Can I use my Claude Code subscription to build an app?

For personal scripts on your own machine, yes. For a centralized server serving multiple users, no — that violates Anthropic's terms. For any external commercial product, you must use an API key. Anthropic's commercial terms explicitly allow API keys to 'power products for its own customers and end users', but the consumer subscription is restricted to 'ordinary, individual usage'.

Can I use Codex CLI subscription in a third-party app?

Yes — uniquely among the four vendors, OpenAI actively endorses individual developers using their own ChatGPT/Codex subscription in third-party tools and harnesses. They hired the creator of OpenClaw and published embedding guides. However, this still applies to individual use, not building a product on someone else's subscription.

Which AI CLI licensing is most permissive for building commercial products?

For commercial products, API key / pay-per-token is the only clean path across all four vendors. Gemini CLI (API + Vertex AI) is generally the most permissive and cheapest option for external products — the CLI itself is Apache 2.0 open source. No subscription from any vendor allows powering external products.

Can I run Claude Code on a VPS for a centralized server?

If it's for your own use only, yes — there is no ToS restriction on where you run the Claude CLI. If the VPS serves multiple users through one subscription, no — that violates terms. For a multi-user server, you must authenticate each user with their own credentials, or use API keys at the server level.

AI CLI Licensing Models — Claude Code, Codex, Gemini & Copilot CLI Compared

Updated April 2026 · Based on published Terms of Service

AI CLI
Licensing Models

Not all authentication methods are created equal. Before you build, understand what your subscription actually allows — and where you must switch to API keys. The rules differ significantly across vendors and deployment scenarios.

⚠️ Disclaimer — This information was researched and verified using Claude Opus 4.6, Gemini 3 Pro, and GPT-5.4 against each vendor's published Terms of Service as of April 2026. We are not responsible for any inaccuracies, omissions, or changes in terms since publication. Always check your own subscription's allowance details before building. This is not legal advice.

Verified with Claude Opus 4.6 Verified with Gemini 3 Pro Verified with GPT-5.4

Section 1

Personal or Internal Use

A single developer or a company building an internal tool — a script, a Make.com/n8n workflow, a Slack bot, a web app, a cron job — that calls an AI coding CLI programmatically via its official headless mode (claude -p, codex exec, gemini -p). The tool is for personal use or company employees only — not sold externally.

Environment	Claude Code	Codex CLI (OpenAI)	Gemini CLI	GitHub Copilot CLI
Script / daemon / cron on own machine	✅ API Key · ✅ Subscription	✅ API Key · ✅ Subscription	✅ API Key · ✅ Subscription	✅ BYOK · ✅ Subscription
Own VPS	✅ API Key · ✅ Subscription — No ToS ban on where you run the official CLI. Auth needs periodic browser refresh	✅ API Key · ✅ Subscription — Device code flow (`codex login --device-auth`) enables headless auth. Officially documented	✅ API Key · ⚠️ Subscription — Google account login requires a browser; cached credentials work in `-p` mode after initial login, but headless mode cannot initiate a fresh Google login	✅ BYOK · ⚠️ Subscription — Device code flow (RFC 8628) works but may need workspace admin approval
Each user has own CLI + own subscription; internal app triggers their local CLI	✅ API Key · ✅ Subscription — Each person uses their own seat, their own CLI. Standard usage	✅ API Key · ✅ Subscription — Each person uses their own Codex via `exec`. Standard usage	✅ API Key · ✅ Subscription — Each person uses their own Gemini CLI via `-p`. Standard usage	✅ BYOK · ✅ Subscription — Each person uses their own Copilot license
Centralized server, one subscription, multiple users	✅ API Key · ❌ Subscription — One subscription serving multiple users violates terms. OAuth is for that user's own CLI usage, not a shared backend	✅ API Key · ❌ Subscription — One sub = one user. A single subscription cannot serve multiple people through a shared backend	✅ API Key · ✅ Vertex AI · ❌ Subscription — Google account auth is per-individual. Cannot share across multiple users	✅ BYOK · ❌ Subscription — Per-user licensing. Each user needs their own Copilot license
CI/CD pipeline (own repos)	✅ API Key · ✅ Subscription — Anthropic docs show GitHub Actions with subscription auth	✅ API Key · ✅ Subscription — Official CI/CD examples in docs	✅ API Key · ✅ Vertex AI · ✅ Subscription — Headless mode with cached credentials or service account	✅ BYOK · ✅ Subscription — Developer running the pipeline uses their own license

