LLM-Server/docs/research/connecting-cloud-providers.md

Connecting real cloud LLM providers (Anthropic Claude et al.) behind the LiteLLM gateway

Date: 2026-08-26 Scope: Can the existing $20/mo Claude Pro subscription be used as a backend behind our self-hosted LiteLLM gateway (docker-compose.yml, litellm-config.yaml) instead of, or alongside, llama.cpp? If not, what's the concrete path to add real Anthropic (and other) cloud models?

1. Claude Pro subscription quota vs. Anthropic API — is it the same thing?

No. They are two separate products with separate billing, and Anthropic's own documentation and Terms of Service explicitly prohibit routing Pro/Max subscription credentials through third-party tools like a self-hosted gateway.

1a. Pro plan does not include API access

Anthropic's help center is explicit:

"The Pro plan does not include API usage through the Claude Console. If you're interested in both enhanced Claude features and the Claude API, you'll need to set up Console access to pay for API usage separately." — https://support.claude.com/en/articles/8325606-what-is-the-pro-plan

Pro/Max are flat-fee subscriptions to products (claude.ai web/desktop/mobile chat, and Claude Code) with rolling usage limits. The Anthropic API (Console/platform.claude.com) is a metered, pay-per-token product with its own separate billing account. There is no documented way to authenticate a non-Anthropic tool against Pro/Max quota "as if" it were an API key — no such integration exists.

1b. How Claude Code itself authenticates, and why that path is closed off to other tools

When you run claude and log in via /login with a claude.ai account, Claude Code obtains an OAuth token scoped to the subscription (standard OAuth 2.0 authorization-code flow against Anthropic's consent page). Anthropic also documents claude setup-token, which mints a long-lived (1-year) OAuth token (CLAUDE_CODE_OAUTH_TOKEN, prefixed sk-ant-oat01-...) explicitly for use outside interactive login — e.g. CI. This is real, officially documented, subscription-backed credential material that is technically exportable as an environment variable. — https://code.claude.com/docs/en/authentication

However, Anthropic's official Legal & Compliance page for Claude Code states this is authorized for Claude Code (and other native Anthropic apps) only, not for arbitrary third-party tools:

"OAuth authentication is intended exclusively for purchasers of Claude Free, Pro, Max, Team, and Enterprise subscription plans and is designed to support ordinary use of Claude Code and other native Anthropic applications."

"Anthropic does not permit third-party developers to offer Claude.ai login into their own applications, or to route requests through Free, Pro, or Max plan credentials on behalf of their users. Moreover, developers may not collect, store, or intermediate Claude.ai credentials or session tokens — sign-in to a Claude account must complete through Anthropic's own flow."

"Anthropic reserves the right to take measures to enforce these restrictions and may do so without prior notice." — https://code.claude.com/docs/en/legal-and-compliance ("Authentication and credential use" section)

That page cites the governing documents directly:

• Consumer Terms of Service (Free/Pro/Max): https://www.anthropic.com/legal/consumer-terms
• Commercial Terms of Service (Team/Enterprise/API): https://www.anthropic.com/legal/commercial-terms
• Anthropic Usage Policy: https://www.anthropic.com/legal/aup

This is not just a ToS technicality — it's actively enforced. In March 2026 Anthropic used server-side enforcement (in addition to legal action) to block third-party "harnesses" (e.g. OpenClaw and similar tools) from routing traffic through Claude subscription OAuth credentials, specifically citing that such traffic bypasses the telemetry/behavior the Claude Code harness provides. Coverage: https://www.theregister.com/software/2026/02/20/anthropic-clarifies-ban-on-third-party-tool-access-to-claude/ (secondary source; the primary enforcement basis is the Legal & Compliance page above, which is current as fetched today).

