diff --git a/common/json_tok.c b/common/json_tok.c
index b03be4d41..6174aa60f 100644
--- a/common/json_tok.c
+++ b/common/json_tok.c
@@ -6,170 +6,165 @@
 #include <common/jsonrpc_errors.h>
 #include <common/param.h>
 
-bool json_tok_array(struct command *cmd, const char *name,
-		    const char *buffer, const jsmntok_t *tok,
-		    const jsmntok_t **arr)
+struct command_result *param_array(struct command *cmd, const char *name,
+				   const char *buffer, const jsmntok_t *tok,
+				   const jsmntok_t **arr)
 {
-	if (tok->type == JSMN_ARRAY)
-		return (*arr = tok);
+	if (tok->type == JSMN_ARRAY) {
+		*arr = tok;
+		return NULL;
+	}
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be an array, not '%.*s'",
-		     name, tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be an array, not '%.*s'",
+			    name, tok->end - tok->start, buffer + tok->start);
 }
 
-bool json_tok_bool(struct command *cmd, const char *name,
-		   const char *buffer, const jsmntok_t *tok,
-		   bool **b)
+struct command_result *param_bool(struct command *cmd, const char *name,
+				  const char *buffer, const jsmntok_t *tok,
+				  bool **b)
 {
 	*b = tal(cmd, bool);
 	if (json_to_bool(buffer, tok, *b))
-		return true;
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be 'true' or 'false', not '%.*s'",
-		     name, tok->end - tok->start, buffer + tok->start);
-	return false;
+		return NULL;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be 'true' or 'false', not '%.*s'",
+			    name, tok->end - tok->start, buffer + tok->start);
 }
 
-bool json_tok_double(struct command *cmd, const char *name,
-		     const char *buffer, const jsmntok_t *tok,
-		     double **num)
+struct command_result *param_double(struct command *cmd, const char *name,
+				    const char *buffer, const jsmntok_t *tok,
+				    double **num)
 {
 	*num = tal(cmd, double);
 	if (json_to_double(buffer, tok, *num))
-		return true;
+		return NULL;
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be a double, not '%.*s'",
-		     name, tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be a double, not '%.*s'",
+			    name, tok->end - tok->start, buffer + tok->start);
 }
 
-bool json_tok_escaped_string(struct command *cmd, const char *name,
-			     const char * buffer, const jsmntok_t *tok,
-			     const char **str)
+struct command_result *param_escaped_string(struct command *cmd,
+					    const char *name,
+					    const char * buffer,
+					    const jsmntok_t *tok,
+					    const char **str)
 {
 	struct json_escaped *esc = json_to_escaped_string(cmd, buffer, tok);
 	if (esc) {
 		*str = json_escaped_unescape(cmd, esc);
 		if (*str)
-			return true;
+			return NULL;
 	}
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be a string, not '%.*s'"
-		     " (note, we don't allow \\u)",
-		     name,
-		     tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be a string, not '%.*s'"
+			    " (note, we don't allow \\u)",
+			    name,
+			    tok->end - tok->start, buffer + tok->start);
 }
 
-bool json_tok_string(struct command *cmd, const char *name,
-		     const char * buffer, const jsmntok_t *tok,
-		     const char **str)
+struct command_result *param_string(struct command *cmd, const char *name,
+				    const char * buffer, const jsmntok_t *tok,
+				    const char **str)
 {
 	*str = tal_strndup(cmd, buffer + tok->start,
 			   tok->end - tok->start);
-	return true;
+	return NULL;
 }
 
-bool json_tok_label(struct command *cmd, const char *name,
-		    const char * buffer, const jsmntok_t *tok,
-		    struct json_escaped **label)
+struct command_result *param_label(struct command *cmd, const char *name,
+				   const char * buffer, const jsmntok_t *tok,
+				   struct json_escaped **label)
 {
 	/* We accept both strings and number literals here. */
 	*label = json_escaped_string_(cmd, buffer + tok->start, tok->end - tok->start);
 	if (*label && (tok->type == JSMN_STRING || json_tok_is_num(buffer, tok)))
-		    return true;
+		return NULL;
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be a string or number, not '%.*s'",
-		     name, tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be a string or number, not '%.*s'",
+			    name, tok->end - tok->start, buffer + tok->start);
 }
 
-bool json_tok_number(struct command *cmd, const char *name,
-		     const char *buffer, const jsmntok_t *tok,
-		     unsigned int **num)
+struct command_result *param_number(struct command *cmd, const char *name,
+				    const char *buffer, const jsmntok_t *tok,
+				    unsigned int **num)
 {
 	*num = tal(cmd, unsigned int);
 	if (json_to_number(buffer, tok, *num))
-		return true;
+		return NULL;
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be an integer, not '%.*s'",
-		     name, tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be an integer, not '%.*s'",
+			    name, tok->end - tok->start, buffer + tok->start);
 }
 
-bool json_tok_sha256(struct command *cmd, const char *name,
-		     const char *buffer, const jsmntok_t *tok,
-		     struct sha256 **hash)
+struct command_result *param_sha256(struct command *cmd, const char *name,
+				    const char *buffer, const jsmntok_t *tok,
+				    struct sha256 **hash)
 {
 	*hash = tal(cmd, struct sha256);
 	if (hex_decode(buffer + tok->start,
 		       tok->end - tok->start,
 		       *hash, sizeof(**hash)))
-		return true;
+		return NULL;
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be a 32 byte hex value, not '%.*s'",
-		     name, tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be a 32 byte hex value, not '%.*s'",
+			    name, tok->end - tok->start, buffer + tok->start);
 }
 
-bool json_tok_msat(struct command *cmd, const char *name,
-		   const char *buffer, const jsmntok_t * tok,
-		   u64 **msatoshi_val)
+struct command_result *param_msat(struct command *cmd, const char *name,
+				  const char *buffer, const jsmntok_t * tok,
+				  u64 **msatoshi_val)
 {
 	if (json_tok_streq(buffer, tok, "any")) {
 		*msatoshi_val = NULL;
-		return true;
+		return NULL;
 	}
 	*msatoshi_val = tal(cmd, u64);
 
 	if (json_to_u64(buffer, tok, *msatoshi_val) && *msatoshi_val != 0)
-		return true;
-
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be a positive number or 'any', not '%.*s'",
-		     name,
-		     tok->end - tok->start,
-		     buffer + tok->start);
-	return false;
+		return NULL;
+
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be a positive number or 'any', not '%.*s'",
+			    name,
+			    tok->end - tok->start,
+			    buffer + tok->start);
 }
 
-bool json_tok_percent(struct command *cmd, const char *name,
-		      const char *buffer, const jsmntok_t *tok,
-		      double **num)
+struct command_result *param_percent(struct command *cmd, const char *name,
+				     const char *buffer, const jsmntok_t *tok,
+				     double **num)
 {
 	*num = tal(cmd, double);
 	if (json_to_double(buffer, tok, *num) && **num >= 0.0)
-		return true;
+		return NULL;
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be a positive double, not '%.*s'",
-		     name, tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be a positive double, not '%.*s'",
+			    name, tok->end - tok->start, buffer + tok->start);
 }
 
-bool json_tok_u64(struct command *cmd, const char *name,
-		  const char *buffer, const jsmntok_t *tok,
-		  uint64_t **num)
+struct command_result *param_u64(struct command *cmd, const char *name,
+				 const char *buffer, const jsmntok_t *tok,
+				 uint64_t **num)
 {
 	*num = tal(cmd, uint64_t);
 	if (json_to_u64(buffer, tok, *num))
-		return true;
+		return NULL;
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be an unsigned 64 bit integer, not '%.*s'",
-		     name, tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be an unsigned 64 bit integer, not '%.*s'",
+			    name, tok->end - tok->start, buffer + tok->start);
 }
 
-bool json_tok_tok(struct command *cmd, const char *name,
-		  const char *buffer, const jsmntok_t * tok,
-		  const jsmntok_t **out)
+struct command_result *param_tok(struct command *cmd, const char *name,
+				 const char *buffer, const jsmntok_t * tok,
+				 const jsmntok_t **out)
 {
-	return (*out = tok);
+	*out = tok;
+	return NULL;
 }
diff --git a/common/json_tok.h b/common/json_tok.h
index d2b82b97c..ff6434f38 100644
--- a/common/json_tok.h
+++ b/common/json_tok.h
@@ -5,61 +5,64 @@
 #include <common/json.h>
 
 struct command;
+struct command_result;
 
 /* Extract json array token */
-bool json_tok_array(struct command *cmd, const char *name,
-		    const char *buffer, const jsmntok_t *tok,
-		    const jsmntok_t **arr);
+struct command_result *param_array(struct command *cmd, const char *name,
+				   const char *buffer, const jsmntok_t *tok,
+				   const jsmntok_t **arr);
 
 /* Extract boolean this (must be a true or false) */
-bool json_tok_bool(struct command *cmd, const char *name,
-		   const char *buffer, const jsmntok_t *tok,
-		   bool **b);
+struct command_result *param_bool(struct command *cmd, const char *name,
+				  const char *buffer, const jsmntok_t *tok,
+				  bool **b);
 
 /* Extract double from this (must be a number literal) */
-bool json_tok_double(struct command *cmd, const char *name,
-		     const char *buffer, const jsmntok_t *tok,
-		     double **num);
+struct command_result *param_double(struct command *cmd, const char *name,
+				    const char *buffer, const jsmntok_t *tok,
+				    double **num);
 
