pi (gateway)

Route pi ’s LLM calls through the Respan gateway for automatic logging, caching, and model switching. pi loads custom providers from ~/.pi/agent/models.json, so only your RESPAN_API_KEY is needed.

Trace pi sessions

This page covers gateway routing. To also capture turns, tool calls, and compactions from inside pi, see pi (tracing).

Paste this into your coding agent:


Help me set up the Respan gateway with the pi integration.
Follow https://www.respan.ai/docs/integrations/gateway/pi.md

Setup

Install pi


npm install -g --ignore-scripts @earendil-works/pi-coding-agent

Add Respan as a provider

Create or edit ~/.pi/agent/models.json:


{
  "providers": {
    "respan": {
      "baseUrl": "https://api.respan.ai/api",
      "api": "openai-completions",
      "apiKey": "$RESPAN_API_KEY",
      "models": [
        {
          "id": "gpt-4o",
          "name": "GPT-4o",
          "reasoning": false,
          "input": ["text", "image"],
          "cost": { "input": 2.5, "output": 10, "cacheRead": 1.25, "cacheWrite": 0 },
          "contextWindow": 128000,
          "maxTokens": 16384
        },
        {
          "id": "claude-sonnet-4-5-20250929",
          "name": "Claude Sonnet 4.5",
          "reasoning": true,
          "input": ["text", "image"],
          "cost": { "input": 3, "output": 15, "cacheRead": 0.3, "cacheWrite": 3.75 },
          "contextWindow": 200000,
          "maxTokens": 64000
        }
      ]
    }
  }
}

Then export the key in your shell profile:


export RESPAN_API_KEY="YOUR_RESPAN_API_KEY"

No separate provider key needed. The Respan gateway handles provider authentication.

Run pi


pi --model respan/gpt-4o

For a one-shot, non-interactive run:


pi -p --model respan/gpt-4o "your prompt"

All LLM calls now route through Respan.

Switch models

Add more entries to the models array and pick any of them with --model respan/<id>. Any of the 1000+ models available through the gateway work, for example:


gpt-4o
claude-sonnet-4-5-20250929
gemini/gemini-3.5-flash

See the full model list .

Use a provider-native API

pi also speaks the Anthropic Messages and OpenAI Responses protocols. Point those at the matching Respan passthrough if you prefer the native format:


{
  "providers": {
    "respan-anthropic": {
      "baseUrl": "https://api.respan.ai/api/anthropic",
      "api": "anthropic-messages",
      "apiKey": "$RESPAN_API_KEY",
      "models": [{ "id": "claude-haiku-4-5-20251001", "name": "Claude Haiku 4.5", "reasoning": true, "input": ["text", "image"], "cost": { "input": 1, "output": 5, "cacheRead": 0.1, "cacheWrite": 1.25 }, "contextWindow": 200000, "maxTokens": 64000 }]
    },
    "respan-responses": {
      "baseUrl": "https://api.respan.ai/api",
      "api": "openai-responses",
      "apiKey": "$RESPAN_API_KEY",
      "models": [{ "id": "gpt-5.5", "name": "GPT-5.5", "reasoning": true, "input": ["text", "image"], "cost": { "input": 2, "output": 8, "cacheRead": 0.2, "cacheWrite": 0 }, "contextWindow": 400000, "maxTokens": 128000 }]
    }
  }
}

The openai-responses route only serves OpenAI models. Use openai-completions for Claude, Gemini, and other providers.