mailsocket — Python SDK

The official Python client for the mailsocket v1 REST API. Per-test email inboxes, message retrieval, and — the whole point — wait for the OTP in one line. For testing apps you own or are authorized to test. Not for creating accounts on services you don't control.

import time

from mailsocket import Client

client = Client("ms_live_...")            # your API key from the dashboard
inbox = client.create_inbox(label="signup")  # -> {"id": "inbox_...", "address": "..."}

started = time.time()                         # take the cutoff BEFORE the trigger
# use inbox["address"] in your app's signup form, then:
result = client.wait_for_otp(inbox["id"], since=started)  # blocks up to 60s
print(result.otp)         # "123456"
print(result.confidence)  # 0.95

Take started just before you trigger the email and pass it as since: a code that lands before wait_for_otp starts is still caught, and an older code in a reused inbox is not.

No email handy? client.send_test_code(inbox_id) drops a sample code into the inbox so you can see the whole loop work:

started = time.time()
client.send_test_code(inbox["id"])            # -> {"message_id": "msg_...", "sent_at": "..."}
result = client.wait_for_otp(inbox["id"], since=started)
print(result.otp)         # the sample code

No polling loop. No regex over the email body. wait_for_otp long-polls the server (which already knows how to extract the code) and hands back a deterministic result with a confidence score.

Install

pip install mailsocket

Zero runtime dependencies — pure standard library (urllib). Python 3.9+.

API

client = Client(api_key, base_url="https://dash.mailsocket.app/api/v1")

The moat

result = client.wait_for_otp("inbox_abc123", timeout=60, min_confidence=0.0, since=None)
result = client.wait_for_link("inbox_abc123", timeout=60, since=None)
result = client.wait("inbox_abc123", timeout=60, min_confidence=0.0, since=None)  # otp OR link

With a cutoff taken before the trigger (the usual case):

started = time.time()
# trigger the email here
result = client.wait_for_otp("inbox_abc123", since=started)

All three return a WaitResult and take keyword-only arguments after inbox_id. timeout/min_confidence/since shown above are the defaults — call with no extra arguments for the common case.

since=None (the default) omits the param, so the server uses its own default: the request start time — a code that arrives during this call is caught, and a stale code already in a reused inbox is not. Pass since=0 to restore the old "any message already in the inbox" behaviour (useful right after create_inbox, where there's nothing stale to match), or a message id / timestamp to continue after a specific point.

WaitResult exposes .otp, .confidence, .magic_link (and .link as an alias), plus the full .message dict. str(result) is the OTP (or the link).

Semantics:

• Each HTTP call blocks server-side for up to 25s (timeout is clamped to [1, 25]); the SDK re-calls until the overall timeout (seconds, default 60) elapses.
• 200 → the matching message. 204 → nothing yet, re-call immediately.
• 429 → honours Retry-After and retries within the deadline. 404 → raises.
• On overall deadline → WaitTimeout.

Errors

MailsocketError (base) with subclasses:

• AuthError — HTTP 401 (bad/missing key).
• NotFound — HTTP 404 (also an unknown, deleted or foreign inbox in send_test_code).
• RateLimited — HTTP 429, carries .subcode (rate_limited, too_many_wait_requests, wait_capacity) and .retry_after.
• WaitTimeout — no matching message within the overall deadline.

send_test_code on a disabled inbox raises the base MailsocketError with code="inbox_disabled" and status=409. Over its hourly quota it raises RateLimited; .retry_after says how many seconds until it frees up.

Develop

cd python
python -m pytest -q

Tests make no external or live-API requests. Most monkeypatch urllib.request.urlopen with a scripted responder, and a few start a real local http.server on 127.0.0.1 to check actual request behaviour, e.g. that an invalid id never reaches the network.

Changelog

• 0.3.2 — docs only: README positions mailsocket as email testing for apps you own or are authorized to test. No code change.
• 0.3.1 — the wait* helpers no longer miss a message that lands between two long-poll calls. When you pass no since, the first call still omits it (the server uses the request start), and every following call sends the cutoff the server reported in the Mailsocket-Wait-Since response header of the previous call. With an older server that sends no such header, behaviour is unchanged. An explicit since is used as before on every call.
• 0.3.0 — new Client.send_test_code(inbox_id) (POST /inboxes/{id}/test-code): puts one sample OTP email into your own inbox without going through the mail server, and returns {"message_id", "sent_at"}. README samples now take started = time.time() before the trigger and pass since=started.
• 0.2.0 — BEHAVIOUR CHANGE: wait_for_otp/wait_for_link/wait now default since=None, which omits the param so the server uses the request start time, instead of the old since=0 ("any message already in the inbox"). The old default silently returned a STALE OTP/link from a reused inbox. Pass since=0 explicitly to keep the old behaviour.
• 0.1.3 — _seg now rejects an empty id or a bare ./.. id with a MailsocketError (code="invalid_id") before any request is made, matching the TypeScript SDK's contract.