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> A comprehensive, beginner-friendly guide to the **omniroute** multi-provider AI proxy router.
---
## 1. What Is omniroute?
omniroute is a **proxy router** that sits between AI clients (Claude CLI, Codex, Cursor IDE, etc.) and AI providers (Anthropic, Google, OpenAI, AWS, GitHub, etc.). It solves one big problem:
> **Different AI clients speak different "languages" (API formats), and different AI providers expect different "languages" too.** omniroute translates between them automatically.
Think of it like a universal translator at the United Nations — any delegate can speak any language, and the translator converts it for any other delegate.
---
## 2. Architecture Overview
```mermaid
graph LR
subgraph Clients
A[Claude CLI]
B[Codex]
C[Cursor IDE]
D[OpenAI-compatible]
end
subgraph omniroute
E[Handler Layer]
F[Translator Layer]
G[Executor Layer]
H[Services Layer]
end
subgraph Providers
I[Anthropic Claude]
J[Google Gemini]
K[OpenAI / Codex]
L[GitHub Copilot]
M[AWS Kiro]
N[Antigravity]
O[Cursor API]
end
A --> E
B --> E
C --> E
D --> E
E --> F
F --> G
G --> I
G --> J
G --> K
G --> L
G --> M
G --> N
G --> O
H -.-> E
H -.-> G
```
### Core Principle: Hub-and-Spoke Translation
All format translation passes through **OpenAI format as the hub**:
```
Client Format → [OpenAI Hub] → Provider Format (request)
Provider Format → [OpenAI Hub] → Client Format (response)
```
This means you only need **N translators** (one per format) instead of **N²** (every pair).
---
## 3. Project Structure
```
omniroute/
├── open-sse/ ← Core proxy library (portable, framework-agnostic)
│ ├── index.js ← Main entry point, exports everything
│ ├── config/ ← Configuration & constants
│ ├── executors/ ← Provider-specific request execution
│ ├── handlers/ ← Request handling orchestration
│ ├── services/ ← Business logic (auth, models, fallback, usage)
│ ├── translator/ ← Format translation engine
│ │ ├── request/ ← Request translators (8 files)
│ │ ├── response/ ← Response translators (7 files)
│ │ └── helpers/ ← Shared translation utilities (6 files)
│ └── utils/ ← Utility functions
├── src/ ← Application layer (Express/Worker runtime)
│ ├── app/ ← Web UI, API routes, middleware
│ ├── lib/ ← Database, auth, and shared library code
│ ├── mitm/ ← Man-in-the-middle proxy utilities
│ ├── models/ ← Database models
│ ├── shared/ ← Shared utilities (wrappers around open-sse)
│ ├── sse/ ← SSE endpoint handlers
│ └── store/ ← State management
├── data/ ← Runtime data (credentials, logs)
│ └── provider-credentials.json (external credentials override, gitignored)
└── tester/ ← Test utilities
```
---
## 4. Module-by-Module Breakdown
### 4.1 Config (`open-sse/config/`)
The **single source of truth** for all provider configuration.
| File | Purpose |
| ----------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `constants.ts` | `PROVIDERS` object with base URLs, OAuth credentials (defaults), headers, and default system prompts for every provider. Also defines `HTTP_STATUS`, `ERROR_TYPES`, `COOLDOWN_MS`, `BACKOFF_CONFIG`, and `SKIP_PATTERNS`. |
| `credentialLoader.ts` | Loads external credentials from `data/provider-credentials.json` and merges them over the hardcoded defaults in `PROVIDERS`. Keeps secrets out of source control while maintaining backwards compatibility. |
| `providerModels.ts` | Central model registry: maps provider aliases → model IDs. Functions like `getModels()`, `getProviderByAlias()`. |
| `codexInstructions.ts` | System instructions injected into Codex requests (editing constraints, sandbox rules, approval policies). |
| `defaultThinkingSignature.ts` | Default "thinking" signatures for Claude and Gemini models. |
| `ollamaModels.ts` | Schema definition for local Ollama models (name, size, family, quantization). |
#### Credential Loading Flow
```mermaid
flowchart TD
A["App starts"] --> B["constants.ts defines PROVIDERS\nwith hardcoded defaults"]
B --> C{"data/provider-credentials.json\nexists?"}
C -->|Yes| D["credentialLoader reads JSON"]
C -->|No| E["Use hardcoded defaults"]
D --> F{"For each provider in JSON"}
F --> G{"Provider exists\nin PROVIDERS?"}
G -->|No| H["Log warning, skip"]
G -->|Yes| I{"Value is object?"}
I -->|No| J["Log warning, skip"]
I -->|Yes| K["Merge clientId, clientSecret,\ntokenUrl, authUrl, refreshUrl"]
K --> F
H --> F
J --> F
F -->|Done| L["PROVIDERS ready with\nmerged credentials"]
E --> L
```
---
### 4.2 Executors (`open-sse/executors/`)
Executors encapsulate **provider-specific logic** using the **Strategy Pattern**. Each executor overrides base methods as needed.
