Add OIDC authentication with API key fallback - enabled by default for Claude

pkg/parser/schemas/main_workflow_schema.json

@@ -2974,6 +2974,34 @@
                 "type": "string"
               },
               "description": "Optional array of command-line arguments to pass to the AI engine CLI. These arguments are injected after all other args but before the prompt."
+            },
+            "oidc": {
+              "type": "object",
+              "description": "OpenID Connect authentication configuration for agentic engines. When configured, the workflow will use OIDC to obtain tokens with PAT fallback support.",
+              "properties": {
+                "audience": {
+                  "type": "string",
+                  "description": "OIDC audience identifier (e.g., 'claude-code-github-action'). Defaults to engine-specific audience if not specified."
+                },
+                "token_exchange_url": {
+                  "type": "string",
+                  "description": "URL endpoint to exchange OIDC token for an app token (required for OIDC authentication)"
+                },
+                "token_revoke_url": {
+                  "type": "string",
+                  "description": "URL endpoint to revoke the app token after workflow execution (optional)"
+                },
+                "oauth_token_env_var": {
+                  "type": "string",
+                  "description": "Environment variable name for OAuth token obtained via OIDC. For Claude: CLAUDE_CODE_OAUTH_TOKEN. Defaults to engine-specific variable."
+                },
+                "api_token_env_var": {
+                  "type": "string",
+                  "description": "Environment variable name for API key used as fallback. For Claude: ANTHROPIC_API_KEY. Defaults to engine-specific variable."
+                }
+              },
+              "required": ["token_exchange_url"],
+              "additionalProperties": false
             }
           },
           "required": [

pkg/workflow/agentic_engine.go

@@ -70,6 +70,21 @@ type CodingAgentEngine interface {
 	// GetVersionCommand returns the command to get the version of the agent (e.g., "copilot --version")
 	// Returns empty string if the engine does not support version reporting
 	GetVersionCommand() string
+
+	// GetOIDCConfig returns the OIDC configuration for this engine
+	// Returns nil if the engine does not support OIDC or OIDC is not configured
+	GetOIDCConfig(workflowData *WorkflowData) *OIDCConfig
+
+	// GetTokenEnvVarName returns the environment variable name for API key authentication tokens
+	// For Claude: ANTHROPIC_API_KEY (used as fallback when OIDC fails)
+	// For Copilot: GITHUB_TOKEN
+	// For Codex: OPENAI_API_KEY
+	GetTokenEnvVarName() string
+
+	// GetOAuthTokenEnvVarName returns the environment variable name for OAuth tokens obtained via OIDC
+	// For Claude: CLAUDE_CODE_OAUTH_TOKEN
+	// For other engines: typically same as GetTokenEnvVarName()
+	GetOAuthTokenEnvVarName() string
 }
 
 // ErrorPattern represents a regex pattern for extracting error information from logs
@@ -155,6 +170,23 @@ func (e *BaseEngine) GetVersionCommand() string {
 	return ""
 }
 
+// GetOIDCConfig returns nil by default (engines can override for OIDC support)
+func (e *BaseEngine) GetOIDCConfig(workflowData *WorkflowData) *OIDCConfig {
+	return nil
+}
+
+// GetTokenEnvVarName returns the default API token environment variable name
+// Engines should override this to return engine-specific values
+func (e *BaseEngine) GetTokenEnvVarName() string {
+	return "GITHUB_TOKEN"
+}
+
+// GetOAuthTokenEnvVarName returns the default OAuth token environment variable name
+// By default, uses the same as API token. Engines can override for different OAuth token variables.
+func (e *BaseEngine) GetOAuthTokenEnvVarName() string {
+	return e.GetTokenEnvVarName()
+}
+
 // GetLogFileForParsing returns the default log file path for parsing
 // Engines can override this to use engine-specific log files
 func (e *BaseEngine) GetLogFileForParsing() string {

pkg/workflow/claude_engine.go

@@ -83,11 +83,46 @@ func (e *ClaudeEngine) GetVersionCommand() string {
 	return "claude --version"
 }
 
