feat(provider): add chatgpt provider with ChatGPT account sign-in

agent-schema.json

@@ -184,7 +184,7 @@
       "properties": {
         "provider": {
           "type": "string",
-          "description": "The underlying provider type. Defaults to \"openai\" when not set. Supported values: openai, anthropic, google, amazon-bedrock, dmr, and any built-in alias (requesty, openrouter, azure, xai, ollama, mistral, baseten, ovhcloud, groq, fireworks, deepseek, cerebras, together, huggingface, moonshot, vercel, cloudflare-workers-ai, cloudflare-ai-gateway, nvidia, etc.).",
+          "description": "The underlying provider type. Defaults to \"openai\" when not set. Supported values: openai, anthropic, google, amazon-bedrock, dmr, and any built-in alias (requesty, openrouter, azure, xai, ollama, mistral, baseten, ovhcloud, groq, fireworks, deepseek, cerebras, together, huggingface, moonshot, vercel, cloudflare-workers-ai, cloudflare-ai-gateway, nvidia, github-copilot, chatgpt, etc.).",
           "examples": [
             "openai",
             "anthropic",
@@ -1446,7 +1446,8 @@
             "anthropic",
             "dmr",
             "ollama",
-            "github-copilot"
+            "github-copilot",
+            "chatgpt"
           ]
         },
         "model": {

cmd/root/doctor.go

@@ -14,6 +14,7 @@ import (
 	"github.com/docker/cli/cli"
 	"github.com/spf13/cobra"
 
+	"github.com/docker/docker-agent/pkg/chatgpt"
 	"github.com/docker/docker-agent/pkg/config"
 	"github.com/docker/docker-agent/pkg/environment"
 	"github.com/docker/docker-agent/pkg/model/provider/dmr"
@@ -266,8 +267,8 @@ func (f *doctorFlags) buildReport(ctx context.Context, agentRef string) (*doctor
 		if found, known := credFound[auto.Provider]; known && !found {
 			autoStatus.Usable = false
 			report.Issues = append(report.Issues, fmt.Sprintf(
-				"the configured default model %s/%s has no credential for provider %s; set %s (%s)",
-				auto.Provider, auto.Model, auto.Provider, primaryEnvVar[auto.Provider], environment.SecretsDocsURL))
+				"the configured default model %s/%s has no credential for provider %s; %s (%s)",
+				auto.Provider, auto.Model, auto.Provider, providerCredentialHint(auto.Provider, primaryEnvVar[auto.Provider]), environment.SecretsDocsURL))
 		}
 	}
 	report.AutoModel = autoStatus
@@ -366,6 +367,16 @@ func (f *doctorFlags) listDMRModels(ctx context.Context) ([]string, error) {
 	return dmr.ListModels(ctx)
 }
 
+// providerCredentialHint phrases the remediation for a missing provider
+// credential: account-based providers point at the setup wizard's sign-in,
+// the rest at their API-key env var.
+func providerCredentialHint(provider, envVar string) string {
+	if provider == chatgpt.ProviderName {
+		return "sign in with `docker agent setup` (pick chatgpt) or set " + envVar
+	}
+	return "set " + envVar
+}
+
 // findSource returns the name of the first secret source that supplies a
 // non-empty value for the variable. Empty values are skipped so a source that
 // merely defines the variable (e.g. an env file with `KEY=`) is not reported

cmd/root/doctor_test.go

@@ -82,6 +82,44 @@ func TestDoctorCommand_SourcePrecedenceMatchesProviderChain(t *testing.T) {
 	assert.Regexp(t, `openai\s+found\s+OPENAI_API_KEY\s+env-file`, output)
 }
 
