--- title: "Service Accounts vs API Keys vs OAuth Tokens: What Should Developers Use?" url: https://daily.dev/posts/service-accounts-vs-api-keys-vs-oauth-tokens-what-should-developers-use--nv2plxsww source_url: https://www.sitepoint.com/service-accounts-vs-api-keys-vs-oauth-tokens-what-should-developers-use type: article source: "SitePoint" published: 2026-08-25T15:02:55.613Z updated: 2026-08-25T15:09:02.742Z tags: ["security", "authentication", "oauth", "iam"] reading_time: 11 upvotes: 1 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Service Accounts vs API Keys vs OAuth Tokens: What Should Developers Use? **[SitePoint](https://daily.dev/sources/sitepoint)** · 11 min read · 1 upvotes · 0 comments ## Summary A comparison of three commonly confused credential mechanisms for API authentication: API keys, OAuth 2.0 tokens, and service accounts. API keys are static, long-lived secrets suited only for low-risk public APIs with rate limiting or billing needs. OAuth 2.0 tokens (RFC 6749, RFC 9068) are short-lived, scoped, cryptographically verifiable grants used when crossing trust boundaries, calling SaaS vendors, or acting on behalf of a user. Service accounts are IAM identities representing automated workloads, best paired with Workload Identity Federation to avoid storing static keys entirely. The piece covers implementation code samples, common mistakes (hardcoded secrets, missing OAuth scopes, unmetered proxying), and a decision framework for choosing between the three based on architecture and trust boundaries. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### When should I use an API key versus an OAuth token for authenticating a backend service? Use API keys only for low-risk public APIs where identifying the caller for rate limiting or billing matters more than securing sensitive data; never use them to protect sensitive user data or an internal control plane. Use OAuth 2.0 tokens, typically via the Client Credentials grant, when crossing a trust boundary, calling a third-party SaaS vendor, or acting on behalf of a real user, since tokens carry scope and audience claims and expire in minutes to hours. _daily.dev surfaces practical breakdowns like this for developers deciding how to secure service-to-service calls._ ### What is the confused deputy problem in the context of AI agents and service accounts? It is a security failure where an autonomous agent's over-broad IAM permissions let an attacker trick the agent into performing an unauthorized action, such as reading production values and posting them publicly, while the request still appears technically authorized. The fix is enforcing least privilege so a service account only holds the exact permissions its job requires, mapped through central IAM policy rather than left to application code. _Teams building AI agents with cloud access track issues like the confused deputy problem on daily.dev._ ### How does Workload Identity Federation avoid storing static service account keys? Instead of creating a static JSON key for a service account, the cloud runtime issues short-lived credentials automatically through a metadata server or volume-mounted token, so no secret is ever stored manually. For example, GitHub Actions signs an OIDC JWT and AWS exchanges it for a short-lived session token tied to an IAM role, eliminating the need for a stored access key. _daily.dev helps developers keep up with keyless cloud authentication patterns like workload identity federation._ ## Similar posts on daily.dev - [API Authentication Methods Explained: API Keys, OAuth, JWT & HMAC Compared](https://daily.dev/posts/api-authentication-methods-explained-api-keys-oauth-jwt-hmac-compared-b3g34ltcj) · Security Boulevard · 1 upvotes · 0 comments - [Modernize Datadog API authentication with scoped credentials](https://daily.dev/posts/modernize-datadog-api-authentication-with-scoped-credentials-hqg9vowte) · Datadog · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#authentication](https://daily.dev/tags/authentication), [#oauth](https://daily.dev/tags/oauth), [#iam](https://daily.dev/tags/iam) [View this post on daily.dev](https://daily.dev/posts/service-accounts-vs-api-keys-vs-oauth-tokens-what-should-developers-use--nv2plxsww)