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use crate::CanonicalValue;
use serde::{Deserialize, Serialize};
use sha2::{Digest, Sha256};
use std::collections::{BTreeMap, BTreeSet};
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
/// Runtime value schema used to validate inputs and analyze programs.
pub enum Schema {
/// The `null` value.
Null,
/// A Boolean value.
Boolean,
/// A signed 64-bit integer with optional inclusive bounds.
Integer {
/// Inclusive lower bound.
min: Option<i64>,
/// Inclusive upper bound.
max: Option<i64>,
},
/// A finite binary64 number with optional inclusive bounds.
Number {
/// Inclusive lower bound.
min: Option<f64>,
/// Inclusive upper bound.
max: Option<f64>,
},
/// A Unicode string with optional semantic and size constraints.
String {
/// Host-defined semantic format name.
format: Option<String>,
/// Allowed values; empty means unrestricted.
enumeration: Vec<String>,
/// Minimum number of Unicode scalar values.
min_len: Option<usize>,
/// Maximum number of Unicode scalar values.
max_len: Option<usize>,
},
/// An opaque byte sequence.
Bytes,
/// A homogeneous ordered list.
List {
/// Schema shared by every element.
items: Box<Schema>,
/// Minimum element count.
min_len: Option<usize>,
/// Maximum element count.
max_len: Option<usize>,
},
/// An object with named properties.
Object {
/// Known property definitions.
properties: BTreeMap<String, Property>,
/// Properties that must be present.
required: BTreeSet<String>,
/// Whether properties absent from `properties` are accepted.
additional: bool,
},
/// An object whose arbitrary keys share one value schema.
Map {
/// Schema accepted by every map value.
values: Box<Schema>,
},
/// A value accepted by any of several schemas.
Union {
/// Alternative accepted schemas.
variants: Vec<Schema>,
/// Optional object property used to distinguish variants.
discriminator: Option<String>,
},
/// Any canonical Runlet value.
Any,
/// The type of expressions that never produce a value (`fail(...)`).
/// Never unifies with anything: a branch that fails contributes nothing
/// to the surrounding schema. No runtime value has this schema.
Never,
}
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
/// Schema and host metadata for an object property.
pub struct Property {
/// Value schema for the property.
pub schema: Schema,
#[serde(default)]
/// Human-readable guidance for tool callers.
pub documentation: String,
#[serde(default)]
/// Whether observability systems should treat the value as sensitive.
pub sensitive: bool,
#[serde(default)]
/// Whether the value is a secret that must not be exposed.
pub secret: bool,
#[serde(default)]
/// Alternative names accepted by a host adapter.
pub aliases: Vec<String>,
}
impl Property {
/// Creates a property with no metadata flags or aliases.
pub fn new(schema: Schema) -> Self {
Self {
schema,
documentation: String::new(),
sensitive: false,
secret: false,
aliases: vec![],
}
}
}
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
/// Ordered parameter schema for a tool call.
pub struct CallSchema {
/// Schemas for positional parameters in call order.
pub parameters: Vec<Schema>,
/// How many leading parameters a call must provide; the rest are
/// optional trailing parameters. `None` means every parameter is
/// required.
#[serde(default)]
pub required: Option<usize>,
}
impl CallSchema {
/// Creates a call schema in which every parameter is required.
pub fn positional(parameters: Vec<Schema>) -> Self {
Self {
parameters,
required: None,
}
}
/// Creates a required single-parameter call schema.
pub fn one(schema: Schema) -> Self {
Self::positional(vec![schema])
}
/// A schema whose trailing parameters past `required` may be omitted.
pub fn optional_trailing(parameters: Vec<Schema>, required: usize) -> Self {
debug_assert!(required <= parameters.len());
Self {
parameters,
required: Some(required),
}
}
/// The minimum number of arguments a call must provide.
pub fn required_count(&self) -> usize {
self.required.unwrap_or(self.parameters.len())
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
/// Effect and retry semantics declared by a host tool.
pub enum ExecutionPolicy {
/// No external effects; unused calls may be pruned and results reused.
Pure,
/// Repeating the operation is safe and produces the same external effect.
Idempotent,
/// The host can recover or reconcile an interrupted operation.
Recoverable,
/// The operation must not be dispatched more than once.
AtMostOnce,
/// The operation has effects without stronger retry guarantees.