+func TestDoctorCommand_ChatGPTLoginSource(t *testing.T) {
+	t.Parallel()
+
+	// The chatgpt-login source serves the virtual CHATGPT_OAUTH_TOKEN
+	// variable from the stored browser sign-in.
+	login := environment.NewMapEnvProvider(map[string]string{"CHATGPT_OAUTH_TOKEN": "chatgpt-access-token"})
+
+	output, err := executeDoctor(t, nil, func(f *doctorFlags) {
+		f.runConfig.EnvProviderForTests = login
+		f.sourcesForTests = []environment.Source{
+			{Name: "environment", Provider: environment.NewMapEnvProvider(nil)},
+			{Name: "chatgpt-login", Provider: login},
+		}
+		f.dmrLister = func(context.Context) ([]string, error) { return []string{"ai/qwen3:latest"}, nil }
+		f.loadUserConfig = func() (*userconfig.Config, error) { return &userconfig.Config{}, nil }
+	})
+
+	require.NoError(t, err)
+	assert.Regexp(t, `chatgpt\s+found\s+CHATGPT_OAUTH_TOKEN\s+chatgpt-login`, output)
+	assert.Contains(t, output, "auto -> chatgpt/gpt-5.2")
+	assert.Contains(t, output, "No issues found.")
+	assert.NotContains(t, output, "chatgpt-access-token", "secret values must never be printed")
+}
+
+func TestDoctorCommand_ChatGPTDefaultModelWithoutLoginSuggestsSignIn(t *testing.T) {
+	t.Parallel()
+
+	output, err := executeDoctor(t, nil,
+		withDoctorTestEnv(nil, []string{"ai/qwen3:latest"}, nil),
+		func(f *doctorFlags) {
+			f.runConfig.DefaultModel = &latest.ModelConfig{Provider: "chatgpt", Model: "gpt-5.2"}
+		})
+
+	require.Error(t, err, "a default model without credentials is an issue")
+	assert.Regexp(t, `chatgpt\s+not set\s+CHATGPT_OAUTH_TOKEN`, output)
+	assert.Contains(t, output, "sign in with `docker agent setup` (pick chatgpt) or set CHATGPT_OAUTH_TOKEN")
+}
+
 func TestDoctorCommand_EmptyValueIsNotACredential(t *testing.T) {
 	t.Parallel()
 

cmd/root/setup.go

@@ -15,6 +15,7 @@ import (
 	"github.com/spf13/cobra"
 	"golang.org/x/term"
 
+	"github.com/docker/docker-agent/pkg/chatgpt"
 	"github.com/docker/docker-agent/pkg/cli"
 	"github.com/docker/docker-agent/pkg/config"
 	"github.com/docker/docker-agent/pkg/environment"
@@ -52,10 +53,11 @@ type setupWizard struct {
 	in  *bufio.Reader
 	out io.Writer
 
-	readSecret func(prompt string) (string, error)
-	stores     []environment.SecretStore
-	dmrLister  config.DMRModelLister
-	pullModel  func(ctx context.Context, model string) error
+	readSecret   func(prompt string) (string, error)
+	stores       []environment.SecretStore
+	dmrLister    config.DMRModelLister
+	pullModel    func(ctx context.Context, model string) error
+	chatgptLogin func(ctx context.Context, out io.Writer) (*chatgpt.LoginResult, error)
 }
 
 func newSetupCmd() *cobra.Command {
@@ -66,7 +68,9 @@ func newSetupCmd() *cobra.Command {
 
 Two paths:
   - Cloud provider: pick a provider, paste its API key, and choose where to
-    store it (OS keychain, pass, or the docker agent env file).
+    store it (OS keychain, pass, or the docker agent env file). Picking
+    chatgpt signs in with your ChatGPT account in the browser instead of
+    asking for an API key.
   - Local model: check Docker Model Runner and pull a model. No API key needed.
 
 Ends with the exact command to start chatting. Secret values are stored where
@@ -116,9 +120,10 @@ func newTerminalSetupWizard(in io.Reader, out io.Writer) *setupWizard {
 			}
 			return string(value), nil
 		},
-		stores:    environment.SecretStores(),
-		dmrLister: dmr.ListModels,
-		pullModel: dmr.Pull,
+		stores:       environment.SecretStores(),
+		dmrLister:    dmr.ListModels,
+		pullModel:    dmr.Pull,
+		chatgptLogin: chatgpt.Login,
 	}
 }
 
