# Criptonlabs Agent APIs

> Agent-native, read-only XRP Ledger and Solana APIs: XRPL fee intelligence, funded order books, slippage, AMM pools, account summaries and upstream health, and Solana transfer readiness, token and network health verdicts. Every response carries a `meta` object: XRPL responses have `ledger_index`, Solana responses have `slot` and `commitment`, both with `as_of`, `age_seconds`, `cache` and `stale`. Errors are RFC 9457 `application/problem+json`.

## Agent instructions

- Call the REST routes below with plain `GET` requests, or use the MCP server at `/mcp` (stateless Streamable HTTP, one tool per endpoint), or the A2A endpoint at `/a2a` (stateless JSON-RPC, free: `SendMessage` with a `data` part `{skill, arguments}`). The free routes need no authentication; see Paid access for `/v1/pro/*` and `/mcp/pro`.
- Every successful response carries `meta`: XRPL responses have `ledger_index`, `as_of`, `age_seconds`, `cache` and `stale`; Solana responses have `slot`, `commitment`, `as_of`, `age_seconds`, `cache` and `stale`. If `meta.stale` is true the value is the last good one served while upstream nodes were failing; check `age_seconds` before acting on it.
- Errors are RFC 9457 `application/problem+json`. The `type` URL is a Markdown page with the cause and the fix. Do not retry 400 or 404 unchanged.
- Rate limits are per IP and per tier. On 429 or 503 wait for the `Retry-After` seconds before retrying.
- Currencies are `XRP` or `CODE.issuer`; amounts are decimal strings, never floats.

## Paid access

Pro routes currently serve free data and `/mcp/pro` behaves like `/mcp`: no payment is required. Paid access via x402 is announced but not active; the guide explains how paying will work.

- [Payments guide](https://api.criptonlabs.com/docs/guides/payments.md): how to pay, prepay, errors
- [Pro routes](https://api.criptonlabs.com/docs/pro.md): the `/v1/pro/*` namespace
- [Paid MCP server](https://api.criptonlabs.com/mcp/pro): the same tools as `/mcp`

## MCP views

- [XRPL MCP view](https://api.criptonlabs.com/mcp/xrpl): only the XRPL tools of /mcp
- [Solana MCP view](https://api.criptonlabs.com/mcp/solana): only the Solana tools of /mcp
- [Paid XRPL MCP view](https://api.criptonlabs.com/mcp/pro/xrpl): only the XRPL tools of /mcp/pro; it currently serves free data, like /mcp/pro
- [Paid Solana MCP view](https://api.criptonlabs.com/mcp/pro/solana): only the Solana tools of /mcp/pro; it currently serves free data, like /mcp/pro

