### Release Priority Level (Zinc)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

This example demonstrates how to release a priority level for a writable point by writing a null value. This effectively relinquishes control at that specific priority.

```bash
curl -X POST "https://server/haystack/pointWrite" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" 
id,val,level,who
@thermostat.tempSp,N,8,"Alice"'
```

--------------------------------

### Haystack HTTP API: Read Operation (Filter Query - Bash and Zinc)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Illustrates querying Haystack entities using filter expressions via the HTTP API's 'Read' operation. Shows cURL examples for GET and POST requests with different filter criteria and serialization formats (JSON and Zinc), along with example filter expressions.

```bash
# Query all sites
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: application/json"

# Query points with specific conditions
curl -X GET "https://server/haystack/read?filter=point%20and%20temp%20and%20sensor" \
  -H "Accept: application/json"

# POST request with filter and limit (Zinc format)
curl -X POST "https://server/haystack/read" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -H "Accept: text/zinc" \
  -d 'ver:"3.0"\nfilter,limit\n"equip and hvac and siteRef==@site-123",100'

# Response (Zinc)
ver:"3.0"
id,dis,equip,hvac,ahu,siteRef
@ahu-1,"AHU-1",M,M,M,@site-123
@ahu-2,"AHU-2",M,M,M,@site-123

# Filter expression examples
site                           // Has site marker tag
equip and hvac                 // Has both equip AND hvac tags
point and not temp             // Has point but NOT temp tag
curVal > 75                    // curVal greater than 75
curVal >= 72°F                 // With unit (must match exactly)
geoCity == "Chicago"           // String equality
siteRef->geoCity == "Chicago"  // Dereference ref to check nested value

```

--------------------------------

### Read Point Write Priority Array (Zinc)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

This example demonstrates how to read the current priority array state for a writable point. The request specifies the point ID, and the response details the values and sources at each priority level.

```bash
curl -X POST "https://server/haystack/pointWrite" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -H "Accept: text/zinc" \
  -d 'ver:"3.0" 
id
@thermostat.tempSp'
```

--------------------------------

### Create Real-time Watch Subscription (Zinc)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

This example shows how to create a real-time subscription to monitor point value changes using the watchSub operation. It specifies the Haystack version, a display name for the watch, a lease duration, and the IDs of the points to monitor. The response includes a watchId for subsequent operations.

```bash
curl -X POST "https://server/haystack/watchSub" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -H "Accept: text/zinc" \
  -d 'ver:"3.0" watchDis:"MyApp Monitor" lease:5min
id
@vav-101.zoneTemp
@vav-101.damperCmd
@vav-102.zoneTemp'
```

--------------------------------

### Haystack Filter Query Language Examples

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Demonstrates the declarative filter language used in Haystack for querying entities. It supports tag presence/absence, equality and numeric comparisons (with units), logical operators, and reference traversal.

```text
// Tag presence (has tag)
site                              // All entities with site marker
equip                             // All equipment
point and sensor                  // Points that are sensors

// Tag absence
not temp                          // Missing temp tag
point and not his                 // Points without history

// Equality comparisons
geoCity == "Chicago"              // Exact string match
kind == "Number"                  // Match kind value
curStatus == "ok"                 // Status check

// Numeric comparisons (unit must match exactly)
curVal > 75                       // Greater than (unitless)
curVal >= 72°F                    // With unit
curVal < 100kW                    // Less than
area <= 50000ft²                  // Less or equal

// Logical operators
site or equip                     // Either tag
equip and hvac                    // Both tags
equip and hvac and not ahu        // Complex logic
(temp or humidity) and sensor     // Parentheses for grouping

// Reference traversal (dereference)
siteRef->geoCity == "Chicago"     // Follow ref, check nested value
equipRef->siteRef->dis == "HQ"    // Multi-level traversal
siteRef->weatherStationRef->tz == "New_York"  // Deep path

// Combining patterns
point and sensor and siteRef->geoCity == "Chicago" and curVal > 70
equip and elec and meter and siteRef == @main-site
```