Note — Gemini Free Tier

Since March 25, 2026, the free subscription tier (Google account login) is limited to Flash models only. Pro models require a paid Google AI Pro/Ultra subscription or API key.

Key Takeaway

If each person uses their own subscription + own CLI installation, everything is allowed. The moment you route multiple users through a single centralized subscription, it's not allowed on any vendor — you need API keys (pay-per-token). For a centralized Make.com/n8n workflow or web app on a server used by multiple people: use API keys.

Section 2

Commercial Use (External Product)

You're building a product or service for external customers — a SaaS tool, a client-facing automation, a white-label solution — that calls an AI coding CLI programmatically on a server. End users are outside your organization.

Environment	Claude Code	Codex CLI (OpenAI)	Gemini CLI	GitHub Copilot CLI
Backend service powering a product	✅ API Key — Commercial Terms: "permission to power products for its own customers and end users" · ❌ Subscription — Consumer ToS: "ordinary, individual usage" only. Enforced Jan 2026	✅ API Key — Standard API terms allow building products · ❌ Subscription — One sub = one user. Cannot power a product serving external customers	✅ API Key · ✅ Vertex AI — CLI is Apache 2.0 OSS. Pay-per-token, no per-user restriction · ❌ Subscription — Not designed for powering external products	✅ BYOK — Bypasses Copilot licensing entirely · ❌ Subscription — Cannot use one subscription to serve external customers
Multi-tenant SaaS	✅ API Key · ❌ Subscription	✅ API Key · ❌ Subscription	✅ API Key · ✅ Vertex AI · ❌ Subscription	✅ BYOK · ❌ Subscription
Own subscription in a third-party coding tool	❌ Subscription — Feb 2026: "OAuth is intended exclusively for Claude Code and Claude.ai. Using OAuth tokens in any other product, tool, or service is not permitted" · ✅ API Key	✅ Subscription — OpenAI actively endorses third-party harness use. Hired OpenClaw creator. Published embedding guides · ✅ API Key	❌ Subscription — Google FAQ: "Using third-party software, tools, or services to access Gemini CLI is a violation" · ✅ API Key · ✅ Vertex AI	✅ Copilot SDK (public preview) — Designed for embedding · ✅ BYOK · ⚠️ Subscription — Users need their own Copilot license

Key Takeaway

For any product serving external customers, API key / pay-per-token is the only clean path across all four vendors. No subscription allows powering external products. Gemini (API + Vertex AI) is the most permissive and cheapest for external products. OpenAI is uniquely permissive about individual developers using their own subscription in third-party tools — but that doesn't extend to building products on someone else's subscription.

Quick Reference

Subscription Allowed?

Scenario	Claude Code	Codex CLI	Gemini CLI	Copilot CLI
Own machine, own scripts	✅	✅	✅	✅
Own VPS	✅	✅	⚠️ needs cached auth	⚠️ device code flow
Each user on own seat, app triggers their local CLI	✅	✅	✅	✅
Centralized server, one sub, multiple users	❌	❌	❌	❌
CI/CD for own repos	✅	✅	✅	✅
Powering an external product	❌	❌	❌	❌
Own sub in a third-party coding tool	❌	✅	❌	✅

Final Reminder

Not legal advice. Verify current terms directly with each vendor before building products on any of these tools. Terms change — the row for "Subscription allowed in third-party tools" shifted for both Anthropic and OpenAI between 2025 and 2026.