```mermaid
classDiagram
class BaseExecutor {
+buildUrl(model, stream, options)
+buildHeaders(credentials, stream, body)
+transformRequest(body, model, stream, credentials)
+execute(url, options)
+shouldRetry(status, error)
+refreshCredentials(credentials, log)
}
class DefaultExecutor {
+refreshCredentials()
}
class AntigravityExecutor {
+buildUrl()
+buildHeaders()
+transformRequest()
+shouldRetry()
+refreshCredentials()
}
class CursorExecutor {
+buildUrl()
+buildHeaders()
+transformRequest()
+parseResponse()
+generateChecksum()
}
class KiroExecutor {
+buildUrl()
+buildHeaders()
+transformRequest()
+parseEventStream()
+refreshCredentials()
}
BaseExecutor <|-- DefaultExecutor
BaseExecutor <|-- AntigravityExecutor
BaseExecutor <|-- CursorExecutor
BaseExecutor <|-- KiroExecutor
BaseExecutor <|-- CodexExecutor
BaseExecutor <|-- GeminiCLIExecutor
BaseExecutor <|-- GithubExecutor
```
| Executor | Provider | Key Specializations |
| ---------------- | ------------------------------------------ | ------------------------------------------------------------------------------------------------------------------- |
| `base.ts` | — | Abstract base: URL building, headers, retry logic, credential refresh |
| `default.ts` | Claude, Gemini, OpenAI, GLM, Kimi, MiniMax | Generic OAuth token refresh for standard providers |
| `antigravity.ts` | Google Cloud Code | Project/session ID generation, multi-URL fallback, custom retry parsing from error messages ("reset after 2h7m23s") |
| `cursor.ts` | Cursor IDE | **Most complex**: SHA-256 checksum auth, Protobuf request encoding, binary EventStream → SSE response parsing |
| `codex.ts` | OpenAI Codex | Injects system instructions, manages thinking levels, removes unsupported parameters |
| `gemini-cli.ts` | Google Gemini CLI | Custom URL building (`streamGenerateContent`), Google OAuth token refresh |
| `github.ts` | GitHub Copilot | Dual token system (GitHub OAuth + Copilot token), VSCode header mimicking |
| `kiro.ts` | AWS CodeWhisperer | AWS EventStream binary parsing, AMZN event frames, token estimation |
| `index.ts` | — | Factory: maps provider name → executor class, with default fallback |
---
### 4.3 Handlers (`open-sse/handlers/`)
The **orchestration layer** — coordinates translation, execution, streaming, and error handling.
| File | Purpose |
| --------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `chatCore.ts` | **Central orchestrator** (~600 lines). Handles the complete request lifecycle: format detection → translation → executor dispatch → streaming/non-streaming response → token refresh → error handling → usage logging. |
| `responsesHandler.ts` | Adapter for OpenAI's Responses API: converts Responses format → Chat Completions → sends to `chatCore` → converts SSE back to Responses format. |
| `embeddings.ts` | Embedding generation handler: resolves embedding model → provider, dispatches to provider API, returns OpenAI-compatible embedding response. Supports 6+ providers. |
| `imageGeneration.ts` | Image generation handler: resolves image model → provider, supports OpenAI-compatible, Gemini-image (Antigravity), and fallback (Nebius) modes. Returns base64 or URL images. |
#### Request Lifecycle (chatCore.ts)
```mermaid
sequenceDiagram
participant Client
participant chatCore
participant Translator
participant Executor
participant Provider
Client->>chatCore: Request (any format)
chatCore->>chatCore: Detect source format
chatCore->>chatCore: Check bypass patterns
chatCore->>chatCore: Resolve model & provider
chatCore->>Translator: Translate request (source → OpenAI → target)
chatCore->>Executor: Get executor for provider
Executor->>Executor: Build URL, headers, transform request
Executor->>Executor: Refresh credentials if needed
Executor->>Provider: HTTP fetch (streaming or non-streaming)
alt Streaming
Provider-->>chatCore: SSE stream
chatCore->>chatCore: Pipe through SSE transform stream
Note over chatCore: Transform stream translates<br/>each chunk: target → OpenAI → source
chatCore-->>Client: Translated SSE stream
else Non-streaming
Provider-->>chatCore: JSON response
chatCore->>Translator: Translate response
chatCore-->>Client: Translated JSON
end
alt Error (401, 429, 500...)
