Cline, Roo Code and Kilo Code on the Claude plan you already pay for
API provider "Anthropic". Two base URLs, one key. Anthropic-shaped clients talk to http://localhost:3456; OpenAI-shaped clients — chat/completions and, since 6.3, the Responses API — talk to http://localhost:3456/v1. The key is dario (any value works until you set DARIO_API_KEY, which then has to match).
Cline · Roo Code · Kilo Code
Provider Anthropic · API key dario · Anthropic Base URL http://localhost:3456 · model claude-sonnet-5 / claude-opus-5 / claude-haiku-4-5.
These clients speak an XML tool protocol. dario detects them from their system-prompt identity markers and flips into preserve-tools mode on its own, so their schemas pass through and their parsers keep working. --no-auto-detect if you'd rather choose. Details.
Install dario, log in, leave it running
Three commands, once. The proxy binds 127.0.0.1:3456 and holds your login; every tool on the machine shares it. Add a ChatGPT plan with dario add altman and the two fail over to each other.
$ npm install -g @askalf/dario $ dario login # your Claude plan: Pro, Max 5x or Max 20x Login successful. $ dario proxy # leave it running dario · http://localhost:3456 Your Claude subscription is now an API.
Same URL, same key
Something not listed? If it reads ANTHROPIC_BASE_URL or OPENAI_BASE_URL, or has a "Base URL" field, it works. The compatibility matrix says which tools are exercised end-to-end, which are inferred from a shared code path, and which are untested — one honest cell per tool.