HTTP API

Mirra’s control plane is a REST API at https://api.mirra.run. Everything the CLI does maps to an API call — and everything the dashboard shows is read through the same API. This page is the bare surface. The CLI and the Vitest plugin wrap it with better UX; reach for the raw API only when you’re building a custom integration.

Authentication

All requests require a bearer token:

Authorization: Bearer mt_pat_...

Tokens are issued from app.mirra.run/settings/tokens. Scope them to a workspace (not global) and give them a descriptive name.

Base URL

https://api.mirra.run

All endpoints are HTTPS. Rate limits apply per workspace, documented in response headers:

x-mirra-ratelimit-limit: 600
x-mirra-ratelimit-remaining: 597
x-mirra-ratelimit-reset: 1713802534

Sessions

Create a session

POST /v1/sessions
Authorization: Bearer mt_pat_...
Content-Type: application/json

{
  "mirrors": ["stripe", "resend", "twilio"],
  "seeds": {
    "stripe": "subscription-lifecycle"
  },
  "persistent": false,
  "name": "ci-run-42",
  "timeoutSeconds": 3600
}

mirrors

string[]

required

Mirrors to provision. Must be names from the mirror catalog.

seeds

object

Map of mirror name → fixture name. Mirrors not listed use their default empty fixture.

persistent

boolean

default:"false"

Create a persistent session. Requires the Team plan or higher.

name

string

Human-readable session name. Required for persistent sessions. Ephemeral sessions auto-generate one if omitted.

timeoutSeconds

integer

default:"3600"

Ephemeral-session auto-expire. Capped at your plan’s max session length.

Response:

sessionId

string

Session identifier like ses_a7k2.

status

enum

provisioning initially, ready when all mirrors are up, failed on provisioning error.

mirrors

object[]

One entry per provisioned mirror with vendor, url, and mirror version.

createdAt

timestamp

expiresAt

timestamp

For ephemeral sessions only.

Example success body:

{
  "sessionId": "ses_a7k2",
  "status": "ready",
  "mirrors": [
    { "vendor": "stripe", "url": "https://stripe-a7k2.mirra.run", "version": "0.7.3" },
    { "vendor": "resend", "url": "https://resend-a7k2.mirra.run", "version": "0.3.1" },
    { "vendor": "twilio", "url": "https://twilio-a7k2.mirra.run", "version": "0.4.0" }
  ],
  "createdAt": "2026-04-22T18:02:14Z",
  "expiresAt": "2026-04-22T19:02:14Z"
}

Get a session

GET /v1/sessions/{sessionId}

Returns the same shape as create, plus a stats block with request count, webhook count, and error count since creation.

End a session

DELETE /v1/sessions/{sessionId}

Tears down ephemeral sessions (state cleared). For persistent sessions, ends the session and archives state — restore via snapshot if you need it back.

List sessions

GET /v1/sessions?workspace={workspace_id}&mode=ephemeral&status=ready

Paginated. Default sort: createdAt desc.

Scenarios and runs

Execute a scenario

POST /v1/runs
Content-Type: application/json

{
  "scenario": {
    "title": "Send Welcome Email on Signup",
    "setup": "A Resend account with one verified domain `mail.acme.com`…",
    "prompt": "When a user signs up with email `alice@example.com`…",
    "expectedBehavior": "The integration should create the email…",
    "criteria": [
      { "tag": "check", "text": "Exactly 1 email is created in the Resend mirror" },
      { "tag": "judge", "text": "Error handling for bounces is implemented" }
    ],
    "config": {
      "mirrors": ["resend"],
      "fixture": "resend:transactional-busy",
      "timeout": 60,
      "runs": 3
    }
  }
}

Alternatively, send the raw markdown as scenarioMarkdown and Mirra parses it server-side:

POST /v1/runs
Content-Type: application/json

{
  "scenarioMarkdown": "# Send Welcome Email on Signup\n\n## Setup\n…"
}

Response:

{
  "runId": "run_9xkp2m",
  "status": "running",
  "sessionId": "ses_a7k2",
  "dashboardUrl": "https://app.mirra.run/runs/run_9xkp2m"
}

Get a run

GET /v1/runs/{runId}

Returns progress while running, final verdict when complete:

{
  "runId": "run_9xkp2m",
  "status": "complete",
  "scenario": { "title": "Send Welcome Email on Signup" },
  "satisfactionScore": 0.87,
  "runs": 3,
  "criteria": [
    { "label": "Exactly 1 email is created...", "kind": "check", "passed": 3, "total": 3 },
    { "label": "Error handling for bounces...", "kind": "judge", "passed": 0, "total": 3 }
  ],
  "durationMs": 14812
}

Live events

Mirra publishes every request, webhook, state change, and lifecycle event to a per-session event stream. Subscribe via Server-Sent Events:

GET /v1/sessions/{sessionId}/events
Accept: text/event-stream
Authorization: Bearer mt_pat_...

