Changelog

Zero-Config Compile

No anvil.config.ts required. All 10 targets are built into the CLI:

anvil compile --target mcp                # just what you need
anvil compile --target mcp,docs,anthropic # pick multiple
anvil compile --all                       # everything

Running anvil compile without a target shows interactive help with all available options.

Production MCP Serve

anvil serve now uses the real @modelcontextprotocol/sdk with full protocol compliance:

anvil serve --stub tools.anvil.yaml

Works directly in Claude Desktop, Cursor, and Claude Code configs:

{
  "mcpServers": {
    "my-tools": {
      "command": "npx",
      "args": ["@anvil-tools/cli", "serve", "--stub", "tools.anvil.yaml"]
    }
  }
}

New --handler flag for custom implementations:

anvil serve tools.anvil.yaml --handler ./my-handlers.js

Improvements

• All targets bundled in CLI — no separate npm install for each target
• Interactive help when running anvil compile without arguments
• Full MCP protocol: initialize handshake, tool annotations, typed schemas
• Graceful shutdown on SIGINT

Core

• YAML parser with rich Zod-based validation and source location error reporting
• TypeScript builder API (defineService, field, permission helpers)
• Intermediate Representation (IR) with fieldToJsonSchema and toolParametersToJsonSchema utilities
• Compilation pipeline with parallel target generation

Compilation Targets (10)

• @anvil-tools/target-mcp — MCP server with tool registration and annotations
• @anvil-tools/target-openapi — OpenAPI 3.1 spec (YAML/JSON)
• @anvil-tools/target-docs — Markdown documentation
• @anvil-tools/target-agent-schema — LLM-optimized tool schema
• @anvil-tools/target-eval — Vitest/Jest test harness + agent eval scaffolding
• @anvil-tools/target-sdk-ts — Typed TypeScript SDK with Zod validation
• @anvil-tools/target-cli-gen — Commander-based CLI generator
• @anvil-tools/target-anthropic — Claude Messages API tool format
• @anvil-tools/target-openai — OpenAI function calling format
• @anvil-tools/target-vercel-ai — Vercel AI SDK tool definitions

CLI

• anvil init — project scaffolding
• anvil validate — definition validation with rich diagnostics
• anvil compile — multi-target compilation
• anvil dev — watch mode
• anvil serve — local MCP server for testing
• anvil publish / anvil search — registry operations

Runtime (@anvil-tools/runtime)

• Input/output validation with Zod
• Permission enforcement engine
• Composable middleware: validation, rate limiting, caching, logging
• Structured JSON logging
• Cost tracking
• Circuit breaker
• OpenTelemetry instrumentation (optional)

Registry (@anvil-tools/registry)

• HTTP client for hosted registry
• Local file-based registry for development
• Publish, search, get, version management

Examples

• Weather tools (current weather, forecast)
• Filesystem tools (read, write, list)
• GitHub tools (issues, search, pull requests)
• Linear tools (issues, search)
• PostgreSQL tools (query, tables, mutations)
• Browser tools (navigate, screenshot, extract links)