> ## 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. # Expand one command file into text > Expands one command file and returns the text: its shell blocks run, their output spliced in where they stood, and the arguments substituted into what that produced. The order is deliberate and is not the caller's to choose — a pasted issue body carrying a backtick block must never become a block. Shell blocks run only in a repository somebody has trusted, and never at all for a command a package shipped; a block that did not run is replaced by a sentence saying why. They run in the named repository's own directory, and only when that repository is trusted — an untrusted checkout is never a working directory. One expansion's blocks share a ten-second deadline, so this call can take that long. A name two command files both claim is refused with 409 naming both, never awarded to one of them: listCommands lists every claimant for exactly that reason, and there is never an implicit winner. ## OpenAPI ````yaml /en/openapi/v3-current/narya.yaml post /v1/commands/{name}/expansion 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/commands/{name}/expansion: parameters: - $ref: '#/components/parameters/CommandNameParam' post: tags: - ladder summary: Expand one command file into text description: >- Expands one command file and returns the text: its shell blocks run, their output spliced in where they stood, and the arguments substituted into what that produced. The order is deliberate and is not the caller's to choose — a pasted issue body carrying a backtick block must never become a block. Shell blocks run only in a repository somebody has trusted, and never at all for a command a package shipped; a block that did not run is replaced by a sentence saying why. They run in the named repository's own directory, and only when that repository is trusted — an untrusted checkout is never a working directory. One expansion's blocks share a ten-second deadline, so this call can take that long. A name two command files both claim is refused with 409 naming both, never awarded to one of them: listCommands lists every claimant for exactly that reason, and there is never an implicit winner. operationId: expandCommand requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/ExpansionRequest' responses: '200': description: The expanded text. content: application/json: schema: $ref: '#/components/schemas/Expansion' '400': $ref: '#/components/responses/BadRequest' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/Conflict' '500': $ref: '#/components/responses/InternalServerError' components: parameters: CommandNameParam: name: name in: path required: true description: The command's name — what "/" reaches it by. schema: type: string pattern: ^[^\s/\\]+$ maxLength: 128 schemas: ExpansionRequest: type: object description: >- What to expand a skill or a command file against: the repository the work is happening in, and whatever the person typed after the name. properties: repository: type: string description: >- Absolute path of the repository, which decides which rungs are read and — for a command — where its shell blocks run and whether they may. maxLength: 4096 arguments: type: string description: >- Everything typed after the name, verbatim. A command file's $ARGUMENTS and $1..$9 are filled from it, AFTER its shell blocks have already run, so text pasted here can never become a block. maxLength: 65536 examples: - repository: /home/dev/repos/narya arguments: internal/wire Expansion: type: object description: >- The text one expansion produced, ready to be put in front of a person. It is never sent anywhere on their behalf: the whole point of expanding into a composer is that somebody reads what a file wrote in their name before a model does. required: - text properties: text: type: string examples: - text: |- Review the working tree. On branch develop internal/wire Error: type: object description: >- The single error envelope every operation returns. Codes are NRY- followed by four digits and are catalogued in the top-level x-error-catalog extension. fields appears only on 422 validation errors, mapping each offending property to its problem. required: - code - title - message properties: code: type: string pattern: ^NRY-[0-9]{4}$ 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' Conflict: description: >- The resource's current state rejects the request — archived session, busy lane, slot conflict, failed build, already-final state. 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' ````