Response (streaming):

event: traffic.request_completed
data: { "mirror": "resend", "method": "POST", "path": "/emails", "status": 200, "durationMs": 34, "at": "2026-04-22T18:02:18Z" }

event: webhook.dispatched
data: { "mirror": "resend", "type": "email.sent", "emailId": "em_abc", "at": "2026-04-22T18:02:18.1Z", "signature": "..." }

event: state.changed
data: { "mirror": "resend", "entity": "email", "entityId": "em_abc", "before": { "status": "queued" }, "after": { "status": "sent" } }

Five event types:

traffic.request_completed — after every mirror request
webhook.dispatched — when a webhook fires
state.changed — when mirror state mutates
session.lifecycle — start, end, reset, snapshot, restore
evaluation.criterion_graded — during scenario runs, as each criterion resolves

The Vitest plugin subscribes to this stream under the hood for waitForWebhook().

Admin endpoints (per mirror)

Every mirror exposes admin endpoints at /_mirra/* on its mirror URL (not the control plane):

Reset state

POST https://stripe-a7k2.mirra.run/_mirra/state/reset
Content-Type: application/json

{
  "seed": "stripe:subscription-lifecycle"
}

Resets this mirror’s state to the seed. seed is optional — defaults to whatever seed the session started with.

Simulate events

POST https://stripe-a7k2.mirra.run/_mirra/simulate
Content-Type: application/json

{
  "event": "invoice.payment_failed",
  "subscription": "sub_Qzp"
}

Fires a vendor event as if it occurred naturally. The simulation cascade — state changes, dependent webhooks, timers — runs exactly as it would for the real event. Valid event names are documented on each mirror’s page.

Snapshot and restore (persistent sessions only)

POST /_mirra/state/snapshot
→ { "snapshotId": "snap_xyz" }

POST /_mirra/state/restore
{ "snapshotId": "snap_xyz" }

Snapshots are scoped to the session and the mirror. A 4-mirror session with 10 snapshots uses ~40 snapshot rows; each is a SQLite dump in object storage.

State dump

GET https://stripe-a7k2.mirra.run/_mirra/state

Returns the mirror’s current state as JSON. Used by the MCP server’s introspection tools and by the dashboard’s state view.

Metadata

GET https://stripe-a7k2.mirra.run/_mirra/metadata

Returns mirror name, version, target vendor API version, supported endpoints, webhook event types.

Errors

All errors follow a standard shape:

{
  "error": {
    "code": "mirra.session.mirror_not_in_catalog",
    "message": "Unknown mirror 'github'. Not in the current catalog.",
    "hint": "See https://mirra.run/docs/mirrors/overview for supported mirrors."
  }
}

Standard HTTP codes:

Code	When
`400`	Bad request — malformed body, invalid parameter
`401`	Missing or invalid token
`402`	Monthly minute quota exhausted and overage disabled
`403`	Token doesn’t have permission for this workspace
`404`	Resource (session, run, snapshot) not found
`409`	Conflict — session name already in use, snapshot already exists
`429`	Rate-limited
`500`	Mirra internal error (report to us)
`502`	Upstream mirror host unreachable; retry
`503`	Mirra under maintenance

Start here

Concepts

CLI

Guides

Mirrors

Reference

Authentication

Base URL

Sessions

Create a session

Get a session

End a session

List sessions

Scenarios and runs

Execute a scenario

Get a run

Live events

Admin endpoints (per mirror)

Reset state

Simulate events

Snapshot and restore (persistent sessions only)

State dump

Metadata

Errors

Where to go next

CLI reference

Coding agents + MCP

Start here

Concepts

CLI

Guides

Mirrors

Reference

​Authentication

​Base URL

​Sessions

​Create a session

​Get a session

​End a session

​List sessions

​Scenarios and runs

​Execute a scenario

​Get a run

​Live events

​Admin endpoints (per mirror)

​Reset state

​Simulate events

​Snapshot and restore (persistent sessions only)

​State dump

​Metadata

​Errors

​Where to go next

CLI reference

Coding agents + MCP

Authentication

Base URL

Sessions

Create a session

Get a session

End a session

List sessions

Scenarios and runs

Execute a scenario

Get a run

Live events

Admin endpoints (per mirror)

Reset state

Simulate events

Snapshot and restore (persistent sessions only)

State dump

Metadata

Errors

Where to go next