# BeliefState Compare Beliefs

> BeliefState Compare Beliefs is a paid API for AI agents from beliefstate.ai, paid per call via x402, $0.5/call, status unknown (last checked 2026-10-29).

Compares two analyst belief/thesis records side-by-side, highlighting similarities, divergences, and key differentiators as of a specified date.

## Facts

- Endpoint: POST https://beliefstate.ai/v1/research/compare_beliefs?utm_source=zero.xyz
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/beliefstate-compare-beliefs-7caea097
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wC4S_YnY_8pG0X_R8w5mZ

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 beliefstate-compare-beliefs-7caea097 -d '<json body>'
```

Example prompt: Using BeliefState, compare the analyst belief on Tesla's EV market share thesis (belief ID a3f1c2d4-1234-4abc-8def-123456789abc) against the bearish thesis (belief ID b7e2f3a1-5678-4def-9abc-987654321fed), focusing on competitive moat assumptions, as of October 1st 2025.

## When to prefer this

Use this endpoint when you need a structured, AI-generated side-by-side comparison of two specific analyst theses or beliefs indexed on BeliefState, especially when point-in-time accuracy matters (via the as_of parameter) or when you want to focus the comparison on a specific analytical dimension. Prefer this over manually reading two separate research reports when you need a synthesized divergence analysis with dated evidence.

## Known failure modes

- Invalid UUID format for belief_id or compare_to_belief_id returns 400 validation error
- Belief IDs that do not exist in the platform return 404 not found
- as_of timestamp outside available data range may return empty or partial comparison
- Malformed date-time string for as_of field fails schema validation
- Payment of 0.5 USDC not completed results in 402 Payment Required
- comparison_focus string exceeding 500 characters triggers validation error

## How this service works

The first AI-powered platform for top analyst research. Get theses from top analysts, dated evidence, and available outcomes for your AI.

## Output

Returns a structured JSON envelope (schema_version 1) containing a generated_at timestamp, an as_of date reflecting the point-in-time requested, and a detailed comparison of the two analyst beliefs including thesis divergences, evidential differences, and key differentiating assumptions.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input",
  "output"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "belief_id",
      "compare_to_belief_id"
     ],
     "properties": {
      "as_of": {
       "type": "string",
       "format": "date-time",
       "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z))$"
      },
      "belief_id": {
       "type": "string",
       "format": "uuid",
       "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
      },
      "comparison_focus": {
       "type": "string",
       "maxLength": 500,
       "minLength": 1
      },
      "compare_to_belief_id": {
       "type": "string",
       "format": "uuid",
       "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "type": "string",
     "const": "POST"
    },
    "bodyType": {
     "type": "string",
     "const": "json"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type",
    "example"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "$comment": "Envelope excerpt only. Complete response schema: https://beliefstate.ai/v1/research/compare_beliefs?schema=output",
     "required": [
      "schema_version",
      "generated_at",
      "as_of"
     ],
     "properties": {
      "as_of": {
       "type": "string",
       "format": "date-time"
      },
      "generated_at": {
       "type": "string",
       "format": "date-time"
      },
      "schema_version": {
       "type": "string",
       "const": "1"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "as_of": "2026-10-24T00:00:00.000Z",
  "generated_at": "2026-10-24T00:00:00.000Z",
  "schema_version": "1"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/beliefstate-compare-beliefs-7caea097/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from beliefstate.ai](https://www.zero.xyz/host/beliefstate.ai/llms.txt)