--------------------------------

### Serialize Grids with JSON Format

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Serializes grids using JSON, preserving full type fidelity through the `_kind` discriminator pattern. This example demonstrates a grid representing equipment with metadata and typed values.

```json
{
  "_kind": "grid",
  "meta": {
    "ver": "3.0",
    "database": "production",
    "dis": "Equipment List"
  },
  "cols": [
    { "name": "dis", "meta": { "dis": "Display Name" } },
    { "name": "equip" },
    { "name": "siteRef", "meta": { "dis": "Site" } },
    { "name": "installed" }
  ],
  "rows": [
    {
      "dis": "RTU-1",
      "equip": { "_kind": "marker" },
      "siteRef": { "_kind": "ref", "val": "site-a", "dis": "HQ" },
      "installed": { "_kind": "date", "val": "2005-06-01" }
    },
    {
      "dis": "RTU-2",
      "equip": { "_kind": "marker" },
      "siteRef": { "_kind": "ref", "val": "site-a", "dis": "HQ" },
      "installed": { "_kind": "date", "val": "1999-07-12" }
    },
    {
      "dis": "Chiller-1",
      "equip": { "_kind": "marker" },
      "siteRef": { "_kind": "ref", "val": "site-b", "dis": "Branch" },
      "installed": { "_kind": "date", "val": "2010-03-15" }
    }
  ]
}
```

--------------------------------

### Haystack HTTP API: About Operation (Bash and JSON)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Demonstrates how to query basic server information using the Haystack HTTP API's 'About' operation. Includes a cURL command for a GET request and the expected JSON response structure containing server metadata.

```bash
# GET request (no authentication shown for brevity)
curl -X GET "https://server/haystack/about" \
  -H "Accept: application/json"

# Response (JSON)
{
  "_kind": "grid",
  "meta": { "ver": "3.0" },
  "cols": [
    { "name": "haystackVersion" },
    { "name": "tz" },
    { "name": "serverName" },
    { "name": "serverTime" },
    { "name": "productName" },
    { "name": "productVersion" }
  ],
  "rows": [{
    "haystackVersion": "4.0",
    "tz": "New_York",
    "serverName": "Demo Server",
    "serverTime": { "_kind": "dateTime", "val": "2024-01-15T10:30:00-05:00", "tz": "New_York" },
    "productName": "Acme Haystack Server",
    "productVersion": "2.1.0"
  }]
}

```

--------------------------------

### Site Entity Model (JSON)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

This example shows the equivalent of the Trio Site entity definition, but represented in JSON format. It uses Haystack's JSON encoding for entities, including nested objects for references, numbers with units, and coordinates.

```json
{
  "id": { "_kind": "ref", "val": "whitehouse", "dis": "White House" },
  "dis": "White House",
  "site": { "_kind": "marker" },
  "area": { "_kind": "number", "val": 55000, "unit": "ft²" },
  "tz": "New_York",
  "weatherStationRef": { "_kind": "ref", "val": "weather.washington" },
  "yearBuilt": 1792,
  "geoAddr": "1600 Pennsylvania Avenue NW, Washington, DC",
  "geoCity": "Washington D.C.",
  "geoCountry": "US",
  "geoCoord": { "_kind": "coord", "lat": 38.898, "lng": -77.037 }
}
```

--------------------------------

### Serialize Grids with Zinc Format

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Serializes tabular data using Zinc, a typed CSV format that supports metadata at grid and column levels. Examples include basic grids, nested structures, sparse data, error responses, and incomplete data.

```zinc
// Basic grid with metadata
ver:"3.0" database:"production" dis:"Equipment List"
dis dis:"Display Name",equip,siteRef dis:"Site",installed
"RTU-1",M,@site-a "HQ",2005-06-01
"RTU-2",M,@site-a "HQ",1999-07-12
"Chiller-1",M,@site-b "Branch",2010-03-15

// Grid with nested structures
ver:"3.0"
type,val
"list",[1,2,3]
"dict",{dis:"Example" foo bar:123}
"nested grid",<<
  ver:"3.0"
  a,b
  1,2
  3,4
  >>

// Sparse data with nulls
ver:"3.0"
id,dis,curVal,curStatus
@point-1,"Temp Sensor",72.5°F,"ok"
@point-2,"Humidity",N,"fault"
@point-3,"Pressure",29.92inHg,N

// Error grid response
ver:"3.0" err dis:"Cannot resolve id: badId" errTrace:"UnknownRecErr: badId\n  at Server.read..."
empty

// Incomplete data response (throttled)
ver:"3.0" incomplete:{dis:"Request timeout exceeded!" timeout:1min}
ts,val
2024-01-15T00:00:00-05:00 New_York,72.1°F
2024-01-15T00:15:00-05:00 New_York,72.3°F
```

