From 98a1e7b86bf7ee64f85692b40df1096e45b75325 Mon Sep 17 00:00:00 2001
From: Mario Zechner <badlogicgames@gmail.com>
Date: Mon, 26 Jan 2026 00:11:10 +0100
Subject: [PATCH] docs(coding-agent): add models.md for custom providers and
 models

---
 packages/coding-agent/docs/models.md | 166 +++++++++++++++++++++++++++
 1 file changed, 166 insertions(+)
 create mode 100644 packages/coding-agent/docs/models.md

diff --git a/packages/coding-agent/docs/models.md b/packages/coding-agent/docs/models.md
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+# Custom Models
+
+Add custom providers and models (Ollama, vLLM, LM Studio, proxies) via `~/.pi/agent/models.json`.
+
+## Table of Contents
+
+- [Basic Example](#basic-example)
+- [Supported APIs](#supported-apis)
+- [Provider Configuration](#provider-configuration)
+- [Model Configuration](#model-configuration)
+- [Overriding Built-in Providers](#overriding-built-in-providers)
+- [OpenAI Compatibility](#openai-compatibility)
+
+## Basic Example
+
+```json
+{
+  "providers": {
+    "ollama": {
+      "baseUrl": "http://localhost:11434/v1",
+      "api": "openai-completions",
+      "models": [
+        {
+          "id": "llama-3.1-8b",
+          "name": "Llama 3.1 8B (Local)",
+          "contextWindow": 128000,
+          "maxTokens": 32000
+        }
+      ]
+    }
+  }
+}
+```
+
+The file reloads each time you open `/model`. Edit during session; no restart needed.
+
+## Supported APIs
+
+| API | Description |
+|-----|-------------|
+| `openai-completions` | OpenAI Chat Completions (most compatible) |
+| `openai-responses` | OpenAI Responses API |
+| `anthropic-messages` | Anthropic Messages API |
+| `google-generative-ai` | Google Generative AI |
+
+Set `api` at provider level (default for all models) or model level (override per model).
+
+## Provider Configuration
+
+| Field | Description |
+|-------|-------------|
+| `baseUrl` | API endpoint URL |
+| `api` | API type (see above) |
+| `apiKey` | API key (see value resolution below) |
+| `headers` | Custom headers (see value resolution below) |
+| `authHeader` | Set `true` to add `Authorization: Bearer <apiKey>` automatically |
+| `models` | Array of model configurations |
+
+### Value Resolution
+
+The `apiKey` and `headers` fields support three formats:
+
+- **Shell command:** `"!command"` executes and uses stdout
+  ```json
+  "apiKey": "!security find-generic-password -ws 'anthropic'"
+  "apiKey": "!op read 'op://vault/item/credential'"
+  ```
+- **Environment variable:** Uses the value of the named variable
+  ```json
+  "apiKey": "MY_API_KEY"
+  ```
+- **Literal value:** Used directly
+  ```json
+  "apiKey": "sk-..."
+  ```
+
+### Custom Headers
+
+```json
+{
+  "providers": {
+    "custom-proxy": {
+      "baseUrl": "https://proxy.example.com/v1",
+      "apiKey": "MY_API_KEY",
+      "api": "anthropic-messages",
+      "headers": {
+        "x-portkey-api-key": "PORTKEY_API_KEY",
+        "x-secret": "!op read 'op://vault/item/secret'"
+      },
+      "models": [...]
+    }
+  }
+}
+```
+
+## Model Configuration
+
+| Field | Required | Description |
+|-------|----------|-------------|
+| `id` | Yes | Model identifier |
+| `name` | No | Display name |
+| `api` | No | Override provider's API for this model |
+| `contextWindow` | No | Context window size in tokens |
+| `maxTokens` | No | Maximum output tokens |
+| `reasoning` | No | Supports extended thinking |
+| `input` | No | Input types: `["text"]` or `["text", "image"]` |
+| `cost` | No | `{"input": 0, "output": 0, "cacheRead": 0, "cacheWrite": 0}` |
+
+## Overriding Built-in Providers
+
+Route a built-in provider through a proxy without redefining models:
+
+```json
+{
+  "providers": {
+    "anthropic": {
+      "baseUrl": "https://my-proxy.example.com/v1"
+    }
+  }
+}
+```
+
+All built-in Anthropic models remain available. Existing OAuth or API key auth continues to work.
+
+To fully replace a built-in provider with custom models, include the `models` array:
+
+```json
+{
+  "providers": {
+    "anthropic": {
+      "baseUrl": "https://my-proxy.example.com/v1",
+      "apiKey": "ANTHROPIC_API_KEY",
+      "api": "anthropic-messages",
+      "models": [...]
+    }
+  }
+}
+```
+
+## OpenAI Compatibility
+
+For providers with partial OpenAI compatibility, use the `compat` field:
+
+```json
+{
+  "providers": {
+    "local-llm": {
+      "baseUrl": "http://localhost:8080/v1",
+      "api": "openai-completions",
+      "compat": {
+        "supportsUsageInStreaming": false,
+        "maxTokensField": "max_tokens"
+      },
+      "models": [...]
+    }
+  }
+}
+```
+
+| Field | Description |
+|-------|-------------|
+| `supportsStore` | Provider supports `store` field |
+| `supportsDeveloperRole` | Use `developer` vs `system` role |
+| `supportsReasoningEffort` | Support for `reasoning_effort` parameter |
+| `supportsUsageInStreaming` | Supports `stream_options: { include_usage: true }` (default: `true`) |
+| `maxTokensField` | Use `max_completion_tokens` or `max_tokens` |