> ## 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. # Get a session > Returns one session with its status, model in use, token usage totals and cost. ## OpenAPI ````yaml /en/openapi/v3-current/narya.yaml get /v1/sessions/{sessionId} 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}: parameters: - $ref: '#/components/parameters/SessionIdParam' get: tags: - sessions summary: Get a session description: >- Returns one session with its status, model in use, token usage totals and cost. operationId: getSession responses: '200': description: The session. content: application/json: schema: $ref: '#/components/schemas/Session' '400': $ref: '#/components/responses/BadRequest' '404': $ref: '#/components/responses/NotFound' '500': $ref: '#/components/responses/InternalServerError' components: parameters: SessionIdParam: name: sessionId in: path required: true description: The session's id. schema: type: string format: uuid schemas: Session: type: object description: >- A durable conversation container. Survives the process that created it; archiving hides it from active lists but its transcript remains queryable and exportable forever. required: - id - repository - status - clientKind - createdAt - updatedAt properties: id: type: string format: uuid description: The session's id. title: type: string maxLength: 512 description: Human-readable title. repository: type: string maxLength: 4096 description: Absolute path of the repository the session works in. status: type: string enum: - idle - running - waiting - archived description: >- Lifecycle: running while a turn executes or normal follow-ups chain; waiting after interrupt when admitted steering or follow-up inputs remain queued; idle only when neither execution nor queued input exists; archived accepts no new work. provider: type: string description: The model provider currently in use. model: type: string description: The model currently in use. variant: type: string description: >- The preset of request options this session's turns run under — the name, not the options it stands for, since what a name means is the catalogue's answer and can change while the session's own choice cannot. Absent on a session that never chose one, which is every session running its model at the model's own defaults. style: type: string maxLength: 64 description: >- The named response style this session's answers are shaped by — the name, not the prompt it appends, since what a name means is configuration's answer and changes when somebody edits that file while the session's own choice does not. Absent on a session that never chose one, which is every session answering in narya's own voice. Unlike `variant` it survives a model switch: a style is a fact about how the conversation reads rather than about the model answering it. A client renders this and derives nothing — the names that exist are the host's answer (setSessionStyle refuses the rest). clientKind: $ref: '#/components/schemas/ClientKind' description: >- Which kind of client opened this session, recorded when it was created and never rewritten. Always present: `unknown` for a session created before this host recorded the datum, which is the honest answer rather than a guessed frontend. modelNotice: type: string maxLength: 1024 description: >- One sentence stating what a client could not otherwise know about the model this session opened on or was just moved to, present on the responses to createSession and setSessionModel. Two facts earn it. The first is a model narya chose itself rather than being told to use: no default_model configured and no model previously chosen, so the first provider holding a usable credential answered — or a named model the catalogue no longer carries, for which the provider default was substituted. It names the alternatives that also qualified and how to choose another, because a choice nobody made has to be stated to be a choice at all rather than something that merely happened. The second is a level this session will run without: a model reference may carry one (see the variant field), and an endpoint that does not take the field runs at its own default instead — so a level named at creation or at a switch, or configured beside default_model, is said here rather than quoted in a picker while every request drops it. A client that renders the live event stream rather than the session's transcript has no other road to it. Otherwise absent, including for a model that was simply configured, chosen or named; absent on getSession and listSessions, which report state rather than how it came about. usage: $ref: '#/components/schemas/TokenUsage' description: >- What this session has consumed and cost across every turn it has run — a running total, not the last turn's figure. Carried by getSession and by every row of listSessions, so a client drawing a list of sessions can say what each one has cost without asking per row. Absent on a session that has never completed a turn, and its costUsd is absent whenever any one of that session's turns could not be priced: the sum