Module tool_format 

Provider tool formatters.

Each provider (or family) shapes ToolDefinition into the JSON it expects on the wire. Historically, this logic was scattered across the request builders of each provider crate, making it hard to verify cross-provider invariants (e.g. that defer_loading, strict, input_examples, allowed_callers are preserved when they apply). This module introduces a single trait that all providers can implement, plus ready-made implementations for the most common cases.

The trait is intentionally additive: existing callers can keep using the per-provider helpers (e.g. serialize_tools_openai_format, anthropic::request_builder::tools::build_tools). New callers should reach for formatter_for(provider_id, model) instead.

See The Hitchhiker’s Guide to Agentic AI §18.4.1 for the underlying model (separate OpenAI / Anthropic / Gemini / MCP wire shapes) and §18.4.2 for the selection / routing concerns that sit above this layer.

Structs

AnthropicFormatter

Anthropic formatter — extracts logic from crates/codegen/vtcode-llm/src/providers/anthropic/request_builder/tools.rs::build_tools.

GeminiFormatter

Gemini formatter — uses function_declarations plus native hosted tool shapes.

OpenAIChatFormatter

OpenAI Chat Completions formatter — extracts logic from crates/codegen/vtcode-llm/src/providers/common.rs::serialize_tools_openai_format.

OpenAICompatibleFormatter

Generic OpenAI-compatible formatter. Unlike OpenAIChatFormatter, this one is intentionally conservative: it only emits function-shaped tools and silently drops hosted / native tool types because most compatible providers don’t support them.

OpenAIResponsesFormatter

OpenAI Responses API formatter — model-aware, preserves defer_loading.

Enums

ProviderFamily

Identifies a provider family for the purpose of tool formatting.

ProviderFormatter

Static-dispatch formatter covering every provider family.

Traits

ProviderToolFormatter

Trait implemented by every provider tool formatter.

Functions

formatter

Build a formatter for a given provider family without heap allocation or dynamic dispatch.

formatter_for

Convenience: resolve a formatter using the explicit ProviderFamily. Useful in tests or when the runloop already knows the family without parsing the provider string.