diff --git a/e2e/internal/testutil/client.go b/e2e/internal/testutil/client.go
index 16f0ef351..80a8bee9e 100644
--- a/e2e/internal/testutil/client.go
+++ b/e2e/internal/testutil/client.go
@@ -24,9 +24,11 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"fmt"
+	"io"
 	"net/http"
 	"net/http/cookiejar"
 	"net/url"
+	"strings"
 	"testing"
 	"time"
 
@@ -53,16 +55,19 @@ const (
 )
 
 type Client struct {
-	T              testing.TB
-	httpClient     *http.Client
-	baseURL        string
-	mailpitBaseURL string
-	role           TestRole
-	userID         gid.GID
-	profileID      gid.GID
-	organizationID gid.GID
-	email          string
-	password       string
+	T               testing.TB
+	httpClient      *http.Client
+	proboHTTPClient *http.Client
+	trustClient     *http.Client
+	trustHost       string
+	baseURL         string
+	mailpitBaseURL  string
+	role            TestRole
+	userID          gid.GID
+	profileID       gid.GID
+	organizationID  gid.GID
+	email           string
+	password        string
 }
 
 func NewClient(t testing.TB, role TestRole) *Client {
@@ -544,11 +549,7 @@ func NewClientWithNewSession(t testing.TB, from *Client) *Client {
 	return client
 }
 
-// SelfProvisionTrustCenterVisitor signs a brand-new email up as a trust
-// center visitor through the public magic-link flow (send + verify), the
-// same path a real visitor takes. It returns a Client bound to that
-// visitor's own session and cookie jar, scoped to no organization.
-func SelfProvisionTrustCenterVisitor(t testing.TB, trustCenterID string) *Client {
+func SelfProvisionTrustCenterVisitor(t testing.TB, trustHost string) *Client {
 	t.Helper()
 
 	jar, err := cookiejar.New(nil)
@@ -561,47 +562,170 @@ func SelfProvisionTrustCenterVisitor(t testing.TB, trustCenterID string) *Client
 		baseURL:        GetBaseURL(),
 		mailpitBaseURL: GetMailpitBaseURL(),
 		email:          email,
+		trustHost:      trustHost,
 		httpClient: &http.Client{
 			Jar:     jar,
 			Timeout: 30 * time.Second,
 		},
+		trustClient: trustHTTPClientWithJar(trustHost, jar),
+		proboHTTPClient: &http.Client{
+			Jar:     jar,
+			Timeout: 30 * time.Second,
+		},
 	}
 
-	visitor.sendMagicLink(trustCenterID, email)
-	token := visitor.pollForLinkToken(fmt.Sprintf("to:%s", email))
-	visitor.verifyMagicLink(trustCenterID, token)
+	visitor.connectViaCIMD(email)
 
 	return visitor
 }
 
-func (c *Client) sendMagicLink(trustCenterID, email string) {
-	const query = `
-		mutation($input: SendMagicLinkInput!) {
-			sendMagicLink(input: $input) {
-				success
-			}
-		}
-	`
+func (c *Client) connectViaCIMD(email string) {
+	c.T.Helper()
 
