# BeliefState Get Belief Changes

> BeliefState Get Belief Changes is a paid API for AI agents from beliefstate.ai, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Retrieves a paginated feed of changes to analyst belief records, filterable by ticker, domain, entity, person, or source, as of a given timestamp.

## Facts

- Endpoint: POST https://beliefstate.ai/v1/research/get_belief_changes?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/beliefstate-get-belief-changes-b74ba57c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yJxSpjVfkSoZmiRXdYtsO

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-get-belief-changes-b74ba57c -d '<json body>'
```

Example prompt: Pull the latest belief changes for ticker AAPL from BeliefState as of today, using the 'engine_assessment' domain, and give me up to 20 results.

## When to prefer this

Use this endpoint when you need to incrementally track or detect changes in analyst beliefs over time — especially for building change-detection pipelines, syncing new research updates since a known checkpoint, or monitoring how analyst views on specific tickers or entities shift. Prefer this over a bulk fetch endpoint when you need delta/change-aware data rather than a full snapshot of current beliefs.

## Known failure modes

- Invalid UUID format for belief_id, entity_id, person_id, or source_id returns a validation error
- as_of timestamp not in strict ISO 8601 UTC format causes schema rejection
- limit outside 1–50 range returns a constraint violation
- Unknown domain enum value returns a 400 bad request
- Expired or invalid cursor causes pagination failure
- No matching records returns empty result set
- Malformed checkpoint string causes sync 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

A JSON object containing a list of belief change records timestamped with as_of and generated_at fields, a schema_version, and optionally a cursor or checkpoint for pagination. Each record reflects a detected change in an analyst's belief across the requested domain (e.g. engine_assessment, author_view, distribution).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input",
  "output"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "properties": {
      "as_of": {
       "type": "string",
       "format": "date-time",
       "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z))$"
      },
      "limit": {
       "type": "integer",
       "maximum": 50,
       "minimum": 1
      },
      "corpus": {
       "type": "string",
       "const": "released"
      },
      "cursor": {
       "type": "string",
       "maxLength": 2048,
       "minLength": 1
      },
      "domain": {
       "enum": [
        "author_view",
        "author_condition",
        "engine_assessment",
        "calculated_publication_outcome",
        "distribution",
        "identity_resolution",
        "provenance",
        "engine_quality",
        "engine_plan"
       ],
       "type": "string"
      },
      "resync": {
       "type": "boolean"
      },
      "ticker": {
       "type": "string"
      },
      "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)$"
      },
      "entity_id": {
       "type": "string",
       "format": "uuid",
       "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
      },
      "person_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)$"
      },
      "source_id": {
       "type": "string",
       "format": "uuid",
       "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
      },
      "checkpoint": {
       "ty
… (truncated)
```

## 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-get-belief-changes-b74ba57c/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)