feat: implement opencode OAuth handling

Author: caozhiyuan

README.md

@@ -39,6 +39,7 @@ A reverse-engineered proxy for the GitHub Copilot API that exposes it as an Open
 - **Token Visibility**: Option to display GitHub and Copilot tokens during authentication and refresh for debugging (`--show-token`).
 - **Flexible Authentication**: Authenticate interactively or provide a GitHub token directly, suitable for CI/CD environments.
 - **Support for Different Account Types**: Works with individual, business, and enterprise GitHub Copilot plans.
+- **Opencode OAuth Support**: Use opencode GitHub Copilot authentication by setting `COPILOT_API_OAUTH_APP=opencode` environment variable.
 
 ## Demo
 
@@ -302,6 +303,28 @@ npx copilot-api@latest debug --json
 
 # Initialize proxy from environment variables (HTTP_PROXY, HTTPS_PROXY, etc.)
 npx copilot-api@latest start --proxy-env
+
+# Use opencode GitHub Copilot authentication
+COPILOT_API_OAUTH_APP=opencode npx @jeffreycao/copilot-api@latest start
+```
+
+### Opencode OAuth Authentication
+
+You can use opencode GitHub Copilot authentication instead of the default one:
+
+```sh
+# Set environment variable before running any command
+export COPILOT_API_OAUTH_APP=opencode
+
+# Then run start or auth commands
+npx @jeffreycao/copilot-api@latest start
+npx @jeffreycao/copilot-api@latest auth
+```
+
+Or use inline environment variable:
+
+```sh
+COPILOT_API_OAUTH_APP=opencode npx @jeffreycao/copilot-api@latest start
 ```
 
 ## Using the Usage Viewer

src/lib/api-config.ts

@@ -2,6 +2,98 @@ import { randomUUID } from "node:crypto"
 
 import type { State } from "./state"
 
+export const isOpencodeOauthApp = (): boolean => {
+  return process.env.COPILOT_API_OAUTH_APP === "opencode"
+}
+
+export const normalizeDomain = (input: string): string => {
+  return input
+    .trim()
+    .replace(/^https?:\/\//u, "")
+    .replace(/\/+$/u, "")
+}
+
+export const getEnterpriseDomain = (): string | null => {
+  const raw = (process.env.COPILOT_API_ENTERPRISE_URL ?? "").trim()
+  if (!raw) return null
+  const normalized = normalizeDomain(raw)
+  return normalized || null
+}
+
+export const getGitHubBaseUrl = (): string => {
+  const resolvedDomain = getEnterpriseDomain()
+  return resolvedDomain ? `https://${resolvedDomain}` : GITHUB_BASE_URL
+}
+
+export const getGitHubApiBaseUrl = (): string => {
+  const resolvedDomain = getEnterpriseDomain()
+  return resolvedDomain ?
+      `https://${resolvedDomain}/api/v3`
+    : GITHUB_API_BASE_URL
+}
+
+export const getOpencodeOauthHeaders = (): Record<string, string> => {
+  return {
+    Accept: "application/json",
+    "Content-Type": "application/json",
+    "User-Agent":
+      "opencode/1.2.16 ai-sdk/provider-utils/3.0.21 runtime/bun/1.3.10, opencode/1.2.16",
+  }
+}
+
+export const getOauthUrls = (): {
+  deviceCodeUrl: string
+  accessTokenUrl: string
+} => {
+  const githubBaseUrl = getGitHubBaseUrl()
+
+  return {
+    deviceCodeUrl: `${githubBaseUrl}/login/device/code`,
+    accessTokenUrl: `${githubBaseUrl}/login/oauth/access_token`,
+  }
+}
+
+interface OauthAppConfig {
+  clientId: string
+  headers: Record<string, string>
+  scope: string
+}
+
+export const getOauthAppConfig = (): OauthAppConfig => {
+  if (isOpencodeOauthApp()) {
+    return {
+      clientId: OPENCODE_GITHUB_CLIENT_ID,
+      headers: getOpencodeOauthHeaders(),
+      scope: GITHUB_APP_SCOPES,
+    }
+  }
+
+  return {
+    clientId: GITHUB_CLIENT_ID,
+    headers: standardHeaders(),
+    scope: GITHUB_APP_SCOPES,
+  }
+}
+
+export const prepareInteractionHeaders = (
+  sessionId: string | undefined,
+  isSubagent: boolean,
+  headers: Record<string, string>,
+) => {
+  const sendInteractionHeaders = !isOpencodeOauthApp()
+
+  if (isSubagent) {
+    headers["x-initiator"] = "agent"
+    if (sendInteractionHeaders) {
+      headers["x-interaction-type"] = "conversation-subagent"
+    }
+  }
+
