Crate tokn_headers 

Foundational header primitives for the LLM router workspace.

This crate provides:

• HeaderName — a case- and order-preserving header name backed by [SmolStr].
• HeaderValue — a header value stored as Cow<'static, str> for zero-cost static defaults.
• HeaderMap — a Vec-backed map that preserves insertion order and original case while supporting case-insensitive lookup and duplicate names.
• keys — a catalogue of static HeaderName constants for popular headers.
• TemplateVars — per-request correlation metadata extracted from inbound headers, shared between header rendering and provider header construction.
• HeaderSchema — a trait implemented by typed (provider, client) header structs to round-trip between their typed form and a HeaderMap.
• HeaderNormalizer — a trait for rebuilding client-derived headers into a provider-owned wire shape.
• schemas — concrete client/overlay structs implementing HeaderSchema.
• agent — agent-specific outbound header builders.
• registry — runtime lookup of (AgentKind, OverlayKind) for a given (provider_id, agent_id) pair.

Phase 1 is purely additive: nothing in the workspace depends on this crate yet. Phase 2 will swap HeaderMap in for reqwest::header::HeaderMap workspace-wide; Phase 3 will route provider header construction through the schema registry.

Re-exports

pub use agent_id::AgentId;

pub use error::Error;

pub use map::HeaderMap;

pub use name::HeaderName;

pub use normalizer::HeaderNormalizeCtx;

pub use normalizer::HeaderNormalizer;

pub use schema::HeaderSchema;

pub use value::HeaderValue;

pub use vars::TemplateVars;

Modules

agent

Agent-specific header builders used to synthesize outbound request headers.

agent_id

Logical identifier for the agent whose behavior an upstream call should impersonate. Carried end-to-end through the pipeline so downstream stages (header shaping, provider selection) can branch on it without reparsing inbound traffic.

error

Errors produced by the headers crate.

inbound

keys

Catalogue of popular header names as compile-time static constants.

map

Vec-backed, order- and case-preserving header map.

name

Case- and order-preserving HTTP header name.

normalizer

Header normalizers rebuild client-derived maps into provider-owned wire shapes after credentials have been injected.

registry

Registry mapping (provider, agent_id) to the typed header schema pair.

reqwest_compat

Conversions between crate::HeaderMap and reqwest::header::HeaderMap used at the wire boundary.

schema

The HeaderSchema trait + helper functions used by per-(persona, overlay) schema structs to round-trip between their typed Rust form and the generic HeaderMap.

schemas

Module index for persona and overlay header schemas.

value

Header value storage. Values are kept as Cow<'static, str> so static defaults (e.g. "application/json") cost zero allocations while dynamic values (auth tokens, session IDs) heap-allocate on demand.

vars

Per-request template variables resolved from inbound headers.