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claude-code-proxy

Compatibility and limitations

claude-code-proxy targets Claude Code’s practical Anthropic API usage rather than complete protocol equivalence.

Accounts and provider policy

Section titled “Accounts and provider policy”
  • Provider subscriptions, allowed models, regions, quotas, and enforcement remain under each provider’s control.
  • OpenAI has publicly welcomed using Codex through other coding harnesses, but public statements do not guarantee future policy or account treatment.
  • Kimi, Grok, and Cursor use unofficial client integrations. Review the terms and account risk for your use.
  • Upstream rate limits are shared with other clients on the same account.

Listener security

Section titled “Listener security”
  • Incoming clients are not authenticated.
  • The default bind address is 127.0.0.1.
  • A non-loopback listener requires an external firewall or authenticating reverse proxy.
  • The proxy stores subscription credentials and can consume account quota, so an exposed listener is equivalent to exposing that capability.

Anthropic API scope

Section titled “Anthropic API scope”
  • Messages supports streaming and non-streaming responses for the fields exercised by Claude Code.
  • ?beta=true does not select a separate implementation.
  • Token counts are local estimates, not exact upstream tokenizer or billing counts.
  • Claude Code title generation and other structured background requests are forwarded and consume provider tokens.
  • Anthropic-specific fields without a provider mapping can be dropped.
  • Native OpenAI Responses passthrough is opt-in and limited to registered Codex models and response creation.

Models and context

Section titled “Models and context”
  • Local registration does not guarantee account access to a model.
  • Unknown model IDs have no implicit provider fallback.
  • Anthropic-style aliases route only to the configured Codex or Kimi alias provider.
  • [1m] is a Claude Code client hint and does not change upstream context.
  • Provider context limits can be lower than Claude Code’s local threshold.
  • Switching provider or model can clear provider-specific continuation assumptions while Claude Code retains portable history.

Codex

Section titled “Codex”
  • Base64 user images and supported base64 tool-result images map to Responses images. Remote URLs and malformed or unsupported nested images remain text placeholders.
  • Reasoning summaries can appear as thinking blocks. Codex decides whether a summary is emitted.
  • Encrypted reasoning and compaction items remain provider continuation data and are not exposed as raw chain of thought.
  • Hosted web search supports mapped domain filters, but the Anthropic max_uses value is not enforced because Codex exposes no equivalent limit.
  • Strict JSON schema output is translated. Other Anthropic-only output settings can be omitted.
  • previous_response_id and server compaction state are in memory and require stable session routing.
  • Automatic transport fallback occurs only before an upstream request is sent, which avoids replaying possible side effects.

Kimi

Section titled “Kimi”
  • The proxy exposes one Kimi Code wire model plus local aliases.
  • Reasoning effort supports Kimi’s low, medium, and high levels.
  • Images in tool results use Kimi tool-message image parts.
  • The persistent device ID is part of the login identity and must remain stable.

Grok

Section titled “Grok”
  • Model availability varies by account and region.
  • Hosted general web search and X search are translated with citations and usage.
  • The implemented multimodal path does not claim general image or video compatibility.

Cursor Agent

Section titled “Cursor Agent”
  • An installed Cursor Agent JavaScript bundle supplies protobuf classes.
  • The dynamic catalog reflects the installed Cursor Agent and can differ across machines.
  • The native tool bridge covers recognized Read, Write, and Bash calls when matching tools and a session ID are present.
  • Cursor workspace callbacks and arbitrary native tool forms do not have a general Claude tool bridge.
  • Conversation and pending tool state are in memory. Restarts clear them.
  • Cursor count-tokens uses a rough rendered-prompt estimate.

Diagnostics and privacy

Section titled “Diagnostics and privacy”
  • Structured logs redact known credential keys, but user-provided strings can still contain secrets.
  • Error captures contain complete redacted failed responses.
  • Traffic captures intentionally preserve prompts and tool content.
  • Verbose logging and traffic capture should be scoped to a focused local investigation.

For provider-specific behavior, use the provider pages. For released changes, see the Changelog.