--------------------------------

### Read Operation (Filter Query)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Queries entities using filter expressions. This operation supports tag presence checks, comparison operators, and logical operators (and, or, not). It can be used with GET or POST requests.

```APIDOC
## GET /haystack/read (Filter Query)
## POST /haystack/read (Filter Query)

### Description
Query entities using filter expressions. Supports tag presence checks, comparison operators, and logical operators (and, or, not).

### Method
GET or POST

### Endpoint
/haystack/read

### Parameters
#### Query Parameters (for GET requests)
- **filter** (string) - Required - The filter expression to select entities.
- **limit** (number) - Optional - The maximum number of results to return.

#### Request Body (for POST requests)
- **filter** (string) - Required - The filter expression to select entities.
- **limit** (number) - Optional - The maximum number of results to return.

### Request Example
```bash
# GET request to query all sites
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: application/json"

# GET request to query points with specific conditions
curl -X GET "https://server/haystack/read?filter=point%20and%20temp%20and%20sensor" \
  -H "Accept: application/json"

# POST request with filter and limit (Zinc format)
curl -X POST "https://server/haystack/read" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -H "Accept: text/zinc" \
  -d 'ver:"3.0"
filter,limit
"equip and hvac and siteRef==@site-123",100'
```

### Response
#### Success Response (200)
- The response format depends on the `Accept` header (e.g., JSON, Zinc).
- Returns a grid of entities matching the filter criteria.
  - **id** (Ref) - The unique identifier of the entity.
  - **dis** (Str) - The display name of the entity.
  - Other columns represent tags present on the matched entities.

#### Response Example (Zinc)
```zinc
ver:"3.0"
id,dis,equip,hvac,ahu,siteRef
@ahu-1,"AHU-1",M,M,M,@site-123
@ahu-2,"AHU-2",M,M,M,@site-123
```

### Filter Expression Examples
- `site`
- `equip and hvac`
- `point and not temp`
- `curVal > 75`
- `curVal >= 72°F`
- `geoCity == "Chicago"`
- `siteRef->geoCity == "Chicago"`
```

--------------------------------

### HisRead Operation - Single Point (GET/POST)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Reads time-series history data for a single point. Supports various range formats including 'today', 'yesterday', specific dates, and datetime ranges. Can be performed via GET or POST requests, with Zinc being a common format for POST.

```bash
# GET request for yesterday's data
curl -X GET "https://server/haystack/hisRead?id=@outsideAirTemp&range=yesterday" \
  -H "Accept: application/json"

```

```bash
# POST request with date range (Zinc)
curl -X POST "https://server/haystack/hisRead" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -H "Accept: text/zinc" \
  -d 'ver:"3.0"
id,range
@sensor-123,"2024-01-01,2024-01-02"'

```

```zinc
ver:"3.0" id:@sensor-123 hisStart:2024-01-01T00:00:00-05:00 New_York hisEnd:2024-01-02T00:00:00-05:00 New_York
ts,val
2024-01-01T00:15:00-05:00 New_York,68.2°F
2024-01-01T00:30:00-05:00 New_York,68.5°F
2024-01-01T00:45:00-05:00 New_York,69.1°F
2024-01-01T01:00:00-05:00 New_York,69.4°F

```

--------------------------------

### Haystack Defs, Ops, Filetypes, and Libs Operations

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Demonstrates API calls to query ontology definitions (defs), operations (ops), available file types, and library information from a Haystack server. These operations are crucial for understanding the server's capabilities and data semantics.

```bash
# Query all defs
curl -X GET "https://server/haystack/defs" \
  -H "Accept: text/zinc"

# Query specific def by filter
curl -X POST "https://server/haystack/defs" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0"
filter
"def==^point"'

# Response
ver:"3.0"
def,lib,is,mandatory,docTaxonomy,doc
^point,^lib:phIoT,[^entity],M,M,"Data point such as a sensor or actuator."

# Query ops definitions
curl -X GET "https://server/haystack/ops" \
  -H "Accept: application/json"

# Query available file types
curl -X GET "https://server/haystack/filetypes" \
  -H "Accept: application/json"

# Query library definitions
curl -X GET "https://server/haystack/libs" \
  -H "Accept: application/json"
```

