> ## 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. # Write working memory > An agent's working state, written by its code and never by a model: `cas` replaces the whole state at a version, `merge_by_key` replaces the named fields. Over the cap it answers `stored: false`, never an error. The `agent_state` feature. ## OpenAPI ````yaml openapi/en/cell.json PUT /v1/agent-state 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/agent-state: put: tags: - state summary: Write working memory description: >- A write by the agent's code: over the cap it answers `stored: false`, never an error. **Authentication.** Source key: `Authorization: Bearer nia_sk_...`. Required scope: `agent_state`. It answers only in a space with the `agent_state` feature on (the `features` document); in a space without it, 404. operationId: write_agent_state_v1_agent_state_put requestBody: content: application/json: schema: $ref: '#/components/schemas/AgentStateWrite' required: true responses: '200': content: application/json: schema: $ref: '#/components/schemas/AgentStateWriteResult' description: Successful Response '412': description: '`agent_state_conflict`: the version moved since `if_version`.' '422': content: application/problem+json: schema: $ref: '#/components/schemas/Problem' description: The request does not match the contract. security: - sourceKey: [] x-codeSamples: - lang: python label: Python source: >- # Written by the agent's code, never by a model; merge by key keeps the other fields written = conversation.agent_state.put({"offer": {"plan": "familia-plus", "status": "shown"}}) if not written.stored: print(written.reason) # over_cap or not_declared_field, never an exception - lang: typescript label: TypeScript source: >- // Written by the agent's code, never by a model; merge by key keeps the other fields const written = await convo.agentState.put({ offer: { plan: "familia-plus", status: "shown" } }); if (!written.stored) console.log(written.reason); // over_cap or not_declared_field, never a rejection components: schemas: AgentStateWrite: additionalProperties: false description: >- A write of an agent's working state, by its code and never by a model: `cas` replaces the whole state at `if_version` (0 when it must not exist yet); `merge_by_key` replaces each top-level field it names and removes a field written as exactly `{"$delete": true}`. properties: agent: maxLength: 256 minLength: 1 title: Agent type: string body: additionalProperties: true title: Body type: object if_version: anyOf: - minimum: 0 type: integer - type: 'null' title: If Version mode: enum: - cas - merge_by_key title: Mode type: string scope: $ref: '#/components/schemas/AgentStateScope' subject: anyOf: - $ref: '#/components/schemas/Handle' - type: 'null' description: >- The customer the state is about, when its scope does not name them: erasing the customer and their data package find the state by it. required: - scope - agent - mode - body title: AgentStateWrite type: object AgentStateWriteResult: additionalProperties: false properties: reason: anyOf: - enum: - over_cap - not_declared_field type: string - type: 'null' title: Reason stored: title: Stored type: boolean version: title: Version type: integer required: - stored - version title: AgentStateWriteResult 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 AgentStateScope: additionalProperties: false description: >- What one working state belongs to. The id travels in the body, never in a URL: a conversation id may look like a phone number. properties: id: maxLength: 512 minLength: 1 title: Id type: string kind: enum: - conversation - task - object - subject title: Kind type: string required: - kind - id title: AgentStateScope type: object Handle: additionalProperties: false description: >- An identifier of a subject in some channel or system: a phone, an e-mail, a CRM id. properties: scope: anyOf: - maxLength: 256 minLength: 1 type: string - type: 'null' description: >- Namespace for scoped identifiers: the WhatsApp Business account for `wa_bsuid`, the system for `system_id`, the country for `gov_id_hmac`. title: Scope subject_kind: anyOf: - $ref: '#/components/schemas/SubjectKind' - type: 'null' description: Defaults to `person`, except for organization-only handle types. type: $ref: '#/components/schemas/HandleType' value: maxLength: 320 minLength: 1 title: Value type: string description: >- The identifier. Normalized on the server: E.164 for phones, lowercase for e-mail. required: - type - value title: Handle type: object SubjectKind: enum: - person - account - partner title: SubjectKind type: string description: >- A person, a customer organization (`account`) or an organization that takes part without being a customer (`partner`). HandleType: enum: - phone_e164 - wa_id - wa_jid - wa_lid - wa_bsuid - email - gov_id_hmac - app_user_id - system_id - org_registry_hmac - email_domain - anon_id title: HandleType type: string description: >- The kind of identifier. The value is classified by its format, never by the field it came from. securitySchemes: sourceKey: type: http scheme: bearer description: nia_sk_... ````