Claude Standard
StartupAPI Standard traffic is routed through Kiro via PayGo.
This is our lower-cost routing path for supported Claude models.
Claude Code
Use Claude Code with StartupAPI
Claude Code is Anthropic’s coding agent for the terminal. Configure its API transport to use StartupAPI credits and model routing.
Verified compatibility
The core Claude Code workflow works through StartupAPI: interactive prompts, file and shell tools, non-streaming and enabled streaming Messages requests, and usage settlement. StartupAPI authenticates each request with your StartupAPI API key.
Advanced Claude Code features can depend on gateway support for extra endpoints, beta headers, streaming event types, or Anthropic-hosted services. Remote Control is disabled by Claude Code on a custom base URL, and MCP tool search or fine-grained tool streaming can require explicit gateway support. Do not assume every advanced feature behaves exactly like a direct Anthropic connection.
Minimum connection settings
The minimum reliable connection selects the StartupAPI base URL, uses ANTHROPIC_AUTH_TOKEN so Claude Code sends a Bearer token, and selects a model identifier currently enabled by StartupAPI.
| Setting | What it does |
|---|---|
| ANTHROPIC_BASE_URL | Routes Claude API requests to https://startupapi.io. |
| ANTHROPIC_AUTH_TOKEN | Sends Authorization: Bearer followed by your StartupAPI key, which StartupAPI requires. |
| ANTHROPIC_MODEL | Selects the model for the launched session. Use an identifier from the live catalog. |
Model selection is broader than one variable
Modern Claude Code can select models from a launch flag, a saved model setting, ANTHROPIC_MODEL, ANTHROPIC_DEFAULT_MODEL, family defaults, restored sessions, and subagent configuration. The setup blocks pin the paths most likely to create an unsupported request.
| Setting | StartupAPI guidance |
|---|---|
| ANTHROPIC_DEFAULT_SONNET_MODEL | Maps the sonnet alias to an enabled Sonnet example. |
| ANTHROPIC_DEFAULT_OPUS_MODEL | Maps the opus alias to an enabled Opus example. |
| ANTHROPIC_DEFAULT_HAIKU_MODEL | Maps haiku and background work to an enabled Haiku example. |
| ANTHROPIC_DEFAULT_FABLE_MODEL | Optional alias mapping for a Max-only Fable model; use only the exact identifier documented on the Models page. |
| CLAUDE_CODE_SUBAGENT_MODEL | Pins subagents, teams, and workflow agents to an enabled model. |
| ANTHROPIC_DEFAULT_MODEL | Optional default for new sessions on current Claude Code; ANTHROPIC_MODEL, --model, or a saved model setting can take precedence. |
Switch models manually
Run /model to open Claude Code’s normal picker. If the StartupAPI model you want is missing from that list, enter the full command manually.
Current catalog example
/model claude-sonnet-4-6Claude Max-only manual model
/model claude-fable-5A model not appearing in Claude Code’s picker does NOT necessarily mean it is unavailable through StartupAPI. Always use the exact identifier shown in the current Models documentation.
Upstream Routing
Claude Max
StartupAPI Max traffic uses our dedicated Max routing infrastructure.
The underlying upstream provider and routing implementation are not publicly disclosed.
Max is the dedicated routing path for its exclusive model.
Claude Standard and Claude Max use separate routing paths.
Set it up
Pick your operating system for the step-by-step install and configuration commands. The Windows guide has separate paths for PowerShell and Command Prompt (CMD), so shell syntax is never mixed.