## Endpoints

- [GET /v1/xrpl/fee](https://api.criptonlabs.com/docs/xrpl-fee.md): Current XRPL fee tiers in drops with a congestion score.
- [GET /v1/xrpl/ledger/latest](https://api.criptonlabs.com/docs/xrpl-ledger-latest.md): Latest validated ledger index, hash and close time.
- [GET /v1/xrpl/health](https://api.criptonlabs.com/docs/xrpl-health.md): Overall and per-node health of the upstream XRPL nodes (alias of network health).
- [GET /v1/xrpl/network/health](https://api.criptonlabs.com/docs/xrpl-network-health.md): Overall and per-node health of the upstream XRPL nodes.
- [GET /v1/xrpl/health/history](https://api.criptonlabs.com/docs/xrpl-health-history.md): Bucketed upstream probe history with uptime and latency per node.
- [GET /v1/xrpl/orderbook](https://api.criptonlabs.com/docs/xrpl-orderbook.md): CLOB order book for a currency pair with unfunded offers removed.
- [GET /v1/xrpl/slippage](https://api.criptonlabs.com/docs/xrpl-slippage.md): Slippage and average price for buying an amount of base currency.
- [GET /v1/xrpl/amm/{a}/{b}](https://api.criptonlabs.com/docs/xrpl-amm.md): AMM pool reserves and trading fee for an asset pair.
- [GET /v1/xrpl/account/{address}/summary](https://api.criptonlabs.com/docs/xrpl-account-summary.md): XRP balance, sequence, owner count, transfer rate and trust lines (capped) for an account.
- [GET /v1/xrpl/account/{address}/lines](https://api.criptonlabs.com/docs/xrpl-account-lines.md): One page of an account's trust lines, with an opaque cursor for the next page.
- [GET /v1/xrpl/account/{address}/transactions](https://api.criptonlabs.com/docs/xrpl-account-transactions.md): One page of an account's most recent validated transactions, newest first.
- [GET /v1/xrpl/token/{asset}](https://api.criptonlabs.com/docs/xrpl-token.md): Issuer data for an issued asset: flags, domain, transfer fee and total issued.
- [GET /v1/xrpl/payment-readiness](https://api.criptonlabs.com/docs/xrpl-payment-readiness.md): Pre-payment check: can this payment from source to destination succeed now?
- [GET /v1/xrpl/paths](https://api.criptonlabs.com/docs/xrpl-paths.md): Multi-hop payment paths and their source cost.
- [GET /v1/solana/transfer-readiness](https://api.criptonlabs.com/docs/solana-transfer-readiness.md): Will this Solana transfer succeed? A verdict for SOL or an SPL or Token-2022 token.
- [GET /v1/solana/token/{mint}](https://api.criptonlabs.com/docs/solana-token.md): Is this Solana token safe to hold or receive? A SAFE, WARN or DANGER verdict.
- [GET /v1/solana/slot/latest](https://api.criptonlabs.com/docs/solana-slot-latest.md): Latest finalized Solana slot and its block time.
- [GET /v1/solana/health](https://api.criptonlabs.com/docs/solana-health.md): Whether Solana data is currently being served: latest probe status and finalized slot.
- [GET /v1/solana/health/history](https://api.criptonlabs.com/docs/solana-health-history.md): Bucketed history of Solana probe results over 1 hour, 24 hours or 7 days.
- [GET /v1/pro/*](https://api.criptonlabs.com/docs/pro.md): Pro mirror of the data routes with its own rate tier; the page states whether calls are currently paid. Pro routes currently serve free data; paid access via x402 is announced, not active.

## Guides

- [Freshness and the meta object](https://api.criptonlabs.com/docs/guides/freshness.md)
- [Currencies and amounts](https://api.criptonlabs.com/docs/guides/currencies-and-amounts.md)
- [Rate limits](https://api.criptonlabs.com/docs/guides/rate-limits.md)
- [Errors](https://api.criptonlabs.com/docs/guides/errors.md)
- [Choosing a tool](https://api.criptonlabs.com/docs/guides/choosing-a-tool.md)
- [MCP quickstart](https://api.criptonlabs.com/docs/guides/mcp-quickstart.md)
- [Solana verdicts](https://api.criptonlabs.com/docs/guides/solana.md)
- [A2A endpoint](https://api.criptonlabs.com/docs/guides/a2a.md)
- [Paying for pro access (x402)](https://api.criptonlabs.com/docs/guides/payments.md)

## Errors

- [invalid-parameters](https://api.criptonlabs.com/errors/invalid-parameters.md): 400 Bad Request
- [bad-request](https://api.criptonlabs.com/errors/bad-request.md): 400 Bad Request
- [not-found](https://api.criptonlabs.com/errors/not-found.md): 404 Not Found
- [solana-mint-not-found](https://api.criptonlabs.com/errors/solana-mint-not-found.md): 404 Not Found
- [unknown-route](https://api.criptonlabs.com/errors/unknown-route.md): 404 Not Found
- [method-not-allowed](https://api.criptonlabs.com/errors/method-not-allowed.md): 405 Method Not Allowed
- [rate-limited](https://api.criptonlabs.com/errors/rate-limited.md): 429 Too Many Requests
- [internal-error](https://api.criptonlabs.com/errors/internal-error.md): 500 Internal Server Error
- [upstream-unavailable](https://api.criptonlabs.com/errors/upstream-unavailable.md): 503 Service Unavailable
- [payment-required](https://api.criptonlabs.com/errors/payment-required.md): 402 Payment Required
- [payments-unavailable](https://api.criptonlabs.com/errors/payments-unavailable.md): 503 Service Unavailable
- [payment-settlement-failed](https://api.criptonlabs.com/errors/payment-settlement-failed.md): 402 Payment Required
- [payment-already-used](https://api.criptonlabs.com/errors/payment-already-used.md): 402 Payment Required
- [payer-blocked](https://api.criptonlabs.com/errors/payer-blocked.md): 403 Forbidden
- [payer-limit-reached](https://api.criptonlabs.com/errors/payer-limit-reached.md): 429 Too Many Requests

