mails-ai Metrics API
Sent, delivered, bounced, complained, received and reply counts over time.
Sent, delivered, bounced, complained, received and reply counts over time.
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openapi: 3.2.0
info:
title: Mails.ai Metrics API
version: 0.2.0
description: 'The Mails.ai API gives AI agents a real email identity: send and receive
transactional email. Mail received within your plan''s limits is scanned for prompt injection and
reaches you as a typed event. With classification turned on (a paid-plan feature), new mail can also
be read for intent; a reply in a thread never is.
## Authentication
All endpoints take a Bearer API key:
```
Authorization: Bearer mk_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
```
Keys carry one or more scopes — `send`, `read`, `draft` (writes drafts, but can neither send nor
schedule one) and `manage` — and a mode: **live** (`mk_live_…`) or **test** (`mk_test_…`).
## Test mode
A `mk_test_` key exercises the entire API — real validation, persisted resources, real
`message.sent`/`*.received` events and webhooks — without sending real email or incurring cost. Build and
test your whole integration on a test key, then flip one character to `mk_live_` to go live.
`POST /v1/test/inbound` (test key only) lets you simulate inbound mail end-to-end.
## Idempotency
Send endpoints accept an `Idempotency-Key` header; a repeated key replays the stored response instead of
sending twice, with an `Idempotent-Replay: true` header.
## Pagination
List endpoints are cursor-paginated: pass `limit` (1–100) and the `next_cursor` from the previous page.
## Errors
Errors use a stable envelope: `{ "error": { "type", "code", "message", "param", "request_id" } }`. Every
response carries an `X-Request-Id` header for support correlation.'
contact:
name: Mails.ai Support
url: https://mails.ai
email: support@mails.ai
license:
name: Proprietary
identifier: LicenseRef-Proprietary
servers:
- url: https://api.mails.ai
description: Production
security:
- bearerAuth: []
tags:
- name: Metrics
description: Sent, delivered, bounced, complained, received and reply counts over time.
paths:
/v1/metrics:
get:
tags:
- Metrics
summary: Mail metrics
operationId: getMetrics
description: '**Requires scope:** `read`. Counts of sent, delivered, bounced, complained, received and reply messages per day or hour (UTC). Defaults to the last 30 days by day, or the last 48 hours by hour; at most 366 days or 744 hours per call. A test key counts test mail only and a live key live mail only.'
parameters:
- name: from
in: query
required: false
schema:
type: string
description: Start of the range (ISO 8601, or YYYY-MM-DD).
- name: to
in: query
required: false
schema:
type: string
description: End of the range, exclusive (ISO 8601, or YYYY-MM-DD).
- name: agent_id
in: query
required: false
schema:
type: string
description: Filter by agent id or name. A key tied to one agent always reads that agent's mail, and naming another agent is a 403.
- name: interval
in: query
required: false
schema:
type: string
enum:
- day
- hour
default: day
description: Bucket size.
responses:
'200':
description: Buckets for the range, oldest first.
content:
application/json:
schema:
$ref: '#/components/schemas/Metrics'
'400':
description: Invalid request — malformed JSON or a field failed validation. Also `feature_not_enabled` when this server has a feature switched off (custom domains before they are available).
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'401':
description: Missing or invalid API key.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'403':
description: The API key lacks the required scope (`insufficient_scope`), or the token belongs to an app connected by sign-in and this operation is closed to connected apps (`connected_app_not_allowed`).
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'404':
description: Resource not found in this workspace, or the agent a send names is archived (`agent_archived`).
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'409':
description: 'Conflict — duplicate resource, an in-progress idempotent request, a draft or scheduled message that started sending while it was being changed, or a thread deleted for good while one of its messages is being sent (`duplicate_resource`); or an agent name more than one agent has (`agent_name_conflict`: use the agent''s id); or a status change on an archived agent, since archiving cannot be undone (`agent_archived`).'