@@ -158,7 +163,11 @@ func (w *setupWizard) setupCloudProvider(ctx context.Context) (*setupResult, err
 	fmt.Fprintln(w.out)
 	fmt.Fprintln(w.out, "Pick a provider:")
 	for i, p := range providers {
-		fmt.Fprintf(w.out, "  %2d. %-15s (%s)\n", i+1, p.Provider, p.EnvVars[0])
+		credential := p.EnvVars[0]
+		if p.Provider == chatgpt.ProviderName {
+			credential = "ChatGPT account sign-in, no API key"
+		}
+		fmt.Fprintf(w.out, "  %2d. %-15s (%s)\n", i+1, p.Provider, credential)
 	}
 
 	choice, err := w.promptChoice(ctx, len(providers), 1)
@@ -168,6 +177,22 @@ func (w *setupWizard) setupCloudProvider(ctx context.Context) (*setupResult, err
 	selected := providers[choice-1]
 	envVar := selected.EnvVars[0]
 
+	// The chatgpt provider signs in with a browser flow instead of a pasted
+	// API key; the credential is stored by the login itself.
+	if selected.Provider == chatgpt.ProviderName {
+		fmt.Fprintln(w.out)
+		result, err := w.chatgptLogin(ctx, w.out)
+		if err != nil {
+			return nil, err
+		}
+		if result.Email != "" {
+			fmt.Fprintf(w.out, "Signed in as %s.\n", result.Email)
+		} else {
+			fmt.Fprintln(w.out, "Signed in with your ChatGPT account.")
+		}
+		return &setupResult{Model: selected.Provider + "/" + config.DefaultModels[selected.Provider]}, nil
+	}
+
 	key, err := w.promptSecret(ctx, fmt.Sprintf("\nPaste your %s API key (%s, input hidden): ", selected.Provider, envVar))
 	if err != nil {
 		return nil, err

cmd/root/setup_test.go

@@ -6,12 +6,15 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
+	"slices"
 	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
+	"github.com/docker/docker-agent/pkg/chatgpt"
 	"github.com/docker/docker-agent/pkg/config"
 	"github.com/docker/docker-agent/pkg/config/latest"
 	"github.com/docker/docker-agent/pkg/environment"
@@ -135,6 +138,36 @@ func TestSetupWizard_CloudPathReasksOnEmptyKey(t *testing.T) {
 	assert.Equal(t, "sk-key", store.stored["ANTHROPIC_API_KEY"])
 }
 
+func TestSetupWizard_ChatGPTPathRunsBrowserSignIn(t *testing.T) {
+	t.Parallel()
+
+	providers := config.CloudProviderEnvVars()
+	idx := slices.IndexFunc(providers, func(p config.ProviderEnvVars) bool { return p.Provider == "chatgpt" })
+	require.GreaterOrEqual(t, idx, 0, "chatgpt must be offered by the wizard")
+
+	store := &fakeSecretStore{name: "keychain"}
+	// cloud -> chatgpt: no key prompt, no store prompt.
+	wizard, out, _ := newTestWizard(fmt.Sprintf("1\n%d\n", idx+1), nil, []environment.SecretStore{store}, nil, nil)
+	loginCalled := false
+	wizard.chatgptLogin = func(_ context.Context, _ io.Writer) (*chatgpt.LoginResult, error) {
+		loginCalled = true
+		return &chatgpt.LoginResult{Email: "user@example.com", Plan: "plus"}, nil
+	}
+
+	result, err := wizard.run(t.Context())
+	require.NoError(t, err)
+
+	assert.True(t, loginCalled)
+	assert.Empty(t, result.EnvVar, "the sign-in stores the credential itself; nothing to export")
+	assert.Equal(t, "chatgpt/"+config.DefaultModels["chatgpt"], result.Model)
+	assert.Empty(t, store.stored, "no secret store is involved")
+
+	output := out.String()
+	assert.Contains(t, output, "ChatGPT account sign-in")
+	assert.Contains(t, output, "Signed in as user@example.com.")
+	assert.Contains(t, output, "--model chatgpt/"+config.DefaultModels["chatgpt"])
+}
+
 func TestSetupWizard_LocalPathWithPulledModels(t *testing.T) {
 	t.Parallel()
 

docs/concepts/models/index.md

@@ -99,6 +99,7 @@ for details.
 | Azure OpenAI        | `azure`          | gpt-4o, gpt-5 on Azure               | `AZURE_API_KEY` + `base_url`        |
 | Ollama              | `ollama`         | Any local Ollama model               | None (local; optional `base_url`)   |
 | GitHub Copilot      | `github-copilot` | Copilot-hosted OpenAI/Anthropic      | `GITHUB_TOKEN` (PAT with `copilot`) |
+| ChatGPT (OpenAI account) | `chatgpt`   | gpt-5 family via ChatGPT subscription | None (sign in via `docker agent setup`) |
 
