diff --git a/docs/man/nng_http_req_get_header.3http.adoc b/docs/man/nng_http_req_get_header.3http.adoc
index 2b01f959d..cbc6ec493 100644
--- a/docs/man/nng_http_req_get_header.3http.adoc
+++ b/docs/man/nng_http_req_get_header.3http.adoc
@@ -20,7 +20,7 @@ nng_http_req_get_header - return HTTP request header
 #include <nng/nng.h>
 #include <nng/supplemental/http/http.h>
 
-const char *nng_http_req_get_header(nng_http_req *req, const char *key);
+const char *nng_http_req_get_header(const nng_http_req *req, const char *key);
 ----
 
 == DESCRIPTION
diff --git a/docs/man/nng_http_req_get_method.3http.adoc b/docs/man/nng_http_req_get_method.3http.adoc
index 85e81278b..20f6010b1 100644
--- a/docs/man/nng_http_req_get_method.3http.adoc
+++ b/docs/man/nng_http_req_get_method.3http.adoc
@@ -20,7 +20,7 @@ nng_http_req_get_method - return HTTP request method
 #include <nng/nng.h>
 #include <nng/supplemental/http/http.h>
 
-const char *nng_http_req_get_method(nng_http_req *req);
+const char *nng_http_req_get_method(const nng_http_req *req);
 ----
 
 == DESCRIPTION
diff --git a/docs/man/nng_http_req_get_uri.3http.adoc b/docs/man/nng_http_req_get_uri.3http.adoc
index 6239efce8..8e664a1fd 100644
--- a/docs/man/nng_http_req_get_uri.3http.adoc
+++ b/docs/man/nng_http_req_get_uri.3http.adoc
@@ -20,7 +20,7 @@ nng_http_req_get_uri - return HTTP request URI
 #include <nng/nng.h>
 #include <nng/supplemental/http/http.h>
 
-const char *nng_http_req_get_uri(nng_http_req *req);
+const char *nng_http_req_get_uri(const nng_http_req *req);
 ----
 
 == DESCRIPTION
diff --git a/docs/man/nng_http_req_get_version.3http.adoc b/docs/man/nng_http_req_get_version.3http.adoc
index ef526df83..537f6caf3 100644
--- a/docs/man/nng_http_req_get_version.3http.adoc
+++ b/docs/man/nng_http_req_get_version.3http.adoc
@@ -20,7 +20,7 @@ nng_http_req_get_version - return HTTP request protocol version
 #include <nng/nng.h>
 #include <nng/supplemental/http/http.h>
 
-const char *nng_http_req_get_version(nng_http_req *req);
+const char *nng_http_req_get_version(const nng_http_req *req);
 ----
 
 == DESCRIPTION
diff --git a/docs/man/nng_http_res_get_header.3http.adoc b/docs/man/nng_http_res_get_header.3http.adoc
index 34c5b0150..51d37abab 100644
--- a/docs/man/nng_http_res_get_header.3http.adoc
+++ b/docs/man/nng_http_res_get_header.3http.adoc
@@ -20,7 +20,7 @@ nng_http_res_get_header - return HTTP response header
 #include <nng/nng.h>
 #include <nng/supplemental/http/http.h>
 
-const char *nng_http_res_get_header(nng_http_res *res, const char *key);
+const char *nng_http_res_get_header(const nng_http_res *res, const char *key);
 ----
 
 == DESCRIPTION
diff --git a/docs/man/nng_http_res_get_reason.3http.adoc b/docs/man/nng_http_res_get_reason.3http.adoc
index a4167a0ac..3b9fdd587 100644
--- a/docs/man/nng_http_res_get_reason.3http.adoc
+++ b/docs/man/nng_http_res_get_reason.3http.adoc
@@ -20,7 +20,7 @@ nng_http_res_get_reason - return HTTP response reason
 #include <nng/nng.h>
 #include <nng/supplemental/http/http.h>
 
-const char *nng_http_res_get_reason(nng_http_res *res);
+const char *nng_http_res_get_reason(const nng_http_res *res);
 ----
 
 == DESCRIPTION
diff --git a/docs/man/nng_http_res_get_status.3http.adoc b/docs/man/nng_http_res_get_status.3http.adoc
index 0ad9092ad..827cfbf6b 100644
--- a/docs/man/nng_http_res_get_status.3http.adoc
+++ b/docs/man/nng_http_res_get_status.3http.adoc
@@ -20,7 +20,7 @@ nng_http_res_get_status - return HTTP status code
 #include <nng/nng.h>
 #include <nng/supplemental/http/http.h>
 