--------------------------------

### About Operation

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Retrieves basic server information, including version, timezone, and product details. This operation returns a single-row grid containing server metadata.

```APIDOC
## GET /haystack/about

### Description
Query basic server information including version, timezone, and product details. Returns a single-row grid with server metadata.

### Method
GET

### Endpoint
/haystack/about

### Parameters
#### Query Parameters
None

#### Request Body
None

### Request Example
```bash
curl -X GET "https://server/haystack/about" \
  -H "Accept: application/json"
```

### Response
#### Success Response (200)
- **_kind** (string) - Indicates the response is a grid.
- **meta** (object) - Contains metadata about the grid, including version.
- **cols** (array) - An array of column definitions.
- **rows** (array) - An array containing a single row with server metadata.
  - **haystackVersion** (string) - The version of Haystack supported.
  - **tz** (string) - The server's default timezone.
  - **serverName** (string) - The name of the server.
  - **serverTime** (object) - The current server time, including timezone.
  - **productName** (string) - The name of the product running on the server.
  - **productVersion** (string) - The version of the product.

#### Response Example
```json
{
  "_kind": "grid",
  "meta": { "ver": "3.0" },
  "cols": [
    { "name": "haystackVersion" },
    { "name": "tz" },
    { "name": "serverName" },
    { "name": "serverTime" },
    { "name": "productName" },
    { "name": "productVersion" }
  ],
  "rows": [{
    "haystackVersion": "4.0",
    "tz": "New_York",
    "serverName": "Demo Server",
    "serverTime": { "_kind": "dateTime", "val": "2024-01-15T10:30:00-05:00", "tz": "New_York" },
    "productName": "Acme Haystack Server",
    "productVersion": "2.1.0"
  }]
}
```
```

--------------------------------

### Haystack Content Negotiation with HTTP Accept Header

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Shows how to request different data formats (Zinc, JSON, Trio, CSV, RDF) from a Haystack server using the HTTP Accept header. The default format is Zinc.

```bash
# Request Zinc format (default)
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: text/zinc"

# Request JSON format (Haystack 4)
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: application/json"

# Request JSON format (Haystack 3 legacy)
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: application/vnd.haystack+json;version=3"

# Request Trio format
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: text/trio"

# Request CSV format (type info is lost)
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: text/csv"

# CSV response example
dis,area,geoAddr
Site A,2000ft²,"1000 Main St,Richmond,VA"
Site B,3000ft²,"2000 Cary St,Richmond,VA"

# Request RDF Turtle format
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: text/turtle"

# Request JSON-LD format
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: application/ld+json"
```

--------------------------------

### Defs Operation

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Query ontology definitions (defs) from the server's namespace. Defs define the semantics for all tags in the ontology. Also includes endpoints for querying operations, file types, and libraries.

```APIDOC
## Defs Operation

### Description
Query ontology definitions from the server's namespace. Defs define the semantics for all tags in the ontology. This section also covers querying operations, available file types, and library definitions.

### Endpoints

**Query all defs:**
```bash
curl -X GET "https://server/haystack/defs" \
  -H "Accept: text/zinc"
```

**Query specific def by filter (POST with Zinc body):**
```bash
curl -X POST "https://server/haystack/defs" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0"
filter
"def==^point"'
```

**Response Example (for specific def query):**
```
ver:"3.0"
def,lib,is,mandatory,docTaxonomy,doc
^point,^lib:phIoT,[^entity],M,M,"Data point such as a sensor or actuator."
```

**Query ops definitions:**
```bash
curl -X GET "https://server/haystack/ops" \
  -H "Accept: application/json"
```

**Query available file types:**
```bash
curl -X GET "https://server/haystack/filetypes" \
  -H "Accept: application/json"
```

**Query library definitions:**
```bash
curl -X GET "https://server/haystack/libs" \
  -H "Accept: application/json"
```
```

