> ## Documentation Index > Fetch the complete documentation index at: https://docs.hex-api.app/llms.txt > Use this file to discover all available pages before exploring further. # Every bridge's health over 24 hours > The HOT bridge's deposits and withdrawals by chain over a 24-hour window, both kit's direct transfers and 1Click's legs over the HOT bridge (referral `intents.tg`): what finished and how long it took (p50, p90), what is in flight, stuck, in the old backlog or refund-only, what failed, an hourly trend, and the stuck and failed transfers themselves. Feeds HEX's `/bridges` page. What is in flight is split by what it needs (`triage`): the live flow (in flight for less than the window; `stuck` past `stuck_after_s`), the **backlog** (in flight longer than the window, still payable) and **refund**-only withdrawals that no payout can land (to the token contract, to the zero address, Stellar nonces past 60 days). A chain's `health` is the live flow's. A chain with `error_kind: "read"` has its withdrawals in flight unknown, not zero. Without the database it answers an empty picture. ## OpenAPI ````yaml https://mpc.hex-api.app/openapi.json get /bridge/monitor openapi: 3.1.0 info: title: HEX MPC API version: 1.0.0 summary: HOT bridge signatures and relay, the bridge registry and monitor. description: > The public API of `hex-mpc`, a Cloudflare Worker in front of the HOT MPC nodes. It replaces the old HOT backend's bridge endpoints (`api0.herewallet.app`: `process_bridge_deposit`, `auto_deposit_register`, ...) and HOR (`rpc1.hotdao.ai`, `rpc2.hotdao.ai`). ## Which routes to use - **Credit a deposit to NEAR Intents**: `POST /relay/deposit` with the source tx (or the deposit's fields). The service reads the deposit on its chain, signs it and sends `mt_deposit_call` on NEAR, paying the gas. This is what `process_bridge_deposit` did. - **Pay out withdrawals**: `POST /relay/withdraw` with the chain and the receiver; poll `GET /relay/jobs/{chain}/{id}`. - **Clear a paid withdrawal**: `POST /relay/clear`. - **Submit transactions yourself**: the `Signatures` routes return the MPC signatures only. - **Record what your users do** (optional, for support and recovery): `POST /bridge/register`, `/bridge/deposits`, `/bridge/withdrawals`. Every relay call sends only what holds on chain (a deposit that happened, the payout of a withdrawal omni holds, the clear of a paid one), and each at most once, so retrying a call is safe. ## Conventions - **Bodies** are JSON objects, at most 32 KiB (`/intents/solver`: 128 KiB). A body that is not a JSON object is a `422`, a larger one a `413`. - **Big integers.** Nonces and amounts are answered as decimal strings. In requests they may be decimal strings or JSON integers: integers above 2^53 are read exactly (the bridge's nonces are about 1.8e21), but a decimal string is the safer choice for clients whose JSON encoder uses doubles. - **Nonces** are omni's: `unix seconds * 10^12 + n`. - **Encodings.** omni's token ids, receivers and the bridge signatures are base58; NEAR tx hashes are base58. - **Chain ids.** Chain ids are omni's (`v2_1.omni.hot.tg`), not always the chain's own: EVM chains use their EIP-155 id (Ethereum 1, Optimism 10, BNB 56, Polygon 137, Monad 143, X Layer 196, Base 8453, Arbitrum 42161, Avalanche 43114, ...); the others have omni's numbers: Solana 1001, NEAR 1010, Stellar 1100, TON 1117 (TON v1, 1111, is dead), Juno 4444118, Gonka 4444119. - **Errors** are `{ "detail": "..." }` with an HTTP status (FastAPI's format, kept from HOR), the router's own `404`, `405` and `429` included. Clients should branch on the status and show or log the `detail`. A `5xx` (and a `502`/`503` in particular) is worth retrying with backoff; a `4xx` will answer the same until something changes on chain. - **CORS.