-uint16_t nng_http_res_get_status(nng_http_res *res);
+uint16_t nng_http_res_get_status(const nng_http_res *res);
 ----
 
 == DESCRIPTION
diff --git a/include/nng/supplemental/http/http.h b/include/nng/supplemental/http/http.h
index ff8616ca3..fa81f984d 100644
--- a/include/nng/supplemental/http/http.h
+++ b/include/nng/supplemental/http/http.h
@@ -1,5 +1,5 @@
 //
-// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2024 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 // Copyright 2020 Dirac Research <robert.bielik@dirac.com>
 //
@@ -22,7 +22,7 @@ extern "C" {
 
 #include <stdint.h>
 
-struct nng_tls_config;
+#include <nng/nng.h>
 
 // HTTP status codes.  This list is not exhaustive.
 enum nng_http_status {
@@ -101,14 +101,14 @@ NNG_DECL int nng_http_req_alloc(nng_http_req **, const nng_url *);
 NNG_DECL void nng_http_req_free(nng_http_req *);
 
 // nng_http_req_get_method returns the method.
-NNG_DECL const char *nng_http_req_get_method(nng_http_req *);
+NNG_DECL const char *nng_http_req_get_method(const nng_http_req *);
 
 // nng_http_req_get_version returns the version, usually HTTP/1.1.
-NNG_DECL const char *nng_http_req_get_version(nng_http_req *);
+NNG_DECL const char *nng_http_req_get_version(const nng_http_req *);
 
 // nng_http_req_get_uri returns the "abs-uri", which is URL without
 // the scheme, host, or port.
-NNG_DECL const char *nng_http_req_get_uri(nng_http_req *);
+NNG_DECL const char *nng_http_req_get_uri(const nng_http_req *);
 
 // nng_http_req_set_header sets an HTTP header, replacing any previous value
 // that might have been present.
@@ -125,7 +125,8 @@ NNG_DECL int nng_http_req_del_header(nng_http_req *, const char *);
 
 // nng_http_req_get_header looks up a header with the named, returns NULL
 // if not found.
-NNG_DECL const char *nng_http_req_get_header(nng_http_req *, const char *);
+NNG_DECL const char *nng_http_req_get_header(
+    const nng_http_req *, const char *);
 
 // nng_http_req_set_method is used to change the method of a request.
 // The method should be an upper case HTTP method, like POST, or DELETE.
@@ -174,14 +175,14 @@ NNG_DECL int nng_http_res_alloc_error(nng_http_res **, uint16_t);
 NNG_DECL void nng_http_res_free(nng_http_res *);
 
 // nng_http_res_get_status returns the HTTP status code from the server.
-NNG_DECL uint16_t nng_http_res_get_status(nng_http_res *);
+NNG_DECL uint16_t nng_http_res_get_status(const nng_http_res *);
 
 // nng_http_res_set_status sets the HTTP status code.
 NNG_DECL int nng_http_res_set_status(nng_http_res *, uint16_t);
 
 // nng_http_res_get_reason returns the human readable status message
 // that the server responds (or responded) with.
-NNG_DECL const char *nng_http_res_get_reason(nng_http_res *);
+NNG_DECL const char *nng_http_res_get_reason(const nng_http_res *);
 
 // nng_http_res_set_reason sets the human readable status message.
 // NULL means that a default reason is used based on the status code.
@@ -202,7 +203,8 @@ NNG_DECL int nng_http_res_del_header(nng_http_res *, const char *);
 
 // nng_http_res_get_header looks up a header with the named, returns NULL
 // if not found.
-NNG_DECL const char *nng_http_res_get_header(nng_http_res *, const char *);
+NNG_DECL const char *nng_http_res_get_header(
+    const nng_http_res *, const char *);
 
 // nng_http_res_set_version is used to change the version of a response.
 // Normally the version is "HTTP/1.1".  Note that the framework does
@@ -210,7 +212,7 @@ NNG_DECL const char *nng_http_res_get_header(nng_http_res *, const char *);
 NNG_DECL int nng_http_res_set_version(nng_http_res *, const char *);
 