over only the priced turns is smaller than what the session actually cost, and a figure that quietly understates money is worse than an admitted unknown. lastTurnUsage: $ref: '#/components/schemas/TokenUsage' description: >- What the newest round of this session's own conversation sent and produced — the LAST turn's figure, not the running total above. Carried by getSession only. It exists because the two are not interchangeable for the one question a reader reopening a long conversation asks: how much room is left before this compacts. That answer is the size of the prompt last sent, and usage above is a sum over every turn the session ever ran, which is a larger number growing without bound and means nothing as a fraction of a context window. The live event stream carries this figure on turn-finished, so a client watching a session has always had it; a client that READ the session had no source for it at all and drew no context figure until it spent a turn of its own. Restoring a recorded reading rather than deriving one is the whole of it — nothing here is computed from the transcript. The newest round of the MAIN lane: a delegation's rounds are another conversation's prompts, and the figure is about the reader's. Absent on a session that has never completed a round, and on one whose rounds all ran on delegates. Its costUsd is that one round's price, absent when the round could not be priced. pendingInputs: type: array description: >- Pending steering and follow-up references in durable operation order. Content is intentionally absent; fetch the transcript by entryId. items: $ref: '#/components/schemas/PendingInputReference' parentSessionId: type: string format: uuid description: When the session was branched, the session it branched from. summary: type: string maxLength: 4096 description: >- What a model said this conversation tried and concluded. Absent until somebody asks for it (summarizeSession) — nothing summarises a branch because a rewind moved away from it. A model that answers past this length is trimmed to it, with a marker saying so rather than a sentence that just stops. summaryAt: type: string format: date-time description: >- When the summary was taken. Read against updatedAt it answers whether the summary predates the last thing that happened here. posture: $ref: '#/components/schemas/Posture' description: >- Whether somebody is there to answer a permission prompt raised here. Absent on a session nobody ever said either way about, which reads as `attended` — the posture is only ever recorded because somebody stated it (setSessionPosture), never inferred from whether a client happens to be connected. warming: $ref: '#/components/schemas/Warming' description: >- Whether this session pays to keep its provider cache alive while nobody is using it, and the most it may ever spend doing so. Absent on a session nobody ever turned it on for, which is every session until somebody does — warming is off unless somebody asked (setSessionWarming). viewedAt: type: string format: date-time description: >- When a reader last had this session in front of them (acknowledgeSessionViewed). Read against updatedAt it answers whether anything has happened here since somebody looked, which is what lets a client mark a background conversation as carrying news — and, because the fact is held here rather than in a window, what makes two clients agree about it and makes the answer survive a relaunch. ABSENT on a session nobody has ever viewed, which is not the same as viewed long ago: one has nothing to report, the other has everything that ever happened in it. lastOutcome: type: string enum: - finished - failed description: >- How the last turn here ended. It is what lets a client that was not running at the time tell a conversation that finished from one that failed. Absent on a session that has never run a turn. An interrupt is not among the values: somebody was there and stopped it themselves, so it is not news to bring back to them. cacheSpend: $ref: '#/components/schemas/CacheSpend' description: >- What this session's provider prompt cache has cost it, from both sides: what letting it expire cost, and what keeping it alive cost. Present only on getSession, and only once one of the two has happened — a session that has never paid for either carries nothing here rather than a pair of zeros. tasks: type: array description: >- The agent's own task list for this session — every item it has written, in the order it wrote them, whatever is in the store right now. It is here rather than behind a listing of its own because the list is a stored row and every client already reads the session when it attaches, so one optional field costs no round trip and no second operation. A change to the list is announced as `task-list`, which carries the same whole list for the same reason; this is where a client that was not attached at the time gets it. Present on getSession only, like `lastTurnUsage` and `cacheSpend` and for their reason: a listing that carried it would read every row's tasks to draw a