 /* Extract an escaped string (and unescape it) */
-bool json_tok_escaped_string(struct command *cmd, const char *name,
-			     const char * buffer, const jsmntok_t *tok,
-			     const char **str);
+struct command_result *param_escaped_string(struct command *cmd,
+					    const char *name,
+					    const char *buffer,
+					    const jsmntok_t *tok,
+					    const char **str);
 
 /* Extract a string */
-bool json_tok_string(struct command *cmd, const char *name,
-		     const char * buffer, const jsmntok_t *tok,
-		     const char **str);
+struct command_result *param_string(struct command *cmd, const char *name,
+				    const char * buffer, const jsmntok_t *tok,
+				    const char **str);
 
 /* Extract a label. It is either an escaped string or a number. */
-bool json_tok_label(struct command *cmd, const char *name,
-		    const char * buffer, const jsmntok_t *tok,
-		    struct json_escaped **label);
+struct command_result *param_label(struct command *cmd, const char *name,
+				   const char * buffer, const jsmntok_t *tok,
+				   struct json_escaped **label);
 
 /* Extract number from this (may be a string, or a number literal) */
-bool json_tok_number(struct command *cmd, const char *name,
-		     const char *buffer, const jsmntok_t *tok,
-		     unsigned int **num);
+struct command_result *param_number(struct command *cmd, const char *name,
+				    const char *buffer, const jsmntok_t *tok,
+				    unsigned int **num);
 
 /* Extract sha256 hash */
-bool json_tok_sha256(struct command *cmd, const char *name,
-		     const char *buffer, const jsmntok_t *tok,
-		     struct sha256 **hash);
+struct command_result *param_sha256(struct command *cmd, const char *name,
+				    const char *buffer, const jsmntok_t *tok,
+				    struct sha256 **hash);
 
 /* Extract positive integer, or NULL if tok is 'any'. */
-bool json_tok_msat(struct command *cmd, const char *name,
-		   const char *buffer, const jsmntok_t * tok,
-		   u64 **msatoshi_val);
+struct command_result *param_msat(struct command *cmd, const char *name,
+				  const char *buffer, const jsmntok_t * tok,
+				  u64 **msatoshi_val);
 
 /* Extract double in range [0.0, 100.0] */
-bool json_tok_percent(struct command *cmd, const char *name,
-		      const char *buffer, const jsmntok_t *tok,
-		      double **num);
+struct command_result *param_percent(struct command *cmd, const char *name,
+				     const char *buffer, const jsmntok_t *tok,
+				     double **num);
 
 /* Extract number from this (may be a string, or a number literal) */
-bool json_tok_u64(struct command *cmd, const char *name,
-		  const char *buffer, const jsmntok_t *tok,
-		  uint64_t **num);
+struct command_result *param_u64(struct command *cmd, const char *name,
+				 const char *buffer, const jsmntok_t *tok,
+				 uint64_t **num);
 
 /*
  * Set the address of @out to @tok.  Used as a callback by handlers that
@@ -68,8 +71,8 @@ bool json_tok_u64(struct command *cmd, const char *name,
  * Usage of this is discouraged.  Writing a local static bespoke handler is
  * preferred.
  */
-bool json_tok_tok(struct command *cmd, const char *name,
-		  const char *buffer, const jsmntok_t * tok,
-		  const jsmntok_t **out);
+struct command_result *param_tok(struct command *cmd, const char *name,
+				 const char *buffer, const jsmntok_t * tok,
+				 const jsmntok_t **out);
 
 #endif /* LIGHTNING_COMMON_JSON_TOK_H */
diff --git a/common/param.c b/common/param.c
index bcdd0773a..7b67d0c98 100644
--- a/common/param.c
+++ b/common/param.c
@@ -31,16 +31,18 @@ static bool param_add(struct param **params,
 	return true;
 }
 
-static bool make_callback(struct command *cmd,
-			  struct param *def,
-			  const char *buffer, const jsmntok_t *tok)
+static struct command_result *make_callback(struct command *cmd,
+					     struct param *def,
+					     const char *buffer,
+					     const jsmntok_t *tok)
 {
 	def->is_set = true;
 
 	return def->cbx(cmd, def->name, buffer, tok, def->arg);
 }
 
-static bool post_check(struct command *cmd, struct param *params)
+static struct command_result *post_check(struct command *cmd,
+					 struct param *params)
 {
 	struct param *first = params;
 	struct param *last = first + tal_count(params);
@@ -48,42 +50,43 @@ static bool post_check(struct command *cmd, struct param *params)
 	/* Make sure required params were provided. */
 	while (first != last && first->required) {
 		if (!first->is_set) {
-			command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-				     "missing required parameter: '%s'",
-				     first->name);
-			return false;
+			return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+					    "missing required parameter: '%s'",
+					    first->name);
 		}
 		first++;
 	}
-	return true;
+	return NULL;
 }
 
-static bool parse_by_position(struct command *cmd,
-			      struct param *params,
-			      const char *buffer,
-			      const jsmntok_t tokens[],
-			      bool allow_extra)
+static struct command_result *parse_by_position(struct command *cmd,
+						struct param *params,
+						const char *buffer,
+						const jsmntok_t tokens[],
+						bool allow_extra)
 {
+	struct command_result *res;
 	const jsmntok_t *tok = tokens + 1;
 	const jsmntok_t *end = json_next(tokens);
 	struct param *first = params;
 	struct param *last = first + tal_count(params);
 
 	while (first != last && tok != end) {
-		if (!json_tok_is_null(buffer, tok))
-			if (!make_callback(cmd, first, buffer, tok))
-				return NULL;
+		if (!json_tok_is_null(buffer, tok)) {
+			res = make_callback(cmd, first, buffer, tok);
+			if (res)
+				return res;
+		}
 		tok = json_next(tok);
 		first++;
 	}
 
 	/* check for unexpected trailing params */
 	if (!allow_extra && tok != end) {
-		command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-			     "too many parameters:"
-			     " got %u, expected %zu",
-			     tokens->size, tal_count(params));
-		return false;
+		return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+				    "too many parameters:"
+				    " got %u, expected %zu",
+				    tokens->size, tal_count(params));
 	}
 
 	return post_check(cmd, params);
@@ -104,11 +107,11 @@ static struct param *find_param(struct param *params, const char *start,
 	return NULL;
 }
 
-static bool parse_by_name(struct command *cmd,
-			  struct param *params,
-			  const char *buffer,
-			  const jsmntok_t tokens[],
-			  bool allow_extra)
+static struct command_result *parse_by_name(struct command *cmd,
+					    struct param *params,
+					    const char *buffer,
+					    const jsmntok_t tokens[],
+					    bool allow_extra)
 {
 	const jsmntok_t *first = tokens + 1;
 	const jsmntok_t *last = json_next(tokens);
@@ -118,21 +121,23 @@ static bool parse_by_name(struct command *cmd,
 					     first->end - first->start);
 		if (!p) {
 			if (!allow_extra) {
-				command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-					     "unknown parameter: '%.*s'",
-					     first->end - first->start,
-					     buffer + first->start);
-				return false;
+				return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+						    "unknown parameter: '%.*s'",
+						    first->end - first->start,
+						    buffer + first->start);
 			}
 		} else {
+			struct command_result *res;
+
 			if (p->is_set) {
-				command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-					     "duplicate json names: '%s'", p->name);
-				return false;
+				return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+						    "duplicate json names: '%s'",
+						    p->name);
 			}
 
-			if (!make_callback(cmd, p, buffer, first + 1))
-				return false;
+			res = make_callback(cmd, p, buffer, first + 1);
+			if (res)
+				return res;
 		}
 		first = json_next(first + 1);
 	}
@@ -237,15 +242,15 @@ static char *param_usage(const tal_t *ctx,
 	return usage;
 }
 
-static bool param_arr(struct command *cmd, const char *buffer,
-		      const jsmntok_t tokens[],
-		      struct param *params,
-		      bool allow_extra)
+static struct command_result *param_arr(struct command *cmd, const char *buffer,
+					const jsmntok_t tokens[],
+					struct param *params,
+					bool allow_extra)
 {
 #if DEVELOPER
 	if (!check_params(params)) {
-		command_fail(cmd, PARAM_DEV_ERROR, "developer error: check_params");
-		return false;
+		return command_fail(cmd, PARAM_DEV_ERROR,
+				    "developer error: check_params");
 	}
 #endif
 	if (tokens->type == JSMN_ARRAY)
@@ -253,9 +258,8 @@ static bool param_arr(struct command *cmd, const char *buffer,
 	else if (tokens->type == JSMN_OBJECT)
 		return parse_by_name(cmd, params, buffer, tokens, allow_extra);
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "Expected array or object for params");
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "Expected array or object for params");
 }
 
 bool param(struct command *cmd, const char *buffer,
@@ -291,6 +295,6 @@ bool param(struct command *cmd, const char *buffer,
 
 	/* Always return false if we're simply checking command parameters;
 	 * normally this returns true if all parameters are valid. */
-	return param_arr(cmd, buffer, tokens, params, allow_extra)
+	return param_arr(cmd, buffer, tokens, params, allow_extra) == NULL
 		&& !command_check_only(cmd);
 }
diff --git a/common/param.h b/common/param.h
index b8214e077..d0f160095 100644
--- a/common/param.h
+++ b/common/param.h
@@ -35,6 +35,10 @@
  */
 struct command;
 
