Crate nexo_tool_meta 

Wire-shape types shared between the Nexo agent runtime and any third-party microapp that consumes its events.

Provider-agnostic by construction: no transport layer (no axum, no tokio), no broker, no agent runtime. Pulling this crate in is a four-dependency, sub-second compile and exposes only the data shapes a downstream consumer needs to read what the daemon emits.

What lives here

• BindingContext — identifies the inbound binding a tool call originated from. Microapps read it from params._meta.nexo.binding.
• InboundMessageMeta — per-turn metadata about the inbound message that triggered the agent turn (sender id, msg id, timestamp, …). Microapps read it from params._meta.nexo.inbound.
• build_meta_value / parse_binding_from_meta / parse_inbound_from_meta — the inverse trio around the dual-write _meta payload.
• WebhookEnvelope — JSON envelope nexo publishes to NATS after every accepted webhook request.
• format_webhook_source — turn-log marker helper.

Round-trip example

use nexo_tool_meta::{build_meta_value, parse_binding_from_meta, BindingContext};
use uuid::Uuid;

// Daemon side: build the `_meta` payload for a tool call.
let mut binding = BindingContext::agent_only("ana");
binding.channel = Some("whatsapp".into());
binding.account_id = Some("personal".into());
binding.binding_id = Some("whatsapp:personal".into());
let meta = build_meta_value("ana", Some(Uuid::nil()), Some(&binding), None);

// Microapp side: extract the binding back.
let parsed = parse_binding_from_meta(&meta).unwrap();
assert_eq!(parsed.channel.as_deref(), Some("whatsapp"));
assert_eq!(parsed.binding_id.as_deref(), Some("whatsapp:personal"));

Re-exports

pub use admin::audit::AdminAuditResult;

pub use admin::audit::AdminAuditRow;

pub use admin::audit::AuditTailFilter;

pub use admin::audit::AuditTailPage;

pub use binding::binding_id_render;

pub use binding::BindingContext;

pub use event_source::format_dispatch_source;

pub use event_source::format_event_subscriber_source;

pub use event_source::format_rate_limit_hit;

pub use event_source::EventSourceMeta;

pub use inbound::InboundKind;

pub use inbound::InboundMessageMeta;

pub use locale::LangCode;

pub use locale::Locale;

pub use locale::LocaleParseError;

pub use locale::RegionCode;

pub use meta::build_meta_value;

pub use meta::parse_binding_from_meta;

pub use meta::parse_inbound_from_meta;

pub use meta::BINDING_KEY;

pub use meta::INBOUND_KEY;

pub use meta::META_KEY;

pub use meta::NEXO_NAMESPACE;

pub use microapp_error::MicroappError;

pub use microapp_error::MicroappErrorKind;

pub use microapp_error::MICROAPP_ERROR_NOTIFY_METHOD;

pub use template::render_template;

pub use template::MISSING_PLACEHOLDER;

pub use webhook::format_webhook_source;

pub use webhook::WebhookEnvelope;

pub use webhook::ENVELOPE_SCHEMA_VERSION;

Modules

admin

Admin RPC wire-shape types.

binding

BindingContext — the (channel, account_id, agent_id, session_id, binding_id) tuple stamped on every tool call so a downstream microapp knows which inbound binding the call originated from.

event_source

EventSourceMeta — typed metadata describing the NATS subject + envelope that triggered an agent turn via the event-subscriber pipeline.

http_server

HTTP server capability wire shapes.

inbound

InboundMessageMeta — per-turn metadata about the inbound message that triggered an agent turn. Stamped under _meta.nexo.inbound (peer of _meta.nexo.binding).

locale

Locale validation. Lives here (rather than in nexo-microapp-sdk) so nexo-config can consume the closed-enum validator at YAML deserialise time. SDK still re-exports for back-compat. BCP-47 locale subset for agent language configuration.

marketing

marketing wire types for the nexo-rs-extension-marketing extension + agent-creator microapp.

meta

Helpers around the _meta payload nexo emits on every tool call. The wire shape is dual-write:

microapp_error

nexo/notify/microapp_error wire shape.

reply_kind

OutboundReplyKind — channel-agnostic shape for what the agent is about to send back on the wire.

template

Minimal mustache-lite template renderer.

voice_addenda

Per-locale system-prompt addenda + voice picker tables.

webhook

WebhookEnvelope — the JSON payload nexo publishes to NATS after a webhook source verifies and parses an inbound HTTP request.