+  if (sessionId && sendInteractionHeaders) {
+    headers["x-interaction-id"] = sessionId
+  }
+}
+
 export const standardHeaders = () => ({
   "content-type": "application/json",
   accept: "application/json",
@@ -13,15 +105,34 @@ const USER_AGENT = `GitHubCopilotChat/${COPILOT_VERSION}`
 
 const API_VERSION = "2025-10-01"
 
-export const copilotBaseUrl = (state: State) =>
-  state.accountType === "individual" ?
-    "https://api.githubcopilot.com"
-  : `https://api.${state.accountType}.githubcopilot.com`
+export const copilotBaseUrl = (state: State) => {
+  const enterpriseDomain = getEnterpriseDomain()
+  if (enterpriseDomain) {
+    return `https://copilot-api.${enterpriseDomain}`
+  }
+
+  return state.accountType === "individual" ?
+      "https://api.githubcopilot.com"
+    : `https://api.${state.accountType}.githubcopilot.com`
+}
+
 export const copilotHeaders = (
   state: State,
   requestId?: string,
   vision: boolean = false,
 ) => {
+  if (isOpencodeOauthApp()) {
+    const headers: Record<string, string> = {
+      Authorization: `Bearer ${state.copilotToken}`,
+      ...getOpencodeOauthHeaders(),
+      "Openai-Intent": "conversation-edits",
+    }
+
+    if (vision) headers["Copilot-Vision-Request"] = "true"
+
+    return headers
+  }
+
   const requestIdValue = requestId ?? randomUUID()
   const headers: Record<string, string> = {
     Authorization: `Bearer ${state.copilotToken}`,
@@ -65,3 +176,4 @@ export const githubHeaders = (state: State) => ({
 export const GITHUB_BASE_URL = "https://github.com"
 export const GITHUB_CLIENT_ID = "Iv1.b507a08c87ecfe98"
 export const GITHUB_APP_SCOPES = ["read:user"].join(" ")
+export const OPENCODE_GITHUB_CLIENT_ID = "Ov23li8tweQw6odWQebz"

src/lib/paths.ts

@@ -2,9 +2,17 @@ import fs from "node:fs/promises"
 import os from "node:os"
 import path from "node:path"
 
-const APP_DIR = path.join(os.homedir(), ".local", "share", "copilot-api")
+const AUTH_APP = process.env.COPILOT_API_OAUTH_APP || ""
+const ENTERPRISE_PREFIX = process.env.COPILOT_API_ENTERPRISE_URL ? "ent_" : ""
 
-const GITHUB_TOKEN_PATH = path.join(APP_DIR, "github_token")
+const DEFAULT_DIR = path.join(os.homedir(), ".local", "share", "copilot-api")
+const APP_DIR = process.env.COPILOT_API_HOME || DEFAULT_DIR
+
+const GITHUB_TOKEN_PATH = path.join(
+  APP_DIR,
+  AUTH_APP,
+  ENTERPRISE_PREFIX + "github_token",
+)
 const CONFIG_PATH = path.join(APP_DIR, "config.json")
 
 export const PATHS = {
@@ -14,7 +22,7 @@ export const PATHS = {
 }
 
 export async function ensurePaths(): Promise<void> {
-  await fs.mkdir(PATHS.APP_DIR, { recursive: true })
+  await fs.mkdir(path.join(PATHS.APP_DIR, AUTH_APP), { recursive: true })
   await ensureFile(PATHS.GITHUB_TOKEN_PATH)
   await ensureFile(PATHS.CONFIG_PATH)
 }

src/lib/token.ts

@@ -1,6 +1,8 @@
 import consola from "consola"
 import fs from "node:fs/promises"
+import { setTimeout as delay } from "node:timers/promises"
 
+import { isOpencodeOauthApp } from "~/lib/api-config"
 import { PATHS } from "~/lib/paths"
 import { getCopilotToken } from "~/services/github/get-copilot-token"
 import { getDeviceCode } from "~/services/github/get-device-code"
@@ -10,12 +12,37 @@ import { pollAccessToken } from "~/services/github/poll-access-token"
 import { HTTPError } from "./error"
 import { state } from "./state"
 
+let copilotRefreshLoopController: AbortController | null = null
+
+export const stopCopilotRefreshLoop = () => {
+  if (!copilotRefreshLoopController) {
+    return
+  }
+
+  copilotRefreshLoopController.abort()
+  copilotRefreshLoopController = null
+}
+
 const readGithubToken = () => fs.readFile(PATHS.GITHUB_TOKEN_PATH, "utf8")
 
 const writeGithubToken = (token: string) =>
   fs.writeFile(PATHS.GITHUB_TOKEN_PATH, token)
 
 export const setupCopilotToken = async () => {
+  if (isOpencodeOauthApp()) {
+    if (!state.githubToken) throw new Error(`opencode token not found`)
+