** Any origin; the request's `Origin` is echoed with `access-control-allow-credentials: true`, and preflights allow `GET, POST, OPTIONS` with any header. - **Times** in answers are milliseconds since the epoch unless named `*_s` (seconds). ## Rate limits Per client IP (an IPv6 client by its /64), over 60 seconds, counted per Cloudflare location: | Class | Limit | Routes | | --- | --- | --- | | `bridge` | 300 / 60 s | `/withdraw/sign`, `/deposit/sign`, `/clear/sign`, `/relay/*`, `/bridge/*` | | `solver` | 120 / 60 s | `/intents/solver` | `/v1/health`, `/v1/time` and `/openapi.json` are not limited. Over the limit the answer is `429` `{ "detail": "Too many requests" }` with `Retry-After: 60`. ## Load protection The MPC nodes are a fixed quorum: every signature is a round on each of them. So on top of the per-IP limits, every call that reaches the nodes (the `Signatures` routes, and the relay's own signing) is admitted globally, whoever asks: - **Rate per kind of signing**, by default 300 a minute each for withdrawals, deposits and clears: over it, `429` with `Retry-After`. - **Signings at once**, 60 in all, each kind its own share: over it, `503` `MPC nodes are busy, try again shortly` with `Retry-After`. Also `503` with `Retry-After` when the nodes answer `429` or too few of them are up. - **One signing per message.** A signature is kept for a day and answered again (a retry, another client, the relay), and while it is being made a second request waits for it (or gets `503` `This signature is being made, try again shortly` after 45 s). A refusal of the bridge (`400`) is answered again for 5 seconds. - **Refusals before the nodes**: a deposit omni already credited (`400` `Deposit … is already credited`), a withdrawal no payout can land (`400` `Withdrawal … : it can only be refunded`: it pays the token contract itself, the zero address, or a Stellar nonce past its 60 days). Retry a `429` or `503` after its `Retry-After`. servers: - url: https://mpc.hex-api.app description: Production security: [] tags: - name: Relay description: >- The recommended integration: the service sends the bridge's transactions and pays for them. Deposits are credited to NEAR Intents; withdrawals are paid out on their chain and cleared on omni. - name: Signatures description: >- The bridge's MPC signatures, for callers that submit the transactions themselves (HOR-compatible: same bodies, answers and errors). Each signature needs omni's word, and a deposit or clear also its AuthCall on chain, so a caller cannot forge or redirect one. - name: Registry description: >- The bridge registry: what users do on the bridge, as clients report it and as the relay sees it on chain. A post only records a claim: nothing is signed or sent for it, and what the relay reads on chain overrides it. Lookups answer 503 while the registry's database is not configured. - name: Monitor description: Health of every bridge HEX moves funds through, over 24 hours. - name: Intents description: >- NEAR Intents solver relay passthrough, used by HEX/HOT kit to publish signed intents. - name: Service description: Health, time and this document. paths: /bridge/monitor: get: tags: - Monitor summary: Every bridge's health over 24 hours description: >- The HOT bridge's deposits and withdrawals by chain over a 24-hour window, both kit's direct transfers and 1Click's legs over the HOT bridge (referral `intents.tg`): what finished and how long it took (p50, p90), what is in flight, stuck, in the old backlog or refund-only, what failed, an hourly trend, and the stuck and failed transfers themselves. Feeds HEX's `/bridges` page. What is in flight is split by what it needs (`triage`): the live flow (in flight for less than the window; `stuck` past `stuck_after_s`), the **backlog** (in flight longer than the window, still payable) and **refund**-only withdrawals that no payout can land (to the token contract, to the zero address, Stellar nonces past 60 days). A chain's `health` is the live flow's. A chain with `error_kind: "read"` has its withdrawals in flight unknown, not zero. Without the database it answers an empty picture. operationId: getBridgeMonitor responses: '200': description: The monitor. content: application/json: schema: $ref: '#/components/schemas/MonitorResponse' examples: example: summary: One chain value: now: 