Other API providers

--upstream accepts any base URL that speaks the Anthropic Messages API. It defaults to real Claude. Each engagement remembers its own choice in upstream.txt, so different client projects can run against different providers side by side.

Note

A provider with a genuinely different wire format, such as the OpenAI-shaped tools Codex CLI uses, will not work. The detection and streaming code is built around the Messages API shape specifically. z.ai works because it deliberately exposes an Anthropic-compatible endpoint, not because this proxy is provider-agnostic.

Choosing a provider

Re-run the wizard at any time and answer the provider question differently to switch an engagement:

Which API is this engagement talking to?
  1) Claude (Anthropic): uses whatever Claude Code is already signed in with
  2) z.ai
  3) Manual / another provider: writes a placeholder skeleton to edit by hand
  (currently: Claude)

Whichever you pick, the wizard clears out every env var a different provider choice would have set. Switching in any direction cannot leave a previous provider’s auth token, model name, or tuning variable behind.

Only three choices are offered, deliberately. Claude needs no input at all, z.ai is a known and verified integration that can be configured from one API key, and anything else gets a placeholder skeleton rather than a guess. A wrong guess at which auth header some provider expects fails silently rather than loudly, which is worse than asking you to fill it in.

1. Claude

The default. redactproxy never asks for an Anthropic credential: whatever Claude Code is already signed in with, subscription login or otherwise, reaches the upstream exactly as before, because every client header is forwarded untouched. The proxy only ever needs to know a URL.

Switching an engagement back to Claude removes upstream.txt entirely rather than leaving an empty file behind.

2. z.ai

The wizard asks for one thing, your API key, and fills in the rest from z.ai’s own published configuration:

The main model resolves ANTHROPIC_MODEL plus the opus and sonnet aliases, so a fresh launch, /model opus and /model sonnet all land on it. The background model covers the haiku alias and Claude Code’s own internal background calls.

Leaving the key prompt blank means “don’t touch the existing one”, not “clear it”. Re-running the wizard on a working z.ai engagement to add a rule and pressing Enter at the key prompt will not silently delete a working credential.

3. Manual / another provider

Two paths. Answer yes to enter the details now, and the wizard asks for the base URL (validated as absolute), the API key, which auth header to send it in, and the model names. Answer no and it writes a deliberately non-functional skeleton for you to edit:

• upstream.txt gets https://REPLACE-ME.example.com
• .claude/settings.local.json gets REPLACE-ME env values

Non-functional on purpose. Starting redactproxy without editing it first fails loudly rather than quietly talking to whatever REPLACE-ME.example.com happens to resolve to.

Adding another fully-supported provider like z.ai is a code change, not a config option. See CONTRIBUTING.md’s “Adding a provider”.

Why ANTHROPIC_API_KEY gets blanked

Picking z.ai or manual sets ANTHROPIC_API_KEY to an empty string in the folder’s env block.

Every client header is forwarded untouched. So if you, your shell, or your user-level Claude settings already have a real Anthropic API key set, and this folder’s ANTHROPIC_BASE_URL now points at a third party, that real Anthropic credential would go out as a header on every request the proxy forwards, straight to that third party.

Blanking the key overrides any inherited value for this project only. Switching back to Claude clears the override out rather than leaving it blank, so Claude’s own key resolution isn’t permanently short-circuited.

Overriding per run

redactproxy --upstream https://api.z.ai/api/anthropic

An explicit --upstream wins over the persisted value for that run only, the same “CLI flag is a this-run override” convention --disable follows.

The URL must be absolute and must use http or https. A typo like htps:// is caught at startup rather than surfacing later as a generic “request to provider failed” the first time Claude Code sends something.

What redactproxy stores

upstream.txt holds the bare base URL and never a credential. The provider’s auth token is a Claude Code concern: it’s sent as a header Claude Code already attaches, forwarded through untouched, and it lives in .claude/settings.local.json.