+    state.copilotToken = state.githubToken
+
+    consola.debug("GitHub Copilot token set from opencode auth token")
+    if (state.showToken) {
+      consola.info("Copilot token:", state.copilotToken)
+    }
+
+    stopCopilotRefreshLoop()
+    return
+  }
+
   const { token, refresh_in } = await getCopilotToken()
   state.copilotToken = token
 
@@ -25,21 +52,48 @@ export const setupCopilotToken = async () => {
     consola.info("Copilot token:", token)
   }
 
-  const refreshInterval = (refresh_in - 60) * 1000
-  setInterval(async () => {
+  stopCopilotRefreshLoop()
+
+  const controller = new AbortController()
+  copilotRefreshLoopController = controller
+
+  runCopilotRefreshLoop(refresh_in, controller.signal)
+    .catch(() => {
+      consola.warn("Copilot token refresh loop stopped")
+    })
+    .finally(() => {
+      if (copilotRefreshLoopController === controller) {
+        copilotRefreshLoopController = null
+      }
+    })
+}
+
+const runCopilotRefreshLoop = async (
+  refreshIn: number,
+  signal: AbortSignal,
+) => {
+  let nextRefreshDelayMs = (refreshIn - 60) * 1000
+
+  while (!signal.aborted) {
+    await delay(nextRefreshDelayMs, undefined, { signal })
+
     consola.debug("Refreshing Copilot token")
+
     try {
-      const { token } = await getCopilotToken()
+      const { token, refresh_in } = await getCopilotToken()
       state.copilotToken = token
       consola.debug("Copilot token refreshed")
       if (state.showToken) {
         consola.info("Refreshed Copilot token:", token)
       }
+
+      nextRefreshDelayMs = (refresh_in - 60) * 1000
     } catch (error) {
       consola.error("Failed to refresh Copilot token:", error)
-      throw error
+      nextRefreshDelayMs = 15_000
+      consola.warn(`Retrying Copilot token refresh in ${nextRefreshDelayMs}ms`)
     }
-  }, refreshInterval)
+  }
 }
 
 interface SetupGitHubTokenOptions {

src/services/copilot/create-chat-completions.ts

@@ -3,7 +3,11 @@ import { events } from "fetch-event-stream"
 
 import type { SubagentMarker } from "~/routes/messages/subagent-marker"
 
-import { copilotHeaders, copilotBaseUrl } from "~/lib/api-config"
+import {
+  copilotBaseUrl,
+  copilotHeaders,
+  prepareInteractionHeaders,
+} from "~/lib/api-config"
 import { HTTPError } from "~/lib/error"
 import { state } from "~/lib/state"
 
@@ -40,14 +44,11 @@ export const createChatCompletions = async (
     "x-initiator": isAgentCall ? "agent" : "user",
   }
 
-  if (options.subagentMarker) {
-    headers["x-initiator"] = "agent"
-    headers["x-interaction-type"] = "conversation-subagent"
-  }
-
-  if (options.sessionId) {
-    headers["x-interaction-id"] = options.sessionId
-  }
+  prepareInteractionHeaders(
+    options.sessionId,
+    options.subagentMarker !== null,
+    headers,
+  )
 
   const response = await fetch(`${copilotBaseUrl(state)}/chat/completions`, {
     method: "POST",

src/services/copilot/create-messages.ts

@@ -7,7 +7,11 @@ import type {
 } from "~/routes/messages/anthropic-types"
 import type { SubagentMarker } from "~/routes/messages/subagent-marker"
 
-import { copilotBaseUrl, copilotHeaders } from "~/lib/api-config"
+import {
+  copilotBaseUrl,
+  copilotHeaders,
+  prepareInteractionHeaders,
+} from "~/lib/api-config"
 import { HTTPError } from "~/lib/error"
 import { state } from "~/lib/state"
 
@@ -84,14 +88,11 @@ export const createMessages = async (
     "x-initiator": isInitiateRequest ? "user" : "agent",
   }
 
-  if (options.subagentMarker) {
-    headers["x-initiator"] = "agent"
-    headers["x-interaction-type"] = "conversation-subagent"
-  }
-
-  if (options.sessionId) {
-    headers["x-interaction-id"] = options.sessionId
-  }
+  prepareInteractionHeaders(
+    options.sessionId,
+    options.subagentMarker !== null,
+    headers,
+  )
 
   // align with vscode copilot extension anthropic-beta
   const anthropicBeta = buildAnthropicBetaHeader(