Unsafe,
}
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
/// Host-facing declaration of a callable tool.
pub struct ToolDescriptor {
/// Fully qualified source name, such as `profile.lookup`.
pub name: String,
/// Concise description for callers and generated tool catalogs.
pub summary: String,
/// Positional input schema.
pub input: CallSchema,
/// Successful output schema.
pub output: Schema,
/// Effect and retry policy.
pub execution: ExecutionPolicy,
/// Host-controlled version included in operation identity.
pub schema_version: String,
}
#[derive(Debug, Clone, Default)]
/// Deterministically ordered collection of tool descriptors.
pub struct ToolRegistry {
tools: BTreeMap<String, ToolDescriptor>,
}
impl ToolRegistry {
/// Creates an empty registry.
pub fn new() -> Self {
Self::default()
}
/// Registers a descriptor, rejecting malformed or duplicate names.
pub fn register(&mut self, descriptor: ToolDescriptor) -> Result<(), String> {
if descriptor.name.split('.').any(|x| x.is_empty()) {
return Err("tool names must contain non-empty path segments".into());
}
if self.tools.contains_key(&descriptor.name) {
return Err(format!("duplicate tool `{}`", descriptor.name));
}
self.tools.insert(descriptor.name.clone(), descriptor);
Ok(())
}
/// Looks up a descriptor by its fully qualified name.
pub fn get(&self, name: &str) -> Option<&ToolDescriptor> {
self.tools.get(name)
}
/// Iterates over fully qualified tool names in lexical order.
pub fn names(&self) -> impl Iterator<Item = &str> {
self.tools.keys().map(String::as_str)
}
/// Returns the top-level namespace segments used by registered tools.
pub fn roots(&self) -> BTreeSet<&str> {
self.tools
.keys()
.filter_map(|n| n.split('.').next())
.collect()
}
/// Returns a deterministic hex digest of all descriptors.
pub fn digest(&self) -> String {
let bytes = serde_json::to_vec(&self.tools).expect("serializable");
hex::encode(Sha256::digest(bytes))
}
}
impl Schema {
/// Unbounded signed 64-bit integer schema.
pub const INTEGER: Self = Self::Integer {
min: None,
max: None,
};
/// Unbounded finite binary64 number schema.
pub const NUMBER: Self = Self::Number {
min: None,
max: None,
};
/// Creates an unconstrained string schema.
pub fn string() -> Self {
Self::String {
format: None,
enumeration: vec![],
min_len: None,
max_len: None,
}
}
/// Creates an unconstrained list with the given element schema.
pub fn list(items: Schema) -> Self {
Self::List {
items: Box::new(items),
min_len: None,
max_len: None,
}
}
/// Short lowercase name of the schema's kind, for diagnostics.
pub fn kind_name(&self) -> &'static str {
match self {
Self::Any => "any",
Self::Null => "null",
Self::Boolean => "boolean",
Self::Integer { .. } => "integer",
Self::Number { .. } => "number",
Self::String { .. } => "string",
Self::Bytes => "bytes",
Self::List { .. } => "list",
Self::Map { .. } => "map",
Self::Object { .. } => "object",
Self::Union { .. } => "union",
Self::Never => "never",
}
}
/// Returns whether a canonical value satisfies this schema.
pub fn accepts(&self, v: &CanonicalValue) -> bool {
match (self, v) {
(Self::Never, _) => false,
(Self::Any, _) => true,
(Self::Null, CanonicalValue::Null) => true,
(Self::Boolean, CanonicalValue::Boolean(_)) => true,
(Self::Integer { min, max }, CanonicalValue::Integer(x)) => {
min.is_none_or(|m| *x >= m) && max.is_none_or(|m| *x <= m)
}
(Self::Number { min, max }, CanonicalValue::Number(x)) => {
x.is_finite() && min.is_none_or(|m| *x >= m) && max.is_none_or(|m| *x <= m)
}
(
Self::String {
enumeration,
min_len,
max_len,
..
},
CanonicalValue::String(x),
) => {
(enumeration.is_empty() || enumeration.contains(x))
&& min_len.is_none_or(|m| x.chars().count() >= m)
&& max_len.is_none_or(|m| x.chars().count() <= m)
}
(Self::Bytes, CanonicalValue::Bytes(_)) => true,
(
Self::List {
items,
min_len,
max_len,
},
CanonicalValue::List(xs),
) => {
min_len.is_none_or(|m| xs.len() >= m)
&& max_len.is_none_or(|m| xs.len() <= m)
&& xs.iter().all(|x| items.accepts(x))
}
(
Self::Object {
properties,
required,
additional,
},
CanonicalValue::Object(o),
) => {
required.iter().all(|k| o.contains_key(k))
&& (*additional || o.keys().all(|k| properties.contains_key(k)))
&& o.iter()
.all(|(k, v)| properties.get(k).is_none_or(|p| p.schema.accepts(v)))
}
(Self::Map { values }, CanonicalValue::Object(o)) => {
o.values().all(|v| values.accepts(v))
}
(Self::Union { variants, .. }, v) => variants.iter().any(|s| s.accepts(v)),
_ => false,
}
}
}