page nobody asked for. ABSENT MEANS EMPTY, and it cannot mean anything narrower: the store holds rows, so a list nobody ever wrote and a list somebody cleared are the same read. The live stream is where those two differ — a clearing write announces `task-list` carrying an empty array — and a read that returned `[]` would be claiming to know which of the two it was looking at. items: $ref: '#/components/schemas/Task' createdAt: type: string format: date-time updatedAt: type: string format: date-time examples: - id: 6b9f6d2e-1c3a-4f5b-9d7e-2a8c4e6f0b1d title: Fix flaky ledger test repository: /Users/dev/repos/midaz status: running provider: anthropic model: claude-sonnet-4-5 clientKind: inline usage: inputTokens: 152000 outputTokens: 8400 costUsd: 1.87 createdAt: '2026-08-08T12:00:00.000Z' updatedAt: '2026-08-08T12:34:56.000Z' ClientKind: type: string enum: - inline - tui - oneshot - api - unknown x-enum-varnames: - ClientKindInline - ClientKindTui - ClientKindOneshot - ClientKindApi - ClientKindUnknown description: >- Which kind of client opened a session — the coarse classification a client filters and mixes on when it lists sessions it did not itself open. inline — the terminal client (`narya`). tui — the full-screen client (`narya --tui`). oneshot — a one-shot command (`narya -p`). api — a caller of this contract that named no kind; every narya frontend names itself, so this is what speaking the contract directly is. unknown — never recorded, which is every session created before this host carried the datum; a read answers `unknown` rather than picking a kind, and a create request naming it records nothing. Presentation metadata only: nothing in the host behaves differently because of its value. TokenUsage: type: object description: >- Token consumption totals and their cost. costUsd is priced from the catalogue's published rates for the model that ran, and is absent whenever no rate is known for it — a model configured by hand against a private endpoint, say. Absent means unknown; a false zero would mean free. On a session total it is absent unless every turn in the session could be priced. required: - inputTokens - outputTokens properties: inputTokens: type: integer minimum: 0 description: Input tokens consumed. outputTokens: type: integer minimum: 0 description: Output tokens produced. cacheReadTokens: type: integer minimum: 0 description: Tokens served from the provider's prompt cache. cacheWriteTokens: type: integer minimum: 0 description: Tokens written to the provider's prompt cache. costUsd: type: number minimum: 0 description: Total cost in US dollars. examples: - inputTokens: 152000 outputTokens: 8400 cacheReadTokens: 120000 cacheWriteTokens: 9000 costUsd: 1.87 PendingInputReference: type: object description: >- A content-free durable queued-input reference. Message content remains only in the transcript. required: - entryId - turnId - kind - sequence - enqueuedAt properties: entryId: type: string format: uuid turnId: type: string format: uuid kind: type: string enum: - steer - follow-up sequence: type: integer format: int64 minimum: 1 enqueuedAt: type: string format: date-time examples: - entryId: 4d8e2f6a-0b1c-4d3e-9f5a-7b9c1d3e5f0a turnId: 4d8e2f6a-0b1c-4d3e-9f5a-7b9c1d3e5f0a kind: follow-up sequence: 7 enqueuedAt: '2026-08-10T15:04:05.000Z' Posture: type: string enum: - attended - detached x-enum-varnames: - PostureAttended - PostureDetached description: >- Whether somebody is there to answer a permission prompt raised in a session. attended — a prompt is shown and waited on, which is what every session starts as. detached — nobody is watching, so a prompt is refused and recorded with its reason rather than blocking the turn forever on a question nothing can answer. Orthogonal to clientKind, and deliberately not a value of it: clientKind is stamped once at creation and never rewritten, whereas a session BECOMES detached when somebody says so. It is a recorded fact with exactly one transition (setSessionPosture) and is never inferred from the presence or absence of a connection — a client that crashed, a lid that closed and a pipe that dropped all leave it exactly as it was. Warming: type: object description: >- One session's standing instruction about its provider cache while nobody is using it: whether to pay to hold the cached prefix past the five minutes a provider keeps it for free, and the lifetime dollars this session may spend doing so. Both fields travel together because they are one decision. Turning warming on without saying what it may cost is not a decision anybody makes, and there is no default narya could supply that is not a guess about somebody else's bill. The ceiling is a LIFETIME figure for this session, not a daily one: a session is a bounded thing with an end, and "this conversation may cost me at most fifty cents to keep warm" is the sentence a person means. A second, separate ceiling bounds the whole store's spending per UTC day and is operator configuration rather than part of any session — either one being reached stops warming rather than