copilot-go

copilot-go copilot provides the types and functions for authoring GitHub Copilot Extensions.

Use this package to build GitHub Copilot agents and skillsets.

Installing

copilot-go is compatible with modern Go releases in module mode, with Go installed:

go get github.com/colbylwilliams/copilot-go

will resolve and add the package to the current development module, along with its dependencies.

Alternatively the same can be achieved if you use import in a package:

import "github.com/colbylwilliams/copilot-go"

and run go get without parameters.

Finally, to use the top-of-trunk version of this repo, use the following command:

go get github.com/colbylwilliams/copilot-go@main

Usage

See the _examples directory for complete and runnable examples.

This simple example agent uses chi and go-github:

package main

import (
    "context"
    "net/http"

    "github.com/colbylwilliams/copilot-go"
    "github.com/go-chi/chi/v5"
    "github.com/go-chi/chi/v5/middleware"
    "github.com/google/go-github/v67/github"
)

func main() {
    cfg, _ := copilot.LoadConfig()
    v, _ := copilot.NewPayloadVerifier()

    a := &MyAgent{cfg: cfg}

    r := chi.NewRouter()
    r.Use(middleware.Logger)
    r.Use(middleware.RequestID)

    r.Post("/agent", copilot.AgentHandler(v, a))

    return http.ListenAndServe(":3333", r)
}

type MyAgent struct{ cfg *copilot.Config }

func (a *MyAgent) Execute(ctx context.Context, token string, req *copilot.Request, w http.ResponseWriter) error {
    rid := middleware.GetReqID(ctx)
    gh := github.NewClient(nil).WithAuthToken(token)

    me, _, _ := gh.Users.Get(ctx, "")

    sse.WriteStreamingHeaders(w)

    sse.WriteDelta(w, rid, fmt.Sprintf("Hello %s\n", me.GetName()))
    sse.WriteDelta(w, rid, "How are you today?\n")

    sse.WriteStop(w, rid)
}

Configuration

LoadConfig above loads .env file(s) with godotenv, then loads the required configuration information from environment variables. Here's an example .env file with the required variables:

GITHUB_APP_CLIENT_ID=Iv23abcdef1234567890
GITHUB_APP_PRIVATE_KEY_PATH=my-agent.2024-08-20.private-key.pem
GITHUB_APP_FQDN=https://my_unique_devtunnelid-3333.use2.devtunnels.ms

These values will come from your Copilot extension's GitHub App. See "Creating a GitHub App for your Copilot Extension" and "Configuring your GitHub App for your Copilot extension" for details.

See the Config and azure.Config types for a full set of available configuration variables.

Copilot's LLM

In the first example, the agent replies with a static message. We can easily enhance it to use Copilot's LLM to generate the response.

package main

import (
    "context"
    "net/http"

    "github.com/colbylwilliams/copilot-go"
    "github.com/go-chi/chi/v5"
    "github.com/go-chi/chi/v5/middleware"
    "github.com/google/go-github/v67/github"
)

func main() {
    cfg, _ := copilot.LoadConfig()
    v, _ := copilot.NewPayloadVerifier()

    a := &MyAgent{cfg: cfg}

    r := chi.NewRouter()
    r.Use(middleware.Logger)
    r.Use(middleware.RequestID)

    r.Post("/agent", copilot.AgentHandler(v, a))

    return http.ListenAndServe(":3333", r)
}

type MyAgent struct{ cfg *copilot.Config }

func (a *MyAgent) Execute(ctx context.Context, token string, req *copilot.Request, w http.ResponseWriter) error {

    const prompt = "You are a helpful AI assistant."

    msg := &copilot.Message{Role: copilot.ChatRoleSystem, Content: prompt}

    comp := &copilot.CompletionsRequest{
        Messages: []*copilot.Message{msg},
        Model:    copilot.CopilotModelGPT4o,
    }

    comp.Messages = append(comp.Messages, req.Messages...)

    stream, _ := copilot.ChatCompletionsStream(ctx, token, *comp, w)

    _, err = io.Copy(w, stream)

    return nil
}