+/* A dummy type returned by command_ functions, to ensure you return them
+ * immediately */
+struct command_result;
+
 /*
  * Parse the json tokens.  @params can be an array of values or an object
  * of named values.
@@ -43,14 +47,16 @@ bool param(struct command *cmd, const char *buffer,
 	   const jsmntok_t params[], ...) LAST_ARG_NULL;
 
 /*
- * The callback signature.  Callbacks must return true on success.  On failure they
- * must call comand_fail and return false.
+ * The callback signature.
+ *
+ * Callbacks must return NULL on success.  On failure they
+ * must return command_fail(...).
  */
-typedef bool(*param_cbx)(struct command *cmd,
-			 const char *name,
-			 const char *buffer,
-			 const jsmntok_t *tok,
-			 void **arg);
+typedef struct command_result *(*param_cbx)(struct command *cmd,
+					    const char *name,
+					    const char *buffer,
+					    const jsmntok_t *tok,
+					    void **arg);
 
 /*
  * Add a required parameter.
@@ -63,7 +69,7 @@ typedef bool(*param_cbx)(struct command *cmd,
 			       (const char *)NULL,           \
 			       (const char *)NULL,           \
 			       (const jsmntok_t *)NULL,      \
-			       (arg)) == true)
+			       (arg)) == (struct command_result *)NULL)
 
 /*
  * Add an optional parameter.  *arg is set to NULL if it isn't found.
@@ -77,7 +83,7 @@ typedef bool(*param_cbx)(struct command *cmd,
 		                  (const char *)NULL,           \
 				  (const char *)NULL,           \
 				  (const jsmntok_t *)NULL,      \
-				  (arg)) == true); })
+				  (arg)) == (struct command_result *)NULL); })
 
 /*
  * Add an optional parameter.  *arg is set to @def if it isn't found.
@@ -92,7 +98,7 @@ typedef bool(*param_cbx)(struct command *cmd,
 				   (const char *)NULL,		    \
 				   (const char *)NULL,		    \
 				   (const jsmntok_t *)NULL,	    \
-				   (arg)) == true); })
+				   (arg)) == (struct command_result *)NULL); })
 
 /* Special flag for 'check' which allows any parameters. */
 #define p_opt_any() "", false, NULL, NULL
diff --git a/common/test/run-param.c b/common/test/run-param.c
index 80ea498a3..2909329c1 100644
--- a/common/test/run-param.c
+++ b/common/test/run-param.c
@@ -22,6 +22,10 @@ static bool check_fail(void) {
 
 struct command *cmd;
 
+struct command_result {
+};
+static struct command_result cmd_failed;
+
 struct command_result *command_fail(struct command *cmd,
 				    int code, const char *fmt, ...)
 {
@@ -30,7 +34,7 @@ struct command_result *command_fail(struct command *cmd,
 	va_start(ap, fmt);
 	fail_msg = tal_vfmt(cmd, fmt, ap);
 	va_end(ap);
-	return NULL;
+	return &cmd_failed;
 }
 
 /* AUTOGENERATED MOCKS START */
@@ -144,8 +148,8 @@ static void stest(const struct json *j, struct sanity *b)
 	u64 *ival;
 	double *dval;
 	if (!param(cmd, j->buffer, j->toks,
-		   p_req("u64", json_tok_u64, &ival),
-		   p_req("double", json_tok_double, &dval), NULL)) {
+		   p_req("u64", param_u64, &ival),
+		   p_req("double", param_double, &dval), NULL)) {
 		assert(check_fail());
 		assert(b->failed == true);
 		if (!strstr(fail_msg, b->fail_str)) {
@@ -182,7 +186,7 @@ static void tok_tok(void)
 		struct json *j = json_parse(cmd, "{ 'satoshi', '546' }");
 
 		assert(param(cmd, j->buffer, j->toks,
-			     p_req("satoshi", json_tok_tok, &tok), NULL));
+			     p_req("satoshi", param_tok, &tok), NULL));
 		assert(tok);
 		assert(json_to_number(j->buffer, tok, &n));
 		assert(n == 546);
@@ -194,7 +198,7 @@ static void tok_tok(void)
 
 		struct json *j = json_parse(cmd, "{}");
 		assert(param(cmd, j->buffer, j->toks,
-			     p_opt("satoshi", json_tok_tok, &tok), NULL));
+			     p_opt("satoshi", param_tok, &tok), NULL));
 
 		/* make sure it *is* NULL */
 		assert(tok == NULL);
@@ -211,8 +215,8 @@ static void dup_names(void)
 	u64 *i;
 	double *d;
 	assert(!param(cmd, j->buffer, j->toks,
-		      p_req("u64", json_tok_u64, &i),
-		      p_req("double", json_tok_double, &d), NULL));
+		      p_req("u64", param_u64, &i),
+		      p_req("double", param_double, &d), NULL));
 }
 
 static void null_params(void)
@@ -223,13 +227,13 @@ static void null_params(void)
 	    json_parse(cmd, "[ '10', '11', '12', '13', '14', '15', '16']");
 
 	assert(param(cmd, j->buffer, j->toks,
-		     p_req("0", json_tok_u64, &intptrs[0]),
-		     p_req("1", json_tok_u64, &intptrs[1]),
-		     p_req("2", json_tok_u64, &intptrs[2]),
-		     p_req("3", json_tok_u64, &intptrs[3]),
-		     p_opt_def("4", json_tok_u64, &intptrs[4], 999),
-		     p_opt("5", json_tok_u64, &intptrs[5]),
-		     p_opt("6", json_tok_u64, &intptrs[6]),
+		     p_req("0", param_u64, &intptrs[0]),
+		     p_req("1", param_u64, &intptrs[1]),
+		     p_req("2", param_u64, &intptrs[2]),
+		     p_req("3", param_u64, &intptrs[3]),
+		     p_opt_def("4", param_u64, &intptrs[4], 999),
+		     p_opt("5", param_u64, &intptrs[5]),
+		     p_opt("6", param_u64, &intptrs[6]),
 		     NULL));
 	for (int i = 0; i < tal_count(intptrs); ++i) {
 		assert(intptrs[i]);
@@ -239,13 +243,13 @@ static void null_params(void)
 	/* missing at end */
 	j = json_parse(cmd, "[ '10', '11', '12', '13', '14']");
 	assert(param(cmd, j->buffer, j->toks,
-		     p_req("0", json_tok_u64, &intptrs[0]),
-		     p_req("1", json_tok_u64, &intptrs[1]),
-		     p_req("2", json_tok_u64, &intptrs[2]),
-		     p_req("3", json_tok_u64, &intptrs[3]),
-		     p_opt("4", json_tok_u64, &intptrs[4]),
-		     p_opt("5", json_tok_u64, &intptrs[5]),
-		     p_opt_def("6", json_tok_u64, &intptrs[6], 888),
+		     p_req("0", param_u64, &intptrs[0]),
+		     p_req("1", param_u64, &intptrs[1]),
+		     p_req("2", param_u64, &intptrs[2]),
+		     p_req("3", param_u64, &intptrs[3]),
+		     p_opt("4", param_u64, &intptrs[4]),
+		     p_opt("5", param_u64, &intptrs[5]),
+		     p_opt_def("6", param_u64, &intptrs[6], 888),
 		     NULL));
 	assert(*intptrs[0] == 10);
 	assert(*intptrs[1] == 11);
@@ -279,30 +283,30 @@ static void bad_programmer(void)
 
 	/* check for repeated names */
 	assert(!param(cmd, j->buffer, j->toks,
-		      p_req("repeat", json_tok_u64, &ival),
-		      p_req("double", json_tok_double, &dval),
-		      p_req("repeat", json_tok_u64, &ival2), NULL));
+		      p_req("repeat", param_u64, &ival),
+		      p_req("double", param_double, &dval),
+		      p_req("repeat", param_u64, &ival2), NULL));
 	assert(check_fail());
 	assert(strstr(fail_msg, "developer error"));
 
 	assert(!param(cmd, j->buffer, j->toks,
-		      p_req("repeat", json_tok_u64, &ival),
-		      p_req("double", json_tok_double, &dval),
-		      p_req("repeat", json_tok_u64, &ival), NULL));
+		      p_req("repeat", param_u64, &ival),
+		      p_req("double", param_double, &dval),
+		      p_req("repeat", param_u64, &ival), NULL));
 	assert(check_fail());
 	assert(strstr(fail_msg, "developer error"));
 
 	assert(!param(cmd, j->buffer, j->toks,
-		      p_req("u64", json_tok_u64, &ival),
-		      p_req("repeat", json_tok_double, &dval),
-		      p_req("repeat", json_tok_double, &dval), NULL));
+		      p_req("u64", param_u64, &ival),
+		      p_req("repeat", param_double, &dval),
+		      p_req("repeat", param_double, &dval), NULL));
 	assert(check_fail());
 	assert(strstr(fail_msg, "developer error"));
 
 	/* check for repeated arguments */
 	assert(!param(cmd, j->buffer, j->toks,
-		      p_req("u64", json_tok_u64, &ival),
-		      p_req("repeated-arg", json_tok_u64, &ival), NULL));
+		      p_req("u64", param_u64, &ival),
+		      p_req("repeated-arg", param_u64, &ival), NULL));
 	assert(check_fail());
 	assert(strstr(fail_msg, "developer error"));
 
