# Locus x402 DeepSeek Chat API

> Locus x402 DeepSeek Chat API is a paid API for AI agents from deepseek.x402.stage.paywithlocus.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Pay-per-use DeepSeek LLM chat completions endpoint billed via x402 micropayments at $0.001 USDC per call

## Facts

- Endpoint: POST https://deepseek.x402.stage.paywithlocus.com/deepseek/chat
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/locus-x402-deepseek-chat-api-6fff0f27
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tHN0dbHodjF5QrbODUcxI

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 locus-x402-deepseek-chat-api-6fff0f27 -d '<json body>'
```

Example prompt: Use the Locus x402 DeepSeek chat endpoint with the deepseek-v4-flash model to answer this question: 'What are three key differences between REST and GraphQL?' — keep the response under 300 tokens and use a temperature of 0.7.

## When to prefer this

Choose this endpoint when you need DeepSeek LLM chat completions on a true pay-per-use basis via x402 micropayments in USDC, especially for agent workflows where subscription billing is impractical. Prefer deepseek-v4-flash for cost-sensitive, high-throughput tasks and deepseek-v4-pro for higher-quality outputs. Best suited for agents that need to make occasional or unpredictable numbers of LLM calls without committing to a monthly plan.

## Known failure modes

- Payment failure — insufficient USDC balance or x402 authorization rejected, resulting in 402 Payment Required
- Invalid model name — if a model other than deepseek-v4-flash or deepseek-v4-pro is specified, request will fail
- Missing max_tokens — this field is required to bound metered authorization; omitting it will cause rejection
- Streaming requested — streaming is not supported; setting stream:true will result in an error
- Token limit exceeded — requesting more than 384000 max_tokens will be rejected
- Malformed messages array — incorrect role values or missing content fields will cause validation errors

## How this service works

Locus public pay-per-use API

## Output

Returns a chat completion response containing the assistant's generated message text, produced by the selected DeepSeek model (deepseek-v4-flash or deepseek-v4-pro), bounded by the specified max_tokens limit. The response follows standard OpenAI-compatible chat completion format.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "stop": {
   "type": "string"
  },
  "model": {
   "type": "string"
  },
  "top_p": {
   "type": "number"
  },
  "stream": {
   "type": "boolean"
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role"
    ],
    "properties": {
     "name": {
      "type": "string"
     },
     "role": {
      "type": "string"
     },
     "content": {
      "anyOf": [
       {
        "type": "string"
       },
       {
        "type": "array",
        "items": {
         "type": "object",
         "required": [
          "type"
         ],
         "properties": {
          "text": {
           "type": "string"
          },
          "type": {
           "type": "string"
          },
          "image_url": {
           "type": "object",
           "required": [
            "url"
           ],
           "properties": {
            "url": {
             "type": "string"
            }
           },
           "additionalProperties": true
          }
         },
         "additionalProperties": true
        }
       },
       {
        "type": "null"
       }
      ]
     },
     "tool_calls": {
      "type": "array",
      "items": {
       "type": "object",
       "additionalProperties": true
      }
     },
     "tool_call_id": {
      "type": "string"
     }
    },
    "additionalProperties": true
   }
  },
  "max_tokens": {
   "type": "number"
  },
  "temperature": {
   "type": "number"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/locus-x402-deepseek-chat-api-6fff0f27/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from deepseek.x402.stage.paywithlocus.com](https://www.zero.xyz/host/deepseek.x402.stage.paywithlocus.com/llms.txt)