chio-openapi

chio-openapi parses OpenAPI 3.0 and 3.1 specifications (JSON or YAML) and converts each operation into a Chio ToolDefinition: an input schema built from path, query, and body parameters, an optional output schema from the response, and annotations (read_only, destructive, idempotent, requires_approval) derived from the HTTP method and x-chio-* extension fields.

Use it to turn an OpenAPI-described HTTP API into Chio tool definitions. This crate produces ToolDefinition values only: it does not assemble or sign a ToolManifest, host tools over MCP, or dispatch HTTP calls. chio-openapi-mcp-bridge adds those steps; chio-api-protect consumes the parser and policy types directly for request-time policy evaluation.

Responsibilities

• Parse OpenAPI 3.0/3.1 documents (JSON or YAML, auto-detected) into an OpenApiSpec, resolving local #/components/... $ref pointers and failing closed on missing required fields or malformed parameters.
• Generate one ToolDefinition per operation: merge path- and operation-level parameters, build an input schema from path/query parameters and the request body, and select an output schema from the first 2xx response.
• Parse x-chio-* operation extensions (ChioExtensions) and apply the publish, side-effect, and approval-required overrides when generating tool annotations.
• Assign a default request policy per HTTP method (DefaultPolicy): safe methods are session-scoped allow, side-effecting methods are deny-by-default, both overridable via extensions.

Public API

• tools_from_spec(input: &str) -> Result<Vec<chio_core_types::ToolDefinition>>
  • parse and generate in one call.
• OpenApiSpec::{parse, from_value}, and the parsed model parser::{Operation, Parameter, ParameterLocation, PathItem}.
• GeneratorConfig, ManifestGenerator::{new, generate_tools} - tool generation from a parsed spec.
• ChioExtensions::from_operation, Sensitivity - x-chio-* field extraction.
• DefaultPolicy::{for_method, for_method_with_extensions, has_side_effects}, PolicyDecision - method- and extension-driven policy.
• OpenApiError, Result<T> - the crate error type and its alias.

Usage

// spec_text is an OpenAPI 3.0/3.1 document, JSON or YAML.
let tools = chio_openapi::tools_from_spec(spec_text)?;

Testing

cargo test -p chio-openapi

See also

• chio-openapi-mcp-bridge - wraps this crate's ToolDefinitions into an MCP-visible surface, assembles and signs the ToolManifest, and dispatches invocations through the kernel.
• chio-api-protect - consumes OpenApiSpec, ChioExtensions, and DefaultPolicy directly for request-time policy evaluation.
• chio-core-types - supplies the ToolDefinition/ToolAnnotations types this crate produces.
• chio-http-core - supplies HttpMethod, used for method parsing and default policy.