@@ -316,10 +320,10 @@ static void bad_programmer(void)
 	unsigned int *msatoshi;
 	double *riskfactor;
 	assert(!param(cmd, j->buffer, j->toks,
-		      p_req("u64", json_tok_u64, &ival),
-		      p_req("double", json_tok_double, &dval),
-		      p_opt_def("msatoshi", json_tok_number, &msatoshi, 100),
-		      p_req("riskfactor", json_tok_double, &riskfactor), NULL));
+		      p_req("u64", param_u64, &ival),
+		      p_req("double", param_double, &dval),
+		      p_opt_def("msatoshi", param_number, &msatoshi, 100),
+		      p_req("riskfactor", param_double, &riskfactor), NULL));
 	assert(*msatoshi);
 	assert(*msatoshi == 100);
 	assert(check_fail());
@@ -340,8 +344,8 @@ static void add_members(struct param **params,
 		tal_append_fmt(obj, "\"%i\" : %i", i, i);
 		tal_append_fmt(arr, "%i", i);
 		param_add(params, name, true,
-			  typesafe_cb_preargs(bool, void **,
-					      json_tok_number,
+			  typesafe_cb_preargs(struct command_result *, void **,
+					      param_number,
 					      &ints[i],
 					      struct command *,
 					      const char *,
@@ -368,7 +372,7 @@ static void five_hundred_params(void)
 
 	/* first test object version */
 	struct json *j = json_parse(params, obj);
-	assert(param_arr(cmd, j->buffer, j->toks, params, false));
+	assert(param_arr(cmd, j->buffer, j->toks, params, false) == NULL);
 	for (int i = 0; i < tal_count(ints); ++i) {
 		assert(ints[i]);
 		assert(*ints[i] == i);
@@ -377,7 +381,7 @@ static void five_hundred_params(void)
 
 	/* now test array */
 	j = json_parse(params, arr);
-	assert(param_arr(cmd, j->buffer, j->toks, params, false));
+	assert(param_arr(cmd, j->buffer, j->toks, params, false) == NULL);
 	for (int i = 0; i < tal_count(ints); ++i) {
 		assert(*ints[i] == i);
 	}
@@ -394,10 +398,10 @@ static void sendpay(void)
 	unsigned *cltv;
 
 	if (!param(cmd, j->buffer, j->toks,
-		   p_req("route", json_tok_tok, &routetok),
-		   p_req("cltv", json_tok_number, &cltv),
-		   p_opt("note", json_tok_tok, &note),
-		   p_opt("msatoshi", json_tok_u64, &msatoshi),
+		   p_req("route", param_tok, &routetok),
+		   p_req("cltv", param_number, &cltv),
+		   p_opt("note", param_tok, &note),
+		   p_opt("msatoshi", param_u64, &msatoshi),
 		   NULL))
 		assert(false);
 
@@ -417,10 +421,10 @@ static void sendpay_nulltok(void)
 	unsigned *cltv;
 
 	if (!param(cmd, j->buffer, j->toks,
-		   p_req("route", json_tok_tok, &routetok),
-		   p_req("cltv", json_tok_number, &cltv),
-		   p_opt("note", json_tok_tok, &note),
-		   p_opt("msatoshi", json_tok_u64, &msatoshi),
+		   p_req("route", param_tok, &routetok),
+		   p_req("cltv", param_number, &cltv),
+		   p_opt("note", param_tok, &note),
+		   p_opt("msatoshi", param_u64, &msatoshi),
 		   NULL))
 		assert(false);
 
@@ -439,11 +443,11 @@ static void advanced(void)
 		const jsmntok_t *tok;
 
 		assert(param(cmd, j->buffer, j->toks,
-			     p_req("description", json_tok_label, &label),
-			     p_req("msat", json_tok_msat, &msat),
-			     p_req("tok", json_tok_tok, &tok),
-			     p_opt("msat_opt1", json_tok_msat, &msat_opt1),
-			     p_opt("msat_opt2", json_tok_msat, &msat_opt2),
+			     p_req("description", param_label, &label),
+			     p_req("msat", param_msat, &msat),
+			     p_req("tok", param_tok, &tok),
+			     p_opt("msat_opt1", param_msat, &msat_opt1),
+			     p_opt("msat_opt2", param_msat, &msat_opt2),
 			     NULL));
 		assert(label != NULL);
 		assert(streq(label->s, "lightning"));
@@ -457,8 +461,8 @@ static void advanced(void)
 		struct json *j = json_parse(cmd, "[ 3 'foo' ]");
 		struct json_escaped *label, *foo;
 		assert(param(cmd, j->buffer, j->toks,
-			      p_req("label", json_tok_label, &label),
-			      p_opt("foo", json_tok_label, &foo),
+			      p_req("label", param_label, &label),
+			      p_opt("foo", param_label, &foo),
 			      NULL));
 		assert(streq(label->s, "3"));
 		assert(streq(foo->s, "foo"));
@@ -468,8 +472,8 @@ static void advanced(void)
 		u64 *msat2;
 		struct json *j = json_parse(cmd, "[ 3 ]");
 		assert(param(cmd, j->buffer, j->toks,
-			      p_opt_def("msat", json_tok_msat, &msat, 23),
-			      p_opt_def("msat2", json_tok_msat, &msat2, 53),
+			      p_opt_def("msat", param_msat, &msat, 23),
+			      p_opt_def("msat2", param_msat, &msat2, 53),
 			      NULL));
 		assert(*msat == 3);
 		assert(msat2);
@@ -483,7 +487,7 @@ static void advanced_fail(void)
 		struct json *j = json_parse(cmd, "[ 'anyx' ]");
 		u64 *msat;
 		assert(!param(cmd, j->buffer, j->toks,
-			      p_req("msat", json_tok_msat, &msat),
+			      p_req("msat", param_msat, &msat),
 			      NULL));
 		assert(check_fail());
 		assert(strstr(fail_msg, "'msat' should be a positive"
@@ -495,31 +499,31 @@ static void advanced_fail(void)
 { \
 	struct json *j = json_parse(cmd, json_); \
 	T *v; \
-	bool ret = cb(cmd, "name", j->buffer, j->toks + 1, &v); \
-	assert(ret == pass); \
-	if (ret) { \
+	struct command_result *ret = cb(cmd, "name", j->buffer, j->toks + 1, &v); \
+	assert((ret == NULL) == pass);					\
+	if (ret == NULL) { \
 		assert(v); \
 		assert(*v == value); \
 	} \
 }
 
-static void json_tok_tests(void)
+static void param_tests(void)
 {
-	test_cb(json_tok_bool, bool, "[ true ]", true, true);
-	test_cb(json_tok_bool, bool, "[ false ]", false, true);
-	test_cb(json_tok_bool, bool, "[ tru ]", false, false);
-	test_cb(json_tok_bool, bool, "[ 1 ]", false, false);
-
-	test_cb(json_tok_percent, double, "[ -0.01 ]", 0, false);
-	test_cb(json_tok_percent, double, "[ 0.00 ]", 0, true);
-	test_cb(json_tok_percent, double, "[ 1 ]", 1, true);
-	test_cb(json_tok_percent, double, "[ 1.1 ]", 1.1, true);
-	test_cb(json_tok_percent, double, "[ 1.01 ]", 1.01, true);
-	test_cb(json_tok_percent, double, "[ 99.99 ]", 99.99, true);
-	test_cb(json_tok_percent, double, "[ 100.0 ]", 100, true);
-	test_cb(json_tok_percent, double, "[ 100.001 ]", 100.001, true);
-	test_cb(json_tok_percent, double, "[ 1000 ]", 1000, true);
-	test_cb(json_tok_percent, double, "[ 'wow' ]", 0, false);
+	test_cb(param_bool, bool, "[ true ]", true, true);
+	test_cb(param_bool, bool, "[ false ]", false, true);
+	test_cb(param_bool, bool, "[ tru ]", false, false);
+	test_cb(param_bool, bool, "[ 1 ]", false, false);
+
+	test_cb(param_percent, double, "[ -0.01 ]", 0, false);
+	test_cb(param_percent, double, "[ 0.00 ]", 0, true);
+	test_cb(param_percent, double, "[ 1 ]", 1, true);
+	test_cb(param_percent, double, "[ 1.1 ]", 1.1, true);
+	test_cb(param_percent, double, "[ 1.01 ]", 1.01, true);
+	test_cb(param_percent, double, "[ 99.99 ]", 99.99, true);
+	test_cb(param_percent, double, "[ 100.0 ]", 100, true);
+	test_cb(param_percent, double, "[ 100.001 ]", 100.001, true);
+	test_cb(param_percent, double, "[ 1000 ]", 1000, true);
+	test_cb(param_percent, double, "[ 'wow' ]", 0, false);
 }
 
 static void test_invoice(struct command *cmd,
@@ -536,12 +540,12 @@ static void test_invoice(struct command *cmd,
 
 	assert(cmd->mode == CMD_USAGE);
 	if(!param(cmd, buffer, params,
-		  p_req("msatoshi", json_tok_msat, &msatoshi_val),
-		  p_req("label", json_tok_label, &label_val),
-		  p_req("description", json_tok_escaped_string, &desc_val),
-		  p_opt("expiry", json_tok_u64, &expiry),
-		  p_opt("fallbacks", json_tok_array, &fallbacks),
-		  p_opt("preimage", json_tok_tok, &preimagetok), NULL))
+		  p_req("msatoshi", param_msat, &msatoshi_val),
+		  p_req("label", param_label, &label_val),
+		  p_req("description", param_escaped_string, &desc_val),
+		  p_opt("expiry", param_u64, &expiry),
+		  p_opt("fallbacks", param_array, &fallbacks),
+		  p_opt("preimage", param_tok, &preimagetok), NULL))
 		return;
 