chatCore->>Executor: Retry with credential refresh
chatCore->>chatCore: Account fallback logic
end
```
---
### 4.4 Services (`open-sse/services/`)
Business logic that supports the handlers and executors.
| File | Purpose |
| -------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `provider.ts` | **Format detection** (`detectFormat`): analyzes request body structure to identify Claude/OpenAI/Gemini/Antigravity/Responses formats (includes `max_tokens` heuristic for Claude). Also: URL building, header building, thinking config normalization. Supports `openai-compatible-*` and `anthropic-compatible-*` dynamic providers. |
| `model.ts` | Model string parsing (`claude/model-name` → `{provider: "claude", model: "model-name"}`), alias resolution with collision detection, input sanitization (rejects path traversal/control chars), and model info resolution with async alias getter support. |
| `accountFallback.ts` | Rate-limit handling: exponential backoff (1s → 2s → 4s → max 2min), account cooldown management, error classification (which errors trigger fallback vs. not). |
| `tokenRefresh.ts` | OAuth token refresh for **every provider**: Google (Gemini, Antigravity), Claude, Codex, Qwen, iFlow, GitHub (OAuth + Copilot dual-token), Kiro (AWS SSO OIDC + Social Auth). Includes in-flight promise deduplication cache and retry with exponential backoff. |
| `combo.ts` | **Combo models**: chains of fallback models. If model A fails with a fallback-eligible error, try model B, then C, etc. Returns actual upstream status codes. |
| `usage.ts` | Fetches quota/usage data from provider APIs (GitHub Copilot quotas, Antigravity model quotas, Codex rate limits, Kiro usage breakdowns, Claude settings). |
| `accountSelector.ts` | Smart account selection with scoring algorithm: considers priority, health status, round-robin position, and cooldown state to pick the optimal account for each request. |
| `contextManager.ts` | Request context lifecycle management: creates and tracks per-request context objects with metadata (request ID, timestamps, provider info) for debugging and logging. |
| `ipFilter.ts` | IP-based access control: supports allowlist and blocklist modes. Validates client IP against configured rules before processing API requests. |
| `sessionManager.ts` | Session tracking with client fingerprinting: tracks active sessions using hashed client identifiers, monitors request counts, and provides session metrics. |
| `signatureCache.ts` | Request signature-based deduplication cache: prevents duplicate requests by caching recent request signatures and returning cached responses for identical requests within a time window. |
| `systemPrompt.ts` | Global system prompt injection: prepends or appends a configurable system prompt to all requests, with per-provider compatibility handling. |
| `thinkingBudget.ts` | Reasoning token budget management: supports passthrough, auto (strip thinking config), custom (fixed budget), and adaptive (complexity-scaled) modes for controlling thinking/reasoning tokens. |
| `wildcardRouter.ts` | Wildcard model pattern routing: resolves wildcard patterns (e.g., `*/claude-*`) to concrete provider/model pairs based on availability and priority. |
#### Token Refresh Deduplication
```mermaid
sequenceDiagram
participant R1 as Request 1
participant R2 as Request 2
participant Cache as refreshPromiseCache
participant OAuth as OAuth Provider
R1->>Cache: getAccessToken("gemini", token)
Cache->>Cache: No in-flight promise
Cache->>OAuth: Start refresh
R2->>Cache: getAccessToken("gemini", token)
Cache->>Cache: Found in-flight promise
Cache-->>R2: Return existing promise
OAuth-->>Cache: New access token
Cache-->>R1: New access token
Cache-->>R2: Same access token (shared)
Cache->>Cache: Delete cache entry
```
#### Account Fallback State Machine
```mermaid
stateDiagram-v2
[*] --> Active
Active --> Error: Request fails (401/429/500)
Error --> Cooldown: Apply backoff
Cooldown --> Active: Cooldown expires
Active --> Active: Request succeeds (reset backoff)
state Error {
[*] --> ClassifyError
ClassifyError --> ShouldFallback: Rate limit / Auth / Transient
ClassifyError --> NoFallback: 400 Bad Request
}
state Cooldown {
[*] --> ExponentialBackoff
ExponentialBackoff: Level 0 = 1s
ExponentialBackoff: Level 1 = 2s
ExponentialBackoff: Level 2 = 4s
ExponentialBackoff: Max = 2min
}
```
#### Combo Model Chain
```mermaid
flowchart LR
A["Request with\ncombo model"] --> B["Model A"]
B -->|"2xx Success"| C["Return response"]
B -->|"429/401/500"| D{"Fallback\neligible?"}
D -->|Yes| E["Model B"]
D -->|No| F["Return error"]
E -->|"2xx Success"| C
E -->|"429/401/500"| G{"Fallback\neligible?"}
G -->|Yes| H["Model C"]
G -->|No| F
H -->|"2xx Success"| C
H -->|"Fail"| I["All failed →\nReturn last status"]
```
---
### 4.5 Translator (`open-sse/translator/`)
The **format translation engine** using a self-registering plugin system.