1792944180000 window_s: 86400 stuck_after_s: deposit: 900 withdrawal: 600 backlog_after_s: 86400 sources: hot_sweep: 1792944150000 oneclick: 1792944160000 oneclick_enabled: true totals: deposit: done: 42 oneclick: 30 usd: 18250.4 pending: 1 stuck: 0 backlog: 0 refund: 0 failed: 0 p50_s: 95 p90_s: 240 samples: 38 oldest_s: 60 withdrawal: done: 17 oneclick: 9 usd: 6100 pending: 2 stuck: 1 backlog: 0 refund: 0 failed: 0 p50_s: 120 p90_s: 600 samples: 15 oldest_s: 900 chains: - chain: '1100' name: Stellar deposit: done: 42 oneclick: 30 usd: 18250.4 pending: 1 stuck: 0 backlog: 0 refund: 0 failed: 0 p50_s: 95 p90_s: 240 samples: 38 oldest_s: 60 withdrawal: done: 17 oneclick: 9 usd: 6100 pending: 2 stuck: 1 backlog: 0 refund: 0 failed: 0 p50_s: 120 p90_s: 600 samples: 15 oldest_s: 900 health: slow items: - source: hot direction: withdrawal chain: '1100' id: '1792944123000000004211' state: pending triage: stuck status: running created_at: 1792943280000 age_s: 900 amount: 2.5 USDC receiver: >- GDJ4JZXZELZD737NVFORH4PSSQDWFDZTKW3AIDKHYQG23ZXBPDGGQBJK txs: - kind: near hash: 2rQmS4n4TxT7GJ26XLDDZEHEmsizLb1ezGC81zr8dpkR url: >- https://nearblocks.io/txns/2rQmS4n4TxT7GJ26XLDDZEHEmsizLb1ezGC81zr8dpkR detail: >- payment of 1792944123000000004211 is not at latest - 1 yet series: - t: 1792940580000 deposit: done: 3 oneclick: 2 failed: 0 p50_s: 90 usd: 1200 withdrawal: done: 1 oneclick: 0 failed: 0 p50_s: 130 usd: null '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/InternalError' components: schemas: MonitorResponse: type: object required: - now - window_s - stuck_after_s - backlog_after_s - sources - totals - chains - items - series properties: now: type: integer description: When this answer was built, ms. window_s: type: integer description: The statistics' window (24 h), s. stuck_after_s: type: object required: - deposit - withdrawal properties: deposit: type: integer withdrawal: type: integer description: In flight longer than this is stuck, s. backlog_after_s: type: integer description: In flight longer than this is backlog, s. sources: type: object required: - hot_sweep - oneclick - oneclick_enabled description: When each source was last read (ms; null when never). properties: hot_sweep: type: - integer - 'null' oneclick: type: - integer - 'null' oneclick_enabled: type: boolean totals: type: object required: - deposit - withdrawal properties: deposit: $ref: '#/components/schemas/FlowStats' withdrawal: $ref: '#/components/schemas/FlowStats' chains: type: array items: $ref: '#/components/schemas/MonitorChain' items: type: array items: $ref: '#/components/schemas/MonitorItem' description: >- Stuck, failed, refund and backlog transfers in that order, oldest first, at most 100 of each. series: type: array items: $ref: '#/components/schemas/MonitorBucket' description: The window by the hour, oldest first. FlowStats: type: object description: A chain's deposits or withdrawals over the window. required: - done - oneclick - refuel - usd - pending - stuck - backlog - refund - failed - p50_s - p90_s - samples - oldest_s properties: done: type: integer description: Finished in the window. oneclick: type: integer description: Of them, 1Click's deposit legs. refuel: type: integer description: >- Of them, bridge-refuel's withdrawals of HOT wallet users (as the refuel sweep saw omni let them go); the rest are kit's direct ones. usd: type: - number - 'null' description: USD moved, where priced (1Click's legs); null with none priced. pending: type: integer description: In flight for less than the window (the live flow). stuck: type: integer description: Of them, past `stuck_after_s`. backlog: type: integer description: In flight longer than the window, still payable. refund: type: integer description: 'In flight and never payable: refund only.' failed: type: integer description: Refunded or failed in the window. p50_s: type: - number - 'null' description: Median duration of the finished ones, s. p90_s: type: - number - 'null' description: 90th percentile, s. samples: type: integer description: How many durations the