--------------------------------

### WatchSub Operation

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Creates real-time subscriptions to monitor point value changes using stateful polling.

```APIDOC
## POST /haystack/watchSub

### Description
Creates real-time subscriptions to monitor point value changes. Watches use stateful polling for efficient HTTP-based real-time data.

### Method
POST

### Endpoint
/haystack/watchSub

### Parameters
#### Request Body
- **ver** (string) - Required - Version of the protocol, e.g., "3.0".
- **watchDis** (string) - Optional - Display name for the watch.
- **lease** (string) - Optional - Duration for the watch lease, e.g., "5min".
- **watchId** (string) - Optional - Identifier for an existing watch to add points to.
- **id** (string) - Required - The identifier of the point to watch, e.g., "@vav-101.zoneTemp". Can be a list of IDs.

### Request Example (Create new watch)
```bash
curl -X POST "https://server/haystack/watchSub" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -H "Accept: text/zinc" \
  -d 'ver:"3.0" watchDis:"MyApp Monitor" lease:5min
id
@vav-101.zoneTemp
@vav-101.damperCmd
@vav-102.zoneTemp'
```

### Request Example (Add points to existing watch)
```bash
curl -X POST "https://server/haystack/watchSub" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" watchId:"w-abc123" 
id
@vav-103.zoneTemp'
```

### Response
#### Success Response (200)
- **ver** (string) - Protocol version.
- **watchId** (string) - Unique identifier for the watch.
- **lease** (string) - Duration of the watch lease.
- **id** (string) - Identifier of the watched point.
- **dis** (string) - Display name of the watched point.
- **curVal** (any) - Current value of the watched point.
- **curStatus** (string) - Current status of the watched point.

#### Response Example
```zinc
ver:"3.0" watchId:"w-abc123" lease:5min
id,dis,curVal,curStatus
@vav-101.zoneTemp,"VAV-101 ZoneTemp",72.4°F,"ok"
@vav-101.damperCmd,"VAV-101 DamperCmd",45%,"ok"
@vav-102.zoneTemp,"VAV-102 ZoneTemp",71.8°F,"ok"
```
```

--------------------------------

### Site Entity Model (Trio)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

This snippet defines a Site entity using Trio syntax. It includes common properties like ID, display name, site marker, area, timezone, weather station reference, year built, address details, and geographic coordinates.

```trio
// Site entity in Trio format
id: @whitehouse
dis: "White House"
site
area: 55000ft²
tz: "New_York"
weatherStationRef: @weather.washington
yearBuilt: 1792
geoAddr: "1600 Pennsylvania Avenue NW, Washington, DC"
geoStreet: "1600 Pennsylvania Ave NW"
geoCity: "Washington D.C."
geoCountry: "US"
geoPostalCode: "20500"
geoCoord: C(38.898,-77.037)
```

--------------------------------

### Content Negotiation

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Request different response formats using the HTTP Accept header. Supported formats include Zinc (default), JSON, Trio, CSV, and RDF.

```APIDOC
## Content Negotiation

### Description
Request different response formats using the HTTP Accept header. Default is Zinc; JSON, Trio, CSV, and RDF formats are also supported.

### Method
GET

### Endpoint
`/haystack/read?filter=<filter_expression>`

### Headers
`Accept`: Specifies the desired response format.

### Examples

**Request Zinc format (default):**
```bash
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: text/zinc"
```

**Request JSON format (Haystack 4):**
```bash
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: application/json"
```

**Request JSON format (Haystack 3 legacy):**
```bash
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: application/vnd.haystack+json;version=3"
```

**Request Trio format:**
```bash
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: text/trio"
```

**Request CSV format:**
```bash
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: text/csv"
```

**CSV response example:**
```csv
dis,area,geoAddr
Site A,2000ft²,"1000 Main St,Richmond,VA"
Site B,3000ft²,"2000 Cary St,Richmond,VA"
```

**Request RDF Turtle format:**
```bash
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: text/turtle"
```

**Request JSON-LD format:**
```bash
curl -X GET "https://server/haystack/read?filter=site" \
  -H "Accept: application/ld+json"
```
```