-	err := c.ExecuteTrust(trustCenterID, query, map[string]any{
-		"input": map[string]any{"email": email},
-	}, nil)
-	require.NoError(c.T, err, "sendMagicLink mutation failed")
+	WaitForTrustCenterHTTPS(c.T, c.trustHost)
+
+	initiateURL := fmt.Sprintf(
+		"https://%s/initiate?continue=/overview",
+		c.trustHost,
+	)
+
+	authorizeURL := c.redirectLocation(c.trustClient, initiateURL)
+	require.NotEmpty(c.T, authorizeURL, "oauth initiate must redirect to authorize")
+
+	portalLoginURL := c.redirectLocation(c.proboHTTPClient, authorizeURL)
+	require.Contains(c.T, portalLoginURL, "/auth/portal-login", "unauthenticated authorize must redirect to portal login")
+
+	authorizeParam := extractAuthorizeQueryParam(portalLoginURL)
+	require.NotEmpty(c.T, authorizeParam)
+
+	c.postConnectMagicLink(email, authorizeParam)
+
+	token := c.pollForLinkToken(fmt.Sprintf("to:%s", email))
+	verifyURL := c.baseURL + "/api/connect/v1/magic-link/verify?token=" + url.QueryEscape(token)
+
+	resumeAuthorizeURL := c.redirectLocation(c.proboHTTPClient, verifyURL)
+	require.Contains(c.T, resumeAuthorizeURL, "/api/connect/v1/oauth2/authorize")
+
+	authorizeResp := c.redirectHTTPResponse(c.proboHTTPClient, resumeAuthorizeURL)
+	require.False(
+		c.T,
+		IsConsentRedirect(authorizeResp),
+		"compliance portal CIMD must skip oauth consent screen",
+	)
+	require.Equal(c.T, http.StatusFound, authorizeResp.StatusCode)
+
+	_, err := OAuth2AuthorizeCodeFromRedirect(authorizeResp)
+	require.NoError(c.T, err, "compliance portal CIMD must issue authorization code without consent")
+
+	callbackURL := resolveRedirectURL(resumeAuthorizeURL, authorizeResp.Header.Get("Location"))
+	require.Contains(c.T, callbackURL, "/callback")
+
+	finalURL := c.redirectLocation(c.trustClient, callbackURL)
+	require.True(
+		c.T,
+		strings.HasSuffix(finalURL, "/overview") || strings.Contains(finalURL, "/overview"),
+		"oauth callback must redirect to continue URL, got %q",
+		finalURL,
+	)
 }
 
-func (c *Client) verifyMagicLink(trustCenterID, token string) {
-	const query = `
-		mutation($input: VerifyMagicLinkInput!) {
-			verifyMagicLink(input: $input) {
-				continue
-			}
-		}
-	`
+func (c *Client) postConnectMagicLink(email, authorizeParam string) {
+	c.T.Helper()
 
-	err := c.ExecuteTrust(trustCenterID, query, map[string]any{
-		"input": map[string]any{"token": token},
-	}, nil)
-	require.NoError(c.T, err, "verifyMagicLink mutation failed")
+	body := url.Values{}
+	body.Set("email", email)
+	body.Set("authorize", authorizeParam)
+
+	req, err := http.NewRequest(
+		"POST",
+		c.baseURL+"/api/connect/v1/magic-link/send",
+		strings.NewReader(body.Encode()),
+	)
+	require.NoError(c.T, err)
+
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	resp, err := c.proboHTTPClient.Do(req)
+	require.NoError(c.T, err, "magic-link send request failed")
+
+	defer func() { _ = resp.Body.Close() }()
+
+	require.Equal(c.T, http.StatusNoContent, resp.StatusCode, "magic-link send must return 204")
+}
+
+func (c *Client) redirectLocation(client *http.Client, rawURL string) string {
+	c.T.Helper()
+
+	resp := c.redirectHTTPResponse(client, rawURL)
+	require.True(
+		c.T,
+		resp.StatusCode >= http.StatusMultipleChoices && resp.StatusCode < http.StatusBadRequest,
+		"expected redirect from %s, got %d",
+		rawURL,
+		resp.StatusCode,
+	)
+
+	location := resp.Header.Get("Location")
+	require.NotEmpty(c.T, location, "redirect from %s missing Location header", rawURL)
+
+	return resolveRedirectURL(rawURL, location)
+}
+
+func (c *Client) redirectHTTPResponse(client *http.Client, rawURL string) *OAuth2HTTPResponse {
+	c.T.Helper()
+
+	noRedirectClient := &http.Client{
+		Jar:       client.Jar,
+		Timeout:   client.Timeout,
+		Transport: client.Transport,
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+	}
+
+	req, err := http.NewRequest(http.MethodGet, rawURL, nil)
+	require.NoError(c.T, err)
+
+	resp, err := noRedirectClient.Do(req)
+	require.NoError(c.T, err, "request to %s failed", rawURL)
+
+	defer func() { _ = resp.Body.Close() }()
+
+	body, err := io.ReadAll(resp.Body)
+	require.NoError(c.T, err)
+
+	return &OAuth2HTTPResponse{
+		StatusCode: resp.StatusCode,
+		Header:     resp.Header,
+		Body:       body,
+	}
+}
+
+func resolveRedirectURL(baseURL, location string) string {
+	locURL, err := url.Parse(location)
+	if err != nil {
+		return location
+	}
+
+	if locURL.IsAbs() {
+		return locURL.String()
+	}
+
+	base, err := url.Parse(baseURL)
+	if err != nil {
+		return location
+	}
+
+	return base.ResolveReference(locURL).String()
+}
+
+func extractAuthorizeQueryParam(portalLoginURL string) string {
+	parsed, err := url.Parse(portalLoginURL)
+	if err != nil {
+		return ""
+	}
+
+	return parsed.Query().Get("authorize")
 }
 
