behavior
• Docs-only or example-only updates

Implementation Order

• Core Rust

Implement the behavior first in crates/core/src/api/ and

related core modules such as crates/core/src/api/runtime/,

crates/core/src/codec/, or crates/core/src/json.rs.

• FFI / shared C surface

Add or update FFI wrappers in the relevant crates/ffi/src/api/*.rs

module, re-export them through crates/ffi/src/api/mod.rs, and ensure the

generated crates/ffi/nemo_relay.h stays correct.

• Language-native bindings

Update Python, Go, and Node.js for every surface that should expose the

capability.

• Language wrapper helpers

Update Python wrapper modules, Go shorthand packages, typed helpers, or

adaptive/plugin helpers if the new behavior belongs there.

• Docs and examples

Update reference docs, language-binding docs, and examples when the public

surface or expected usage changed.

• Validation

Run the validation matrix from the validate-change skill for the affected

surfaces.

Naming Conventions

| Layer | Convention | Example |

|-------------|-------------------|--------------------------------------|

| Rust | snake_case | nemo_relay_tool_call |

| C FFI | nemo_relay_ prefix | nemo_relay_tool_call |

| Python | snake_case | nemo_relay.tools.call |

| Go | PascalCase | nemo_relay.ToolCall |

| Node.js | camelCase | toolCall |

Parity Checklist

• [ ] Core function with doc comment in crates/core/src/api/
• [ ] Runtime callback/state, codec, JSON, or event/tool/LLM/scope types added

in the relevant core module if needed

• [ ] FFI wrapper in the relevant crates/ffi/src/api/*.rs module and

re-export in crates/ffi/src/api/mod.rs

• [ ] Regenerate the shared library/header path with just build-go
• [ ] Python native binding in crates/python/src/py_api/mod.rs
• [ ] Python wrapper with docstring in python/nemo_relay/<module>.py
• [ ] Python type stubs updated in the relevant python/nemo_relay/*.pyi modules
• [ ] Go wrapper in go/nemo_relay/nemo_relay.go with doc comment
• [ ] Go shorthand package updated if the capability belongs there
• [ ] Node.js binding in crates/node/src/api/mod.rs
• [ ] Typed wrapper or adaptive/plugin helper surfaces updated when applicable
• [ ] Tests added in every affected language surface
• [ ] SPDX license header on any new files
• [ ] Relevant pages under docs/reference/ updated
• [ ] README.md, docs/getting-started/, or binding-level READMEs updated if behavior differs by language
• [ ] Relevant getting-started, README, or example docs updated if usage changed

Decision Points

Lock these before implementing:

• Which bindings actually expose the new surface?
• Is the change part of the plain JSON API, typed wrappers, adaptive/plugin

helpers, or observability helpers?

• Does the new API need manual lifecycle and managed execute variants, or only

one of them?

• Does the new behavior change event fields, metadata, or scope expectations?
• Are docs/examples required because the intended usage changed?

Key References

• Architecture: docs/about/architecture.md
• Reference index: docs/reference/api/index.md
• Getting started and binding status: README.md,

docs/getting-started/quick-start.md,

docs/about/release-notes/support-matrix.md

• Typed wrappers and codecs: docs/integrate-frameworks/using-codecs.md,

docs/integrate-frameworks/provider-codecs.md

• Adaptive config/plugins: docs/about/concepts/plugins.md,

docs/build-plugins/about.md, docs/plugins/adaptive/configuration.md

• Existing pattern: follow a surface already implemented across core, FFI,

Python, Go, and Node.js rather than inventing a new shape