 // nng_http_res_get_version returns the version, usually HTTP/1.1.
-NNG_DECL const char *nng_http_res_get_version(nng_http_res *);
+NNG_DECL const char *nng_http_res_get_version(const nng_http_res *);
 
 // nng_http_res_get_data gets the data for the response.
 NNG_DECL void nng_http_res_get_data(nng_http_res *, void **, size_t *);
@@ -437,14 +439,12 @@ NNG_DECL int nng_http_server_del_handler(
 // server client, so the caller must have configured it reasonably.
 // This API is not recommended unless the caller needs complete control
 // over the TLS configuration.
-NNG_DECL int nng_http_server_set_tls(
-    nng_http_server *, struct nng_tls_config *);
+NNG_DECL int nng_http_server_set_tls(nng_http_server *, nng_tls_config *);
 
 // nng_http_server_get_tls obtains the TLS configuration if one is present,
 // or returns NNG_EINVAL.  The TLS configuration is invalidated if the
 // nng_http_server_set_tls function is called, so be careful.
-NNG_DECL int nng_http_server_get_tls(
-    nng_http_server *, struct nng_tls_config **);
+NNG_DECL int nng_http_server_get_tls(nng_http_server *, nng_tls_config **);
 
 // nng_http_server_get_addr obtains the address with which the server was
 // initialized or returns NNG_EINVAL. Useful for instance when the port has
@@ -504,14 +504,12 @@ NNG_DECL void nng_http_client_free(nng_http_client *);
 // the entire TLS configuration on the client, so the caller must have
 // configured it reasonably.  This API is not recommended unless the
 // caller needs complete control over the TLS configuration.
-NNG_DECL int nng_http_client_set_tls(
-    nng_http_client *, struct nng_tls_config *);
+NNG_DECL int nng_http_client_set_tls(nng_http_client *, nng_tls_config *);
 
 // nng_http_client_get_tls obtains the TLS configuration if one is present,
 // or returns NNG_EINVAL.  The supplied TLS configuration object may
 // be invalidated by any future calls to nni_http_client_set_tls.
-NNG_DECL int nng_http_client_get_tls(
-    nng_http_client *, struct nng_tls_config **);
+NNG_DECL int nng_http_client_get_tls(nng_http_client *, nng_tls_config **);
 
 // nng_http_client_connect establishes a new connection with the server
 // named in the URL used when the client was created.  Once the connection
diff --git a/src/supplemental/http/http_api.h b/src/supplemental/http/http_api.h
index dbda53ae9..46a022113 100644
--- a/src/supplemental/http/http_api.h
+++ b/src/supplemental/http/http_api.h
@@ -118,8 +118,8 @@ extern void nni_http_write_res(nni_http_conn *, nni_http_res *, nni_aio *);
 extern void nni_http_read_req(nni_http_conn *, nni_http_req *, nni_aio *);
 extern void nni_http_read_res(nni_http_conn *, nni_http_res *, nni_aio *);
 
-extern const char *nni_http_req_get_header(nni_http_req *, const char *);
-extern const char *nni_http_res_get_header(nni_http_res *, const char *);
+extern const char *nni_http_req_get_header(const nni_http_req *, const char *);
+extern const char *nni_http_res_get_header(const nni_http_res *, const char *);
 extern int nni_http_req_add_header(nni_http_req *, const char *, const char *);
 extern int nni_http_res_add_header(nni_http_res *, const char *, const char *);
 extern int nni_http_req_set_header(nni_http_req *, const char *, const char *);
@@ -132,17 +132,17 @@ extern int nni_http_req_set_data(nni_http_req *, const void *, size_t);
 extern int nni_http_res_set_data(nni_http_res *, const void *, size_t);
 extern int nni_http_req_alloc_data(nni_http_req *, size_t);
 extern int nni_http_res_alloc_data(nni_http_res *, size_t);
-extern const char *nni_http_req_get_method(nni_http_req *);
-extern const char *nni_http_req_get_version(nni_http_req *);
-extern const char *nni_http_req_get_uri(nni_http_req *);
+extern const char *nni_http_req_get_method(const nni_http_req *);
+extern const char *nni_http_req_get_version(const nni_http_req *);
+extern const char *nni_http_req_get_uri(const nni_http_req *);
 extern int         nni_http_req_set_method(nni_http_req *, const char *);
 extern int         nni_http_req_set_version(nni_http_req *, const char *);
 extern int         nni_http_req_set_uri(nni_http_req *, const char *);
-extern uint16_t    nni_http_res_get_status(nni_http_res *);
+extern uint16_t    nni_http_res_get_status(const nni_http_res *);
 extern int         nni_http_res_set_status(nni_http_res *, uint16_t);
-extern const char *nni_http_res_get_version(nni_http_res *);
+extern const char *nni_http_res_get_version(const nni_http_res *);
 extern int         nni_http_res_set_version(nni_http_res *, const char *);
-extern const char *nni_http_res_get_reason(nni_http_res *);
+extern const char *nni_http_res_get_reason(const nni_http_res *);
 extern int         nni_http_res_set_reason(nni_http_res *, const char *);
 