#### Architecture
```mermaid
graph TD
subgraph "Request Translation"
A["Claude → OpenAI"]
B["Gemini → OpenAI"]
C["Antigravity → OpenAI"]
D["OpenAI Responses → OpenAI"]
E["OpenAI → Claude"]
F["OpenAI → Gemini"]
G["OpenAI → Kiro"]
H["OpenAI → Cursor"]
end
subgraph "Response Translation"
I["Claude → OpenAI"]
J["Gemini → OpenAI"]
K["Kiro → OpenAI"]
L["Cursor → OpenAI"]
M["OpenAI → Claude"]
N["OpenAI → Antigravity"]
O["OpenAI → Responses"]
end
```
| Directory | Files | Description |
| ------------ | ------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `request/` | 8 translators | Convert request bodies between formats. Each file self-registers via `register(from, to, fn)` on import. |
| `response/` | 7 translators | Convert streaming response chunks between formats. Handles SSE event types, thinking blocks, tool calls. |
| `helpers/` | 6 helpers | Shared utilities: `claudeHelper` (system prompt extraction, thinking config), `geminiHelper` (parts/contents mapping), `openaiHelper` (format filtering), `toolCallHelper` (ID generation, missing response injection), `maxTokensHelper`, `responsesApiHelper`. |
| `index.ts` | — | Translation engine: `translateRequest()`, `translateResponse()`, state management, registry. |
| `formats.ts` | — | Format constants: `OPENAI`, `CLAUDE`, `GEMINI`, `ANTIGRAVITY`, `KIRO`, `CURSOR`, `OPENAI_RESPONSES`. |
#### Key Design: Self-Registering Plugins
```javascript
// Each translator file calls register() on import:
import { register } from "../index.js";
register("claude", "openai", translateClaudeToOpenAI);
// The index.js imports all translator files, triggering registration:
import "./request/claude-to-openai.js"; // ← self-registers
```
---
### 4.6 Utils (`open-sse/utils/`)
| File | Purpose |
| ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `error.ts` | Error response building (OpenAI-compatible format), upstream error parsing, Antigravity retry-time extraction from error messages, SSE error streaming. |
| `stream.ts` | **SSE Transform Stream** — the core streaming pipeline. Two modes: `TRANSLATE` (full format translation) and `PASSTHROUGH` (normalize + extract usage). Handles chunk buffering, usage estimation, content length tracking. Per-stream encoder/decoder instances avoid shared state. |
| `streamHelpers.ts` | Low-level SSE utilities: `parseSSELine` (whitespace-tolerant), `hasValuableContent` (filters empty chunks for OpenAI/Claude/Gemini), `fixInvalidId`, `formatSSE` (format-aware SSE serialization with `perf_metrics` cleanup). |
| `usageTracking.ts` | Token usage extraction from any format (Claude/OpenAI/Gemini/Responses), estimation with separate tool/message char-per-token ratios, buffer addition (2000 tokens safety margin), format-specific field filtering, console logging with ANSI colors. |
| `requestLogger.ts` | File-based request logging (opt-in via `ENABLE_REQUEST_LOGS=true`). Creates session folders with numbered files: `1_req_client.json` → `7_res_client.txt`. All I/O is async (fire-and-forget). Masks sensitive headers. |
| `bypassHandler.ts` | Intercepts specific patterns from Claude CLI (title extraction, warmup, count) and returns fake responses without calling any provider. Supports both streaming and non-streaming. Intentionally limited to Claude CLI scope. |
| `networkProxy.ts` | Resolves outbound proxy URL for a given provider with precedence: provider-specific config → global config → environment variables (`HTTPS_PROXY`/`HTTP_PROXY`/`ALL_PROXY`). Supports `NO_PROXY` exclusions. Caches config for 30s. |
