> ## Documentation Index > Fetch the complete documentation index at: https://staging.docs.aile.tech/llms.txt > Use this file to discover all available pages before exploring further. # Levels > For every quoted direction: the largest firm size now, its price after the spread and the reference mid. Indicative; only /quote signs. ## OpenAPI ````yaml openapi.json GET /v1/levels openapi: 3.1.0 info: title: Aile Quote API version: v1-2026-11 description: >- Get a price, send one transaction, receive the exact amount. **How it works** 1. `GET /config` gives you the chain, the order protocol address (`contracts.lop`) and the tokens with their decimals. 2. `GET /quote` gives you a price for a pair and an amount. Pass as `taker` the address that will send the transaction. 3. From that address, approve `fill.allowanceTarget` for the token you sell. 4. Send `fill.to`, `fill.data` and `fill.value` from that address before `expiresAt`. 5. Read the receipt. The transaction delivers exactly `buyAmount` or reverts. **What a quote is** A quote is an order signed by the market maker. It is valid for about 30 seconds, only the `taker` can use it, and it can be used once. `maxFirmSize` is the largest amount you can get right now at this rate, in both tokens. **What you can rely on** - Fields, routes and enumeration values are only ever added, never removed or changed in type. - Send `fill.to`, `fill.data` and `fill.value` exactly as returned. - `order`, `signature`, `maker` and the other `fill` fields are there for your information. Do not hard-code the maker address: it changes. - `maker.kind`, `signature.type`, `fill.method` and the problem `reason` can gain new values. Treat a `reason` you do not know as "no quote". **Access** Aile issues your API key. Send it as `Authorization: Bearer ` and keep it on your backend. `GET /quote` requires it. The other routes work without it; with it, their calls count against your own budget and are attributed to you instead of sharing the anonymous per-address limit. Over budget you get 429 `key-rate-limit` with `Retry-After`. Use **Authorize** to try the routes on this page; the page forgets the key on reload. **Scope** Base mainnet, real assets. The pairs come from the market makers' books, between the tokens `GET /config` lists; a pair nobody quotes answers 400 `bad-pair`. servers: - url: https://staging.app.aile.tech/api/base description: Base security: [] tags: - name: Service description: Discover the chain, the order protocol and the tokens - name: Quotes description: Receive a signed order and ready calldata - name: Orders description: Track a fill by its order hash paths: /v1/levels: get: tags: - Quotes summary: 'Levels: the largest size and its price, before a quote' description: >- For every direction the market makers quote: `maxFirmSize`, the largest quote you can get now, in both tokens (the price after the spread is `buyAmount / sellAmount`), a `ladder` of one rung at that size, and the `reference` mid it is priced from. Use it to show a price before asking `GET /quote`, or to choose a size. A direction that cannot be quoted now reads `firmQuoted: false` with the `reason` a quote of it would get; treat a `reason` you do not know as no quote. `pair=BASE/QUOTE` narrows the answer to one pair, in either order (400 `bad-pair` for a token this network does not offer). Levels are indicative: only `GET /quote` signs. No key is needed; the calls share a limit per address (429 `rate-limited` with `Retry-After`), and the answer may be cached for a few seconds. operationId: getLevels parameters: - schema: type: string in: query name: pair required: false description: >- Only the two directions of one pair: `BASE/QUOTE`, symbols of this network in either order, case-insensitive. 400 `bad-pair` for a symbol the network does not offer. responses: '200': description: Default Response content: application/json: schema: $ref: '#/components/schemas/Levels' '400': description: Default Response content: application/json: schema: $ref: '#/components/schemas/Problem' '429': description: Default Response content: application/json: schema: $ref: '#/components/schemas/Problem' security: - {} - apiKey: [] components: schemas: Levels: type: object properties: indicative: type: boolean const: true description: >- Always true: a level is a price before a quote, not a commitment. Only `GET /quote` signs. readAt: anyOf: - type: integer - type: 'null' description: >- Unix second the maker computed these levels; null before the first reading, with `levels` empty. levels: type: array items: type: object properties: sellToken: type: string description: Symbol of the token the taker pays. buyToken: type: string description: Symbol of the token the taker receives. firmQuoted: type: boolean description: Whether `GET /quote` would answer this direction now. makers: type: integer description: 'Makers quoting this direction now: 1 or 0.' maxFirmSize: type: object properties: sellAmount: type: string description: Base units of the token the taker pays. buyAmount: type: string description: Base units of the token the taker receives. required: - sellAmount - buyAmount additionalProperties: true description: >- The largest quote now, in both tokens. The price after the spread is buyAmount / sellAmount. Zero when not quoted. ladder: type: array items: type: object properties: sellAmount: type: string description: Base units of the token the taker pays. buyAmount: type: string description: Base units of the token the taker receives. required: - sellAmount - buyAmount additionalProperties: true description: >- Sizes and their amounts. One rung at maxFirmSize while the price does not depend on the size; empty when not quoted. reference: anyOf: - type: object properties: rate: type: string description: >- Mid rate the maker prices from, in human units, as the quote's referenceRate. source: type: string description: >- Where the mid comes from: `chainlink` or `api`. Open: new values may be added. at: type: integer description: Unix second of the mid. required: - rate - source - at additionalProperties: true - type: 'null' description: The mid, or null when none could be read. reason: anyOf: - type: string - type: 'null' description: >- Why the direction is not quoted, as a quote of it would be refused (`kill-switch`, `screening-unavailable`, `maker-unavailable`, `no-price`, `no-maker`, `maker-underfunded`, `maker-allowance`, `over-size`); null when quoted. Open: new values may be added. required: - sellToken - buyToken - firmQuoted - makers - maxFirmSize - ladder - reference - reason additionalProperties: true description: One entry per direction of every pair quoted, or of `pair` alone. required: - indicative - readAt - levels additionalProperties: true description: >- Indicative levels per direction: the largest firm size now and its price, before asking for a quote. Problem: type: object properties: type: type: string description: >- Problem type identifier; about:blank unless a machine-readable problem type is defined. title: type: string status: type: integer detail: type: string instance: type: string reason: description: Machine-readable cause, where the route defines one type: string required: - type - title - status additionalProperties: true description: RFC 7807 problem details securitySchemes: apiKey: type: http scheme: bearer description: >- API key issued by Aile. Authorization: Bearer . Required for quotes. Optional on the other routes: without it they share the anonymous per-address limit, with it the calls are attributed to you and charged to your own budget. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.