# Smithy

**Canonical:** https://apis.io/providers/smithy/  
**Website:** https://smithy.io  
**APIs profiled:** 2

Smithy is an open source, protocol-agnostic interface definition language (IDL) and toolchain developed at AWS for defining, validating, and generating API clients, servers, and documentation for any programming language. It powers the AWS SDK code generation pipeline and supports protocol-agnostic API modeling with traits, validators, and code generators. Smithy IDL 2.0 is the current stable version.

## Kin Score — 21.2 / 100 (emerging)

Scored 2026-08-25 under rubric 0.14.0. Trend: flat (+0.0 from 21.2).

| Facet | Score |
|---|---|
| Discoverability | 59.3 |
| Contract Quality | 17.3 |
| Governance | 13.6 |
| Contract Governance | 13.6 |
| Operational Transparency | 10.5 |
| Developer Ergonomics | 23.8 |
| Commercial Clarity | 15.8 |
| Access Clarity | 15.8 |

## Agent readiness — 3.8 (human-only)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | documented |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## Access

Freemium — onboarding: unknown, pricing: freemium, trial: no (confidence: medium).

## APIs (2)

- **Smithy IDL** — The Smithy Interface Definition Language (IDL) is a specification for defining API models using shapes and traits. Models can be written in the Smithy IDL syntax or the JSON AST...
- **Smithy CLI** — The Smithy CLI is a command-line tool for building, validating, diffing, and transforming Smithy models. It can generate JSON AST representations, run model validation, perform ...

## Security (1)

- **Smithy Domain Security** — TLSv1.3

## Plans (1)

- **Smithy Plans Pricing**

## Tags

Code Generation, IDL, SDK, API Design, Interface Definition Language, Toolchain

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/smithy/). Scores are computed from the provider's own public artifacts under a published rubric.