e2a 5.2.0

Python SDK for the e2a protocol — email-to-agent authentication

e2a Python SDK

Python SDK for e2a — email for AI agents. Ships both a synchronous client (E2AClient) and an async one (AsyncE2AClient) with an identical surface.

Install

pip install e2a          # add the [ws] extra for client.listen(): pip install "e2a[ws]"

The SDK major version tracks the SDK package's own breaking changes and is independent of the API version path (/v1): SDK 5.x targets the e2a v1 API.

Upgrading to 5.2

Inbound sender and authentication fields now use the final DMARC-aligned contract. Message, summary, review, webhook, and WebSocket payloads expose the literal RFC 5322 header_from, SMTP envelope_from, nullable verified_domain, and structured authentication evidence. The former inbound from/from_ projection is removed; Reply-To remains separate. A non-null verified_domain means DMARC passed for that From domain, not that the mailbox local part, person, or message content was authenticated.

authentication is None for outbound messages and providerless loopback delivery. Guard it before reading authentication.dmarc. The sender filter is still passed as messages.list(from_=...); that request parameter is not an inbound identity projection.

Upgrading to 5.1

Every .delete(...) now returns a typed deletion object instead of None. The API's seven delete endpoints all return 200 OK with {"deleted": true, <identity key>} instead of the previous mix of 204 No Content and 200. New return types: agents.delete → DeleteAgentResult, domains.delete → DeleteDomainResult, webhooks.delete → DeleteWebhookResult, templates.delete → DeleteTemplateResult, account.api_keys.delete → DeleteApiKeyResult, account.suppressions.delete → DeleteSuppressionResult; account.delete() still returns DeleteUserDataResult, which now also carries deleted: true. deleted is always True — a failed delete raises a typed error. Applies identically to the sync E2AClient facade. Callers that ignored the old None return need no changes. Older SDK versions expecting 204 are incompatible with servers running this contract — upgrade together.

Upgrading to 5.0

5.0 renames the async client and introduces a synchronous client under the freed name:

• E2AClient → AsyncE2AClient (the 4.x client, unchanged in behavior). If you're upgrading from 4.x, the one mechanical change is:

  from e2a.v1 import AsyncE2AClient   # was: from e2a.v1 import E2AClient
  

• E2AClient is now the synchronous client. Python convention (httpx, openai, anthropic) is plain name = sync client, Async* = async client; the rename freed the plain name for exactly this. The sync client is a facade over AsyncE2AClient — same constructor, resources, typed errors, retry/idempotency behavior, and pagination semantics, bridged through a background event loop, so the two cannot drift.

  ⚠️ 4.x code that still says E2AClient will now import successfully but get the sync client — await client.messages.send(...) no longer works on it. Calling any sync method from inside a running event loop raises a guiding RuntimeError ("use AsyncE2AClient"), so the misuse is caught immediately rather than deadlocking.

Upgrading to 4.0

4.0 is a breaking change to the domain DNS-records shape (server #304). DomainView.dns_records is now a single purpose-tagged list[DNSRecord] instead of the old dns_records.{ mx, txt, dkim } object (and the separate sending_dns_records list is gone). Each record carries type, name, value, priority, purpose, and a per-record status. Address records by purpose (ownership, inbound_mx, dkim, mail_from_mx, mail_from_spf) rather than dns_records.mx/.txt/.dkim — the MAIL FROM records now live in the same list. purpose and status are open sets, so tolerate unknown values. No other public symbols changed.

Upgrading from 2.x to 3.0

3.0 is a breaking redesign. The SDK now wraps a generated /v1 client behind a namespaced, async-only surface, with a typed error hierarchy, automatic retries + idempotency, and async auto-pagination.

