# HTTP Server API Reference

## Overview

The CHORUS HTTP Server provides REST API endpoints for accessing the distributed Hypercore log, monitoring system health, and querying system status. All endpoints return JSON responses.

**Base URL**: `http://localhost:8080/api` (default)

## Server Configuration

### Initialization

```go
server := api.NewHTTPServer(port, hypercoreLog, pubsub)
err := server.Start()
```

### Parameters

- `port` (int) - HTTP port to listen on
- `hypercoreLog` (*logging.HypercoreLog) - Distributed log instance
- `pubsub` (*pubsub.PubSub) - Event broadcasting system

### Server Lifecycle

```go
// Start server (blocking)
err := server.Start()

// Stop server gracefully
err := server.Stop()
```

## CORS Configuration

All endpoints support CORS with the following headers:

```
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS
Access-Control-Allow-Headers: Content-Type, Authorization
```

OPTIONS preflight requests return `200 OK` immediately.

## Endpoints

### 1. Health Check

Check if the API server is running and responding.

**Endpoint**: `GET /api/health`

**Parameters**: None

**Response**:

```json
{
  "status": "healthy",
  "timestamp": 1727712345,
  "log_entries": 1024
}
```

**Response Fields**:
- `status` (string) - Always "healthy" if server is responding
- `timestamp` (int64) - Current Unix timestamp in seconds
- `log_entries` (uint64) - Total number of log entries in the Hypercore log

**Example**:

```bash
curl -X GET http://localhost:8080/api/health
```

**Status Codes**:
- `200 OK` - Server is healthy and responding

---

### 2. System Status

Get detailed system status including Hypercore statistics and API version.

**Endpoint**: `GET /api/status`

**Parameters**: None

**Response**:

```json
{
  "status": "running",
  "timestamp": 1727712345,
  "hypercore": {
    "total_entries": 1024,
    "head_hash": "abc123...",
    "peer_id": "12D3KooW...",
    "replicators": 3
  },
  "api_version": "1.0.0"
}
```

**Response Fields**:
- `status` (string) - System operational status ("running")
- `timestamp` (int64) - Current Unix timestamp
- `hypercore` (object) - Hypercore log statistics
- `api_version` (string) - API version string

**Example**:

```bash
curl -X GET http://localhost:8080/api/status
```

**Status Codes**:
- `200 OK` - Status retrieved successfully

---

### 3. Get Log Entries

Query log entries with flexible filtering by range or limit.

**Endpoint**: `GET /api/hypercore/logs`

**Query Parameters**:
- `start` (uint64, optional) - Starting index (inclusive)
- `end` (uint64, optional) - Ending index (exclusive, defaults to current length)
- `limit` (int, optional) - Maximum number of entries to return (default: 100, max: 1000)

**Parameter Behavior**:
- If neither `start` nor `end` are provided, returns most recent `limit` entries
- If only `start` is provided, returns from `start` to current end, up to `limit`
- If both `start` and `end` are provided, returns range [start, end), up to `limit`

**Response**:

```json
{
  "entries": [
    {
      "index": 1023,
      "timestamp": "2025-09-30T14:25:45Z",
      "author": "12D3KooWAbC123...",
      "type": "task_completed",
      "data": {
        "task_id": "TASK-456",
        "result": "success",
        "duration_ms": 2340
      },
      "hash": "sha256:abc123...",
      "prev_hash": "sha256:def456...",
      "signature": "sig:789..."
    }
  ],
  "count": 1,
  "timestamp": 1727712345,
  "total": 1024
}
```

**Response Fields**:
- `entries` (array) - Array of log entry objects
- `count` (int) - Number of entries in this response
- `timestamp` (int64) - Response generation timestamp
- `total` (uint64) - Total number of entries in the log

**Log Entry Fields**:
- `index` (uint64) - Sequential entry index
- `timestamp` (string) - ISO 8601 timestamp
- `author` (string) - Peer ID that created the entry
- `type` (string) - Log entry type (see Log Types section)
- `data` (object) - Entry-specific data payload
- `hash` (string) - SHA-256 hash of this entry
- `prev_hash` (string) - Hash of the previous entry (blockchain-style)
- `signature` (string) - Digital signature

**Examples**:

```bash
# Get most recent 50 entries (default limit: 100)
curl -X GET "http://localhost:8080/api/hypercore/logs?limit=50"

# Get entries from index 100 to 200
curl -X GET "http://localhost:8080/api/hypercore/logs?start=100&end=200"

# Get entries starting at index 500 (up to current end)
curl -X GET "http://localhost:8080/api/hypercore/logs?start=500"

# Get last 10 entries
curl -X GET "http://localhost:8080/api/hypercore/logs?limit=10"
```

**Status Codes**:
- `200 OK` - Entries retrieved successfully
- `400 Bad Request` - Invalid parameter format
- `500 Internal Server Error` - Failed to retrieve log entries

**Error Examples**:

```bash
# Invalid start parameter
curl -X GET "http://localhost:8080/api/hypercore/logs?start=invalid"
# Response: 400 Bad Request - "Invalid start parameter"

# System error
# Response: 500 Internal Server Error - "Failed to get log entries: database error"
```

---

### 4. Get Recent Log Entries

Retrieve the most recent log entries (convenience endpoint).

