# API Reference

Complete documentation of all REST API endpoints.

---

## Base URL

```
http://localhost:8000
```

---

## Endpoints

### Documents

#### `GET /documents`

List all uploaded documents.

**Response:**
```json
{
  "items": [
    {
      "id": "doc-abc123",
      "filename": "insurance.docx",
      "paragraph_count": 245,
      "chunk_counts": {
        "recursive": 218,
        "fixed_size": 117
      },
      "created_at": "2026-07-25T10:00:00"
    }
  ],
  "total": 1,
  "offset": 0,
  "limit": 50
}
```

---

#### `POST /documents`

Upload a document (.docx or .doc).

**Request:**
- Content-Type: `multipart/form-data`
- Body: `file` (binary)

**Response (201):**
```json
{
  "id": "doc-abc123",
  "filename": "insurance.docx",
  "paragraph_count": 245,
  "chunk_counts": {},
  "created_at": "2026-07-25T10:00:00"
}
```

---

#### `DELETE /documents/{doc_id}`

Delete a document and its vectors.

**Response:**
```json
{
  "deleted": true,
  "document_id": "doc-abc123"
}
```

---

#### `POST /documents/{doc_id}/process`

Run chunking strategies on a document.

**Query parameters:**
- `background` (bool, default `false`) — when `true`, enqueue processing and return **202** with a `job_id`; poll `GET /jobs/{job_id}`.

**Request:**
```json
{
  "strategies": [
    "recursive",
    "fixed_size",
    "semantic",
    "contextual_retrieval",
    "semantic_parent_child"
  ]
}
```

**Response:**
```json
{
  "document_id": "doc-abc123",
  "strategies_completed": [
    {
      "strategy": "recursive",
      "status": "completed",
      "chunks_produced": 218
    }
  ],
  "strategies_failed": []
}
```

---

### Strategies

#### `GET /strategies`

List all available chunking strategies.

**Response:**
```json
{
  "strategies": [
    {
      "name": "recursive",
      "description": "Cascade splitting: headers > double newline > ..."
    },
    {
      "name": "fixed_size",
      "description": "Fixed-size token splitting with overlap"
    }
  ]
}
```

---

### Queries

#### `POST /queries`

Ask a question against a document using a specific strategy.

**Request:**
```json
{
  "document_id": "doc-abc123",
  "strategy": "recursive",
  "question": "What are the main topics?",
  "top_k": 5
}
```

**Response (201):**
```json
{
  "query_id": "q-xyz789",
  "document_id": "doc-abc123",
  "strategy": "recursive",
  "question": "What are the main topics?",
  "answer": "The document covers insurance regulations...",
  "retrieved_chunks": [
    {
      "chunk_id": "recursive_doc_000045",
      "score": 0.892,
      "text": " chunk content...",
      "parent_id": null
    }
  ],
  "latency_breakdown": {
    "embed_seconds": 0.15,
    "search_seconds": 0.02,
    "answer_seconds": 1.23,
    "total_seconds": 1.40
  },
  "token_usage": {
    "prompt_tokens": 1250,
    "completion_tokens": 150,
    "total_tokens": 1400
  },
  "created_at": "2026-07-25T12:00:00"
}
```

---

#### `GET /queries/{query_id}`

Retrieve a past query.

**Response:** Same as POST /queries response.

---

### Benchmarks

#### `POST /benchmarks`

Run a benchmark comparing multiple strategies.

**Query parameters:**
- `background` (bool, default `false`) — when `true`, enqueue the run and return **202** with a `job_id`; poll `GET /jobs/{job_id}` for status and result.

**Request:**
```json
{
  "document_id": "doc-abc123",
  "strategies": ["recursive", "fixed_size", "semantic"],
  "questions_file": "files/questions.json",
  "top_k": 5,
  "dry_run": false
}
```

**Response (201):**
```json
{
  "experiment_id": "exp-abc123",
  "document_id": "doc-abc123",
  "strategies_used": ["recursive", "fixed_size", "semantic"],
  "questions_count": 21,
  "aggregate_metrics": {
    "recursive": {
      "avg_context_relevance": 8.5,
      "avg_answer_similarity": 7.8,
      "avg_faithfulness": 9.2,
      "hallucination_rate": 0.05,
      "total_questions": 21,
      "failed_questions": 0
    }
  },
  "best_strategy": "recursive",
  "total_latency_seconds": 120.5,
  "estimated_cost_usd": 0.22,
  "created_at": "2026-07-25T12:00:00"
}
```

---

#### `GET /benchmarks/{experiment_id}`

Retrieve experiment results.

**Response:** Same as POST /benchmarks response.

---

#### `GET /benchmarks/{experiment_id}/report`

Generate HTML report.

**Query Parameters:**
- `view`: `managerial` (default) or `technical`

**Response:** HTML page

---

#### `GET /experiments`

List all experiments.

**Response:**
```json
{
  "items": [
    {
      "id": "exp-abc123",
      "document_id": "doc-abc123",
      "strategies_used": ["recursive", "fixed_size"],
      "created_at": "2026-07-25T12:00:00"
    }
  ],
  "total": 1,
  "offset": 0,
  "limit": 50
}
```

---

### Jobs

Background execution for long-running benchmarks and document processing (FastAPI `BackgroundTasks` + SQLite job records).

#### `GET /jobs`

List jobs (newest first).

**Query parameters:** `job_type`, `status`, `offset`, `limit`

#### `GET /jobs/{job_id}`

Poll job status. When `status` is `completed`, `result` contains the same payload as the synchronous endpoint would return; when `failed`, `error` is set.

**Response (202 enqueue body from POST with `background=true`):**
```json
{
  "job_id": "abc123",
  "job_type": "benchmark",
  "status": "pending",
  "poll_url": "/jobs/abc123"
}
```

---

## Error Responses

All errors return:
```json
{
  "detail": "Error message",
  "type": "ErrorClassName"
}
```

| Status Code | Error Type | Description |
|-------------|------------|-------------|
| 400 | ChunkingError | Invalid request |
| 400 | QueryError | Query failed |
| 400 | BenchmarkError | Benchmark failed |
| 404 | QueryError | Resource not found |
| 422 | ValidationError | Invalid request body |

---

## Rate Limits

None configured. For production, consider adding rate limiting.

---

## Authentication

None configured. For production, add API key or OAuth2 authentication.