Unit 9 · Connect to external tools and data

Classify stateful and stateless MCP

Automatic era classification keeps one client compatible with stateful 2025-11-25 and stateless 2026-07-28 servers. Modern discovery returns supported versions, capabilities, instructions, cache policy, and server identity.

discover()9 focused minutesNot started

Unit example (nearest native match)

See the idea in context

transport, err := ax.NewAxMCPStreamableHTTPTransport(endpoint, nil)
if err != nil { panic(err) }
mcp := ax.NewAxMCPClient(transport, map[string]ax.Value{"namespace": "inventory"})
defer func() { _ = mcp.Close() }()
catalog, err := mcp.InspectCatalog(false)
if err != nil { panic(err) }
fmt.Printf("MCP catalog: %d tools, %d resources, %d templates\n",
    len(catalog.Tools), len(catalog.Resources), len(catalog.ResourceTemplates))
program := ax.NewAx("request:string -> answer:string", map[string]ax.Value{"mcp": mcp})
llm := ax.NewOpenAICompatibleClient(map[string]ax.Value{
    "api_key": key, "model": "gpt-5.4-mini",
})
output, err := program.Forward(context.Background(), llm,
    map[string]ax.Value{"request": "Reindex inventory."}, nil)
if err != nil { panic(err) }
fmt.Println(output)

Keep automatic classification
Pin an era only when deployment policy already knows the endpoint contract.
Read modern discovery
server/discover is stateless and is available only after the endpoint classifies as modern.

Run itIn your own project

go get github.com/ax-llm/ax/packages/go

import axllm "github.com/ax-llm/ax/packages/go"

client := axllm.NewAI("openai", map[string]axllm.Value{"apiKey": os.Getenv("OPENAI_API_KEY")})
classify := axllm.NewAx("review:string -> sentiment:class \"positive, negative, neutral\"", nil)

Set OPENAI_APIKEY in your environment before running provider-backed code.

In the ax repo

From a clone of the ax repo:

npm run example -- go src/examples/go/mcp/native_mcp_tools.go

Active practice

Show that you can use it

Answer 2 in a row to learn this · attempt 1

Keep exploring

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Show that you can use it

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