--------------------------------

### Site Entity Model

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Represents buildings and physical locations with geolocation, timezone, and weather station references.

```APIDOC
## Site Entity Model

### Description
Models buildings and physical locations with geolocation, timezone, and weather station references.

### Method
N/A (This describes a data model, not an API endpoint)

### Endpoint
N/A

### Parameters
N/A

### Request Example (Trio format)
```trio
// Site entity in Trio format
id: @whitehouse
dis: "White House"
site
area: 55000ft²
tz: "New_York"
weatherStationRef: @weather.washington
yearBuilt: 1792
geoAddr: "1600 Pennsylvania Avenue NW, Washington, DC"
geoStreet: "1600 Pennsylvania Ave NW"
geoCity: "Washington D.C."
geoCountry: "US"
geoPostalCode: "20500"
geoCoord: C(38.898,-77.037)
```

### Request Example (JSON format)
```json
{
  "id": { "_kind": "ref", "val": "whitehouse", "dis": "White House" },
  "dis": "White House",
  "site": { "_kind": "marker" },
  "area": { "_kind": "number", "val": 55000, "unit": "ft²" },
  "tz": "New_York",
  "weatherStationRef": { "_kind": "ref", "val": "weather.washington" },
  "yearBuilt": 1792,
  "geoAddr": "1600 Pennsylvania Avenue NW, Washington, DC",
  "geoCity": "Washington D.C.",
  "geoCountry": "US",
  "geoCoord": { "_kind": "coord", "lat": 38.898, "lng": -77.037 }
}
```

### Response
#### Success Response (200)
- **(This is a data model, not an API response. Data conforming to this model would be returned by relevant API endpoints.)**

#### Response Example
```json
{
  "example": "(See JSON format example above)"
}
```
```

--------------------------------

### Write Value to Priority Level (Zinc)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

This command shows how to write a value to a specific priority level of a writable point. It includes the point ID, the value to write, the target priority level, and an optional source identifier.

```bash
curl -X POST "https://server/haystack/pointWrite" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" 
id,val,level,who
@thermostat.tempSp,72°F,16,"Energy App"'
```

--------------------------------

### Define Equipment Entities in Trio

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Models physical assets such as meters, air handlers, and chillers using site containment and equipment nesting. This format is specific to the Trio language.

```trio
// Electric meter equipment
id: @site.mainMeter
dis: "Main Elec Meter"
ac
elec
meter
equip
siteMeter
siteRef: @site
spaceRef: @site.utility-closet

---
// Chilled water plant (logical grouping)
id: @site.chillerPlant
dis: "Chiller Plant"
chilled
water
plant
equip
siteRef: @site

---
// Chiller nested under plant
id: @site.chiller3
dis: "Chiller-3"
chiller
equip
siteRef: @site
equipRef: @site.chillerPlant

---
// Air handler unit
id: @site.ahu1
dis: "AHU-1"
ahu
equip
hvac
siteRef: @site
spaceRef: @site.mechanicalRoom
```

--------------------------------

### Add Points to Existing Watch (Zinc)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

This command demonstrates how to add more points to an already established watch subscription. It uses the existing watchId and specifies the new point IDs to be included in the monitoring.

```bash
curl -X POST "https://server/haystack/watchSub" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" watchId:"w-abc123"
id
@vav-103.zoneTemp'
```

--------------------------------

### Timed Override with Duration (Zinc)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

This command illustrates how to set a timed override for a priority level. It includes the point ID, value, priority level, source, and a duration for which the override should remain active.

```bash
curl -X POST "https://server/haystack/pointWrite" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" 
id,val,level,who,duration
@thermostat.tempSp,74°F,8,"Manual",2hr'
```

--------------------------------

### WatchUnsub Operation

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Closes an existing watch subscription.

```APIDOC
## POST /haystack/watchUnsub

### Description
Closes an existing watch subscription.

### Method
POST

### Endpoint
/haystack/watchUnsub

### Parameters
#### Request Body
- **ver** (string) - Required - Version of the protocol, e.g., "3.0".
- **watchId** (string) - Required - Identifier of the watch to close.
- **close** (marker) - Required - Indicates the action to close the watch.
- **id** (string) - Optional - Can be used to specify which points to unsubscribe from within a watch, or empty to close the entire watch.

### Request Example
```bash
curl -X POST "https://server/haystack/watchUnsub" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" watchId:"w-abc123" close 
id'
```

### Response
#### Success Response (200)
- **(Typically a success confirmation, no specific fields defined in the example.)**

#### Response Example
```json
{
  "example": "(Success response structure not provided in the input)"
}
```
```

