> ## 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 /pt/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. On your own machine, one long-lived host serves this API over a Unix socket in your Narya home. The terminal client and the one-shot command that Lerian ships drive this API, and a client you write drives the same one. Requests authenticate with a bearer token issued by the identity provider the host is configured with. On your own machine, the host also accepts a request with no token from your own operating system user. Once signed-in work has claimed the home for an organization, it does so only while this machine is signed in to that organization. Such a request gets 401 with NRY-0011 on work that reaches your organization beyond the machine. An operation that declares another security scheme also accepts that credential. Any other request without a valid credential gets 401 with NRY-0011. A caller whose role lacks the permission an operation needs gets 403 with NRY-0028. 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 and message. Codes are NRY- followed by four digits. Cursors are opaque. servers: [] security: - bearerAuth: [] 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: extensions description: >- Host-side extensions and the operations each exposes over the wire. This is the generic lane a host extension uses to serve its own client half (a TUI component, a web panel) or any API-only consumer, without adding routes to this contract. - 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: environments description: >- Where a session's code lives and its commands run — this machine, or a container narya operates. A session that names none runs here. - 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. - name: sharing description: >- Publishing a session from a developer's own home to the organisation's, and what is held back before a byte leaves the machine. - name: refinements description: >- What this owner has taught narya and allowed it to keep — distilled facts, and the skills, agents and commands the model wrote for itself. Propose, read, consent, roll back. Nothing here fires until a person answers. - name: platform description: >- Calls Lerian's control plane made to a home it hosts, as this home recorded them. 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' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/Conflict' '413': $ref: '#/components/responses/RequestBodyTooLarge' '422': $ref: '#/components/responses/UnprocessableEntity' '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. A hosted home runs no shell block. On a hosted home it resolves under the home's workspace, and a path outside it is refused 422. maxLength: 4096 sessionId: type: string format: uuid description: >- The conversation to expand against, in place of repository (LadderSessionParam): for one whose code lives in an environment, the clone's skill or command is read there and a command's shell blocks run there, never on this host, starting its stopped container first. Naming both is refused 400. An expansion is a read of that conversation: a colleague's of a shared one is in its disclosure audit before any text comes back, and refused when that record cannot be written (listSessionDisclosures). arguments: type: string description: >- Everything typed after the name, verbatim. A command file's $ARGUMENTS and $1..$9 are filled from it, AFTER its shell blocks have already run, so text pasted here can never become a block. maxLength: 65536 examples: - repository: /home/dev/repos/narya arguments: internal/wire Expansion: type: object description: >- The text one expansion produced, ready to be put in front of a person. It is never sent anywhere on their behalf: the whole point of expanding into a composer is that somebody reads what a file wrote in their name before a model does. required: - text properties: text: type: string examples: - text: |- Review the working tree. On branch develop internal/wire Error: type: object description: >- The single error envelope every operation returns. Codes are NRY- followed by four digits and are catalogued in the top-level x-error-catalog extension. required: - code - title - message properties: code: type: string pattern: ^NRY-[0-9]{4}$ 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. 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' Forbidden: description: >- The caller is authenticated and is not allowed this operation (NRY-0028 or NRY-0030). 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' RequestBodyTooLarge: description: >- The request body weighs more than this operation accepts (NRY-0024). The host holds one ceiling per operation and refuses at the door, in front of every handler: a body whose declared Content-Length is past the ceiling is refused before a byte of it is read, and a body that declares no length is read only as far as the ceiling and refused there. Nothing was read past that point and nothing was written. content: application/json: schema: $ref: '#/components/schemas/Error' UnprocessableEntity: description: The request was well-formed but failed validation. 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' securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT description: >- Enforced on every transport, with no exempt operation. A person's request must carry a JWT issued by the configured identity provider, which the host verifies itself against that issuer's key set: signature, issuer, expiry, and the person and organisation it names. Requests without a valid one receive 401 NRY-0011 — except a request with no token on a laptop's socket from the OS user the kernel names as the host's own, which is that machine's user. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.