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'500':
description: Internal server error.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
x-required-scope: read
components:
schemas:
MetricsBucket:
type: object
properties:
start:
type: string
format: date-time
description: Start of the bucket (UTC).
sent:
type: integer
description: Messages sent in this bucket, one per message whatever its recipient count. A scheduled message counts when it goes out; a send the mail provider refused does not.
delivered:
type: integer
description: 'Messages confirmed delivered in this bucket, counted by delivery time, not send time. Always 0 for a test key: test sends are never transmitted.'
bounced:
type: integer
description: Messages that bounced in this bucket, counted by bounce time. A soft bounce, which marks a message `delayed`, is not counted; always 0 for a test key.
complained:
type: integer
description: Messages a recipient reported as spam in this bucket, counted by complaint time. Always 0 for a test key.
received:
type: integer
description: Messages received in this bucket, counted by arrival time. Quarantined mail and mail received over a limit count too.
replies:
type: integer
description: Received messages that answered a thread.
required:
- start
- sent
- delivered
- bounced
- complained
- received
- replies
Error:
type: object
properties:
error:
type: object
properties:
type:
type: string
enum:
- invalid_request_error
- authentication_error
- permission_error
- rate_limit_error
- resource_error
- payment_error
- abuse_error
- api_error
description: High-level error category.
code:
type: string
enum:
- invalid_field
- missing_field
- missing_param
- invalid_param_value
- method_not_allowed
- invalid_idempotency_key
- duplicate_resource
- slug_invalid
- slug_reserved
- slug_taken
- agent_name_conflict
- body_too_large
- missing_authorization
- missing_api_key
- invalid_api_key
- expired_api_key
- revoked_api_key
- invalid_access_token
- email_not_verified
- insufficient_scope
- connected_app_not_allowed
- sso_required
- workspace_mismatch
- agent_not_owned
- rate_limit_exceeded
- daily_limit_exceeded
- hourly_limit_exceeded
- monthly_limit_exceeded
- agent_not_found
- agent_paused
- agent_archived
- resource_not_found
- recipient_suppressed
- recipient_not_allowed
- domain_not_verified
- ses_role_not_assumable
- ses_role_external_id_not_required
- ses_permission_denied
- ses_setup_failed
- ses_message_rejected
- ses_events_not_confirmed
- payment_required
- payment_method_failed
- subscription_canceled
- billing_state_inconsistent
- free_tier_exceeded
- plan_limit_exceeded
- cold_email_prohibited
- agent_suspended
- new_workspace_fanout_exceeded
- resource_cap_exceeded
- workspace_cap_exceeded
- feature_not_enabled
- test_mode_required
- live_mode_required
- unknown_test_address
- workspace_not_approved
- spam_pattern_detected
- classifier_rejected
- high_injection_score
- complaint_threshold_exceeded
- bounce_threshold_exceeded
- internal_error
- internal_server_error
- upstream_error
- upstream_unavailable
- service_unavailable
description: Stable machine-readable error code.
message:
type: string
description: Human-readable explanation.
param:
type:
- string
- 'null'
description: The offending request field, when applicable.
request_id:
type: string
description: Echo of the X-Request-Id header for support correlation.
errors:
type: array
items:
$ref: '#/components/schemas/FieldError'
description: On a validation failure, EVERY offending field (not just the first). The top-level code/message/param mirror errors[0] for backward compatibility.
resets_at:
type:
- string
- 'null'
format: date-time
description: 'On every 429: when the limit lets the request through again (UTC). Null when waiting will not help, for a cap that only an upgrade or a deletion lifts.'
retry_after_seconds:
type:
- integer
- 'null'
description: 'On every 429: the seconds until `resets_at`, null when it is null. On any other error that says how long to wait, such as a 503 `upstream_unavailable`: the seconds its `Retry-After` header gives.'
upgrade_url:
type: string
format: uri
description: 'On every 402: the dashboard page where the plan can be changed, `https://app.mails.ai/billing`.'
required:
- type
- code
- message
description: 'The error, as every error response carries it: `type`, `code`, `message`, `param` and `request_id`, plus `errors` on a validation failure, `resets_at` and `retry_after_seconds` on a 429, `retry_after_seconds` on any other error with a `Retry-After`, and `upgrade_url` on a 402. A failed item in a batch send is the same error, and `retry_after_seconds` is how it says how long to wait, since an item has no headers of its own.'
required:
- error
Metrics:
type: object
properties:
interval:
type: string
enum:
- day
- hour
description: 'Bucket size, in UTC: `day` or `hour`, as requested; `day` when the request names none.'