 // nni_http_res_is_error is true if the status was allocated as part of
diff --git a/src/supplemental/http/http_msg.c b/src/supplemental/http/http_msg.c
index 2c258e2c0..5a0baf370 100644
--- a/src/supplemental/http/http_msg.c
+++ b/src/supplemental/http/http_msg.c
@@ -1,5 +1,5 @@
 //
-// Copyright 2019 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2024 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 //
 // This software is supplied under the terms of the MIT License, a
@@ -262,7 +262,7 @@ nni_http_res_add_header(nni_http_res *res, const char *key, const char *val)
 }
 
 static const char *
-http_get_header(nni_list *hdrs, const char *key)
+http_get_header(const nni_list *hdrs, const char *key)
 {
 	http_header *h;
 	NNI_LIST_FOREACH (hdrs, h) {
@@ -274,13 +274,13 @@ http_get_header(nni_list *hdrs, const char *key)
 }
 
 const char *
-nni_http_req_get_header(nni_http_req *req, const char *key)
+nni_http_req_get_header(const nni_http_req *req, const char *key)
 {
 	return (http_get_header(&req->hdrs, key));
 }
 
 const char *
-nni_http_res_get_header(nni_http_res *res, const char *key)
+nni_http_res_get_header(const nni_http_res *res, const char *key)
 {
 	return (http_get_header(&res->hdrs, key));
 }
@@ -672,25 +672,25 @@ nni_http_res_alloc(nni_http_res **resp)
 }
 
 const char *
-nni_http_req_get_method(nni_http_req *req)
+nni_http_req_get_method(const nni_http_req *req)
 {
 	return (req->meth != NULL ? req->meth : "GET");
 }
 
 const char *
-nni_http_req_get_uri(nni_http_req *req)
+nni_http_req_get_uri(const nni_http_req *req)
 {
 	return (req->uri != NULL ? req->uri : "");
 }
 
 const char *
-nni_http_req_get_version(nni_http_req *req)
+nni_http_req_get_version(const nni_http_req *req)
 {
 	return (req->vers != NULL ? req->vers : "HTTP/1.1");
 }
 
 const char *
-nni_http_res_get_version(nni_http_res *res)
+nni_http_res_get_version(const nni_http_res *res)
 {
 	return (res->vers != NULL ? res->vers : "HTTP/1.1");
 }
@@ -736,7 +736,7 @@ nni_http_res_set_status(nni_http_res *res, uint16_t status)
 }
 
 uint16_t
-nni_http_res_get_status(nni_http_res *res)
+nni_http_res_get_status(const nni_http_res *res)
 {
 	return (res->code);
 }
@@ -1011,7 +1011,7 @@ nni_http_reason(uint16_t code)
 }
 
 const char *
-nni_http_res_get_reason(nni_http_res *res)
+nni_http_res_get_reason(const nni_http_res *res)
 {
 	return (res->rsn ? res->rsn : nni_http_reason(res->code));
 }
diff --git a/src/supplemental/http/http_public.c b/src/supplemental/http/http_public.c
index 633f83c78..161aefd88 100644
--- a/src/supplemental/http/http_public.c
+++ b/src/supplemental/http/http_public.c
@@ -1,5 +1,5 @@
 //
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2024 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 //
 // This software is supplied under the terms of the MIT License, a
@@ -72,7 +72,7 @@ nng_http_res_alloc_error(nng_http_res **resp, uint16_t code)
 }
 
 const char *
-nng_http_req_get_header(nng_http_req *req, const char *key)
+nng_http_req_get_header(const nng_http_req *req, const char *key)
 {
 #ifdef NNG_SUPP_HTTP
 	return (nni_http_req_get_header(req, key));
@@ -84,7 +84,7 @@ nng_http_req_get_header(nng_http_req *req, const char *key)
 }
 