 func (c *Client) GetEmail() string {
diff --git a/e2e/internal/testutil/graphql.go b/e2e/internal/testutil/graphql.go
index 0ec8be32e..ca2524ec2 100644
--- a/e2e/internal/testutil/graphql.go
+++ b/e2e/internal/testutil/graphql.go
@@ -219,9 +219,14 @@ func ConsoleGraphQLWithAccessToken(
 // page's host as TLS SNI. Certificates are Pebble-issued for e2e, so
 // verification is skipped.
 func trustHTTPClient(serverName string) *http.Client {
+	return trustHTTPClientWithJar(serverName, nil)
+}
+
+func trustHTTPClientWithJar(serverName string, jar http.CookieJar) *http.Client {
 	dialer := &net.Dialer{Timeout: 5 * time.Second}
 
 	return &http.Client{
+		Jar:     jar,
 		Timeout: 30 * time.Second,
 		Transport: &http.Transport{
 			DialContext: func(ctx context.Context, _, _ string) (net.Conn, error) {
@@ -235,6 +240,36 @@ func trustHTTPClient(serverName string) *http.Client {
 	}
 }
 
+// WaitForTrustCenterHTTPS blocks until the dedicated trust-center listener
+// serves the page over TLS. Managed domains provision certificates
+// asynchronously after activation.
+func WaitForTrustCenterHTTPS(t testing.TB, host string) {
+	t.Helper()
+
+	client := TrustHTTPClient(host)
+
+	require.Eventually(
+		t,
+		func() bool {
+			resp, err := client.Get("https://" + host + complianceportalOAuthMetadataPath())
+			if err != nil {
+				return false
+			}
+
+			defer func() { _ = resp.Body.Close() }()
+
+			return resp.StatusCode == http.StatusOK
+		},
+		30*time.Second,
+		500*time.Millisecond,
+		"trust center did not become servable on the dedicated listener",
+	)
+}
+
+func complianceportalOAuthMetadataPath() string {
+	return "/.well-known/oauth-client-metadata"
+}
+
 // DoTrust posts a GraphQL query to a compliance page served on the dedicated
 // listener. host is the page's serving domain (a customer custom domain or a
 // managed {slug}.probopage.localhost subdomain).
@@ -249,7 +284,7 @@ func (c *Client) DoTrust(host string, query string, variables map[string]any) (*
 		return nil, fmt.Errorf("cannot marshal request: %w", err)
 	}
 
