OpenAI authentication in 2025: API keys, service accounts, and secure token flows for developers and enterprises

OpenAI uses project-level API keys and service accounts for secure access.

OpenAI’s authentication model in 2025 is built around project-scoped API keys and service accounts. This marks a shift from the older user-bound API keys toward a structure that provides better isolation, key rotation, and auditing. Each project in the OpenAI dashboard can have multiple service accounts, and each service account can have its own key. This means that a compromised key only affects a single service account rather than the entire organization.

When making API calls to OpenAI-hosted models, the client must include an Authorization: Bearer <API_KEY> header. Optionally, the OpenAI-Organization header can be used if multiple organizations are linked to the same account, although most teams now scope billing and usage at the project level.

Keys should be stored in environment variables or in a secure secrets management system (such as AWS Secrets Manager, Azure Key Vault, or HashiCorp Vault). Embedding keys in client-side code or public repositories is a major security risk and can result in unauthorized usage and billing.

Table – API key types and scopes

Key Type	Scope	Use Case	Rotation Method	Billing Level
User API Key	User account	Personal use, prototyping	Manual via dashboard	Per user
Project API Key	Project/account	Team deployments	CLI / API-based	Per project/org

Ephemeral tokens are now required for secure browser and mobile access.

For Realtime API usage (such as WebRTC voice calls, speech-to-text streaming, or live response generation) in browser or mobile environments, OpenAI now recommends an ephemeral token pattern. This approach ensures that long-lived keys never reach the client.

In practice, the backend server holds the permanent API key and uses it to request a short-lived ephemeral token from OpenAI. This token, which typically expires within 1 to 10 minutes, is passed to the browser or mobile app. The client then uses this temporary credential to initiate the realtime session. Once expired, the token cannot be reused, limiting the attack surface.

This method is especially important in public-facing apps or situations where the client environment is not fully trusted. By limiting exposure time and binding the token to a session, the risk of key leakage is drastically reduced.

Table – Token types and safety level

Token Type	Lifetime	Use Location	Safe for Frontend?	Risk Level
API Key	Long-lived	Backend only	❌ Never	High
Ephemeral Token	60–600 seconds	Client/browser	✅ Yes	Low

Azure OpenAI allows API key and Microsoft Entra ID authentication.

Organizations using Azure OpenAI Service have two distinct authentication methods:

a. Azure API key

This method works much like OpenAI’s own API key. The key is issued via the Azure portal for the specific Azure OpenAI resource. It is passed in the HTTP header as:api-key: <AZURE_OPENAI_KEY>

It’s straightforward and ideal for proof-of-concept deployments or backends that run outside Azure. However, it’s still a static secret, requiring secure storage and rotation.

b. Microsoft Entra ID (OAuth 2.0 / Managed Identity)

This method uses token-based authentication obtained from Azure Active Directory (now Microsoft Entra ID). It supports:

• OAuth 2.0: Apps obtain a bearer token via client credentials or authorization code flow.

• Managed Identity: Azure-hosted workloads (VMs, Functions, AKS pods) can obtain tokens without storing secrets.

Managed identities are particularly beneficial for enterprise environments where role-based access control (RBAC), conditional access, and compliance auditing are required.

Table – Azure OpenAI authentication options

Method	Deployment Context	Secrets Required	RBAC Support	Best For
API Key	Any (e.g., on-prem)	Yes	❌	Simple, fast setup
Entra ID OAuth	Web, serverless	Yes (client secret)	✅	SSO, enterprise control
Managed Identity	Azure-hosted workloads	❌	✅	Automation, compliance

Client/server architecture changes with service accounts and project scoping.

Service accounts tied to projects fundamentally change how developers should structure authentication in production systems. Instead of sharing a single key across multiple environments, teams should:

• Create one project per environment (e.g., service-dev, service-staging, service-prod).

• Assign one service account per microservice or integration point.

• Use labels and expiry policies to maintain governance and ensure unused keys are automatically retired.

This approach reduces blast radius and simplifies incident response in case of a breach.

How token-based flows enable delegated permissions (Azure Entra ID only).

In Azure environments, Entra ID enables granular, delegated access. Depending on the authentication flow, applications can act:

• On behalf of a user (OBO flow)

• As an application without user context (Client Credentials)

• Without secrets at all (Managed Identity in Azure)

Table – Entra ID grant types for OpenAI access

Grant Type	Needs User Login	Supports Delegation	Token Scope Level	Used In
Authorization Code	✅ Yes	✅ Yes	Per-user	Web apps, plugins
Client Credentials	❌ No	❌ No	App-only	CI/CD, automation
On-Behalf-Of (OBO)	✅ Yes	✅ Yes	User context	Middle-layer services
Managed Identity	❌ No	❌ No	App-only	Azure-native serverless functions

How plugin developers (Actions API) handle authentication today.

OpenAI Actions and plugins integrate external APIs with ChatGPT. The supported authentication methods are:

• No authentication – for public, read-only endpoints.

• API key authentication – stored server-side and injected into requests.

• OAuth 2.0 authentication – allows users to sign in and grant specific permissions.

For OAuth, the plugin manifest defines:

"auth": {
  "type": "oauth",
  "client_url": "https://yourdomain.com/oauth/start",
  "scope": "read:reports write:actions"
}

How to troubleshoot 401 and 403 errors in OpenAI integrations.

Many integration failures come from authentication misconfigurations. Common causes and fixes include:

Table – Common errors and solutions

HTTP Code	Cause	Fix
401	Missing or invalid key/token	Check Authorization header; rotate key if needed
403	Key valid but access denied	Ensure org/project ID is correct; check permissions
429	Rate limit exceeded	Backoff + retry; monitor usage on dashboard

Compliance and observability for enterprise security teams.

Large organizations must integrate OpenAI authentication with audit logging and usage analytics. This includes:

• Logging all API calls with project/service account context.

• Linking usage data to billing, cost allocation, and chargeback models.

• Tagging requests with custom headers like X-Request-ID for traceability.

• Preparing an incident response plan to revoke and rotate keys quickly.

This operational discipline ensures that OpenAI API usage remains secure, cost-efficient, and compliant with corporate governance standards.

____________

FOLLOW US FOR MORE.

DATA STUDIOS

datastudios.org