#### SSE Streaming Pipeline
```mermaid
flowchart TD
A["Provider SSE stream"] --> B["TextDecoder\n(per-stream instance)"]
B --> C["Buffer lines\n(split on newline)"]
C --> D["parseSSELine()\n(trim whitespace, parse JSON)"]
D --> E{"Mode?"}
E -->|TRANSLATE| F["translateResponse()\ntarget → OpenAI → source"]
E -->|PASSTHROUGH| G["fixInvalidId()\nnormalize chunk"]
F --> H["hasValuableContent()\nfilter empty chunks"]
G --> H
H -->|"Has content"| I["extractUsage()\ntrack token counts"]
H -->|"Empty"| J["Skip chunk"]
I --> K["formatSSE()\nserialize + clean perf_metrics"]
K --> L["TextEncoder\n(per-stream instance)"]
L --> M["Enqueue to\nclient stream"]
style A fill:#f9f,stroke:#333
style M fill:#9f9,stroke:#333
```
#### Request Logger Session Structure
```
logs/
└── claude_gemini_claude-sonnet_20260208_143045/
├── 1_req_client.json ← Raw client request
├── 2_req_source.json ← After initial conversion
├── 3_req_openai.json ← OpenAI intermediate format
├── 4_req_target.json ← Final target format
├── 5_res_provider.txt ← Provider SSE chunks (streaming)
├── 5_res_provider.json ← Provider response (non-streaming)
├── 6_res_openai.txt ← OpenAI intermediate chunks
├── 7_res_client.txt ← Client-facing SSE chunks
└── 6_error.json ← Error details (if any)
```
---
### 4.7 Application Layer (`src/`)
| Directory | Purpose |
| ------------- | ---------------------------------------------------------------------- |
| `src/app/` | Web UI, API routes, Express middleware, OAuth callback handlers |
| `src/lib/` | Database access (`localDb.ts`, `usageDb.ts`), authentication, shared |
| `src/mitm/` | Man-in-the-middle proxy utilities for intercepting provider traffic |
| `src/models/` | Database model definitions |
| `src/shared/` | Wrappers around open-sse functions (provider, stream, error, etc.) |
| `src/sse/` | SSE endpoint handlers that wire the open-sse library to Express routes |
| `src/store/` | Application state management |
#### Notable API Routes
| Route | Methods | Purpose |
| --------------------------------------------- | --------------- | ------------------------------------------------------------------------------------- |
| `/api/provider-models` | GET/POST/DELETE | CRUD for custom models per provider |
| `/api/models/catalog` | GET | Aggregated catalog of all models (chat, embedding, image, custom) grouped by provider |
| `/api/settings/proxy` | GET/PUT/DELETE | Hierarchical outbound proxy configuration (`global/providers/combos/keys`) |
| `/api/settings/proxy/test` | POST | Validates proxy connectivity and returns public IP/latency |
| `/v1/providers/[provider]/chat/completions` | POST | Dedicated per-provider chat completions with model validation |
| `/v1/providers/[provider]/embeddings` | POST | Dedicated per-provider embeddings with model validation |
| `/v1/providers/[provider]/images/generations` | POST | Dedicated per-provider image generation with model validation |
| `/api/settings/ip-filter` | GET/PUT | IP allowlist/blocklist management |
| `/api/settings/thinking-budget` | GET/PUT | Reasoning token budget configuration (passthrough/auto/custom/adaptive) |
| `/api/settings/system-prompt` | GET/PUT | Global system prompt injection for all requests |
| `/api/sessions` | GET | Active session tracking and metrics |
| `/api/rate-limits` | GET | Per-account rate limit status |
---
## 5. Key Design Patterns
### 5.1 Hub-and-Spoke Translation
All formats translate through **OpenAI format as the hub**. Adding a new provider only requires writing **one pair** of translators (to/from OpenAI), not N pairs.