-	endpoint := fmt.Sprintf("https://%s/api/trust/v1/graphql", host)
+	endpoint := fmt.Sprintf("https://%s/graphql", host)
 
 	req, err := http.NewRequest("POST", endpoint, bytes.NewReader(body))
 	if err != nil {
@@ -258,7 +293,12 @@ func (c *Client) DoTrust(host string, query string, variables map[string]any) (*
 
 	req.Header.Set("Content-Type", "application/json")
 
-	resp, err := trustHTTPClient(host).Do(req)
+	client := trustHTTPClient(host)
+	if c.trustClient != nil && host == c.trustHost {
+		client = c.trustClient
+	}
+
+	resp, err := client.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("request failed: %w", err)
 	}
@@ -353,6 +393,10 @@ func (c *Client) BaseURL() string {
 	return c.baseURL
 }
 
+func TrustHTTPClient(trustHost string) *http.Client {
+	return trustHTTPClient(trustHost)
+}
+
 type UploadFile struct {
 	Filename    string
 	ContentType string
diff --git a/e2e/trust/helpers_test.go b/e2e/trust/helpers_test.go
index f01d4cc78..fedc28a3b 100644
--- a/e2e/trust/helpers_test.go
+++ b/e2e/trust/helpers_test.go
@@ -21,6 +21,7 @@
 package trust_test
 
 import (
+	"net/url"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -58,6 +59,42 @@ func lookupTrustCenterID(t *testing.T, owner *testutil.Client) string {
 	return result.Node.TrustCenter.ID
 }
 
+func lookupTrustHost(t *testing.T, owner *testutil.Client, trustCenterID string) string {
+	t.Helper()
+
+	activateTrustCenter(t, owner, trustCenterID)
+
+	const query = `
+		query($organizationId: ID!) {
+			node(id: $organizationId) {
+				... on Organization {
+					trustCenter { publicUrl }
+				}
+			}
+		}
+	`
+
+	var result struct {
+		Node struct {
+			TrustCenter struct {
+				PublicURL string `json:"publicUrl"`
+			} `json:"trustCenter"`
+		} `json:"node"`
+	}
+
+	err := owner.Execute(query, map[string]any{
+		"organizationId": owner.GetOrganizationID().String(),
+	}, &result)
+	require.NoError(t, err)
+	require.NotEmpty(t, result.Node.TrustCenter.PublicURL)
+
+	publicURL, err := url.Parse(result.Node.TrustCenter.PublicURL)
+	require.NoError(t, err)
+	require.NotEmpty(t, publicURL.Host)
+
+	return publicURL.Host
+}
+
 // activateTrustCenter flips the trust center to active so its public surface
 // (NDA, subprocessors, reports, branding) becomes reachable by visitors.
 func activateTrustCenter(t *testing.T, owner *testutil.Client, trustCenterID string) {
diff --git a/e2e/trust/trust_center_nda_signature_test.go b/e2e/trust/trust_center_nda_signature_test.go
index 30a8e2e8e..675abb885 100644
--- a/e2e/trust/trust_center_nda_signature_test.go
+++ b/e2e/trust/trust_center_nda_signature_test.go
@@ -60,12 +60,12 @@ func TestTrustCenter_AcceptElectronicSignature_RejectsForeignSignature(t *testin
 	trustCenterID := lookupTrustCenterID(t, owner)
 
 	uploadTrustCenterNDA(t, owner, trustCenterID)
-	activateTrustCenter(t, owner, trustCenterID)
+	trustHost := lookupTrustHost(t, owner, trustCenterID)
 
-	victim := testutil.SelfProvisionTrustCenterVisitor(t, trustCenterID)
-	attacker := testutil.SelfProvisionTrustCenterVisitor(t, trustCenterID)
+	victim := testutil.SelfProvisionTrustCenterVisitor(t, trustHost)
+	attacker := testutil.SelfProvisionTrustCenterVisitor(t, trustHost)
 