 	/* should not be here since we are in the mode of CMD_USAGE
@@ -583,7 +587,7 @@ int main(void)
 	sendpay_nulltok();
 	advanced();
 	advanced_fail();
-	json_tok_tests();
+	param_tests();
 	usage();
 
 	tal_free(tmpctx);
diff --git a/lightningd/chaintopology.c b/lightningd/chaintopology.c
index c070169dc..c24592f2a 100644
--- a/lightningd/chaintopology.c
+++ b/lightningd/chaintopology.c
@@ -286,16 +286,16 @@ const char *feerate_name(enum feerate feerate)
 	abort();
 }
 
-bool json_feerate_estimate(struct command *cmd,
-			   u32 **feerate_per_kw, enum feerate feerate)
+struct command_result *param_feerate_estimate(struct command *cmd,
+					      u32 **feerate_per_kw,
+					      enum feerate feerate)
 {
 	*feerate_per_kw = tal(cmd, u32);
 	**feerate_per_kw = try_get_feerate(cmd->ld->topology, feerate);
-	if (!**feerate_per_kw) {
-		command_fail(cmd, LIGHTNINGD, "Cannot estimate fees");
-		return false;
-	}
-	return true;
+	if (!**feerate_per_kw)
+		return command_fail(cmd, LIGHTNINGD, "Cannot estimate fees");
+
+	return NULL;
 }
 
 /* Mutual recursion via timer. */
@@ -475,7 +475,7 @@ static void json_feerates(struct command *cmd,
 	enum feerate_style *style;
 
 	if (!param(cmd, buffer, params,
-		   p_req("style", json_tok_feerate_style, &style),
+		   p_req("style", param_feerate_style, &style),
 		   NULL))
 		return;
 
diff --git a/lightningd/chaintopology.h b/lightningd/chaintopology.h
index 175dfcdc5..73d0be0fb 100644
--- a/lightningd/chaintopology.h
+++ b/lightningd/chaintopology.h
@@ -150,9 +150,10 @@ u32 feerate_to_style(u32 feerate_perkw, enum feerate_style style);
 
 const char *feerate_name(enum feerate feerate);
 
-/* Set feerate_per_kw to this estimate, or fail cmd */
-bool json_feerate_estimate(struct command *cmd,
-			   u32 **feerate_per_kw, enum feerate feerate);
+/* Set feerate_per_kw to this estimate & return NULL, or fail cmd */
+struct command_result *param_feerate_estimate(struct command *cmd,
+					      u32 **feerate_per_kw,
+					      enum feerate feerate);
 
 /* Broadcast a single tx, and rebroadcast as reqd (copies tx).
  * If failed is non-NULL, call that and don't rebroadcast. */
diff --git a/lightningd/connect_control.c b/lightningd/connect_control.c
index a15c29d80..9425365b4 100644
--- a/lightningd/connect_control.c
+++ b/lightningd/connect_control.c
@@ -92,9 +92,9 @@ static void json_connect(struct command *cmd,
 	struct peer *peer;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_tok, (const jsmntok_t **) &idtok),
-		   p_opt("host", json_tok_string, &name),
-		   p_opt("port", json_tok_number, &port),
+		   p_req("id", param_tok, (const jsmntok_t **) &idtok),
+		   p_opt("host", param_string, &name),
+		   p_opt("port", param_number, &port),
 		   NULL))
 		return;
 
diff --git a/lightningd/gossip_control.c b/lightningd/gossip_control.c
index 6b6c6bc52..7ad8a88ea 100644
--- a/lightningd/gossip_control.c
+++ b/lightningd/gossip_control.c
@@ -253,7 +253,7 @@ static void json_listnodes(struct command *cmd,
 	struct pubkey *id;
 
 	if (!param(cmd, buffer, params,
-		   p_opt("id", json_tok_pubkey, &id),
+		   p_opt("id", param_pubkey, &id),
 		   NULL))
 		return;
 
@@ -310,13 +310,13 @@ static void json_getroute(struct command *cmd,
 	struct siphash_seed seed;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &destination),
-		   p_req("msatoshi", json_tok_u64, &msatoshi),
-		   p_req("riskfactor", json_tok_double, &riskfactor),
-		   p_opt_def("cltv", json_tok_number, &cltv, 9),
-		   p_opt_def("fromid", json_tok_pubkey, &source, ld->id),
-		   p_opt("seed", json_tok_tok, &seedtok),
-		   p_opt_def("fuzzpercent", json_tok_percent, &fuzz, 75.0),
+		   p_req("id", param_pubkey, &destination),
+		   p_req("msatoshi", param_u64, &msatoshi),
+		   p_req("riskfactor", param_double, &riskfactor),
+		   p_opt_def("cltv", param_number, &cltv, 9),
+		   p_opt_def("fromid", param_pubkey, &source, ld->id),
+		   p_opt("seed", param_tok, &seedtok),
+		   p_opt_def("fuzzpercent", param_percent, &fuzz, 75.0),
 		   NULL))
 		return;
 
@@ -407,7 +407,7 @@ static void json_listchannels(struct command *cmd,
 	u8 *req;
 	struct short_channel_id *id;
 	if (!param(cmd, buffer, params,
-		   p_opt("short_channel_id", json_tok_short_channel_id, &id),
+		   p_opt("short_channel_id", param_short_channel_id, &id),
 		   NULL))
 		return;
 
@@ -463,8 +463,8 @@ static void json_dev_query_scids(struct command *cmd,
 	size_t i;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &id),
-		   p_req("scids", json_tok_array, &scidstok),
+		   p_req("id", param_pubkey, &id),
+		   p_req("scids", param_array, &scidstok),
 		   NULL))
 		return;
 
@@ -504,9 +504,9 @@ static void json_dev_send_timestamp_filter(struct command *cmd,
 	u32 *first, *range;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &id),
-		   p_req("first", json_tok_number, &first),
-		   p_req("range", json_tok_number, &range),
+		   p_req("id", param_pubkey, &id),
+		   p_req("first", param_number, &first),
+		   p_req("range", param_number, &range),
 		   NULL))
 		return;
 
@@ -574,9 +574,9 @@ static void json_dev_query_channel_range(struct command *cmd,
 	u32 *first, *num;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &id),
-		   p_req("first", json_tok_number, &first),
-		   p_req("num", json_tok_number, &num),
+		   p_req("id", param_pubkey, &id),
+		   p_req("first", param_number, &first),
+		   p_req("num", param_number, &num),
 		   NULL))
 		return;
 
@@ -603,7 +603,7 @@ static void json_dev_set_max_scids_encode_size(struct command *cmd,
 	u32 *max;
 
 	if (!param(cmd, buffer, params,
-		   p_req("max", json_tok_number, &max),
+		   p_req("max", param_number, &max),
 		   NULL))
 		return;
 
diff --git a/lightningd/invoice.c b/lightningd/invoice.c
index 2c527971f..771421df5 100644
--- a/lightningd/invoice.c
+++ b/lightningd/invoice.c
@@ -309,12 +309,12 @@ static void json_invoice(struct command *cmd,
 	info->cmd = cmd;
 
 	if (!param(cmd, buffer, params,
-		   p_req("msatoshi", json_tok_msat, &msatoshi_val),
-		   p_req("label", json_tok_label, &info->label),
-		   p_req("description", json_tok_escaped_string, &desc_val),
-		   p_opt_def("expiry", json_tok_u64, &expiry, 3600),
-		   p_opt("fallbacks", json_tok_array, &fallbacks),
-		   p_opt("preimage", json_tok_tok, &preimagetok),
+		   p_req("msatoshi", param_msat, &msatoshi_val),
+		   p_req("label", param_label, &info->label),
+		   p_req("description", param_escaped_string, &desc_val),
+		   p_opt_def("expiry", param_u64, &expiry, 3600),
+		   p_opt("fallbacks", param_array, &fallbacks),
+		   p_opt("preimage", param_tok, &preimagetok),
 		   NULL))
 		return;
 
@@ -425,7 +425,7 @@ static void json_listinvoices(struct command *cmd,
 	struct json_stream *response;
 	struct wallet *wallet = cmd->ld->wallet;
 	if (!param(cmd, buffer, params,
-		   p_opt("label", json_tok_label, &label),
+		   p_opt("label", param_label, &label),
 		   NULL))
 		return;
 	response = json_stream_success(cmd);
@@ -457,8 +457,8 @@ static void json_delinvoice(struct command *cmd,
 	struct wallet *wallet = cmd->ld->wallet;
 
 	if (!param(cmd, buffer, params,
-		   p_req("label", json_tok_label, &label),
-		   p_req("status", json_tok_string, &status),
+		   p_req("label", param_label, &label),
+		   p_req("status", param_string, &status),
 		   NULL))
 		return;
 