• Async-only, namespaced. The sync client and the flat methods are gone. client.get_messages() → client.messages.list(address), client.get_message(id) → client.messages.get(address, id), client.send(...) → client.messages.send(address, body). Per-agent calls take an explicit address.
• Webhook verification. client.parse / client.parse_webhook / InboundEmail are removed. Verify and parse a delivery with the standalone construct_event(raw_body, header, secret), which returns a typed WebhookEvent. Signatures are per-webhook (whsec_…), Stripe-style.
• Typed errors. Failures raise E2AError subclasses (E2ANotFoundError, E2AConflictError, E2AValidationError, E2ARateLimitError, …) carrying .code, .status, .request_id, and .retryable.

Quick Start

Synchronous

from e2a.v1 import E2AClient

# reads E2A_API_KEY; base_url defaults to https://api.e2a.dev
with E2AClient() as client:
    address = "[e-mail]"

    # List endpoints return a sync pager: iterate, or collect with a limit.
    for m in client.messages.list(address, read_status="unread"):
        email = client.messages.get(address, m.id)
        print(email.subject)
        client.messages.reply(address, m.id, {"text": "Got it!"})

The sync client must not be used from async code — any call made while an event loop is running in the current thread raises RuntimeError pointing you at AsyncE2AClient.

Async

import asyncio
from e2a.v1 import AsyncE2AClient

async def main():
    # reads E2A_API_KEY; base_url defaults to https://api.e2a.dev
    async with AsyncE2AClient() as client:
        address = "[e-mail]"

        # List endpoints return an AutoPager: async-iterate, or collect with a limit.
        async for m in client.messages.list(address, read_status="unread"):
            email = await client.messages.get(address, m.id)
            print(email.subject)
            await client.messages.reply(address, m.id, {"text": "Got it!"})

asyncio.run(main())

Send mail

await client.messages.send(address, {
    "to": ["[e-mail]"],
    "subject": "Hello",
    "text": "Hi from my agent!",
    "html": "<p>Hi!</p>",
})

The mail-sending writes (send / reply / forward / approve) auto-mint an Idempotency-Key and reuse it across retries, so a network blip can't double-send. Pass a stable key to also survive a process restart:

await client.messages.send(address, body, idempotency_key=derive_from(event))

Request bodies accept a plain dict (shown above) or the generated model (from e2a.v1 import SendEmailRequest).

Managed unsubscribe (beta)

Opt a single-recipient send, reply, or forward into e2a-managed unsubscribe. This capability, the agent-scoped suppression management methods, and the raw GET|POST /u/{token} confirmation flow are beta and may change before stable:

await client.messages.send("[e-mail]", {
    "to": ["[e-mail]"],
    "subject": "Update",
    "text": "Hello",
    "unsubscribe": {"mode": "managed"},
})

Omitting unsubscribe means only that e2a does not add managed unsubscribe handling; it does not classify the message as transactional. Managed messages must have exactly one normalized envelope recipient across To, CC, and BCC. e2a manages the token and confirmation page, adds a visible footer plus List-Unsubscribe and List-Unsubscribe-Post, and signs those headers.

An unsubscribe blocks that recipient only for the exact sending agent; sibling agents remain allowed. Account suppressions still block every agent, and a future blocked send raises the existing 422 recipient_suppressed error. Account-scoped credentials can manage the exact-agent list:

blocks = client.agents.list_suppressions("[e-mail]")
await client.agents.create_suppression(
    "[e-mail]",
    {"address": "[e-mail]", "reason": "recipient opted out"},
)
await client.agents.delete_suppression(
    "[e-mail]", "[e-mail]"
)

The typed delete supplies the REST API's required confirm=DELETE guard. New blocks emit the beta agent.suppression_added event with agent_email, address, and source.