-	victimSignatureID, victimSignatureStatus := viewerSignature(t, victim, trustCenterID)
+	victimSignatureID, victimSignatureStatus := viewerSignature(t, victim, trustHost)
 	require.NotEmpty(t, victimSignatureID)
 	require.Equal(t, "PENDING", victimSignatureStatus)
 
@@ -77,7 +77,7 @@ func TestTrustCenter_AcceptElectronicSignature_RejectsForeignSignature(t *testin
 		}
 	`
 
-	err := attacker.ExecuteTrust(trustCenterID, acceptMutation, map[string]any{
+	err := attacker.ExecuteTrust(trustHost, acceptMutation, map[string]any{
 		"input": map[string]any{"signatureId": victimSignatureID},
 	}, nil)
 	require.Error(t, err, "attacker must not be able to accept another visitor's signature")
@@ -91,7 +91,7 @@ func TestTrustCenter_AcceptElectronicSignature_RejectsForeignSignature(t *testin
 		}
 	`
 
-	err = attacker.ExecuteTrust(trustCenterID, recordEventMutation, map[string]any{
+	err = attacker.ExecuteTrust(trustHost, recordEventMutation, map[string]any{
 		"input": map[string]any{
 			"signatureId": victimSignatureID,
 			"eventType":   "DOCUMENT_VIEWED",
@@ -100,7 +100,7 @@ func TestTrustCenter_AcceptElectronicSignature_RejectsForeignSignature(t *testin
 	require.Error(t, err, "attacker must not be able to inject events into another visitor's signature")
 	assertForbidden(t, err)
 
-	_, statusAfterAttack := viewerSignature(t, victim, trustCenterID)
+	_, statusAfterAttack := viewerSignature(t, victim, trustHost)
 	assert.Equal(t, "PENDING", statusAfterAttack, "attack attempts must not have mutated the victim's signature")
 
 	var acceptResult struct {
@@ -112,7 +112,7 @@ func TestTrustCenter_AcceptElectronicSignature_RejectsForeignSignature(t *testin
 		} `json:"acceptElectronicSignature"`
 	}
 
-	err = victim.ExecuteTrust(trustCenterID, acceptMutation, map[string]any{
+	err = victim.ExecuteTrust(trustHost, acceptMutation, map[string]any{
 		"input": map[string]any{"signatureId": victimSignatureID},
 	}, &acceptResult)
 	require.NoError(t, err, "the legitimate signer must still be able to accept their own signature")
@@ -147,7 +147,7 @@ func uploadTrustCenterNDA(t *testing.T, owner *testutil.Client, trustCenterID st
 	require.NoError(t, err)
 }
 
-func viewerSignature(t *testing.T, visitor *testutil.Client, trustCenterID string) (string, string) {
+func viewerSignature(t *testing.T, visitor *testutil.Client, trustHost string) (string, string) {
 	t.Helper()
 
 	const query = `
@@ -171,7 +171,7 @@ func viewerSignature(t *testing.T, visitor *testutil.Client, trustCenterID strin
 		} `json:"currentTrustCenter"`
 	}
 
-	err := visitor.ExecuteTrust(trustCenterID, query, nil, &result)
+	err := visitor.ExecuteTrust(trustHost, query, nil, &result)
 	require.NoError(t, err)
 