percentiles stand on. oldest_s: type: - number - 'null' description: The oldest live in-flight one's age, s. MonitorChain: type: object required: - chain - name - deposit - withdrawal - health properties: chain: type: string description: omni's chain id. examples: - '1100' name: type: string examples: - Stellar deposit: $ref: '#/components/schemas/FlowStats' withdrawal: $ref: '#/components/schemas/FlowStats' health: type: string enum: - ok - slow - down description: >- The live flow's: `slow` when something is stuck, `down` when stuck and nothing of that way finished in the window. error: type: string description: Why the chain is not read, or what went wrong on it. error_kind: type: string enum: - read - relay description: >- `read`: its pending withdrawals could not be read (unknown, not zero). `relay`: read, but the relay could not act on them. MonitorItem: type: object description: >- A transfer in flight past its stuck threshold, in the backlog, refund-only, or failed in the window. required: - source - direction - chain - id - state - status - created_at - age_s properties: source: type: string enum: - hot - oneclick description: Seen by the relay (omni, the registry), or in 1Click Explorer. direction: type: string enum: - deposit - withdrawal chain: type: string description: omni's chain id. id: type: string description: >- omni's nonce (a withdrawal), the source tx (a direct deposit), or 1Click's deposit address (and memo) and leg. state: type: string enum: - pending - incomplete - refunded - failed description: '`incomplete`: 1Click got less than quoted.' triage: type: string enum: - stuck - failed - backlog - refund description: What it needs. reason: type: string description: 'Why it can only be refunded (`triage: refund`).' status: type: string description: >- 1Click's status, or the registry's / the relay's (`registered`, `queued`, `active`, `cooldown`, ...). created_at: type: integer description: ms. age_s: type: number amount: type: string description: Readable (`12.5 BNB`), or the raw amount and token id. amount_usd: type: number receiver: type: string description: >- The target chain's receiver (withdrawal) or the intents account (deposit). txs: type: array items: $ref: '#/components/schemas/MonitorTx' detail: type: string description: The relay's or 1Click's last word on it. MonitorBucket: type: object description: 'One hour of the window: what finished in it.' required: - t - deposit - withdrawal properties: t: type: integer description: The hour's start, ms. deposit: $ref: '#/components/schemas/BucketFlow' withdrawal: $ref: '#/components/schemas/BucketFlow' Error: type: object description: 'Every error: FastAPI''s `{ detail }` with the HTTP status.' required: - detail properties: detail: type: string description: What went wrong, readable. examples: - detail: Nonce was not used on target chain MonitorTx: type: object required: - kind - hash properties: kind: type: string enum: - source - near - target hash: type: string url: type: string format: uri BucketFlow: type: object required: - done - oneclick - refuel - failed - p50_s - usd properties: done: type: integer oneclick: type: integer refuel: type: integer failed: type: integer p50_s: type: - number - 'null' usd: type: - number - 'null' responses: TooManyRequests: description: >- Over the route's per-IP rate limit (60 s), or, on a route that signs, over the MPC nodes' signing rate (see Load protection). Wait `Retry-After` seconds. headers: Retry-After: $ref: '#/components/headers/RetryAfter' content: application/json: schema: $ref: '#/components/schemas/Error' examples: limited: value: detail: Too many requests signing: value: detail: Too many bridge_deposit signings, try again in 1 s InternalError: description: An unexpected error. Its message is not exposed. content: application/json: schema: $ref: '#/components/schemas/Error' examples: internal: value: detail: Internal Server Error headers: RetryAfter: description: Seconds to wait. schema: type: integer example: 60 ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.