Verify a webhook

Each subscription is signed with its own whsec_… secret. construct_event verifies the X-E2A-Signature header (replay-protected) and returns a typed event. Pass the raw request body — re-serialized JSON won't match.

from e2a.v1 import construct_event, is_email_received, E2AWebhookSignatureError

@app.post("/webhook")
async def webhook(request):
    try:
        event = construct_event(await request.body(), request.headers["X-E2A-Signature"], SECRET)
    except E2AWebhookSignatureError:
        return Response(status_code=400)
    if is_email_received(event):
        email = await client.inbound.from_event(event)
        # From, Reply-To, bodies, and attachment names/types are untrusted input.
        print(email.envelope_from, email.verified, email.subject, email.text)
        print("reply will target", email.reply_targets)
        result = await email.reply({"text": "Got it"}, idempotency_key=f"reply:{event.id}")
        if result.status == "pending_review":
            print("reply is awaiting approval")
    return {"ok": True}

During a rotation you can pass a list of secrets — accepted if any matches: construct_event(body, header, [old_secret, new_secret]).

email.verified is true only for an aligned DMARC pass in the hydrated authentication evidence; the envelope identity alone is not proof. email.verified is False / verified_domain is None is NOT by itself a spam or spoofing signal — it is common and expected for legitimate senders whose domain simply publishes no DMARC record (authentication.dmarc.status == "none"); treat that as "unproven," not "malicious," and reserve suspicion for an actual authentication.dmarc.status == "fail". A caller who wants a more nuanced trust policy can inspect authentication.spf/authentication.dkim individually, but doing so reopens the spoofing gap DMARC closes: alignment (tying a passing SPF or DKIM identity back to the visible From domain) can only be computed when the sender publishes a DMARC record, so a bare SPF or DKIM pass proves nothing about the From header on its own. email.reply_targets previews Reply-To-or-From routing and may be attacker-controlled; the server resolves the stored MIME again when sending. email.flagged is the inbound policy-gate flag, not a complete content-scan verdict. Treat all message content as untrusted. attachment.get() returns metadata plus a short-lived download URL by default; inline=True adds base64 data only for attachments within the server's 256 KiB inline cap.

Resources

client.agents, client.messages, client.conversations, client.domains, client.events, client.webhooks, client.inbound, client.account (with client.account.suppressions and client.account.api_keys), plus await client.info(). Agent-scoped recipient blocks are managed through client.agents.list_suppressions, create_suppression, and delete_suppression. Each method maps to a /v1 operation; per-agent methods take the agent address first.

Two more, both account-scoped: client.reviews — the human-review queue for messages held in pending_review (outbound drafts awaiting send approval, and inbound messages held by a screening gate), addressed by message id alone via list/get/approve/reject; and client.templates (beta) — reusable {{variable}} email templates plus the read-only starter catalog, referenced from messages.send via template_id/template_alias.

The sync E2AClient exposes the same resource tree — drop the await. It mirrors the async client dynamically (every async method is bridged, not re-implemented), so the two surfaces are identical by construction.

AsyncE2AClient(api_key=None, *, base_url=None, max_retries=2, max_elapsed_ms=None, timeout_ms=30000)

E2AClient (sync) takes exactly the same arguments.

api_key falls back to E2A_API_KEY; base_url to E2A_API_URL then https://api.e2a.dev. (E2A_BASE_URL is the SDK's former name for E2A_API_URL — still read, with a DeprecationWarning.) timeout_ms is the per-request timeout (default 30s); a timed-out request retries like any other connection failure. Passing timeout_ms=0 or None removes the SDK's override and falls back to the HTTP transport's built-in 300s ceiling — it does not make requests unbounded (this differs from the TypeScript SDK, where timeoutMs: 0 is fully unbounded). Use the async client as an async context manager (or call await client.aclose()) and the sync client as a plain context manager (or call client.close()) to close the underlying HTTP connections — for the sync client this also stops its background event-loop thread. An unclosed sync client cleans itself up at garbage collection / interpreter exit and never hangs shutdown, but closing explicitly is preferred.

