copilot

Documentation

Overview

Package copilot implements the GitHub Copilot Provider.

Copilot's chat endpoint is reverse-engineered from public clients (copilot.vim, copilot-language-server). The wire shape is OpenAI-compatible Chat Completions; the auth flow is the distinguishing piece:

1. Device-code OAuth against github.com → user-facing code
2. Poll for GH access token
3. Exchange GH token at api.github.com/copilot_internal/v2/token for a short-lived Copilot internal token (refresh via the same endpoint when it expires)
4. Use the Copilot token against api.githubcopilot.com with Editor-Version + Copilot-Integration-Id headers

The exchange response includes `endpoints.api` which we respect — GitHub has moved this for some users.

Package copilot will implement the GitHub Copilot Provider.

Lands in v0.2 (NOT v0.1). Copilot's chat endpoint is reverse-engineered, not a documented public API, so the adapter carries its own brittleness budget. When v0.2 ships:

• OAuth device-code flow against GitHub
• Token exchange to a short-lived Copilot internal token (refresh transparently; honor `endpoints.api` in the exchange response)
• Required headers: Editor-Version, Copilot-Integration-Id (a known-good ID is required; the whitelist is server-side)
• Streaming response shape differs subtly from official OpenAI
• Failover: Copilot 401 → OpenRouter with same model name (pre-wired)

Until then this package is intentionally empty; the architecture doc commits to the surface at § Providers → v0.2 — GitHub Copilot.

Index

• Constants
• Variables
• func FinishDeviceFlow(ctx context.Context, clientID string, dc *DeviceCode) (string, error)
• type DeviceCode
  • func StartDeviceFlow(ctx context.Context, clientID string) (*DeviceCode, error)
• type Provider
  • func (p *Provider) Chat(ctx context.Context, req *provider.Request) (<-chan provider.StreamEvent, error)
  • func (p *Provider) Models(ctx context.Context) ([]provider.Model, error)
  • func (p *Provider) Name() string
  • func (p *Provider) TokenCount(_ context.Context, _ string, msgs []provider.Message) (int, error)

Constants

const (
	// DefaultClientID is the public Copilot OAuth client ID.
	DefaultClientID = "Iv1.b507a08c87ecfe98"
)

Variables

var (
	ErrNoGHToken = errors.New("copilot: GitHub access token not set; run device-flow auth first")
)

Errors.

Functions

func FinishDeviceFlow

func FinishDeviceFlow(ctx context.Context, clientID string, dc *DeviceCode) (string, error)

FinishDeviceFlow polls until the user completes the GitHub authorization. Returns the GitHub access token.

Types

type DeviceCode

type DeviceCode struct {
	DeviceCode      string `json:"device_code"`
	UserCode        string `json:"user_code"`
	VerificationURI string `json:"verification_uri"`
	ExpiresIn       int    `json:"expires_in"`
	Interval        int    `json:"interval"`
}

DeviceCode is the response from POST /login/device/code.

func StartDeviceFlow

func StartDeviceFlow(ctx context.Context, clientID string) (*DeviceCode, error)

StartDeviceFlow begins a device-code OAuth flow against GitHub. Returns the codes; the caller displays UserCode + VerificationURI to the user and then polls FinishDeviceFlow.

type Provider

type Provider struct {
	// GHToken is the GitHub access token obtained via device-code
	// OAuth. Stored in credstore under (provider="copilot",
	// account="github"); the harness loads it before calling Chat.
	GHToken string

	// IntegrationID overrides the default ("vscode-chat"). Other
	// known-good values: "vscode" / "copilot-chat" / "jetbrains".
	IntegrationID string

	// EditorVersion is the User-Agent-like string Copilot expects.
	EditorVersion string

	HTTP *http.Client
	// contains filtered or unexported fields
}

Provider is the GitHub Copilot Provider.

func (*Provider) Chat

func (p *Provider) Chat(ctx context.Context, req *provider.Request) (<-chan provider.StreamEvent, error)

Chat implements provider.Provider.

func (*Provider) Models

func (p *Provider) Models(ctx context.Context) ([]provider.Model, error)

Models implements provider.Provider. Catalog comes from /models on the Copilot API base. The catalog returned by Copilot depends on the user's subscription tier and per-org policy.

func (*Provider) Name

func (p *Provider) Name() string

Name implements provider.Provider.

func (*Provider) TokenCount

func (p *Provider) TokenCount(_ context.Context, _ string, msgs []provider.Message) (int, error)

TokenCount uses the same heuristic as the OpenAI-compatible adapters.