--------------------------------

### PointWrite Operation

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Commands writable points using a 16-level priority array. Supports reading current state, writing values, and releasing priorities.

```APIDOC
## POST /haystack/pointWrite

### Description
Commands writable points using a 16-level priority array. Level 1 is highest priority; level 17 is relinquish default. Supports reading current priority array state, writing values, and releasing priorities.

### Method
POST

### Endpoint
/haystack/pointWrite

### Parameters
#### Request Body
- **ver** (string) - Required - Version of the protocol, e.g., "3.0".
- **id** (string) - Required - The identifier of the point, e.g., "@thermostat.tempSp".
- **val** (any) - Optional - The value to write to the point. Use 'N' for null/release.
- **level** (number) - Optional - The priority level to write to (1-17).
- **who** (string) - Optional - Identifier for who is performing the write operation.
- **duration** (string) - Optional - Duration for a timed override, e.g., "2hr".

### Request Example (Read current priority array)
```bash
curl -X POST "https://server/haystack/pointWrite" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -H "Accept: text/zinc" \
  -d 'ver:"3.0" 
id
@thermostat.tempSp'
```

### Request Example (Write value to priority level 16)
```bash
curl -X POST "https://server/haystack/pointWrite" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" 
id,val,level,who
@thermostat.tempSp,72°F,16,"Energy App"'
```

### Request Example (Release priority level 8)
```bash
curl -X POST "https://server/haystack/pointWrite" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" 
id,val,level,who
@thermostat.tempSp,N,8,"Alice"'
```

### Request Example (Timed override on level 8)
```bash
curl -X POST "https://server/haystack/pointWrite" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" 
id,val,level,who,duration
@thermostat.tempSp,74°F,8,"Manual",2hr'
```

### Response
#### Success Response (200)
- **ver** (string) - Protocol version.
- **level** (number) - The priority level.
- **levelDis** (string) - Display name of the priority level.
- **val** (any) - The value at that priority level.
- **who** (string) - Identifier of who set the value at that priority level.

#### Response Example (Priority Array State)
```zinc
ver:"3.0"
level,levelDis,val,who
1,"Emergency Override",N,N
2,N,N,N
8,"Manual Override",72°F,"Alice"
14,N,N,N
15,N,N,N
16,"Scheduler",70°F,"Schedule App"
17,"Default",68°F,N
```
```

--------------------------------

### Filter Query Language

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Entities can be queried using a declarative filter language that supports tag presence, absence, equality comparisons, numeric comparisons with units, logical operators, and reference traversal.

```APIDOC
## Filter Query Language

### Description
Query entities using a declarative filter language with tag presence, comparisons, and logical operators.

### Examples

**Tag Presence:**
```
site
equip
point and sensor
```

**Tag Absence:**
```
not temp
point and not his
```

**Equality Comparisons:**
```
geoCity == "Chicago"
kind == "Number"
curStatus == "ok"
```

**Numeric Comparisons:**
```
curVal > 75
curVal >= 72°F
curVal < 100kW
area <= 50000ft²
```

**Logical Operators:**
```
site or equip
equip and hvac
equip and hvac and not ahu
(temp or humidity) and sensor
```

**Reference Traversal:**
```
siteRef->geoCity == "Chicago"
equipRef->siteRef->dis == "HQ"
siteRef->weatherStationRef->tz == "New_York"
```

**Combining Patterns:**
```
point and sensor and siteRef->geoCity == "Chicago" and curVal > 70
equip and elec and meter and siteRef == @main-site
```
```

--------------------------------

### Haystack Data Types (Kinds) in Zinc and JSON

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Demonstrates the scalar and collection data types defined by Project Haystack, shown in both Zinc and JSON formats. These types extend standard JSON to include units, timezones, references, and markers for interoperable data exchange.

```zinc
// Scalar Types in Zinc format
N                              // Null
M                              // Marker (label/type tag)
T                              // Bool true
F                              // Bool false
123                            // Number (unitless)
72.5°F                         // Number with unit
"hello world"                  // Str (string)
`http://example.com/`          // Uri
@abc-123                       // Ref (entity reference)
@abc-123 "Display Name"        // Ref with display name
^hot-water                     // Symbol (def identifier)
2024-01-15                     // Date
14:30:00                       // Time
2024-01-15T14:30:00-05:00 New_York  // DateTime with timezone
C(37.545,-77.449)              // Coord (latitude, longitude)
NA                             // NA (not available)

// Collection Types
[1, 2, "three", 4.0°C]         // List
{dis:"Building" site area:35000ft²}  // Dict (dictionary)