@@ -506,7 +506,7 @@ static void json_delexpiredinvoice(struct command *cmd,
 	u64 *maxexpirytime;
 
 	if (!param(cmd, buffer, params,
-		   p_opt_def("maxexpirytime", json_tok_u64, &maxexpirytime,
+		   p_opt_def("maxexpirytime", param_u64, &maxexpirytime,
 				 time_now().ts.tv_sec),
 		   NULL))
 		return;
@@ -531,8 +531,8 @@ static void json_autocleaninvoice(struct command *cmd,
 	u64 *exby;
 
 	if (!param(cmd, buffer, params,
-		   p_opt_def("cycle_seconds", json_tok_u64, &cycle, 3600),
-		   p_opt_def("expired_by", json_tok_u64, &exby, 86400),
+		   p_opt_def("cycle_seconds", param_u64, &cycle, 3600),
+		   p_opt_def("expired_by", param_u64, &exby, 86400),
 		   NULL))
 		return;
 
@@ -558,7 +558,7 @@ static void json_waitanyinvoice(struct command *cmd,
 	struct wallet *wallet = cmd->ld->wallet;
 
 	if (!param(cmd, buffer, params,
-		   p_opt_def("lastpay_index", json_tok_u64, &pay_index, 0),
+		   p_opt_def("lastpay_index", param_u64, &pay_index, 0),
 		   NULL))
 		return;
 
@@ -596,7 +596,7 @@ static void json_waitinvoice(struct command *cmd,
 	struct json_escaped *label;
 
 	if (!param(cmd, buffer, params,
-		   p_req("label", json_tok_label, &label),
+		   p_req("label", param_label, &label),
 		   NULL))
 		return;
 
@@ -671,8 +671,8 @@ static void json_decodepay(struct command *cmd,
 	char *fail;
 
 	if (!param(cmd, buffer, params,
-		   p_req("bolt11", json_tok_string, &str),
-		   p_opt("description", json_tok_string, &desc),
+		   p_req("bolt11", param_string, &str),
+		   p_opt("description", param_string, &desc),
 		   NULL))
 		return;
 
diff --git a/lightningd/json.c b/lightningd/json.c
index af97c2d20..a4d79b553 100644
--- a/lightningd/json.c
+++ b/lightningd/json.c
@@ -104,18 +104,18 @@ bool json_to_pubkey(const char *buffer, const jsmntok_t *tok,
 				  tok->end - tok->start, pubkey);
 }
 
-bool json_tok_pubkey(struct command *cmd, const char *name,
-		     const char *buffer, const jsmntok_t *tok,
-		     struct pubkey **pubkey)
+struct command_result *param_pubkey(struct command *cmd, const char *name,
+				    const char *buffer, const jsmntok_t *tok,
+				    struct pubkey **pubkey)
 {
 	*pubkey = tal(cmd, struct pubkey);
 	if (json_to_pubkey(buffer, tok, *pubkey))
-		return true;
+		return NULL;
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be a pubkey, not '%.*s'",
-		     name, json_tok_full_len(tok), json_tok_full(buffer, tok));
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be a pubkey, not '%.*s'",
+			    name, json_tok_full_len(tok),
+			    json_tok_full(buffer, tok));
 }
 
 void json_add_short_channel_id(struct json_stream *response,
@@ -133,18 +133,20 @@ bool json_to_short_channel_id(const char *buffer, const jsmntok_t *tok,
 					  tok->end - tok->start, scid));
 }
 
-bool json_tok_short_channel_id(struct command *cmd, const char *name,
-			       const char *buffer, const jsmntok_t *tok,
-			       struct short_channel_id **scid)
+struct command_result *param_short_channel_id(struct command *cmd,
+					      const char *name,
+					      const char *buffer,
+					      const jsmntok_t *tok,
+					      struct short_channel_id **scid)
 {
 	*scid = tal(cmd, struct short_channel_id);
 	if (json_to_short_channel_id(buffer, tok, *scid))
-		return true;
+		return NULL;
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be a short channel id, not '%.*s'",
-		     name, json_tok_full_len(tok), json_tok_full(buffer, tok));
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be a short channel id, not '%.*s'",
+			    name, json_tok_full_len(tok),
+			    json_tok_full(buffer, tok));
 }
 
 const char *json_feerate_style_name(enum feerate_style style)
@@ -158,33 +160,34 @@ const char *json_feerate_style_name(enum feerate_style style)
 	abort();
 }
 
-bool json_tok_feerate_style(struct command *cmd, const char *name,
-			    const char *buffer, const jsmntok_t *tok,
-			    enum feerate_style **style)
+struct command_result *param_feerate_style(struct command *cmd,
+					   const char *name,
+					   const char *buffer,
+					   const jsmntok_t *tok,
+					   enum feerate_style **style)
 {
 	*style = tal(cmd, enum feerate_style);
 	if (json_tok_streq(buffer, tok,
 			   json_feerate_style_name(FEERATE_PER_KSIPA))) {
 		**style = FEERATE_PER_KSIPA;
-		return true;
+		return NULL;
 	} else if (json_tok_streq(buffer, tok,
 				  json_feerate_style_name(FEERATE_PER_KBYTE))) {
 		**style = FEERATE_PER_KBYTE;
-		return true;
+		return NULL;
 	}
 
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be '%s' or '%s', not '%.*s'",
-		     name,
-		     json_feerate_style_name(FEERATE_PER_KSIPA),
-		     json_feerate_style_name(FEERATE_PER_KBYTE),
-		     json_tok_full_len(tok), json_tok_full(buffer, tok));
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be '%s' or '%s', not '%.*s'",
+			    name,
+			    json_feerate_style_name(FEERATE_PER_KSIPA),
+			    json_feerate_style_name(FEERATE_PER_KBYTE),
+			    json_tok_full_len(tok), json_tok_full(buffer, tok));
 }
 
-bool json_tok_feerate(struct command *cmd, const char *name,
-		      const char *buffer, const jsmntok_t *tok,
-		      u32 **feerate)
+struct command_result *param_feerate(struct command *cmd, const char *name,
+				     const char *buffer, const jsmntok_t *tok,
+				     u32 **feerate)
 {
 	jsmntok_t base = *tok, suffix = *tok;
 	enum feerate_style style;
@@ -192,7 +195,7 @@ bool json_tok_feerate(struct command *cmd, const char *name,
 
 	for (size_t i = 0; i < NUM_FEERATES; i++) {
 		if (json_tok_streq(buffer, tok, feerate_name(i)))
-			return json_feerate_estimate(cmd, feerate, i);
+			return param_feerate_estimate(cmd, feerate, i);
 	}
 
 	/* We have to split the number and suffix. */
@@ -203,10 +206,10 @@ bool json_tok_feerate(struct command *cmd, const char *name,
 	}
 
 	if (!json_to_number(buffer, &base, &num)) {
-		command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-			     "'%s' prefix should be an integer, not '%.*s'",
-			     name, base.end - base.start, buffer + base.start);
-		return false;
+		return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+				    "'%s' prefix should be an integer, not '%.*s'",
+				    name, base.end - base.start,
+				    buffer + base.start);
 	}
 
 	if (json_tok_streq(buffer, &suffix, "")
@@ -217,18 +220,18 @@ bool json_tok_feerate(struct command *cmd, const char *name,
 				json_feerate_style_name(FEERATE_PER_KSIPA))) {
 		style = FEERATE_PER_KSIPA;
 	} else {
-		command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-			     "'%s' suffix should be '%s' or '%s', not '%.*s'",
-			     name,
-			     json_feerate_style_name(FEERATE_PER_KSIPA),
-			     json_feerate_style_name(FEERATE_PER_KBYTE),
-			     suffix.end - suffix.start, buffer + suffix.start);
-		return false;
+		return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+				    "'%s' suffix should be '%s' or '%s', not '%.*s'",
+				    name,
+				    json_feerate_style_name(FEERATE_PER_KSIPA),
+				    json_feerate_style_name(FEERATE_PER_KBYTE),
+				    suffix.end - suffix.start,
+				    buffer + suffix.start);
 	}
 
 	*feerate = tal(cmd, u32);
 	**feerate = feerate_from_style(num, style);
-	return true;
+	return NULL;
 }
 
 bool
diff --git a/lightningd/json.h b/lightningd/json.h
index 00f723bd0..984f0379a 100644
--- a/lightningd/json.h
+++ b/lightningd/json.h
@@ -51,17 +51,19 @@ void json_add_txid(struct json_stream *result, const char *fieldname,
 bool json_to_pubkey(const char *buffer, const jsmntok_t *tok,
 		    struct pubkey *pubkey);
 
-bool json_tok_pubkey(struct command *cmd, const char *name,
-		     const char *buffer, const jsmntok_t *tok,
-		     struct pubkey **pubkey);
+struct command_result *param_pubkey(struct command *cmd, const char *name,
+				    const char *buffer, const jsmntok_t *tok,
+				    struct pubkey **pubkey);
 
 /* Extract a short_channel_id from this */
 bool json_to_short_channel_id(const char *buffer, const jsmntok_t *tok,
 			      struct short_channel_id *scid);
 
-bool json_tok_short_channel_id(struct command *cmd, const char *name,
-			       const char *buffer, const jsmntok_t *tok,
-			       struct short_channel_id **scid);
+struct command_result *param_short_channel_id(struct command *cmd,
+					      const char *name,
+					      const char *buffer,
+					      const jsmntok_t *tok,
+					      struct short_channel_id **scid);
 
 enum feerate_style {
 	FEERATE_PER_KSIPA,
@@ -69,16 +71,18 @@ enum feerate_style {
 };
 
