# HP Lattice Protein Folding Energy Evaluator

> HP Lattice Protein Folding Energy Evaluator is a paid API for AI agents from bio.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-14).

Validates a 2D hydrophobic/polar (HP) lattice conformation and computes its energy by counting non-consecutive hydrophobic contacts, assigning -1 energy unit per contact.

## Facts

- Endpoint: POST https://bio.halowerk.com/v1/protein-folding
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hp-lattice-protein-folding-energy-evaluator-df008488
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_biZiKU2dDeqUpWltVMQYR

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability hp-lattice-protein-folding-energy-evaluator-df008488 -d '<json body>'
```

Example prompt: Check whether the HP sequence 'HPPHPPHHPH' placed at coordinates [(0,0),(1,0),(1,1),(0,1),(0,2),(1,2),(2,2),(2,1),(2,0),(3,0)] forms a valid self-avoiding lattice walk and tell me its energy score based on hydrophobic contacts.

## When to prefer this

Use this endpoint when you need to score or validate a specific pre-defined 2D HP lattice conformation rather than predict a fold from scratch. Ideal for validating output from custom lattice search algorithms, checking homework or textbook examples, or benchmarking multiple candidate folds in the HP toy model. Not suitable for real atomic-resolution structure prediction, 3D folds, or biological energy functions.

## Known failure modes

- Coordinates that are not unit steps apart will fail validation
- Path that revisits a lattice point (not self-avoiding) will be rejected
- Sequence length not matching coordinate count will return an error
- Sequence containing characters other than H or P will be rejected
- Fewer than 3 residues or more than 256 will violate schema constraints
- Coordinate values outside [-1000000, 1000000] will be rejected

## How this service works

Checks that a hydrophobic/polar sequence follows a self-avoiding unit-step lattice path, then counts non-consecutive hydrophobic contacts and assigns one negative energy unit per contact. It evaluates a supplied toy conformation only; it neither predicts a fold nor represents atomic chemistry, kinetics, solvent or biological function.

## Output

Returns whether the supplied coordinate path forms a valid self-avoiding unit-step lattice walk for the given HP sequence, along with the computed energy as a non-positive integer (one -1 unit per non-consecutive H-H contact pair).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "coordinates": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "x",
     "y"
    ],
    "properties": {
     "x": {
      "type": "integer",
      "maximum": 1000000,
      "minimum": -1000000
     },
     "y": {
      "type": "integer",
      "maximum": 1000000,
      "minimum": -1000000
     }
    },
    "additionalProperties": false
   },
   "maxItems": 256,
   "minItems": 3
  },
  "hp_sequence": {
   "type": "string",
   "pattern": "^[HP]+$",
   "maxLength": 256,
   "minLength": 3,
   "description": "Hydrophobic/polar toy-model sequence."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hp-lattice-protein-folding-energy-evaluator-df008488/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bio.halowerk.com](https://www.zero.xyz/host/bio.halowerk.com/llms.txt)