> ## Documentation Index > Fetch the complete documentation index at: https://docs.lumeus.dev/llms.txt > Use this file to discover all available pages before exploring further. # Check RPC readiness > Returns `{"ready":true}` when RPC is current with the network tip, else 503 with `{"ready":false}` and Retry-After 5. No authentication. The answer is cached for five seconds. It is not an uptime guarantee. ## OpenAPI ````yaml /api-reference/rpc.json get /readyz openapi: 3.0.3 info: title: Lumeus RPC version: '2026-09-15' description: >- Lumeus RPC: Stellar JSON-RPC 2.0 over `POST /`, with Lumeus keys, metering and limits. Sign up at https://app.lumeus.dev: Free, Starter, Growth and Scale plans are self-serve, Enterprise by agreement. - **Pricing.** Testnet is free: Testnet requests cost no credits and are never billed. Each organization can make 10,000 Testnet requests a day across Activity, Assets and RPC (unlimited on Enterprise); the count resets at 00:00 UTC, and a request over it answers 429 rate_limited with Retry-After set to the seconds until then. Mainnet requests draw from the plan's monthly credits. A Mainnet call costs its method credits plus one credit per started 64 KiB of response. Each call of a batch counts as one request, and a batch that would cross the daily Testnet cap is refused whole. Plans, limits and credit weights: `GET https://api.lumeus.dev/v1/plans`. - **Authentication.** Send `Authorization: Bearer `. Testnet: `lum_test_…`; Mainnet: `lum_live_…`. A key works only on its own network, so pick the server that matches it (the other network answers 401). Publishable `lum_pub_…` keys call read-only methods only, from an allowed browser origin. Dashboard sessions and webhook keys are not accepted. - **Headers.** Every response carries X-Request-Id; authenticated responses carry RateLimit-Limit, RateLimit-Remaining and RateLimit-Reset; 429 and 503 carry Retry-After. - **Errors.** JSON-RPC 2.0 error objects. Gateway errors carry the machine-readable code as the string error.data and the request ID as error.request_id (see [errors](/guides/errors)). A JSON-RPC error can arrive with HTTP 200, from the node or for one call of a batch, so check error before reading result. The REST routes (`/operations/...`, `/healthz`, `/readyz`) answer flat JSON errors. - **CORS.** Browser calls (CORS) are allowed from https://docs.lumeus.dev (the Try it playground of this reference) and https://app.lumeus.dev only, without cookies; responses expose ETag, Link, Location, Retry-After, X-Request-Id, X-Lumeus-Operation-Id, X-Lumeus-Idempotency and RateLimit-Limit, RateLimit-Remaining and RateLimit-Reset (errors included). Other websites cannot read responses made with a server key: use a publishable key with your own allowed origins ([browser keys](/guides/browser-keys)). license: name: Lumeus API contract servers: - url: https://rpc-testnet.lumeus.dev description: Testnet (default) - url: https://rpc.lumeus.dev description: Mainnet security: - Bearer: [] tags: - name: JSON-RPC description: >- Stellar JSON-RPC 2.0 over `POST /`: one call or a batch of up to 20. Each method has its own page with parameters, result fields and a real response. - name: Results description: >- Recover the saved result of a long prepaid call without running it again. Only prepaid accounts receive operation IDs; every other account gets 404 here. - name: Health description: Liveness and readiness probes for monitoring. No authentication. paths: /readyz: get: tags: - Health summary: Check RPC readiness description: >- Returns `{"ready":true}` when RPC is current with the network tip, else 503 with `{"ready":false}` and Retry-After 5. No authentication. The answer is cached for five seconds. It is not an uptime guarantee. operationId: checkRpcReadiness responses: '200': description: 'Ready: the data is current.' content: application/json: schema: $ref: '#/components/schemas/Readiness' example: ready: true headers: X-Request-Id: description: >- Identifier of this request: req_ followed by 24 hex characters. Error bodies repeat it as request_id. Quote it when contacting support. schema: type: string pattern: ^req_[0-9a-f]{24}$ '503': $ref: '#/components/responses/HTTP503_5' security: [] x-codeSamples: - lang: bash label: cURL source: curl --fail-with-body -sS 'https://rpc-testnet.lumeus.dev/readyz' - lang: javascript label: JavaScript source: |- // Node 18+ (ES module) const res = await fetch('https://rpc-testnet.lumeus.dev/readyz', { method: 'GET', }); console.log(res.status, JSON.stringify(await res.json(), null, 2)); - lang: python label: Python source: |- import json import requests res = requests.get( "https://rpc-testnet.lumeus.dev/readyz", timeout=30, ) print(res.status_code, json.dumps(res.json(), indent=2)) components: schemas: Readiness: type: object properties: ready: type: boolean required: - ready responses: HTTP503_5: description: Not ready, or catching up with the network. content: application/json: schema: $ref: '#/components/schemas/Readiness' example: ready: false headers: X-Request-Id: description: >- Identifier of this request: req_ followed by 24 hex characters. Error bodies repeat it as request_id. Quote it when contacting support. schema: type: string pattern: ^req_[0-9a-f]{24}$ Retry-After: description: Seconds to wait before retrying. schema: type: integer securitySchemes: Bearer: type: http scheme: bearer description: >- Send `Authorization: Bearer `. Testnet: `lum_test_…`; Mainnet: `lum_live_…`. A key works only on its own network, so pick the server that matches it (the other network answers 401). Publishable `lum_pub_…` keys call read-only methods only, from an allowed browser origin. Dashboard sessions and webhook keys are not accepted. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.