warning about it. required: - enabled - ceilingUsd properties: enabled: type: boolean description: >- Whether this session is warmed. False with a ceiling recorded is a session somebody turned off, which keeps the number they chose for the day they turn it back on. ceilingUsd: type: number format: double minimum: 0 description: >- The most this session may ever spend on warming, in US dollars, counted across its whole life. Reaching it stops warming this session and nothing else; every other session keeps its own allowance. Zero is a legitimate value and means the same as off. examples: - enabled: true ceilingUsd: 0.5 CacheSpend: type: object description: >- What this session's provider prompt cache has cost it, read from both sides of one decision: what letting the cached prefix expire cost, and what refusing to let it expire cost. The two numbers are reported together because they are the same decision seen from either end. Somebody weighing whether to turn warming on for this session is comparing exactly these figures, and either one alone answers half the question. The headline is the re-billed prompt: rounds that paid full input rates to send again a prefix the provider had been holding, because the session sat idle past the cache's lifetime. A duplicated cache WRITE is a real event too and is deliberately not reported here — it is an internal metric, not what a person reads on a bill. Absent on a session where neither has ever happened, which is every session until one of them does. Never a zero-filled object standing in for "nothing yet". required: - rebilledRounds - rebilledTokens - rebilledUsd - warmingUsd properties: rebilledRounds: type: integer minimum: 0 description: >- How many rounds paid to re-send an expired prefix. Zero here with a warming figure present is a session that has been kept warm and has therefore never paid for its own idleness — which is warming working. rebilledTokens: type: integer minimum: 0 description: >- The prefix re-sent across those rounds: the part of each round's cache write that had genuinely been cached before, never the whole write. A resumed conversation also writes the message that ended the wait, and that content would have been written with the prefix alive too — charging it to the expiry would blame idleness for the weight of the message that ended it. rebilledUsd: type: number format: double minimum: 0 description: >- What that expiry cost, in US dollars: for each round, the difference between what its prompt was billed and what the same prompt would have cost with the prefix still cached. It DECOMPOSES money already reported in `usage.costUsd` rather than adding to it. A re-billed round's whole price is in the session total like every other round's, and this says how much of that price the expiry was; adding the two together counts the same dollars twice. rebilledUsdComplete: type: boolean description: >- Absent means true. Present and false makes `rebilledUsd` a FLOOR — "at least this much" — because at least one re-billed round ran on a model this host cannot price, contributing a real expiry and no dollars. The same honesty `costComplete` carries on a usage report, for the same reason: a total that quietly skipped the rounds it could not price is a number a reader will believe. warmingUsd: type: number format: double minimum: 0 description: >- What this session has spent keeping its cache alive, in US dollars, counted across its whole life and against the ceiling in `warming.ceilingUsd`. Reservations are included: a warm that was paid for and whose outcome was never established is money that may already be gone, and leaving it out would let it be spent twice. examples: - rebilledRounds: 4 rebilledTokens: 18240 rebilledUsd: 0.0312 warmingUsd: 0.045 Task: type: object description: >- One item of the agent's task list: what the work is, and where it stands. Two fields and no more. There is no id, because the list is replaced whole on every write and position is the only order there is — an identifier would be a second thing two surfaces could disagree about. There is no priority, because nothing renders or orders by one. required: - content - status properties: content: type: string description: What the task is, in the agent's own words. status: type: string enum: - pending - in_progress - completed - cancelled description: >- Where the item stands. `cancelled` counts toward the total and not toward what is done — an abandoned step is still a step the list once held. The engine does not enforce "exactly one in_progress": that is guidance in the tool's own description, and a list holding two is drawn honestly rather than refused. x-enum-varnames: - TaskStatusPending - TaskStatusInProgress - TaskStatusCompleted - TaskStatusCancelled examples: - content: Reproduce the flaky ledger test status: completed 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' InternalServerError: description: The host failed — including a store that refuses writes (NRY-0012). content: application/json: schema: $ref: '#/components/schemas/Error' ````