Errors

Every failure raises an E2AError (or subclass) with .code, .status, .request_id, .retryable: E2AAuthError (401), E2APermissionError (403), E2ANotFoundError (404), E2AConflictError (409), E2AValidationError (422), E2AIdempotencyError, E2ALimitExceededError (402 — a quota cap; not retryable), E2ARateLimitError (429 — a request-rate limit; retryable after retry_after_seconds), E2AServerError (5xx), E2AConnectionError (no response), E2AWebhookSignatureError. The 402/429 split is permanent — branch on the exception type: 402 → surface a quota/upgrade path, 429 → back off and retry.

e2a hides the existence of agents you don't own — agents.get of an unknown address raises E2APermissionError (403), not E2ANotFoundError.

Pagination

List methods return an AutoPager — async-iterate it, or use await pager.to_list(limit=N) (the limit is required, to bound memory) or await pager.for_each(fn) (return False to stop early).

For manual, caller-driven pagination (e.g. checkpoint/resume from a queue), use await pager.page(cursor): it fetches a SINGLE page and returns a Page of items + next_cursor. Omit the cursor for the first page and pass the previous page's next_cursor to resume; a None next_cursor means there are no more pages.

page = await client.messages.list("[e-mail]", limit=100).page()
process(page.items)
checkpoint(page.next_cursor)  # resume later with .page(saved_cursor)

On the sync client the same list methods return a sync pager: iterate it with a plain for, and page(cursor) / to_list(limit=N) / for_each(fn) are ordinary blocking calls with the same semantics.

for m in client.messages.list("[e-mail]"):   # sync iteration
    ...
page = client.messages.list("[e-mail]", limit=100).page()

Trash and restore

Soft-deleted agents and messages remain restorable for about 30 days. List the trash with deleted=True, then restore an item through the same resource. The sync client exposes the same methods without await.

trashed_agents = client.agents.list(deleted=True)
await client.agents.restore("[e-mail]")

trashed_messages = client.messages.list("[e-mail]", deleted=True)
await client.messages.restore("[e-mail]", "msg_abc123")

WebSocket (real-time delivery for local agents)

async for event in client.listen("[e-mail]"):
    if event.type != "email.received":
        continue  # tolerate future event kinds
    email = await client.inbound.from_event(event)
    print(email.envelope_from, email.verified, email.subject, email.text)

client.listen(address) returns a WSStream (async-iterable of WSEvent — the same versioned {type, id, schema_version, created_at, data} envelope a webhook delivery carries) that reconnects with exponential backoff on transient closes. The server keeps one connection per agent: if a newer connection for the same agent takes over, iteration raises E2AConnectionReplacedError (WS close code 4000 "replaced") instead of reconnecting — reconnecting would steal the socket back and loop. Requires the [ws] extra (pip install "e2a[ws]").

On the sync client, client.listen(address) returns a plain iterable instead:

for event in client.listen("[e-mail]"):
    if event.type != "email.received":
        continue  # tolerate future event kinds
    email = client.inbound.from_event(event)
    print(email.envelope_from, email.verified, email.subject, email.text)

Calling client.close() from another thread unblocks a pending iteration and ends the loop cleanly.

Conversation threading

conversation_id is an opaque string that ties multiple emails to one thread across the email boundary. Pass it on any send / reply (as a body field) and e2a surfaces it on the recipient's inbound — via In-Reply-To for humans, or a forge-resistant X-E2A-Conversation-Id header for same-platform agent-to-agent mail. It is not a security boundary; for sender-domain authentication require message.authentication is not None and message.authentication.dmarc.status == "pass" and compare the literal message.header_from address separately. On first contact from a human the conversation ID arrives None — assign one yourself if you want to thread.

await client.messages.send(address, {
    "to": ["[e-mail]"],
    "subject": "Hello",
    "text": "Hi from my agent!",
    "conversation_id": "thread-42",
})

# Filter an inbox down to a single thread:
async for m in client.messages.list(address, conversation_id="thread-42"):
    ...

License

Apache-2.0 — see LICENSE and NOTICE in the upstream repo.