> ## Documentation Index
> Fetch the complete documentation index at: https://docs.miraiminds.co/llms.txt
> Use this file to discover all available pages before exploring further.
# Errors
> One error envelope, every status code and error code, and what to do about each.
Every v2 error — validation, auth, billing, rate limiting — uses one envelope.
There is no second shape to special-case.
```json theme={null}
{
"error": {
"code": "invalid_request",
"message": "to must be an E.164 phone number, got '9876543210'"
}
}
```
| Field | Description |
| :-------- | :------------------------------------------------------------------------------------------------------------------------- |
| `code` | Stable, `snake_case`, machine-readable. **Branch on this.** |
| `message` | Human-readable, written for a developer reading a log. Not stable — never parse it, never show it to an end user verbatim. |
## Status codes
| Status | Meaning | Retry? |
| :----- | :--------------------------------------------------------------------------------------------------------------------- | :----------------------------------------------------------------------------------------------- |
| `400` | The request is malformed or a field is invalid. | No — fix the request. |
| `401` | Missing, malformed or unknown key. | No. |
| `402` | Wallet cannot cover the call. | After topping up. |
| `403` | The key is valid but **revoked**. That is the only thing that returns `403`. | No. |
| `404` | No such resource in your workspace — including one that exists in someone else's. | No. |
| `409` | State conflict — a request with the same `Idempotency-Key` still in flight, or an operation the current state forbids. | No. |
| `429` | Request-rate limit. Concurrency does not `429`. | Yes, with backoff. |
| `500` | Our fault. | Yes, with backoff. |
| `501` | The feature exists in the contract but is not live yet. | No. |
| `503` | Temporarily unavailable (deploy, capacity) — or a feature that is not provisioned for your workspace. | Yes for `fleet_offline`; no for `campaigns_unavailable`, which needs provisioning, not patience. |
## Error codes
| `error.code` | Status | When | Fix |
| :---------------------- | :----- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------- |
| `invalid_request` | `400` | Missing required field, wrong type, `to` not E.164, `max_duration_secs` out of range, unknown `voice_id`, malformed JSON. | Read `message`; it names the field. |
| `unauthorized` | `401` | No `Authorization` header, not `Bearer `-prefixed, or the key is unknown. | Check the header. A trailing newline from `cat`-ing a key file is the usual culprit. |
| `forbidden` | `403` | The key was revoked. Nothing else returns `403`. | Get a new key. |
| `insufficient_balance` | `402` | Pre-dial wallet gate. No call was placed and nothing was charged. The same condition inside a running [campaign](/v2/campaigns) is not an error — the campaign pauses with `pause_reason: "insufficient_balance"`. | [Top up](/v2/wallet#top-up) and retry with the same `Idempotency-Key`. |
| `not_found` | `404` | Unknown `agt_`/`call_`/`cmp_` ID, a soft-deleted agent, a number not on the [do-not-call list](/v2/dnc), a transcript or recording that does not exist, or an ID that belongs to another workspace. | Check the ID. For artifacts, check `transcript_available` / `recording_available` on the call. |
| `duplicate_call` | `409` | A request with this `Idempotency-Key` is still being processed; when the original completes, the same key replays its stored response. | Not an error if you are retrying — no second call was placed. |
| `conflict` | `409` | The operation is illegal in the current state: aborting a call that has already ended, editing or starting a campaign that is `play`, adding contacts to one that is `stopped`/`completed`, or resuming one with no running dialler. | Read the resource's `status` first. A paused campaign with no dialler is resumed with [`POST /start`](/v2/campaigns#start-a-campaign). |
| `rate_limited` | `429` | Request rate exceeded, **or** your queue is full (500 calls accepted and not yet ended). Being at your *concurrency* ceiling does **not** produce this: those calls queue. `error.message` says which limit you hit. | Honour `Retry-After` and back off. See [Limits](/v2/limits). |
| `at_capacity` | `429` | Every line on the deployment is busy — a fleet-wide ceiling, not your workspace's. Nothing was charged. | Honour `Retry-After` (30s) and retry. |
| `tier_unavailable` | `501` | `tier` was `t5`. It is announced but not live. | Use `t3` (the default) or `t1`. See [tiers](/general/tiers). |
| `campaigns_unavailable` | `503` | Campaigns are not enabled for your workspace. Every `/v2/campaigns` and `/v2/dnc` route answers this; everything else keeps working. | Not a mistake in your request, and retrying will not clear it — ask your Mirai contact to enable them. |
| `fleet_offline` | `503` | Speech capacity is offline, so a [campaign start](/v2/campaigns#start-a-campaign) was refused. Nothing was charged and the campaign stayed where it was. | Honour `Retry-After` (300s) and start it again. |
| `internal` | `500` | Our bug. Already alarming on our side. | Retry with backoff; if it persists, send us the `call_id`. |
`error.code` is an **open enum**. New codes are added without a version bump.