 	sig := result.CurrentTrustCenter.NonDisclosureAgreement.ViewerSignature
diff --git a/e2e/trust/trust_center_oauth_connect_test.go b/e2e/trust/trust_center_oauth_connect_test.go
new file mode 100644
index 000000000..d3c9c8360
--- /dev/null
+++ b/e2e/trust/trust_center_oauth_connect_test.go
@@ -0,0 +1,134 @@
+// Copyright (c) 2026 Probo Inc <hello@probo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package trust_test
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/url"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.probo.inc/probo/e2e/internal/testutil"
+)
+
+func TestTrustCenter_CIMDMetadataDocument(t *testing.T) {
+	t.Parallel()
+
+	owner := testutil.NewClient(t, testutil.RoleOwner)
+	trustCenterID := lookupTrustCenterID(t, owner)
+	trustHost := lookupTrustHost(t, owner, trustCenterID)
+	testutil.WaitForTrustCenterHTTPS(t, trustHost)
+
+	client := testutil.TrustHTTPClient(trustHost)
+	resp, err := client.Get("https://" + trustHost + "/.well-known/oauth-client-metadata")
+	require.NoError(t, err)
+
+	defer func() { _ = resp.Body.Close() }()
+
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+
+	body, err := io.ReadAll(resp.Body)
+	require.NoError(t, err)
+
+	var doc struct {
+		ClientID                string   `json:"client_id"`
+		ClientName              string   `json:"client_name"`
+		RedirectURIs            []string `json:"redirect_uris"`
+		TokenEndpointAuthMethod string   `json:"token_endpoint_auth_method"`
+		GrantTypes              []string `json:"grant_types"`
+		ResponseTypes           []string `json:"response_types"`
+	}
+	require.NoError(t, json.Unmarshal(body, &doc))
+
+	assert.Equal(
+		t,
+		"https://"+trustHost+"/.well-known/oauth-client-metadata",
+		doc.ClientID,
+	)
+	assert.Equal(
+		t,
+		[]string{"https://" + trustHost + "/callback"},
+		doc.RedirectURIs,
+	)
+	assert.Equal(t, "none", doc.TokenEndpointAuthMethod)
+	assert.Contains(t, doc.GrantTypes, "authorization_code")
+	assert.Equal(t, []string{"code"}, doc.ResponseTypes)
+	assert.NotEmpty(t, doc.ClientName)
+}
+
+func TestTrustCenter_VisitorConnectViaCIMD(t *testing.T) {
+	t.Parallel()
+
+	owner := testutil.NewClient(t, testutil.RoleOwner)
+	trustCenterID := lookupTrustCenterID(t, owner)
+	trustHost := lookupTrustHost(t, owner, trustCenterID)
+
+	visitor := testutil.SelfProvisionTrustCenterVisitor(t, trustHost)
+
+	const query = `
+		query {
+			currentTrustCenter {
+				title
+			}
+		}
+	`
+
+	var result struct {
+		CurrentTrustCenter struct {
+			Title string `json:"title"`
+		} `json:"currentTrustCenter"`
+	}
+
+	err := visitor.ExecuteTrust(trustHost, query, nil, &result)
+	require.NoError(t, err, "visitor session must authenticate trust GraphQL after CIMD connect")
+	assert.NotEmpty(t, result.CurrentTrustCenter.Title)
+}
+
+func TestTrustCenter_UnknownCIMDClientRejected(t *testing.T) {
+	t.Parallel()
+
+	owner := testutil.NewClient(t, testutil.RoleOwner)
+	_, challenge := testutil.GeneratePKCE()
+
+	clientID := "https://unknown-cimd.example.com/.well-known/oauth-client-metadata"
+
+	resp, err := testutil.OAuth2Authorize(owner, url.Values{
+		"client_id":             {clientID},
+		"redirect_uri":          {"https://unknown-cimd.example.com/callback"},
+		"response_type":         {"code"},
+		"scope":                 {"openid profile email"},
+		"state":                 {"rejected"},
+		"code_challenge":        {challenge},
+		"code_challenge_method": {"S256"},
+		"nonce":                 {"test-nonce"},
+	})
+	require.NoError(t, err)
+
+	require.False(
+		t,
+		testutil.IsConsentRedirect(resp),
+		"unknown CIMD client must not reach consent screen",
+	)
+	require.Equal(t, http.StatusUnauthorized, resp.StatusCode)
+
+	var oauthErr struct {
+		Code string `json:"error"`
+	}
+	require.NoError(t, json.Unmarshal(resp.Body, &oauthErr))
+	assert.Equal(t, "invalid_client", oauthErr.Code)
+}