 See the [Model Providers](../../providers/overview/index.md) section for detailed configuration guides.
 

docs/configuration/models/index.md

@@ -50,7 +50,7 @@ models:
 | Property              | Type       | Required | Description                                                                           |
 | --------------------- | ---------- | -------- | ------------------------------------------------------------------------------------- |
 | `first_available`     | array      | ✗        | Candidate model references tried in order; selects the first whose credentials are configured. Mutually exclusive with other model settings. |
-| `provider`            | string     | ✓/✗      | Required for regular model definitions; omitted for `first_available` selectors. Provider: `openai`, `anthropic`, `google`, `amazon-bedrock`, `dmr`, `mistral`, `xai`, `nebius`, `nvidia`, `minimax`, `baseten`, `ovhcloud`, `groq`, `fireworks`, `deepseek`, `cerebras`, `together`, `huggingface`, `moonshot`, `vercel`, `cloudflare-workers-ai`, `cloudflare-ai-gateway`, `requesty`, `openrouter`, `azure`, `ollama`, `github-copilot`, or any [named provider](../../providers/custom/index.md). |
+| `provider`            | string     | ✓/✗      | Required for regular model definitions; omitted for `first_available` selectors. Provider: `openai`, `anthropic`, `google`, `amazon-bedrock`, `dmr`, `mistral`, `xai`, `nebius`, `nvidia`, `minimax`, `baseten`, `ovhcloud`, `groq`, `fireworks`, `deepseek`, `cerebras`, `together`, `huggingface`, `moonshot`, `vercel`, `cloudflare-workers-ai`, `cloudflare-ai-gateway`, `requesty`, `openrouter`, `azure`, `ollama`, `github-copilot`, `chatgpt`, or any [named provider](../../providers/custom/index.md). |
 | `model`               | string     | ✓/✗      | Required for regular model definitions; omitted for `first_available` selectors. Model name (e.g., `gpt-4o`, `claude-sonnet-4-5`, `gemini-3.5-flash`) |
 | `temperature`         | float      | ✗        | Sampling randomness. Range is provider-dependent — typically `0.0–2.0` (Anthropic caps at `1.0`). `0.0` is deterministic. |
 | `max_tokens`          | int        | ✗        | Maximum response length in tokens                                                     |