Always have a default branch keyed on the HTTP status.
**Foreign IDs are `404`, never `403`**
An `agt_`, `call_` or `cmp_` ID that exists in another workspace is answered exactly as
an ID that never existed: `404 not_found`. Anything else would be an enumeration
oracle — a way to probe which IDs are real on the platform by watching the
status code change. `403` is reserved for one situation only: your own key has
been revoked.
## Handling errors
The pattern that covers everything: branch on status, then on code.
```python theme={null}
import random
import time
import httpx
class MiraiError(Exception):
def __init__(self, status: int, code: str, message: str):
super().__init__(f"{status} {code}: {message}")
self.status, self.code, self.message = status, code, message
RETRYABLE = {429, 500, 502, 503, 504}
def request(client: httpx.Client, method: str, path: str, **kw) -> dict:
for attempt in range(5):
r = client.request(method, path, **kw)
if r.is_success:
return r.json() if r.content else {}
body = r.json() if r.headers.get("content-type", "").startswith("application/json") else {}
err = body.get("error", {})
if r.status_code in RETRYABLE and attempt < 4:
# honour Retry-After when we send it, else exponential + jitter
wait = float(r.headers.get("Retry-After", 2**attempt))
time.sleep(wait + random.random())
continue
raise MiraiError(r.status_code, err.get("code", "unknown"), err.get("message", r.text))
raise MiraiError(r.status_code, "retries_exhausted", "gave up after 5 attempts")
```
At the call site, only two codes deserve their own branch:
```python theme={null}
try:
call = request(client, "POST", "/v2/calls", json=payload,
headers={"Idempotency-Key": key})
except MiraiError as e:
if e.code == "insufficient_balance":
pause_campaign(); alert_ops(e.message)
elif e.code == "duplicate_call":
pass # same key still in flight — no second call
else:
raise
```
```javascript theme={null}
export class MiraiError extends Error {
constructor(status, code, message) {
super(`${status} ${code}: ${message}`);
this.status = status;
this.code = code;
}
}
const RETRYABLE = new Set([429, 500, 502, 503, 504]);
const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
export async function request(path, init = {}, attempt = 0) {
const res = await fetch(`https://sandbox.voice.miraiminds.co${path}`, {
...init,
headers: {
Authorization: `Bearer ${process.env.MIRAI_API_KEY}`,
"Content-Type": "application/json",
...init.headers,
},
});
if (res.ok) return res.status === 204 ? null : res.json();
const body = await res.json().catch(() => ({}));
const { code = "unknown", message = res.statusText } = body.error ?? {};
if (RETRYABLE.has(res.status) && attempt < 4) {
const retryAfter = Number(res.headers.get("Retry-After"));
const wait = (Number.isFinite(retryAfter) ? retryAfter : 2 ** attempt) * 1000;
await sleep(wait + Math.random() * 1000);
return request(path, init, attempt + 1);
}
throw new MiraiError(res.status, code, message);
}
```
At the call site:
```javascript theme={null}
try {
const call = await request("/v2/calls", {
method: "POST",
headers: { "Idempotency-Key": key },
body: JSON.stringify(payload),
});
} catch (e) {
if (e.code === "insufficient_balance") {
await pauseCampaign();
await alertOps(e.message);
} else if (e.code !== "duplicate_call") {
throw e; // duplicate_call means the same key is still in flight
}
}
```
### Retry rules
* **Retry** `429`, `500`, `502`, `503`, `504` and network errors. Exponential
backoff with jitter; honour `Retry-After` when present.
* **Never retry** `400`, `401`, `403`, `404`, `501` — the same request will fail
the same way. `503 campaigns_unavailable` belongs in this group too: it is a
provisioning fact, not a wobble.
* **`402` is retryable only after a top-up**, not on a timer.
* **Always send `Idempotency-Key` on `POST /v2/calls`.** A timeout tells you
nothing about whether the phone rang; without the key, your retry is a second
call to a real person.
### What a `409 duplicate_call` actually means
It means a request with this `Idempotency-Key` is **still being processed**. It
is the narrow race, not the normal retry path: we cannot replay a response that
has not been produced yet, and we must not place a second call, so we say so.
When the original request completes, the same key replays its stored response —
so a retry a moment later returns the original `202` and the original `call_id`.
Either way **no second call is placed**. That is usually the *success* path of a
retry, not a failure: log it and move on, do not surface it as an error to your
users.