> ## Documentation Index > Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt > Use this file to discover all available pages before exploring further. # Label one entry of a transcript > Puts a short tag on one moment of a conversation, or takes the tag away by sending an empty one — setting and clearing are the same write, because changing a label and removing it are the same gesture from where a person stands. A label is what makes a branched family navigable by meaning rather than by id: "the version that worked", "before the refactor", "where it broke". One per entry, at most 128 characters, and it appears on the labels of the session's node in getSessionTree, which is also what that operation's label filter matches. The entry must belong to the named session. This is the only write in the transcript's surface that names an entry directly, so it is the only one that could be aimed at another conversation's entry, and one that is gets 404 rather than quietly succeeding. That 404 is deliberately not branchSession's 422 for the same fact. Here the entry is part of the ADDRESS: this session's entry with that id does not exist, which is what 404 says. branchSession carries the entry in its body, so the address (the session) does exist and it is the request that does not make sense against it, which is what 422 says. ## OpenAPI ````yaml /en/openapi/v3-current/narya.yaml put /v1/sessions/{sessionId}/entries/{entryId}/label openapi: 3.1.0 info: title: Narya Host API version: 1.0.0 description: >- The contract between the Narya host and every client. One long-lived host runs on your machine and serves this API over a Unix socket in your Narya home. Narya creates the socket owner-only, and file permissions are the whole authorization. There is no password, no token and no TLS. The terminal client and the one-shot command that Lerian ships drive this API, and a client you write drives the same one. Results never arrive on the response of the request that caused them. Submitting a message returns 202 with a turn id. Everything the turn produces streams over GET /v1/events as server-sent events with a typed envelope, and a stream resumes from a Last-Event-ID header. One error envelope: code, title, message, and fields on 422. Codes are NRY- followed by four digits. A paged list answers items, limit and a nextCursor when more remains. Cursors are opaque. servers: [] security: [] tags: - name: host description: The host process itself — version, uptime, mode, store. - name: sessions description: Durable conversation containers. Archive, never destroy. - name: messages description: Submitting work into a session and interrupting it. - name: events description: The server-sent event stream every client consumes. - name: lanes description: Parallel tracks inside a session — main, subagent, side. - name: agents description: Named recipes — instructions, tools, model, policy. Read-only in v1. - name: ladder description: >- What a person can type: the skills and command files in force for one repository, and expanding one into text. Five origins merged, nearest winning a name, the repository's own rungs gated on trust. - name: permissions description: Pending permission asks, decisions, and the decision audit. - name: intercom description: Sessions on one machine finding and messaging each other. - name: packages description: The one thing a user installs — resources, Go code, or both. - name: workflows description: Deterministic multi-agent orchestration runs. - name: providers description: Model suppliers, their auth state, and the model catalogue. - name: monitors description: >- Long-running watchers a session keeps beside its conversation — a test runner in watch mode, a build, a log being followed. Started by the model or by the person, always listed, always killable. - name: records description: The queryable local record of everything that happened. - name: schedules description: >- Work the host's own clock starts with nobody present — a repository, a prompt, a rule and what one fire may spend. Cancel, never destroy. paths: /v1/sessions/{sessionId}/entries/{entryId}/label: parameters: - $ref: '#/components/parameters/SessionIdParam' - $ref: '#/components/parameters/EntryIdParam' put: tags: - sessions summary: Label one entry of a transcript description: >- Puts a short tag on one moment of a conversation, or takes the tag away by sending an empty one — setting and clearing are the same write, because changing a label and removing it are the same gesture from where a person stands. A label is what makes a branched family navigable by meaning rather than by id: "the version that worked", "before the refactor", "where it broke". One per entry, at most 128 characters, and it appears on the labels of the session's node in getSessionTree, which is also what that operation's label filter matches. The entry must belong to the named session. This is the only write in the transcript's surface that names an entry directly, so it is the only one that could be aimed at another conversation's entry, and one that is gets 404 rather than quietly succeeding. That 404 is deliberately not branchSession's 422 for the same fact. Here the entry is part of the ADDRESS: this session's entry with that id does not exist, which is what 404 says. branchSession carries the entry in its body, so the address (the session) does exist and it is the request that does not make sense against it, which is what 422 says. operationId: setEntryLabel requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/EntryLabel' responses: '204': description: The label was set, or cleared. '400': $ref: '#/components/responses/BadRequest' '404': $ref: '#/components/responses/NotFound' '422': $ref: '#/components/responses/UnprocessableEntity' '500': $ref: '#/components/responses/InternalServerError' components: parameters: SessionIdParam: name: sessionId in: path required: true description: The session's id. schema: type: string format: uuid EntryIdParam: name: entryId in: path required: true description: The transcript entry's id. schema: type: string format: uuid schemas: EntryLabel: type: object description: >- The tag to put on one transcript entry. An empty string clears it — setting and clearing are one write, because from where a person stands renaming a marker and removing it are the same gesture. required: - label properties: label: type: string maxLength: 128 description: >- A short tag a person types to recognise this moment on sight. Empty clears whatever was there. examples: - label: the version that worked Error: type: object description: >- The single error envelope every operation returns. Codes are NRY- followed by four digits and are catalogued in the top-level x-error-catalog extension. fields appears only on 422 validation errors, mapping each offending property to its problem. required: - code - title - message properties: code: type: string pattern: ^NRY-[0-9]{4}$ description: Machine-readable error code from the NRY catalogue. title: type: string maxLength: 256 description: Short human-readable summary of the error class. message: type: string maxLength: 4096 description: Specific, actionable description of what went wrong. fields: type: object description: Per-field validation problems. Present on 422 only. additionalProperties: type: string examples: - code: NRY-0002 title: Session not found message: >- No session with id 6b9f6d2e-1c3a-4f5b-9d7e-2a8c4e6f0b1d exists on this host. responses: BadRequest: description: Malformed request — invalid parameter, cursor, or JSON body. content: application/json: schema: $ref: '#/components/schemas/Error' NotFound: description: The addressed resource does not exist on this host. content: application/json: schema: $ref: '#/components/schemas/Error' UnprocessableEntity: description: >- The request was well-formed but failed validation. The error's fields map names each offending property. content: application/json: schema: $ref: '#/components/schemas/Error' InternalServerError: description: The host failed — including a store that refuses writes (NRY-0012). content: application/json: schema: $ref: '#/components/schemas/Error' ````