docs/providers/chatgpt/index.md

@@ -0,0 +1,122 @@
+---
+title: "ChatGPT (OpenAI account)"
+description: "Use your ChatGPT Plus/Pro/Business subscription with docker-agent by signing in with your OpenAI account, no API key needed."
+keywords: docker agent, ai agents, model providers, llm, chatgpt, openai, codex, subscription
+weight: 55
+canonical: https://docs.docker.com/ai/docker-agent/providers/chatgpt/
+---
+
+_Use your ChatGPT subscription with docker-agent by signing in with your OpenAI account. No API key needed._
+
+## Overview
+
+The `chatgpt` provider authenticates with a ChatGPT account (the same
+"Sign in with ChatGPT" flow used by OpenAI's Codex CLI) instead of an
+`OPENAI_API_KEY`. Usage is billed against your ChatGPT Plus, Pro, or
+Business plan rather than pay-per-token API credits.
+
+Under the hood, docker-agent talks to the ChatGPT Codex backend
+(`https://chatgpt.com/backend-api/codex`), which serves the `gpt-5` model
+family over the OpenAI Responses API.
+
+## Prerequisites
+
+- A paid **ChatGPT** subscription (Plus, Pro, or Business).
+- A browser on the machine running the sign-in (the OAuth flow uses a
+  fixed `localhost:1455` callback).
+
+## Sign In
+
+```bash
+docker agent setup
+```
+
+Pick **chatgpt** in the provider list: instead of asking for an API key, the
+wizard opens your browser on the ChatGPT sign-in page and stores the
+resulting OAuth credential in the docker-agent config directory
+(`~/.config/cagent/chatgpt-auth.json`, owner-only permissions). The access
+token is refreshed automatically; you only need to sign in again if the
+refresh token is revoked.
+
+Related commands:
+
+```bash
+docker agent doctor                        # the chatgpt row shows the credential state
+rm ~/.config/cagent/chatgpt-auth.json      # sign out (remove the stored sign-in)
+```
+
+## Configuration
+
+### Inline
+
+```yaml
+agents:
+  root:
+    model: chatgpt/gpt-5.2
+    instruction: You are a helpful assistant.
+```
+
+### Named model
+
+```yaml
+models:
+  gpt:
+    provider: chatgpt
+    model: gpt-5.2
+    thinking_budget: medium
+
+agents:
+  root:
+    model: gpt
+```
+
+## Available Models
+
+The Codex backend serves the models available to your ChatGPT plan,
+typically:
+
+| Model               | Best For                              |
+| ------------------- | ------------------------------------- |
+| `gpt-5.2`           | General purpose, strong reasoning     |
+| `gpt-5.2-codex`     | Agentic coding workflows              |
+| `gpt-5.1`           | Previous flagship                     |
+| `gpt-5.1-codex-mini`| Fast and cheap coding tasks           |
+
+## How It Works
+
+- **Auth:** the `docker agent setup` sign-in runs an OAuth 2.0
+  authorization-code + PKCE flow against `auth.openai.com`. The stored login
+  is exposed to credential checks (doctor, `first_available`, auto model
+  selection) as the virtual `CHATGPT_OAUTH_TOKEN` variable.
+- **API:** requests go to the Responses API only; the backend has no Chat
+  Completions endpoint, so `api_type` is pinned automatically.
+- **Request shape:** the backend requires stateless requests (`store: false`)
+  and a top-level `instructions` field, so docker-agent moves system messages
+  there. Client-side sampling parameters (`temperature`, `top_p`,
+  `max_tokens`) are not supported by the backend and are dropped.
+
+## Setting the Token Explicitly
+
+`CHATGPT_OAUTH_TOKEN` can also be set like any other credential (shell
+environment, `--env-from-file`, keychain, ...). An explicitly set value takes
+precedence over the stored sign-in. This is useful for short-lived CI runs
+with a pre-minted access token, but note that such a token expires and is not
+refreshed.
+
+## ChatGPT Subscription vs. OpenAI API Key
+
+| | `chatgpt` | `openai` |
+| --- | --- | --- |
+| Credential | ChatGPT account sign-in | `OPENAI_API_KEY` |
+| Billing | Included in the ChatGPT plan (rate-limited) | Pay per token |
+| Models | `gpt-5` family served by the Codex backend | Full OpenAI API catalog |
+| Sampling controls (`temperature`, ...) | Not supported | Supported |
+| Embeddings / reranking | Not supported | Supported |
+
+When both credentials are configured, automatic model selection prefers
+`openai`; pin `--model chatgpt/gpt-5.2` (or use a named model) to use the
+subscription.
+
+> [!NOTE]
+> Use of the Codex backend is governed by OpenAI's terms for ChatGPT and
+> Codex. Sign-in is per user; do not share the stored credential.

docs/providers/openai/index.md

@@ -15,6 +15,11 @@ _Use GPT-4o, GPT-5, GPT-5-mini, and other OpenAI models with docker-agent._
 export OPENAI_API_KEY="sk-..."
 ```
 
+> [!TIP]
+> No API key? A ChatGPT Plus/Pro/Business subscription can be used instead
+> through the [`chatgpt` provider](../chatgpt/index.md): sign in once with
+> `docker agent setup` (pick chatgpt).
+
 ## Configuration
 
 ### Inline

docs/providers/overview/index.md

@@ -36,6 +36,7 @@ docker-agent also includes built-in aliases for these providers:
 
 | Provider       | Alias            | API Key / Env Variable              |
 | -------------- | ---------------- | ----------------------------------- |
+| ChatGPT (OpenAI account) | [`chatgpt`](../chatgpt/index.md) | None (sign in via `docker agent setup`) |
 | OpenCode Zen   | `opencode-zen`   | `OPENCODE_API_KEY`                  |
 | OpenCode Go    | `opencode-go`    | `OPENCODE_API_KEY`                  |
 | Mistral        | `mistral`        | `MISTRAL_API_KEY`                   |