 const char *
-nng_http_res_get_header(nng_http_res *res, const char *key)
+nng_http_res_get_header(const nng_http_res *res, const char *key)
 {
 #ifdef NNG_SUPP_HTTP
 	return (nni_http_res_get_header(res, key));
@@ -248,7 +248,7 @@ nng_http_res_get_data(nng_http_res *res, void **datap, size_t *lenp)
 }
 
 const char *
-nng_http_req_get_method(nng_http_req *req)
+nng_http_req_get_method(const nng_http_req *req)
 {
 #ifdef NNG_SUPP_HTTP
 	return (nni_http_req_get_method(req));
@@ -259,7 +259,7 @@ nng_http_req_get_method(nng_http_req *req)
 }
 
 const char *
-nng_http_req_get_version(nng_http_req *req)
+nng_http_req_get_version(const nng_http_req *req)
 {
 #ifdef NNG_SUPP_HTTP
 	return (nni_http_req_get_version(req));
@@ -270,7 +270,7 @@ nng_http_req_get_version(nng_http_req *req)
 }
 
 const char *
-nng_http_req_get_uri(nng_http_req *req)
+nng_http_req_get_uri(const nng_http_req *req)
 {
 #ifdef NNG_SUPP_HTTP
 	return (nni_http_req_get_uri(req));
@@ -317,7 +317,7 @@ nng_http_req_set_uri(nng_http_req *req, const char *uri)
 }
 
 uint16_t
-nng_http_res_get_status(nng_http_res *res)
+nng_http_res_get_status(const nng_http_res *res)
 {
 #ifdef NNG_SUPP_HTTP
 	return (nni_http_res_get_status(res));
@@ -328,7 +328,7 @@ nng_http_res_get_status(nng_http_res *res)
 }
 
 const char *
-nng_http_res_get_version(nng_http_res *res)
+nng_http_res_get_version(const nng_http_res *res)
 {
 #ifdef NNG_SUPP_HTTP
 	return (nni_http_res_get_version(res));
@@ -339,7 +339,7 @@ nng_http_res_get_version(nng_http_res *res)
 }
 
 const char *
-nng_http_res_get_reason(nng_http_res *res)
+nng_http_res_get_reason(const nng_http_res *res)
 {
 #ifdef NNG_SUPP_HTTP
 	return (nni_http_res_get_reason(res));
@@ -765,7 +765,7 @@ nng_http_server_set_error_file(
 }
 
 int
-nng_http_server_set_tls(nng_http_server *srv, struct nng_tls_config *cfg)
+nng_http_server_set_tls(nng_http_server *srv, nng_tls_config *cfg)
 {
 #if defined(NNG_SUPP_HTTP) && defined(NNG_SUPP_TLS)
 	return (nni_http_server_set_tls(srv, cfg));
@@ -777,7 +777,7 @@ nng_http_server_set_tls(nng_http_server *srv, struct nng_tls_config *cfg)
 }
 
 int
-nng_http_server_get_tls(nng_http_server *srv, struct nng_tls_config **cfg)
+nng_http_server_get_tls(nng_http_server *srv, nng_tls_config **cfg)
 {
 #if defined(NNG_SUPP_HTTP) && defined(NNG_SUPP_TLS)
 	return (nni_http_server_get_tls(srv, cfg));
@@ -850,7 +850,7 @@ nng_http_client_free(nng_http_client *cli)
 }
 
 int
-nng_http_client_set_tls(nng_http_client *cli, struct nng_tls_config *cfg)
+nng_http_client_set_tls(nng_http_client *cli, nng_tls_config *cfg)
 {
 #if defined(NNG_SUPP_HTTP) && defined(NNG_SUPP_TLS)
 	return (nni_http_client_set_tls(cli, cfg));
@@ -862,7 +862,7 @@ nng_http_client_set_tls(nng_http_client *cli, struct nng_tls_config *cfg)
 }
 
 int
-nng_http_client_get_tls(nng_http_client *cli, struct nng_tls_config **cfgp)
+nng_http_client_get_tls(nng_http_client *cli, nng_tls_config **cfgp)
 {
 #if defined(NNG_SUPP_HTTP) && defined(NNG_SUPP_TLS)
 	return (nni_http_client_get_tls(cli, cfgp));