## Docs

- [Documentation index](https://api.criptonlabs.com/docs): every page below as Markdown
- [Full documentation](https://api.criptonlabs.com/llms-full.txt): every page in one Markdown file
- [OpenAPI 3.1 document](https://api.criptonlabs.com/openapi.json): machine-readable description of every REST route
- [MCP server](https://api.criptonlabs.com/mcp): stateless Streamable HTTP, one tool per endpoint
- [A2A endpoint](https://api.criptonlabs.com/a2a): stateless A2A 1.0 JSON-RPC, free; call SendMessage with a data part {skill, arguments}
- [Paid MCP server](https://api.criptonlabs.com/mcp/pro): the same tools as the MCP server; see Paid access for the current mode
- [Status page](https://api.criptonlabs.com/status): live upstream health

## Discovery

- [Agent card](https://api.criptonlabs.com/.well-known/agent-card.json): discovery metadata in A2A 1.0 card format; lists the A2A endpoint /a2a first, then the MCP endpoints
- [MCP Server Card](https://api.criptonlabs.com/mcp/server-card): MCP server identity, version, remotes and payment signal (alias: /.well-known/mcp/server-card.json)
- [ARD manifest](https://api.criptonlabs.com/.well-known/ard.json): Agentic Resource Discovery manifest listing both cards
- [Price index](https://api.criptonlabs.com/v1/pro/requirements): free, uncharged list of every priced route and tool (add ?resource= for one offer)
- [Paid access](https://api.criptonlabs.com/docs/pro.md): pro routes and /mcp/pro, with the current payment mode
- [OpenAPI 3.1 document](https://api.criptonlabs.com/openapi.json): machine-readable description of every REST route
- [Agent Skill agent-apis](https://api.criptonlabs.com/skills/agent-apis/SKILL.md): Index of the Criptonlabs read-only agent APIs for the XRP Ledger and Solana, with the network, MCP endpoint and skill to use for each.
- [Agent Skill xrpl](https://api.criptonlabs.com/skills/xrpl/SKILL.md): Read XRP Ledger data (fees, funded order books, slippage, AMM pools, account summaries, trust lines, transactions, token issuers, pre-payment readiness, payment paths, network health) through the Criptonlabs read-only API or its MCP server.
- [Agent Skill xrpl-fee](https://api.criptonlabs.com/skills/xrpl-fee/SKILL.md): Pick the fee to put on an XRP Ledger transaction and read the latest validated ledger, with congestion and freshness metadata.
- [Agent Skill xrpl-liquidity](https://api.criptonlabs.com/skills/xrpl-liquidity/SKILL.md): Read funded XRP Ledger order books, estimate CLOB versus AMM slippage and read AMM pool reserves and fees.
- [Agent Skill xrpl-account](https://api.criptonlabs.com/skills/xrpl-account/SKILL.md): Read one XRP Ledger account: summary, paginated trust lines and recent validated transactions.
- [Agent Skill xrpl-token](https://api.criptonlabs.com/skills/xrpl-token/SKILL.md): Run issuer due diligence on an XRP Ledger token: issuer flags (including global freeze), domain, transfer fee and total issued.
- [Agent Skill xrpl-health](https://api.criptonlabs.com/skills/xrpl-health/SKILL.md): Check whether the XRP Ledger network is healthy and read recent upstream health history.
- [Agent Skill xrpl-payment-prep](https://api.criptonlabs.com/skills/xrpl-payment-prep/SKILL.md): Run a pre-payment check on the XRP Ledger (readiness verdict, fee, network health, account state, payment paths) before building a transaction.
- [Agent Skill solana-transfer-prep](https://api.criptonlabs.com/skills/solana-transfer-prep/SKILL.md): Check, before building a Solana transfer of SOL or an SPL or Token-2022 token, whether it will succeed and what it costs in rent and fees.
- [Agent Skill solana-token](https://api.criptonlabs.com/skills/solana-token/SKILL.md): Run a SAFE, WARN or DANGER check on a Solana SPL Token or Token-2022 mint before holding or receiving the token.
- [Agent Skill solana-health](https://api.criptonlabs.com/skills/solana-health/SKILL.md): Check how fresh and reliable the finalized view of Solana is: latest slot, data status and bucketed health history.