```

```json
// JSON equivalents
{ "_kind": "marker" }                                    // Marker
{ "_kind": "number", "val": 72.5, "unit": "°F" }        // Number with unit
{ "_kind": "ref", "val": "abc-123", "dis": "Main Meter" }  // Ref
{ "_kind": "dateTime", "val": "2024-01-15T14:30:00-05:00", "tz": "New_York" }  // DateTime
{ "_kind": "coord", "lat": 37.545, "lng": -77.449 }     // Coord

```

--------------------------------

### Poll for Watch Changes (Zinc)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

This snippet illustrates how to poll for changes in a watch subscription. The first command polls for only changed entities, while the second command requests a full refresh, returning all watched entities regardless of changes.

```bash
# Poll for changes (only returns changed entities)
curl -X POST "https://server/haystack/watchPoll" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" watchId:"w-abc123"
empty'

# Poll with full refresh (returns all watched entities)
curl -X POST "https://server/haystack/watchPoll" \
  -H "Content-Type: text/zinc; charset=utf-8" \
  -d 'ver:"3.0" watchId:"w-abc123" refresh
empty'
```

--------------------------------

### Read by Multiple IDs (JSON)

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Performs a POST request to read data for multiple point IDs simultaneously. The request body specifies the grid structure with an array of IDs to retrieve. The response is also a grid, potentially containing null rows for IDs not found.

```bash
curl -X POST "https://server/haystack/read" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -d '{
    "_kind": "grid",
    "meta": { "ver": "3.0" },
    "cols": [{ "name": "id" }],
    "rows": [
      { "id": { "_kind": "ref", "val": "vav-101" } },
      { "id": { "_kind": "ref", "val": "vav-102" } },
      { "id": { "_kind": "ref", "val": "vav-103" } }
    ]'

```

```json
{
  "_kind": "grid",
  "meta": { "ver": "3.0" },
  "cols": [
    { "name": "id" },
    { "name": "dis" },
    { "name": "curVal" }
  ],
  "rows": [
    {
      "id": { "_kind": "ref", "val": "vav-101" },
      "dis": "VAV-101 ZoneTemp",
      "curVal": { "_kind": "number", "val": 72.4, "unit": "°F" }
    },
    { "id": null, "dis": null, "curVal": null },
    {
      "id": { "_kind": "ref", "val": "vav-103" },
      "dis": "VAV-103 ZoneTemp",
      "curVal": { "_kind": "number", "val": 71.8, "unit": "°F" }
    }
  ]
}

```

--------------------------------

### Define Point Entities in Trio

Source: https://context7.com/project-haystack/haystack-defs/llms.txt

Models sensors, setpoints, and commands, specifying containment, kind, and real-time/historical capabilities. This format is specific to the Trio language.

```trio
// Temperature sensor point
id: @whitehouse.ahu3.dat
dis: "White House AHU-3 DischargeAirTemp"
discharge
air
temp
sensor
point
cur
his
siteRef: @whitehouse
equipRef: @whitehouse.ahu3
kind: "Number"
unit: "°F"
tz: "New_York"
curVal: 55.2°F
curStatus: "ok"
hisStatus: "ok"

---
// Writable command point (fan run)
id: @site.ahu1.fanRun
dis: "AHU-1 Fan Run"
fan
run
cmd
point
writable
siteRef: @site
equipRef: @site.ahu1
kind: "Bool"
enum: "off,on"
writeVal: T
writeLevel: 16
writeStatus: "ok"

---
// Zone temperature setpoint with history
id: @room706.tempSp
dis: "Room 706 Temp Setpoint"
effective
zone
air
temp
sp
point
his
siteRef: @site
spaceRef: @room706
equipRef: @room706.thermostat
kind: "Number"
unit: "°C"
tz: "London"
minVal: 15°C
maxVal: 28°C
hisMode: "cov"
```