> ## Documentation Index > Fetch the complete documentation index at: https://docs.niadra.com/llms.txt > Use this file to discover all available pages before exploring further. # Fact history > Every value the slot of a fact held, with validity, origin and the edges between them. ## OpenAPI ````yaml openapi/en/cell.json GET /v1/profiles/{profile_id}/facts/{fact_id}/history openapi: 3.1.0 info: title: Niadra data API version: '1' description: >- Writing, context, history, objects, identity, privacy and governance of one space. Every space has a stable address, with the space and the region in its name. servers: - url: https://{space}.{region}.api.niadra.com variables: space: default: acme-prod description: The space, which comes in the source key. region: default: us-east-2 description: The region of the space, which also comes in the key. security: [] paths: /v1/profiles/{profile_id}/facts/{fact_id}/history: get: tags: - governance summary: Fact history description: >- What a fact's slot held before and after it: the values, when each held, where each came from. **Authentication.** Console person token with the `security`, `review`, `analysis` role (or admin), or a source key with the `admin` scope. operationId: fact_history_v1_profiles__profile_id__facts__fact_id__history_get parameters: - in: path name: profile_id required: true schema: format: uuid title: Profile Id type: string - in: path name: fact_id required: true schema: format: uuid title: Fact Id type: string responses: '200': content: application/json: schema: $ref: '#/components/schemas/FactHistory' description: Successful Response '422': content: application/problem+json: schema: $ref: '#/components/schemas/Problem' description: The request does not match the contract. security: - sourceKey: [] - personToken: [] components: schemas: FactHistory: additionalProperties: false description: >- `GET /v1/profiles/{profile_id}/facts/{fact_id}/history`: every value one slot held (the predicate, on the same handle and object), oldest first, with the edges between them, under the reader's policy. properties: fact_id: title: Fact Id type: string policy_version: title: Policy Version type: string predicate: title: Predicate type: string profile_id: title: Profile Id type: string relations: items: $ref: '#/components/schemas/FactRelationOut' title: Relations type: array versions: items: $ref: '#/components/schemas/FactOut' title: Versions type: array withheld: additionalProperties: type: integer description: Versions left out, by reason. title: Withheld type: object required: - profile_id - fact_id - predicate - policy_version title: FactHistory type: object Problem: additionalProperties: false description: RFC 9457 problem details; `code` comes from the versioned error catalog. properties: code: title: Code type: string detail: anyOf: - type: string - type: 'null' default: null title: Detail request_id: anyOf: - type: string - type: 'null' default: null title: Request Id status: title: Status type: integer title: title: Title type: string type: default: about:blank title: Type type: string required: - title - status - code title: Problem type: object FactRelationOut: additionalProperties: false properties: from_fact_id: description: The newer fact. title: From Fact Id type: string origin: default: model description: >- Who drew the edge: the extraction's `model`, a deterministic `rule` (precedence, a correction) or the nightly similarity `band`, whose edges only warn. enum: - model - rule - band title: Origin type: string to_fact_id: title: To Fact Id type: string type: description: '`supersedes` when a value replaced another, `contradicts`, ...' title: Type type: string required: - from_fact_id - to_fact_id - type title: FactRelationOut type: object FactOut: additionalProperties: false properties: about_handle_id: anyOf: - type: string - type: 'null' title: About Handle Id category: title: Category type: string confidence: title: Confidence type: number contradicts: description: Facts in conflict with this one, with who found the conflict. items: $ref: '#/components/schemas/FactContradictionOut' title: Contradicts type: array evidence_event_ids: items: type: string title: Evidence Event Ids type: array id: title: Id type: string invalid_at: anyOf: - format: date-time type: string - type: 'null' title: Invalid At last_confirmed_at: format: date-time title: Last Confirmed At type: string masked: default: false title: Masked type: boolean object: anyOf: - $ref: '#/components/schemas/ObjectRef' - type: 'null' origin: anyOf: - $ref: '#/components/schemas/Origin' - type: 'null' description: The earliest evidence event. predicate: title: Predicate type: string sensitivity: $ref: '#/components/schemas/Sensitivity' sessions_seen: anyOf: - type: integer - type: 'null' description: >- Distinct conversations or tasks whose turns support the value, which is what confirms it; `times_seen` counts every new piece of evidence. Null on an older fact not counted yet. title: Sessions Seen status: $ref: '#/components/schemas/FactStatus' times_seen: title: Times Seen type: integer unconfirmed_link: default: false description: >- It came through an identifier joined to the profile by a claim nobody confirmed yet (`HandleOut.provisional`). Only the `admin` and `security` roles see such items; every other reader, agents included, gets the profile without them until the link is confirmed. title: Unconfirmed Link type: boolean valid_at: format: date-time title: Valid At type: string value: anyOf: - type: string - type: 'null' description: None when the policy masks it for this reader. title: Value required: - id - predicate - value - category - sensitivity - status - confidence - valid_at - last_confirmed_at - times_seen title: FactOut type: object FactContradictionOut: additionalProperties: false properties: fact_id: description: The other fact of the pair. title: Fact Id type: string live: description: >- Both facts are still active. Retracting or correcting either one closes the pair. title: Live type: boolean origin: description: >- `model` when the extraction marked the conflict; `band` when the nightly comparison of the facts of one predicate found it, without a model. A `band` pair is a warning for review: it never changes a status, and each fact weighs less in the context while the pair is live. enum: - model - rule - band title: Origin type: string required: - fact_id - origin - live title: FactContradictionOut type: object description: A fact in conflict with the one read, and who found the conflict. ObjectRef: additionalProperties: false description: >- A business object in a system of record, e.g. `invoice` / `erp` / `0823`. properties: id: maxLength: 512 minLength: 1 title: Id type: string description: The id in that system. namespace: maxLength: 256 minLength: 1 title: Namespace type: string description: The system it lives in, such as `erp`. type: maxLength: 256 minLength: 1 title: Type type: string description: Object type, such as `invoice`, `order` or `ticket`. required: - type - namespace - id title: ObjectRef type: object Origin: additionalProperties: false description: >- Provenance of an item: the event it came from, its source (agent or system), channel and time. properties: at: anyOf: - format: date-time type: string - type: 'null' title: At channel: anyOf: - type: string - type: 'null' title: Channel conversation_id: anyOf: - type: string - type: 'null' title: Conversation Id event_id: anyOf: - type: string - type: 'null' title: Event Id kind: anyOf: - $ref: '#/components/schemas/EventKind' - type: 'null' source_id: anyOf: - type: string - type: 'null' title: Source Id speaker: anyOf: - $ref: '#/components/schemas/Speaker' - type: 'null' task_id: anyOf: - type: string - type: 'null' title: Task Id title: Origin type: object Sensitivity: enum: - normal - restricted - sensitive title: Sensitivity type: string FactStatus: enum: - active - expired - quarantined - retracted title: FactStatus type: string EventKind: enum: - message - system_event - action title: EventKind type: string description: >- What an event records: something said, a change in a system of record, or what an agent did in a system. Speaker: enum: - customer - ai_agent - human_agent - system title: Speaker type: string description: Who produced the event. securitySchemes: sourceKey: type: http scheme: bearer description: nia_sk_... personToken: type: http scheme: bearer bearerFormat: JWT ````