 /* Extract a feerate style. */
-bool json_tok_feerate_style(struct command *cmd, const char *name,
-			    const char *buffer, const jsmntok_t *tok,
-			    enum feerate_style **style);
+struct command_result *param_feerate_style(struct command *cmd,
+					   const char *name,
+					   const char *buffer,
+					   const jsmntok_t *tok,
+					   enum feerate_style **style);
 
 const char *json_feerate_style_name(enum feerate_style style);
 
 /* Extract a feerate with optional style suffix. */
-bool json_tok_feerate(struct command *cmd, const char *name,
-		      const char *buffer, const jsmntok_t *tok,
-		      u32 **feerate);
+struct command_result *param_feerate(struct command *cmd, const char *name,
+				     const char *buffer, const jsmntok_t *tok,
+				     u32 **feerate);
 
 /* '"fieldname" : "1234:5:6"' */
 void json_add_short_channel_id(struct json_stream *response,
@@ -144,12 +148,12 @@ enum address_parse_result {
  * allocated off ctx if ADDRESS_PARSE_SUCCESS
  */
 enum address_parse_result json_tok_address_scriptpubkey(const tal_t *ctx,
-			      const struct chainparams *chainparams,
-			      const char *buffer,
-			      const jsmntok_t *tok, const u8 **scriptpubkey);
+			     const struct chainparams *chainparams,
+			     const char *buffer,
+			     const jsmntok_t *tok, const u8 **scriptpubkey);
 
 /* Parse the satoshi token in wallet_tx. */
-bool json_tok_wtx(struct wallet_tx * tx, const char * buffer,
-		  const jsmntok_t * sattok, u64 max);
+struct command_result *param_wtx(struct wallet_tx * tx, const char * buffer,
+				 const jsmntok_t * sattok, u64 max);
 
 #endif /* LIGHTNING_LIGHTNINGD_JSON_H */
diff --git a/lightningd/jsonrpc.c b/lightningd/jsonrpc.c
index 0962c386b..ba29ed91e 100644
--- a/lightningd/jsonrpc.c
+++ b/lightningd/jsonrpc.c
@@ -200,7 +200,7 @@ static void json_rhash(struct command *cmd,
 	struct sha256 *secret;
 
 	if (!param(cmd, buffer, params,
-		   p_req("secret", json_tok_sha256, &secret),
+		   p_req("secret", param_sha256, &secret),
 		   NULL))
 		return;
 
@@ -250,7 +250,7 @@ static void json_slowcmd(struct command *cmd,
 
 	sc->cmd = cmd;
 	if (!param(cmd, buffer, params,
-		   p_opt_def("msec", json_tok_number, &sc->msec, 1000),
+		   p_opt_def("msec", param_number, &sc->msec, 1000),
 		   NULL))
 		return;
 
@@ -335,7 +335,7 @@ static void json_help(struct command *cmd,
 	struct json_command **commands = cmd->ld->jsonrpc->commands;
 
 	if (!param(cmd, buffer, params,
-		   p_opt("command", json_tok_tok, &cmdtok),
+		   p_opt("command", param_tok, &cmdtok),
 		   NULL))
 		return;
 
@@ -963,36 +963,37 @@ json_tok_address_scriptpubkey(const tal_t *cxt,
 	return ADDRESS_PARSE_UNRECOGNIZED;
 }
 
-bool json_tok_wtx(struct wallet_tx * tx, const char * buffer,
-                  const jsmntok_t *sattok, u64 max)
+struct command_result *param_wtx(struct wallet_tx * tx, const char * buffer,
+				 const jsmntok_t *sattok, u64 max)
 {
         if (json_tok_streq(buffer, sattok, "all")) {
                 tx->all_funds = true;
 		tx->amount = max;
         } else if (!json_to_u64(buffer, sattok, &tx->amount)) {
-                command_fail(tx->cmd, JSONRPC2_INVALID_PARAMS,
-			     "Invalid satoshis");
-                return false;
+                return command_fail(tx->cmd, JSONRPC2_INVALID_PARAMS,
+				    "Invalid satoshis");
 	} else if (tx->amount > max) {
-                command_fail(tx->cmd, FUND_MAX_EXCEEDED,
-			     "Amount exceeded %"PRIu64, max);
-                return false;
+                return command_fail(tx->cmd, FUND_MAX_EXCEEDED,
+				    "Amount exceeded %"PRIu64, max);
 	}
-        return true;
+        return NULL;
 }
 
-static bool json_tok_command(struct command *cmd, const char *name,
-			     const char *buffer, const jsmntok_t *tok,
-			     const jsmntok_t **out)
+static struct command_result *param_command(struct command *cmd,
+					    const char *name,
+					    const char *buffer,
+					    const jsmntok_t *tok,
+					    const jsmntok_t **out)
 {
 	cmd->json_cmd = find_cmd(cmd->jcon->ld->jsonrpc, buffer, tok);
-	if (cmd->json_cmd)
-		return (*out = tok);
+	if (cmd->json_cmd) {
+		*out = tok;
+		return NULL;
+	}
 
-	command_fail(cmd, JSONRPC2_METHOD_NOT_FOUND,
-		     "Unknown command '%.*s'",
-		     tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_METHOD_NOT_FOUND,
+			    "Unknown command '%.*s'",
+			    tok->end - tok->start, buffer + tok->start);
 }
 
 /* We add this destructor as a canary to detect cmd failing. */
@@ -1018,7 +1019,7 @@ static void json_check(struct command *cmd,
 	}
 
 	if (!param(cmd, buffer, mod_params,
-		   p_req("command_to_check", json_tok_command, &name_tok),
+		   p_req("command_to_check", param_command, &name_tok),
 		   p_opt_any(),
 		   NULL))
 		return;
diff --git a/lightningd/log.c b/lightningd/log.c
index 57de95bcd..bed8e138e 100644
--- a/lightningd/log.c
+++ b/lightningd/log.c
@@ -702,9 +702,11 @@ void json_add_log(struct json_stream *response,
 	json_array_end(info.response);
 }
 
-bool json_tok_loglevel(struct command *cmd, const char *name,
-		       const char *buffer, const jsmntok_t *tok,
-		       enum log_level **level)
+struct command_result *param_loglevel(struct command *cmd,
+				      const char *name,
+				      const char *buffer,
+				      const jsmntok_t *tok,
+				      enum log_level **level)
 {
 	*level = tal(cmd, enum log_level);
 	if (json_tok_streq(buffer, tok, "io"))
@@ -716,14 +718,14 @@ bool json_tok_loglevel(struct command *cmd, const char *name,
 	else if (json_tok_streq(buffer, tok, "unusual"))
 		**level = LOG_UNUSUAL;
 	else {
-		command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-			     "'%s' should be 'io', 'debug', 'info', or "
-			     "'unusual', not '%.*s'",
-			     name,
-			     json_tok_full_len(tok), json_tok_full(buffer, tok));
-		return false;
+		return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+				    "'%s' should be 'io', 'debug', 'info', or "
+				    "'unusual', not '%.*s'",
+				    name,
+				    json_tok_full_len(tok),
+				    json_tok_full(buffer, tok));
 	}
-	return true;
+	return NULL;
 }
 
 static void json_getlog(struct command *cmd,
@@ -736,8 +738,7 @@ static void json_getlog(struct command *cmd,
 	struct log_book *lr = cmd->ld->log_book;
 
 	if (!param(cmd, buffer, params,
-		   p_opt_def("level", json_tok_loglevel, &minlevel,
-				 LOG_INFORM),
+		   p_opt_def("level", param_loglevel, &minlevel, LOG_INFORM),
 		   NULL))
 		return;
 
diff --git a/lightningd/log.h b/lightningd/log.h
index 95e118134..fb38a316c 100644
--- a/lightningd/log.h
+++ b/lightningd/log.h
@@ -103,8 +103,10 @@ void log_backtrace_exit(void);
 void json_add_log(struct json_stream *result,
 		  const struct log_book *lr, enum log_level minlevel);
 
-bool json_tok_loglevel(struct command *cmd, const char *name,
-		       const char *buffer, const jsmntok_t *tok,
-		       enum log_level **level);
+struct command_result *param_loglevel(struct command *cmd,
+				      const char *name,
+				      const char *buffer,
+				      const jsmntok_t *tok,
+				      enum log_level **level);
 
 #endif /* LIGHTNING_LIGHTNINGD_LOG_H */
diff --git a/lightningd/opening_control.c b/lightningd/opening_control.c
index 99c95cbb0..f46c274ab 100644
--- a/lightningd/opening_control.c
+++ b/lightningd/opening_control.c
@@ -767,6 +767,7 @@ static void json_fund_channel(struct command *cmd,
 			      const jsmntok_t *obj UNNEEDED,
 			      const jsmntok_t *params)
 {
+	struct command_result *res;
 	const jsmntok_t *sattok;
 	struct funding_channel * fc = tal(cmd, struct funding_channel);
 	struct pubkey *id;
@@ -781,14 +782,15 @@ static void json_fund_channel(struct command *cmd,
 	fc->uc = NULL;
 	wtx_init(cmd, &fc->wtx);
 	if (!param(fc->cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &id),
-		   p_req("satoshi", json_tok_tok, &sattok),
-		   p_opt("feerate", json_tok_feerate, &feerate_per_kw),
-		   p_opt_def("announce", json_tok_bool, &announce_channel, true),
+		   p_req("id", param_pubkey, &id),
+		   p_req("satoshi", param_tok, &sattok),
+		   p_opt("feerate", param_feerate, &feerate_per_kw),
+		   p_opt_def("announce", param_bool, &announce_channel, true),
 		   NULL))
 		return;
 