Community finding (flagged as unofficial/against ToS): technically, claude setup-token's OAuth token can be handed to LiteLLM (some LiteLLM community docs / discussions describe pointing ANTHROPIC_AUTH_TOKEN/CLAUDE_CODE_OAUTH_TOKEN at a proxy, e.g. https://docs.litellm.ai/docs/tutorials/claude_code_max_subscription and https://github.com/BerriAI/litellm/discussions/30827). This works at the protocol level because the token is a bearer credential like any other. It is exactly the pattern Anthropic's compliance page above says is not permitted ("route requests through Free, Pro, or Max plan credentials on behalf of [other] users" / outside "ordinary use of Claude Code and other native Anthropic applications"). Doing this for personal, single-user use through the unmodified claude binary (e.g. just running claude itself pointed at your own gateway) is different from what's prohibited — the prohibition targets intermediating the subscription credential through a third-party tool/product on behalf of requests that aren't Claude Code itself. Routing arbitrary LiteLLM/OpenWebUI traffic through a subscription OAuth token extracted from claude setup-token falls squarely in the prohibited category. Do not build this into the gateway.

1c. Bottom line on subscription reuse

No documented, ToS-compliant way exists to point LiteLLM (or any third-party gateway) at Claude Pro/Max quota instead of a real API key. The $20/mo subscription is for claude.ai and Claude Code usage only.

2. The real path: an Anthropic API key (Console, pay-per-token)

This is the supported way to add Claude models to LiteLLM, and it's the same config shape already used for llama.cpp in litellm-config.yaml.

LiteLLM's Anthropic provider docs (https://docs.litellm.ai/docs/providers/anthropic) give this model_list shape:

model_list:
  - model_name: claude-sonnet-5   # whatever alias you want callers to use
    litellm_params:
      model: anthropic/claude-sonnet-5    # "anthropic/<model-id>" tells LiteLLM which provider
      api_key: os.environ/ANTHROPIC_API_KEY

Practical steps:

1. Create a Console account / org at https://platform.claude.com (separate from claude.ai login), generate an API key there.
2. Add it to .env as ANTHROPIC_API_KEY=sk-ant-api03-... and reference it via os.environ/ANTHROPIC_API_KEY in litellm-config.yaml, following the existing pattern used for LITELLM_MASTER_KEY/LITELLM_SALT_KEY in docker-compose.yml.
3. Add a model_list entry per Claude model you want exposed (e.g. claude-sonnet-5, claude-haiku-4-5), each with its own input_cost_per_token/output_cost_per_token if you want LiteLLM's cost tracking to reflect real spend (today litellm-config.yaml's cost fields are a shadow estimate against Sonnet 5 pricing for the local model — real Anthropic model entries should carry the model's actual published rate from https://platform.claude.com/docs/en/about-claude/pricing).
4. This is billed separately from, and in addition to, the $20/mo subscription — pay-per-token, metered on the Console account, no relationship to Pro/Max usage limits.

No other config changes are implied — the router/general_settings blocks already in place don't need to change for a second provider; LiteLLM routes per-model_name based on the litellm_params each entry declares.

3. Other providers — same general pattern

Every major consumer AI subscription (OpenAI's ChatGPT Plus, and by the same logic Google's Gemini subscription tiers) works identically to Anthropic's: the consumer chat subscription and the pay-per-token developer API are separate products with separate billing, and the subscription does not unlock API access. Confirmed for OpenAI: "ChatGPT Plus does not include API access... no API key in the box, no monthly API credits, and no discount on per-token prices. The OpenAI API is a separate product with its own billing." There's no equivalent OAuth-token-reuse loophole documented for OpenAI/Google either — this isn't an Anthropic-specific restriction, it's the standard shape of how these companies segment consumer vs. developer products. Adding OpenAI, Gemini, or any other cloud model to LiteLLM means the same recipe as Anthropic: get a real pay-per-token API key from that provider's own developer console and add a model_list entry with litellm_params.model set to that provider's LiteLLM prefix (openai/..., gemini/..., etc.) — see https://docs.litellm.ai/docs/providers for the full prefix list.

4. Recommended next step

• Do not attempt to feed the Claude Pro subscription's OAuth token into LiteLLM/Open WebUI — it's against Anthropic's Consumer Terms of Service and Usage Policy, and Anthropic has shown it will enforce this server-side without notice (per the March 2026 crackdown on third-party harnesses).
• If real cloud Claude models behind the gateway are wanted, get a separate Anthropic Console API key (pay-per-token, its own bill, independent of the $20/mo subscription) and add it as a model_list entry per §2 above. Same recipe for any other provider (§3).
• Keep using the existing $20/mo Claude Pro subscription only for what it's licensed for: the claude.ai web app and the Claude Code CLI itself (this session included) — not as a backend behind the self-hosted gateway.