**Endpoint**: `GET /api/hypercore/logs/recent`

**Query Parameters**:
- `limit` (int, optional) - Maximum number of entries to return (default: 50, max: 1000)

**Response**:

```json
{
  "entries": [
    {
      "index": 1023,
      "timestamp": "2025-09-30T14:25:45Z",
      "author": "12D3KooWAbC123...",
      "type": "task_completed",
      "data": {...}
    }
  ],
  "count": 50,
  "timestamp": 1727712345,
  "total": 1024
}
```

**Response Fields**: Same as "Get Log Entries" endpoint

**Examples**:

```bash
# Get last 10 entries
curl -X GET "http://localhost:8080/api/hypercore/logs/recent?limit=10"

# Get last 50 entries (default)
curl -X GET "http://localhost:8080/api/hypercore/logs/recent"

# Get last 100 entries
curl -X GET "http://localhost:8080/api/hypercore/logs/recent?limit=100"
```

**Status Codes**:
- `200 OK` - Entries retrieved successfully
- `500 Internal Server Error` - Failed to retrieve entries

---

### 5. Get Logs Since Index

Retrieve all log entries created after a specific index (useful for incremental synchronization).

**Endpoint**: `GET /api/hypercore/logs/since/{index}`

**Path Parameters**:
- `index` (uint64, required) - Starting index (exclusive - returns entries after this index)

**Response**:

```json
{
  "entries": [
    {
      "index": 1001,
      "timestamp": "2025-09-30T14:20:00Z",
      "type": "task_claimed",
      "data": {...}
    },
    {
      "index": 1002,
      "timestamp": "2025-09-30T14:21:00Z",
      "type": "task_progress",
      "data": {...}
    }
  ],
  "count": 2,
  "since_index": 1000,
  "timestamp": 1727712345,
  "total": 1024
}
```

**Response Fields**:
- `entries` (array) - Array of log entries after the specified index
- `count` (int) - Number of entries returned
- `since_index` (uint64) - The index parameter provided in the request
- `timestamp` (int64) - Response generation timestamp
- `total` (uint64) - Current total number of entries in the log

**Examples**:

```bash
# Get all entries after index 1000
curl -X GET "http://localhost:8080/api/hypercore/logs/since/1000"

# Get all new entries (poll from last known index)
LAST_INDEX=950
curl -X GET "http://localhost:8080/api/hypercore/logs/since/${LAST_INDEX}"
```

**Use Cases**:
- **Incremental Sync**: Clients can poll this endpoint periodically to get new entries
- **Change Detection**: Detect new log entries since last check
- **Event Streaming**: Simple polling-based event stream

**Status Codes**:
- `200 OK` - Entries retrieved successfully
- `400 Bad Request` - Invalid index parameter
- `500 Internal Server Error` - Failed to retrieve entries

---

### 6. Get Log Statistics

Get comprehensive statistics about the Hypercore log.

**Endpoint**: `GET /api/hypercore/logs/stats`

**Parameters**: None

**Response**:

```json
{
  "total_entries": 1024,
  "head_hash": "sha256:abc123...",
  "peer_id": "12D3KooWAbC123...",
  "replicators": 3,
  "entry_types": {
    "task_announced": 234,
    "task_claimed": 230,
    "task_completed": 215,
    "task_failed": 15,
    "task_progress": 320,
    "peer_joined": 5,
    "peer_left": 3,
    "consensus_reached": 2
  },
  "authors": {
    "12D3KooWAbC123...": 567,
    "12D3KooWDef456...": 457
  },
  "first_entry_time": "2025-09-25T08:00:00Z",
  "last_entry_time": "2025-09-30T14:25:45Z"
}
```

**Response Fields**:
- `total_entries` (uint64) - Total number of log entries
- `head_hash` (string) - Current head hash of the log chain
- `peer_id` (string) - Local peer ID
- `replicators` (int) - Number of active replication connections
- `entry_types` (object) - Count of entries by type
- `authors` (object) - Count of entries by author peer ID
- `first_entry_time` (string) - Timestamp of first entry
- `last_entry_time` (string) - Timestamp of most recent entry

**Example**:

```bash
curl -X GET "http://localhost:8080/api/hypercore/logs/stats"
```

**Status Codes**:
- `200 OK` - Statistics retrieved successfully

---

## Log Entry Types

The Hypercore log supports multiple entry types for different system events:

### Task Coordination (BZZZ)

- `task_announced` - New task announced to the swarm
- `task_claimed` - Agent claims a task
- `task_progress` - Progress update on a task
- `task_completed` - Task successfully completed
- `task_failed` - Task execution failed