from:
type: string
format: date-time
description: 'Start of the range, inclusive: the requested `from` moved back to the start of its UTC day or hour. Left out, 30 days before `to` by day or 48 hours by hour, rounded the same way.'
to:
type: string
format: date-time
description: End of the range, exclusive, as requested and not rounded, so the last bucket can be partial. Left out, the time of the request.
agent_id:
type: string
description: The agent the counts are limited to, as its id even when the request gave its name. Absent when they cover every agent; a key tied to one agent always gets its own.
test_mode:
type: boolean
description: A test key counts test mail only; a live key, live mail only.
data:
type: array
items:
$ref: '#/components/schemas/MetricsBucket'
description: Every bucket in the range, oldest first, zeros included.
totals:
type: object
properties:
sent:
type: integer
description: Messages sent in the range, counted by send time.
delivered:
type: integer
description: Messages confirmed delivered in the range, counted by delivery time.
bounced:
type: integer
description: Messages that bounced in the range, counted by bounce time.
complained:
type: integer
description: Messages reported as spam in the range, counted by complaint time.
received:
type: integer
description: Messages received in the range, counted by arrival time.
replies:
type: integer
description: Received messages in the range that answered a thread.
required:
- sent
- delivered
- bounced
- complained
- received
- replies
description: Each count summed over every bucket in the range.
required:
- interval
- from
- to
- test_mode
- data
- totals
FieldError:
type: object
properties:
code:
type: string
enum:
- invalid_field
- missing_field
- missing_param
- invalid_param_value
- method_not_allowed
- invalid_idempotency_key
- duplicate_resource
- slug_invalid
- slug_reserved
- slug_taken
- agent_name_conflict
- body_too_large
- missing_authorization
- missing_api_key
- invalid_api_key
- expired_api_key
- revoked_api_key
- invalid_access_token
- email_not_verified
- insufficient_scope
- connected_app_not_allowed
- sso_required
- workspace_mismatch
- agent_not_owned
- rate_limit_exceeded
- daily_limit_exceeded
- hourly_limit_exceeded
- monthly_limit_exceeded
- agent_not_found
- agent_paused
- agent_archived
- resource_not_found
- recipient_suppressed
- recipient_not_allowed
- domain_not_verified
- ses_role_not_assumable
- ses_role_external_id_not_required
- ses_permission_denied
- ses_setup_failed
- ses_message_rejected
- ses_events_not_confirmed
- payment_required
- payment_method_failed
- subscription_canceled
- billing_state_inconsistent
- free_tier_exceeded
- plan_limit_exceeded
- cold_email_prohibited
- agent_suspended
- new_workspace_fanout_exceeded
- resource_cap_exceeded
- workspace_cap_exceeded
- feature_not_enabled
- test_mode_required
- live_mode_required
- unknown_test_address
- workspace_not_approved
- spam_pattern_detected
- classifier_rejected
- high_injection_score
- complaint_threshold_exceeded
- bounce_threshold_exceeded
- internal_error
- internal_server_error
- upstream_error
- upstream_unavailable
- service_unavailable
description: Stable machine-readable code for this field.
message:
type: string
description: Human-readable explanation for this field.
param:
type:
- string
- 'null'
description: The offending request field (dot-path), or null.
required:
- code
- message
- param
securitySchemes:
bearerAuth:
type: http
scheme: bearer
bearerFormat: mk_live_<32 hex>, mk_test_<32 hex>, or moa_<48 hex>
description: 'A Mails.ai API key, or an OAuth access token (`moa_…`, valid for 1 hour) from signing in through an app such as the CLI, Claude or ChatGPT. OAuth discovery: https://api.mails.ai/.well-known/oauth-authorization-server and https://api.mails.ai/.well-known/oauth-protected-resource. An access token''s OAuth scope maps onto these API scopes: `full_access` = `send` + `read` + `manage` (not `draft`: the draft routes take those three too), `send` = `send` + `read`, `read` = `read`. Scopes (`send`/`read`/`manage`/`draft`) are noted per operation via `x-required-scope`; when more than one scope opens an operation (the draft routes also take `draft`), `x-accepted-scopes` lists them all. `inbox` appears there too, on the triage routes (changing and trashing threads, labels, cancelling a scheduled send): only a signed-in dashboard session holds it (a workspace Member''s), never an API key or OAuth token, and `x-session-scopes` names it.'