+// GetOIDCConfig returns the OIDC configuration for Claude engine
+// Claude has OIDC enabled by default with Anthropic's token exchange endpoint
+func (e *ClaudeEngine) GetOIDCConfig(workflowData *WorkflowData) *OIDCConfig {
+	// If explicit OIDC config is provided, use it
+	if workflowData.EngineConfig != nil && workflowData.EngineConfig.OIDC != nil && workflowData.EngineConfig.OIDC.TokenExchangeURL != "" {
+		return workflowData.EngineConfig.OIDC
+	}
+
+	// Return default OIDC configuration for Claude
+	return &OIDCConfig{
+		Audience:         "claude-code-github-action",
+		TokenExchangeURL: "https://api.anthropic.com/api/github/github-app-token-exchange",
+		TokenRevokeURL:   "https://api.anthropic.com/api/github/github-app-token-revoke",
+	}
+}
+
+// GetTokenEnvVarName returns the environment variable name for Claude's API key authentication
+// This is used as the fallback when OIDC authentication is not available
+func (e *ClaudeEngine) GetTokenEnvVarName() string {
+	return "ANTHROPIC_API_KEY"
+}
+
+// GetOAuthTokenEnvVarName returns the environment variable name for Claude's OAuth token
+// This is used for OIDC-obtained tokens
+func (e *ClaudeEngine) GetOAuthTokenEnvVarName() string {
+	return "CLAUDE_CODE_OAUTH_TOKEN"
+}
+
 // GetExecutionSteps returns the GitHub Actions steps for executing Claude
 func (e *ClaudeEngine) GetExecutionSteps(workflowData *WorkflowData, logFile string) []GitHubActionStep {
 	// Handle custom steps if they exist in engine config
 	steps := InjectCustomEngineSteps(workflowData, e.convertStepToYAML)
 
+	// Add OIDC setup step - Claude has OIDC enabled by default
+	oidcConfig := e.GetOIDCConfig(workflowData)
+	if oidcConfig != nil {
+		oidcSetupStep := GenerateOIDCSetupStep(oidcConfig, e)
+		steps = append(steps, oidcSetupStep)
+	}
+
 	// Build claude CLI arguments based on configuration
 	var claudeArgs []string
 
@@ -190,8 +225,13 @@ func (e *ClaudeEngine) GetExecutionSteps(workflowData *WorkflowData, logFile str
 	// Add environment section - always include environment section for GH_AW_PROMPT
 	stepLines = append(stepLines, "        env:")
 
-	// Add Anthropic API key
-	stepLines = append(stepLines, "          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}")
+	// Add authentication token - if OIDC is configured, use OAuth token from setup step
+	// Otherwise, use the API key secret directly
+	if oidcConfig != nil {
+		stepLines = append(stepLines, "          CLAUDE_CODE_OAUTH_TOKEN: ${{ steps.setup_oidc_token.outputs.token }}")
+	} else {
+		stepLines = append(stepLines, "          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}")
+	}
 
 	// Disable telemetry, error reporting, and bug command for privacy and security
 	stepLines = append(stepLines, "          DISABLE_TELEMETRY: \"1\"")
@@ -268,6 +308,12 @@ func (e *ClaudeEngine) GetExecutionSteps(workflowData *WorkflowData, logFile str
 		steps = append(steps, cleanupStep)
 	}
 
+	// Add OIDC revoke step - Claude has OIDC enabled by default
+	if oidcConfig != nil {
+		oidcRevokeStep := GenerateOIDCRevokeStep(oidcConfig)
+		steps = append(steps, oidcRevokeStep)
+	}
+
 	return steps
 }
 

pkg/workflow/codex_engine.go

@@ -82,6 +82,19 @@ func (e *CodexEngine) GetVersionCommand() string {
 	return "codex --version"
 }
 
+// GetOIDCConfig returns the OIDC configuration for Codex engine
+func (e *CodexEngine) GetOIDCConfig(workflowData *WorkflowData) *OIDCConfig {
+	if workflowData.EngineConfig != nil && workflowData.EngineConfig.OIDC != nil && workflowData.EngineConfig.OIDC.TokenExchangeURL != "" {
+		return workflowData.EngineConfig.OIDC
+	}
+	return nil
+}
+
+// GetTokenEnvVarName returns the environment variable name for Codex's authentication token
+func (e *CodexEngine) GetTokenEnvVarName() string {
+	return "OPENAI_API_KEY"
+}
+
 // GetDeclaredOutputFiles returns the output files that Codex may produce
 // Codex (written in Rust) writes logs to ~/.codex/log/codex-tui.log
 func (e *CodexEngine) GetDeclaredOutputFiles() []string {

pkg/workflow/copilot_engine.go

@@ -97,6 +97,19 @@ func (e *CopilotEngine) GetVersionCommand() string {
 	return "copilot --version"
 }
 
