---
title: "Call aontu from Go"
description: "Embed the engine with the Go port: the same three calls, with errors returned instead of thrown."
source: "https://aontu.dev/how-to/call-from-go/"
---

# Call aontu from Go

Embed the engine with the Go port: the same three calls, with errors returned instead of thrown.

Rendered from [`docs/how-to/call-from-go.md`](https://github.com/aontu-lang/aontu/blob/main/docs/how-to/call-from-go.md) in the engine repository, where a correction belongs, and where the test suite executes every example on this page.

The Go port is a library first: module `github.com/aontu-lang/aontu/go`, package `aontu`, kept in parity with the canonical TypeScript engine for the subset it implements. The same three calls, in Go’s idiom:

```go
import aontu "github.com/aontu-lang/aontu/go"

a := aontu.New()

out, err := a.Generate("a: 1 b: $.a")   // out = map[string]any{"a":1, "b":1}
v,   err := a.Unify("a: *1 | number")   // v.Canon() == `{"a":*1|number}`
v,   err  = a.Parse("a: number")        // AST, not yet unified
```

Nothing throws or panics for an ordinary conflict: every method returns an `error`, and `Generate` returns `(nil, err)` on any unresolved or conflicting value, so check it. Generated output uses Go’s natural types (`map[string]any`, `[]any`, `int64`, `float64`, `string`, `bool`, `nil`), plus `*big.Int` and `*Decimal` for the two exact leaves, both of which marshal their exact digits as raw JSON numbers ([exact numbers in Go](https://aontu.dev/docs/reference-api#exact-numbers-in-go)).

When a source’s relative `@"file"` loads should resolve from somewhere other than the process working directory (typically the directory of an entry file), construct with a base:

```go
abs, _ := filepath.Abs(file)
a := aontu.NewWithBase(filepath.Dir(abs))
```

(The `aontu` CLI does exactly this for a file argument.) Absolute paths are unaffected.

One difference from the TypeScript port to plan around: the Go port ships no MCP binary: its role is embedding, so `Get`, `Why`, `Diff` and `AgentsMd` are library calls instead ([give an agent an entrypoint](https://aontu.dev/how-to/give-an-agent-an-entrypoint)). For every problem in one pass rather than the first error, use `Check` ([collect errors](https://aontu.dev/how-to/collect-errors)).

The full surface is the [Go API reference](https://aontu.dev/docs/reference-api#go-api); to parameterise a model from code, [inject host values](https://aontu.dev/how-to/inject-host-values). The two ports answer alike by construction, and one shared test suite is what pins it.