### 5.2 Executor Strategy Pattern
Each provider has a dedicated executor class inheriting from `BaseExecutor`. The factory in `executors/index.ts` selects the right one at runtime.
### 5.3 Self-Registering Plugin System
Translator modules register themselves on import via `register()`. Adding a new translator is just creating a file and importing it.
### 5.4 Account Fallback with Exponential Backoff
When a provider returns 429/401/500, the system can switch to the next account, applying exponential cooldowns (1s → 2s → 4s → max 2min).
### 5.5 Combo Model Chains
A "combo" groups multiple `provider/model` strings. If the first fails, fallback to the next automatically.
### 5.6 Stateful Streaming Translation
Response translation maintains state across SSE chunks (thinking block tracking, tool call accumulation, content block indexing) via the `initState()` mechanism.
### 5.7 Usage Safety Buffer
A 2000-token buffer is added to reported usage to prevent clients from hitting context window limits due to overhead from system prompts and format translation.
---
## 6. Supported Formats
| Format | Direction | Identifier |
| ----------------------- | --------------- | ------------------ |
| OpenAI Chat Completions | source + target | `openai` |
| OpenAI Responses API | source + target | `openai-responses` |
| Anthropic Claude | source + target | `claude` |
| Google Gemini | source + target | `gemini` |
| Google Gemini CLI | target only | `gemini-cli` |
| Antigravity | source + target | `antigravity` |
| AWS Kiro | target only | `kiro` |
| Cursor | target only | `cursor` |
---
## 7. Supported Providers
| Provider | Auth Method | Executor | Key Notes |
| ------------------------ | ---------------------- | ----------- | --------------------------------------------- |
| Anthropic Claude | API key or OAuth | Default | Uses `x-api-key` header |
| Google Gemini | API key or OAuth | Default | Uses `x-goog-api-key` header |
| Google Gemini CLI | OAuth | GeminiCLI | Uses `streamGenerateContent` endpoint |
| Antigravity | OAuth | Antigravity | Multi-URL fallback, custom retry parsing |
| OpenAI | API key | Default | Standard Bearer auth |
| Codex | OAuth | Codex | Injects system instructions, manages thinking |
| GitHub Copilot | OAuth + Copilot token | Github | Dual token, VSCode header mimicking |
| Kiro (AWS) | AWS SSO OIDC or Social | Kiro | Binary EventStream parsing |
| Cursor IDE | Checksum auth | Cursor | Protobuf encoding, SHA-256 checksums |
| Qwen | OAuth | Default | Standard auth |
| iFlow | OAuth (Basic + Bearer) | Default | Dual auth header |
| OpenRouter | API key | Default | Standard Bearer auth |
| GLM, Kimi, MiniMax | API key | Default | Claude-compatible, use `x-api-key` |
| `openai-compatible-*` | API key | Default | Dynamic: any OpenAI-compatible endpoint |
| `anthropic-compatible-*` | API key | Default | Dynamic: any Claude-compatible endpoint |
---
## 8. Data Flow Summary
### Streaming Request
```mermaid
flowchart LR
A["Client"] --> B["detectFormat()"]
B --> C["translateRequest()\nsource → OpenAI → target"]
C --> D["Executor\nbuildUrl + buildHeaders"]
D --> E["fetch(providerURL)"]
E --> F["createSSEStream()\nTRANSLATE mode"]
F --> G["parseSSELine()"]
G --> H["translateResponse()\ntarget → OpenAI → source"]
H --> I["extractUsage()\n+ addBuffer"]
I --> J["formatSSE()"]
J --> K["Client receives\ntranslated SSE"]
K --> L["logUsage()\nsaveRequestUsage()"]
```
### Non-Streaming Request
```mermaid
flowchart LR
A["Client"] --> B["detectFormat()"]
B --> C["translateRequest()\nsource → OpenAI → target"]
C --> D["Executor.execute()"]
D --> E["translateResponse()\ntarget → OpenAI → source"]
E --> F["Return JSON\nresponse"]
```
### Bypass Flow (Claude CLI)
```mermaid
flowchart LR
A["Claude CLI request"] --> B{"Match bypass\npattern?"}
B -->|"Title/Warmup/Count"| C["Generate fake\nOpenAI response"]
B -->|"No match"| D["Normal flow"]
C --> E["Translate to\nsource format"]
E --> F["Return without\ncalling provider"]
```
|