+// GetOIDCConfig returns the OIDC configuration for Copilot engine
+func (e *CopilotEngine) GetOIDCConfig(workflowData *WorkflowData) *OIDCConfig {
+	if workflowData.EngineConfig != nil && workflowData.EngineConfig.OIDC != nil && workflowData.EngineConfig.OIDC.TokenExchangeURL != "" {
+		return workflowData.EngineConfig.OIDC
+	}
+	return nil
+}
+
+// GetTokenEnvVarName returns the environment variable name for Copilot's authentication token
+func (e *CopilotEngine) GetTokenEnvVarName() string {
+	return "GITHUB_TOKEN"
+}
+
 // extractAddDirPaths extracts all directory paths from copilot args that follow --add-dir flags
 func extractAddDirPaths(args []string) []string {
 	var dirs []string

pkg/workflow/engine.go

@@ -23,6 +23,7 @@ type EngineConfig struct {
 	Config        string
 	Args          []string
 	Firewall      *FirewallConfig // AWF firewall configuration
+	OIDC          *OIDCConfig     // OIDC authentication configuration
 }
 
 // NetworkPermissions represents network access permissions
@@ -253,6 +254,12 @@ func (c *Compiler) ExtractEngineConfig(frontmatter map[string]any) (string, *Eng
 				}
 			}
 
+			// Extract optional 'oidc' field (object format)
+			config.OIDC = ParseOIDCConfig(engineObj)
+			if config.OIDC != nil {
+				engineLog.Print("Extracted OIDC configuration")
+			}
+
 			// Return the ID as the engineSetting for backwards compatibility
 			engineLog.Printf("Extracted engine configuration: ID=%s", config.ID)
 			return config.ID, config

pkg/workflow/js.go

@@ -87,6 +87,12 @@ var redactSecretsScript string
 //go:embed js/notify_comment_error.cjs
 var notifyCommentErrorScript string
 
+//go:embed js/setup_oidc_token.cjs
+var setupOIDCTokenScript string
+
+//go:embed js/revoke_oidc_token.cjs
+var revokeOIDCTokenScript string
+
 // removeJavaScriptComments removes JavaScript comments (// and /* */) from code
 // while preserving comments that appear within string literals
 func removeJavaScriptComments(code string) string {

pkg/workflow/js/revoke_oidc_token.cjs

@@ -0,0 +1,60 @@
+// @ts-check
+/// <reference types="@actions/github-script" />
+
+/**
+ * Revoke OIDC token
+ *
+ * This script revokes the app token that was obtained via OIDC token exchange.
+ * It only runs if a token was obtained via OIDC (not fallback).
+ */
+
+/**
+ * Main function to revoke OIDC token
+ */
+async function main() {
+  try {
+    // Get configuration from environment variables
+    const revokeUrl = process.env.GH_AW_OIDC_REVOKE_URL;
+    const tokenObtained = process.env.GH_AW_OIDC_TOKEN_OBTAINED;
+    const token = process.env.GH_AW_OIDC_TOKEN;
+
+    // Only revoke if we obtained a token via OIDC
+    if (tokenObtained !== "true") {
+      core.info("No OIDC token to revoke (token from fallback or not obtained)");
+      return;
+    }
+
+    // If no revoke URL is configured, skip revocation
+    if (!revokeUrl) {
+      core.info("No token revoke URL configured, skipping revocation");
+      return;
+    }
+
+    if (!token) {
+      core.warning("No token available for revocation");
+      return;
+    }
+
+    core.info(`Revoking token at: ${revokeUrl}`);
+
+    const response = await fetch(revokeUrl, {
+      method: "POST",
+      headers: {
+        Authorization: `Bearer ${token}`,
+      },
+    });
+
+    if (!response.ok) {
+      // Log warning but don't fail the workflow
+      core.warning(`Token revocation failed: ${response.status} ${response.statusText}`);
+      return;
+    }
+
+    core.info("Token successfully revoked");
+  } catch (error) {
+    // Log warning but don't fail the workflow for revocation errors
+    core.warning(`Failed to revoke token: ${error instanceof Error ? error.message : String(error)}`);
+  }
+}
+
+await main();