Make your legacy APIs agent-ready.
From API to agent
Section titled “From API to agent”- Import your API. Supply a contract and its supporting files.
- Review the operations. Inspect names, typed inputs, and behavior. Approve the operations agents may call.
- Try a request. Preview a call, then test the generated tools against a mock.
- Use the output. Choose the interface your agent or application needs.
The console follows the same flow. Run pnpm anvil console . --open after
building. Start with Import API, then Review. Use API operations
for request previews and Request builder for CLI and MCP drafts.
Interfaces shows generated files and setup steps.

An API operation is one call imported from a specification. A bundle contains the API’s contracts, generated files, and review state. An interface is how an agent or application calls those operations.
Business actions is an optional, separate workflow for tasks that bind one or more API operations. It currently requires a project JSON with action definitions, source snapshots, and evaluation tasks.
Compile your first API
Section titled “Compile your first API”The payments example works locally without credentials. It includes a refund operation with confirmation and idempotency requirements you can inspect and test.
After installing from source:
pnpm anvil compile examples/payments/openapi.yaml \ --manifest examples/payments/anvil.yaml \ --service payments --out generated/paymentspnpm anvil status generated/paymentspnpm anvil inspect generated/paymentsRun the full local quickstart to exercise the policy and test the generated MCP server against a mock.
What you can use afterward
Section titled “What you can use afterward”| Output | Consumer | Shared contract |
|---|---|---|
| Typed CLI | Developer or coding harness | Approved operations and validated arguments |
| MCP server | MCP client | The same operation and runtime policy |
| Four client SDKs | TypeScript, Python, Go, Java application | Generated operation methods and gates |
| Skill and hooks | Coding harness | Operation guidance and supported early refusals |
| Mocks and assurance records | CI or reviewer | Executable checks tied to the bundle hash |
| Gemini Enterprise connector kit | Gemini Enterprise app | MCP integration with explicit authentication and registration setup |
| Deployment inputs | Operator | Configuration and release plans |
The Gemini Enterprise kit is generated separately after reviewing the bundle. Follow Connect Gemini Enterprise to generate, deploy, and register the connector.
The CLI and MCP runtime require installed or linked Anvil packages. The SDK trees can be vendored independently. SDK details.
Start from the material you have
Section titled “Start from the material you have”| Input | First step | What it produces |
|---|---|---|
| API description | anvil agentify | Candidate bundle, assessment, and capability proposals |
| Gateway export | anvil estate inventory | Gateway-aware inventory with provenance |
| Legacy deployment configuration | anvil legacy inventory | Offline evidence and technical candidates |
| Existing MCP server | anvil adopt | Review artifacts and an adoption plan |
agentify stops for review. It does not infer approval or deploy. Legacy
inventory does not generate or run a bridge. Parser support also differs from
wire support: native gRPC requires a JSON transcoder; unsupported streaming
and SOAP bindings are refused. Source support.
The model prevents interfaces from disagreeing
Section titled “The model prevents interfaces from disagreeing”AIR, the Anvil Intermediate Representation, records schema, effect, risk, authentication, approval, confirmation, idempotency, retry, and evidence requirements. Every generated surface reads that model.
| Condition | Result |
|---|---|
| Operation is unapproved | It is absent from callable surfaces |
| Required confirmation is missing | The call fails before execution |
| Idempotency is unproven | Automatic mutation retry is disabled |
| A harness hook is absent | Runtime policy still applies |
| Bundle bytes change | Previous assurance evidence becomes stale |
publish succeeds | An operator plan exists; deployment has not occurred |
The compiler cannot recover a missing business guarantee from an HTTP method. Supply supported semantics in the reviewed manifest.
Pick the next step
Section titled “Pick the next step”| Goal | Guide |
|---|---|
| Compile and exercise one bundle locally | Quickstart |
| Resolve uncertain operations | Enrich and approve |
| Process a gateway export | Gateway import |
| Inventory middleware without an API description | Legacy inventory |
| Require fresh evidence before release | CI integration |
| Understand a refusal or incomplete bundle | Troubleshooting |
Anvil is a source-installed toolchain for reviewed integrations. A small, single-client API wrapper may require less setup. Its value grows when several interfaces must preserve the same operation semantics.