### Meta-Discussion (HMMM)

- `plan_proposed` - Agent proposes a plan
- `objection_raised` - Another agent raises an objection
- `collaboration` - Collaborative work event
- `consensus_reached` - Group consensus achieved
- `escalation` - Issue escalated for human review
- `task_help_requested` - Agent requests help with a task
- `task_help_offered` - Agent offers help with a task
- `task_help_received` - Help received and acknowledged

### System Events

- `peer_joined` - New peer joined the network
- `peer_left` - Peer disconnected from the network
- `capability_broadcast` - Agent broadcasts its capabilities
- `network_event` - General network-level event

## Data Payload Examples

### Task Announced

```json
{
  "type": "task_announced",
  "data": {
    "task_id": "TASK-123",
    "description": "Implement user authentication",
    "capabilities_required": ["go", "security", "api"],
    "priority": "high",
    "estimated_duration_minutes": 180
  }
}
```

### Task Completed

```json
{
  "type": "task_completed",
  "data": {
    "task_id": "TASK-123",
    "result": "success",
    "duration_ms": 172340,
    "commits": ["abc123", "def456"],
    "tests_passed": true,
    "coverage_percent": 87.5
  }
}
```

### Consensus Reached

```json
{
  "type": "consensus_reached",
  "data": {
    "discussion_id": "DISC-456",
    "proposal": "Refactor authentication module",
    "participants": ["agent-1", "agent-2", "agent-3"],
    "votes": {"yes": 3, "no": 0, "abstain": 0},
    "next_steps": ["create_subtasks", "assign_agents"]
  }
}
```

## Error Responses

### 400 Bad Request

Invalid query parameters or path parameters:

```
HTTP/1.1 400 Bad Request
Content-Type: text/plain

Invalid start parameter
```

### 500 Internal Server Error

Server-side processing error:

```
HTTP/1.1 500 Internal Server Error
Content-Type: text/plain

Failed to get log entries: database connection failed
```

## Performance Recommendations

### Pagination

Always use appropriate `limit` values to avoid retrieving large result sets:

```bash
# Good: Limited result set
curl "http://localhost:8080/api/hypercore/logs/recent?limit=50"

# Bad: Could return thousands of entries
curl "http://localhost:8080/api/hypercore/logs"
```

### Polling Strategy

For incremental updates, use the "logs since" endpoint:

```bash
# Initial fetch
LAST_INDEX=$(curl -s "http://localhost:8080/api/hypercore/logs/recent?limit=1" | jq '.entries[0].index')

# Poll for updates (every 5 seconds)
while true; do
    NEW_ENTRIES=$(curl -s "http://localhost:8080/api/hypercore/logs/since/${LAST_INDEX}")
    if [ $(echo "$NEW_ENTRIES" | jq '.count') -gt 0 ]; then
        echo "$NEW_ENTRIES" | jq '.entries'
        LAST_INDEX=$(echo "$NEW_ENTRIES" | jq '.entries[-1].index')
    fi
    sleep 5
done
```

### Caching

Consider caching statistics and status responses that change infrequently:

```bash
# Cache stats for 30 seconds
curl -H "Cache-Control: max-age=30" "http://localhost:8080/api/hypercore/logs/stats"
```

## WebSocket Support (Future)

WebSocket support is planned for real-time log streaming:

```javascript
// Future WebSocket API
const ws = new WebSocket('ws://localhost:8080/api/ws/logs');

ws.onmessage = (event) => {
  const logEntry = JSON.parse(event.data);
  console.log('New log entry:', logEntry);
};
```

## Testing

### Using curl

```bash
# Health check
curl -v http://localhost:8080/api/health

# Get recent logs with pretty-printing
curl -s http://localhost:8080/api/hypercore/logs/recent?limit=5 | jq '.'

# Monitor for new entries
watch -n 2 'curl -s http://localhost:8080/api/hypercore/logs/recent?limit=1 | jq ".entries[0]"'
```

### Using httpie

```bash
# Install httpie
pip install httpie

# Make requests
http GET localhost:8080/api/health
http GET localhost:8080/api/hypercore/logs/recent limit==10
http GET localhost:8080/api/status
```

### Integration Testing

```go
package api_test

import (
    "testing"
    "net/http"
    "net/http/httptest"
)

func TestHealthEndpoint(t *testing.T) {
    // Create test server
    server := api.NewHTTPServer(0, mockHypercoreLog, mockPubSub)

    // Create test request
    req := httptest.NewRequest("GET", "/api/health", nil)
    rec := httptest.NewRecorder()

    // Execute request
    server.ServeHTTP(rec, req)

    // Assert response
    if rec.Code != http.StatusOK {
        t.Errorf("Expected 200, got %d", rec.Code)
    }
}
```

## Related Documentation

- [API Overview](./README.md) - API architecture and integration points
- [Hypercore Log System](../internal/logging.md) - Distributed log internals
- [Setup Manager](./setup-manager.md) - Configuration API (future document)
- [Authentication](./authentication.md) - Authentication guide (future document)