diff --git a/include/bravais.h b/include/bravais.h
index f795dd6..ef3ed6f 100644
--- a/include/bravais.h
+++ b/include/bravais.h
@@ -33,6 +33,8 @@ typedef enum {
     BRAVAIS_ERR_MALFORMED = -3,
     BRAVAIS_ERR_OUT_OF_MEMORY = -4,
     BRAVAIS_ERR_UNSUPPORTED = -5,
+    BRAVAIS_ERR_AUTH = -6,
+    BRAVAIS_ERR_STATE = -7,
 
     BRAVAIS_ERR_UNKNOWN = -1000
 } bravais_result_t;
diff --git a/src/proto/conn.c b/src/proto/conn.c
new file mode 100644
index 0000000..b500127
--- /dev/null
+++ b/src/proto/conn.c
@@ -0,0 +1,125 @@
+// conn.c
+// Top-level connection object and the public API surface
+//
+// Lifecycle made but the data path is a stub for now.
+
+#include "proto/conn.h"
+#include "util/hygiene.h"
+
+#include <stdlib.h>
+
+static void conn_log(const bravais_conn_t* conn, bravais_log_level_t level, const char* msg) {
+    if (!conn->config.logFn) { return; }
+    conn->config.logFn(conn->config.logUserData, level, msg);
+}
+
+static bool config_is_valid(const bravais_config_t* config) {
+    if (!config) { return false; }
+    if (config->role != BRAVAIS_ROLE_INITIATOR && config->role != BRAVAIS_ROLE_RESPONDER) { return false; }
+    if (config->transportMode != BRAVAIS_TRANSPORT_RAW && config->transportMode != BRAVAIS_TRANSPORT_QUIC) { return false; }
+
+    return true;
+}
+
+void bravais_config_init(bravais_config_t* config) {
+    if (!config) { return; }
+
+    config->role = BRAVAIS_ROLE_INITIATOR;
+    config->transportMode = BRAVAIS_TRANSPORT_RAW;
+    config->logFn = nullptr;
+    config->logUserData = nullptr;
+}
+
+bravais_result_t bravais_conn_create(const bravais_config_t* config, bravais_conn_t** outConn) {
+    if (!outConn) { return BRAVAIS_ERR_INVALID_ARG; }
+    *outConn = nullptr;
+
+    if (!config || !config_is_valid(config)) { return BRAVAIS_ERR_INVALID_ARG; }
+    
+    bravais_conn_t* newConn = (bravais_conn_t*)calloc(1, sizeof(*newConn));
+    if (!newConn) { return BRAVAIS_ERR_OUT_OF_MEMORY; }
+
+    newConn->config = *config;
+    newConn->state = BRAVAIS_CONN_STATE_IDLE;
+
+    conn_log(newConn, BRAVAIS_LOG_LEVEL_DEBUG, "Connection created");
+    *outConn = newConn;
+
+    return BRAVAIS_OK;
+}
+
+void bravais_conn_destroy(bravais_conn_t* conn) {
+    if (!conn) { return; }
+
+    bravais_hygiene_zero(conn, sizeof(*conn));
+    free(conn);
+    conn_log(conn, BRAVAIS_LOG_LEVEL_DEBUG, "Connection destroyed");
+}
+
+bravais_result_t bravais_recv_datagram(bravais_conn_t* conn, const uint8_t* buf, size_t bufLen, [[maybe_unused]] uint64_t nowMs) {
+    if (!conn || (!buf && bufLen != 0)) {
+        return BRAVAIS_ERR_INVALID_ARG;
+    }
+    return BRAVAIS_ERR_UNSUPPORTED;
+}
+
+bravais_result_t bravais_send_packet(bravais_conn_t* conn, const uint8_t* buf, size_t bufLen, [[maybe_unused]] uint64_t nowMs) {
+    if (!conn || (!buf && bufLen != 0)) {
+        return BRAVAIS_ERR_INVALID_ARG;
+    }
+
+    if (bufLen > BRAVAIS_MAX_PLAINTEXT_SIZE) {
+        return BRAVAIS_ERR_INVALID_ARG;
+    }
+
+    return BRAVAIS_ERR_UNSUPPORTED;
+}
+
+bravais_result_t bravais_poll_datagram(bravais_conn_t* conn, uint8_t* out, size_t* outLen, [[maybe_unused]] uint64_t nowMs) {
+    if (!conn || !out || !outLen) {
+        return BRAVAIS_ERR_INVALID_ARG;
+    }
+
+    *outLen = 0;
+
+    return BRAVAIS_ERR_UNSUPPORTED;
+}
+
+bravais_result_t bravais_poll_plaintext(bravais_conn_t* conn, uint8_t* out, size_t* outLen, [[maybe_unused]] uint64_t nowMs) {
+    if (!conn || !out || !outLen) {
+        return BRAVAIS_ERR_INVALID_ARG;
+    }
+
+    *outLen = 0;
+
+    return BRAVAIS_EMPTY;
+}
+
+uint64_t bravais_next_timeout([[maybe_unused]] const bravais_conn_t* conn) {
+    return UINT64_MAX;
+}
+
+bravais_result_t bravais_on_timeout(bravais_conn_t* conn, [[maybe_unused]] uint64_t nowMs) {
+    if (!conn) {
+        return BRAVAIS_ERR_INVALID_ARG;
+    }
+    
+    return BRAVAIS_OK;
+}
+
+const char* bravais_result_str(bravais_result_t result) {
+    switch (result) {
+        case BRAVAIS_OK: return "OK";
+        case BRAVAIS_EMPTY: return "Nothing to emit right now";
+        case BRAVAIS_ERR_INVALID_ARG: return "Invalid argument";
+        case BRAVAIS_ERR_BUFFER_TOO_SMALL: return "Buffer too small";
+        case BRAVAIS_ERR_MALFORMED: return "Malformed input";
+        case BRAVAIS_ERR_OUT_OF_MEMORY: return "Out of memory";
+        case BRAVAIS_ERR_UNSUPPORTED: return "Unsupported or unimplemented feature";
+        case BRAVAIS_ERR_UNKNOWN: return "Unknown error";
+        case BRAVAIS_ERR_AUTH: return "Authentication failed";
+        case BRAVAIS_ERR_STATE: return "Invalid state for operation";
+        
+        return "Unknown result";
+    }
+}
diff --git a/src/proto/conn.h b/src/proto/conn.h
new file mode 100644
index 0000000..46d076f
--- /dev/null
+++ b/src/proto/conn.h
@@ -0,0 +1,23 @@
+// conn.h
+// Connection internals for the lib
+//
+// Generally only included from proto/; others should use params instead for field access
+
+#ifndef BRAVAIS_CONN_H
+#define BRAVAIS_CONN_H
+
+#include "bravais.h"
+
+typedef enum {
+    BRAVAIS_CONN_STATE_IDLE,
+    BRAVAIS_CONN_STATE_HANDSHAKE,
+    BRAVAIS_CONN_STATE_ESTABLISHED,
+    BRAVAIS_CONN_STATE_CLOSED
+} bravais_conn_state_t;
+
+struct bravais_conn {
+    bravais_config_t config;
+    bravais_conn_state_t state;
+};
+
+#endif // BRAVAIS_CONN_H