-	if (!json_tok_wtx(&fc->wtx, buffer, sattok, max_funding_satoshi))
+	res = param_wtx(&fc->wtx, buffer, sattok, max_funding_satoshi);
+	if (res)
 		return;
 
 	if (!feerate_per_kw) {
diff --git a/lightningd/options.c b/lightningd/options.c
index 95d4620a1..6e12b9614 100644
--- a/lightningd/options.c
+++ b/lightningd/options.c
@@ -1056,7 +1056,7 @@ static void json_listconfigs(struct command *cmd,
 	const jsmntok_t *configtok;
 
 	if (!param(cmd, buffer, params,
-		   p_opt("config", json_tok_tok, &configtok),
+		   p_opt("config", param_tok, &configtok),
 		   NULL))
 		return;
 
diff --git a/lightningd/pay.c b/lightningd/pay.c
index 52ebd99d5..dcf6c4b74 100644
--- a/lightningd/pay.c
+++ b/lightningd/pay.c
@@ -955,10 +955,10 @@ static void json_sendpay(struct command *cmd,
 	const char *description;
 
 	if (!param(cmd, buffer, params,
-		   p_req("route", json_tok_array, &routetok),
-		   p_req("payment_hash", json_tok_sha256, &rhash),
-		   p_opt("description", json_tok_escaped_string, &description),
-		   p_opt("msatoshi", json_tok_u64, &msatoshi),
+		   p_req("route", param_array, &routetok),
+		   p_req("payment_hash", param_sha256, &rhash),
+		   p_opt("description", param_escaped_string, &description),
+		   p_opt("msatoshi", param_u64, &msatoshi),
 		   NULL))
 		return;
 
@@ -973,10 +973,10 @@ static void json_sendpay(struct command *cmd,
 		unsigned *delay;
 
 		if (!param(cmd, buffer, t,
-			   p_req("msatoshi", json_tok_u64, &amount),
-			   p_req("id", json_tok_pubkey, &id),
-			   p_req("delay", json_tok_number, &delay),
-			   p_req("channel", json_tok_short_channel_id, &channel),
+			   p_req("msatoshi", param_u64, &amount),
+			   p_req("id", param_pubkey, &id),
+			   p_req("delay", param_number, &delay),
+			   p_req("channel", param_short_channel_id, &channel),
 			   NULL))
 			return;
 
@@ -1037,8 +1037,8 @@ static void json_waitsendpay(struct command *cmd,
 	unsigned int *timeout;
 
 	if (!param(cmd, buffer, params,
-		   p_req("payment_hash", json_tok_sha256, &rhash),
-		   p_opt("timeout", json_tok_number, &timeout),
+		   p_req("payment_hash", param_sha256, &rhash),
+		   p_opt("timeout", param_number, &timeout),
 		   NULL))
 		return;
 
@@ -1070,8 +1070,8 @@ static void json_listpayments(struct command *cmd,
 	const char *b11str;
 
 	if (!param(cmd, buffer, params,
-		   p_opt("bolt11", json_tok_string, &b11str),
-		   p_opt("payment_hash", json_tok_sha256, &rhash),
+		   p_opt("bolt11", param_string, &b11str),
+		   p_opt("payment_hash", param_sha256, &rhash),
 		   NULL))
 		return;
 
diff --git a/lightningd/payalgo.c b/lightningd/payalgo.c
index f657bf0b1..4bd67a8cb 100644
--- a/lightningd/payalgo.c
+++ b/lightningd/payalgo.c
@@ -609,15 +609,15 @@ static void json_pay(struct command *cmd,
 	unsigned int *exemptfee;
 
 	if (!param(cmd, buffer, params,
-		   p_req("bolt11", json_tok_string, &b11str),
-		   p_opt("msatoshi", json_tok_u64, &msatoshi),
-		   p_opt("description", json_tok_string, &desc),
-		   p_opt_def("riskfactor", json_tok_double, &riskfactor, 1.0),
-		   p_opt_def("maxfeepercent", json_tok_percent, &maxfeepercent, 0.5),
-		   p_opt_def("retry_for", json_tok_number, &retryfor, 60),
-		   p_opt_def("maxdelay", json_tok_number, &maxdelay,
+		   p_req("bolt11", param_string, &b11str),
+		   p_opt("msatoshi", param_u64, &msatoshi),
+		   p_opt("description", param_string, &desc),
+		   p_opt_def("riskfactor", param_double, &riskfactor, 1.0),
+		   p_opt_def("maxfeepercent", param_percent, &maxfeepercent, 0.5),
+		   p_opt_def("retry_for", param_number, &retryfor, 60),
+		   p_opt_def("maxdelay", param_number, &maxdelay,
 			     cmd->ld->config.locktime_max),
-		   p_opt_def("exemptfee", json_tok_number, &exemptfee, 5000),
+		   p_opt_def("exemptfee", param_number, &exemptfee, 5000),
 		   NULL))
 		return;
 
diff --git a/lightningd/peer_control.c b/lightningd/peer_control.c
index 6bc8e632e..c87b67e17 100644
--- a/lightningd/peer_control.c
+++ b/lightningd/peer_control.c
@@ -814,8 +814,8 @@ static void json_listpeers(struct command *cmd,
 	struct json_stream *response;
 
 	if (!param(cmd, buffer, params,
-		   p_opt("id", json_tok_pubkey, &specific_id),
-		   p_opt("level", json_tok_loglevel, &ll),
+		   p_opt("id", param_pubkey, &specific_id),
+		   p_opt("level", param_loglevel, &ll),
 		   NULL))
 		return;
 
@@ -903,9 +903,9 @@ static void json_close(struct command *cmd,
 	bool *force;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_tok, &idtok),
-		   p_opt_def("force", json_tok_bool, &force, false),
-		   p_opt_def("timeout", json_tok_number, &timeout, 30),
+		   p_req("id", param_tok, &idtok),
+		   p_opt_def("force", param_bool, &force, false),
+		   p_opt_def("timeout", param_number, &timeout, 30),
 		   NULL))
 		return;
 
@@ -1046,8 +1046,8 @@ static void json_disconnect(struct command *cmd,
 	bool *force;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &id),
-		   p_opt_def("force", json_tok_bool, &force, false),
+		   p_req("id", param_pubkey, &id),
+		   p_opt_def("force", param_bool, &force, false),
 		   NULL))
 		return;
 
@@ -1171,7 +1171,7 @@ static void json_sign_last_tx(struct command *cmd,
 	struct channel *channel;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &peerid),
+		   p_req("id", param_pubkey, &peerid),
 		   NULL))
 		return;
 
@@ -1218,7 +1218,7 @@ static void json_dev_fail(struct command *cmd,
 	struct channel *channel;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &peerid),
+		   p_req("id", param_pubkey, &peerid),
 		   NULL))
 		return;
 
@@ -1266,7 +1266,7 @@ static void json_dev_reenable_commit(struct command *cmd,
 	struct channel *channel;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &peerid),
+		   p_req("id", param_pubkey, &peerid),
 		   NULL))
 		return;
 
@@ -1361,9 +1361,9 @@ static void json_dev_forget_channel(struct command *cmd,
 
 	bool *force;
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &peerid),
-		   p_opt("short_channel_id", json_tok_short_channel_id, &scid),
-		   p_opt_def("force", json_tok_bool, &force, false),
+		   p_req("id", param_pubkey, &peerid),
+		   p_opt("short_channel_id", param_short_channel_id, &scid),
+		   p_opt_def("force", param_bool, &force, false),
 		   NULL))
 		return;
 
diff --git a/lightningd/peer_htlcs.c b/lightningd/peer_htlcs.c
index bcac32520..b3b8cdf0b 100644
--- a/lightningd/peer_htlcs.c
+++ b/lightningd/peer_htlcs.c
@@ -1802,8 +1802,8 @@ static void json_dev_ignore_htlcs(struct command *cmd,
 	bool *ignore;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &peerid),
-		   p_req("ignore", json_tok_bool, &ignore),
+		   p_req("id", param_pubkey, &peerid),
+		   p_req("ignore", param_bool, &ignore),
 		   NULL))
 		return;
 
diff --git a/lightningd/ping.c b/lightningd/ping.c
index b379b4244..d63e9f511 100644
--- a/lightningd/ping.c
+++ b/lightningd/ping.c
@@ -89,9 +89,9 @@ static void json_ping(struct command *cmd,
 	struct pubkey *id;
 
 	if (!param(cmd, buffer, params,
-		   p_req("id", json_tok_pubkey, &id),
-		   p_opt_def("len", json_tok_number, &len, 128),
-		   p_opt_def("pongbytes", json_tok_number, &pongbytes, 128),
+		   p_req("id", param_pubkey, &id),
+		   p_opt_def("len", param_number, &len, 128),
+		   p_opt_def("pongbytes", param_number, &pongbytes, 128),
 		   NULL))
 		return;
 
diff --git a/lightningd/test/run-invoice-select-inchan.c b/lightningd/test/run-invoice-select-inchan.c
index 10de66cf1..e9e65d24d 100644
--- a/lightningd/test/run-invoice-select-inchan.c
+++ b/lightningd/test/run-invoice-select-inchan.c
@@ -183,74 +183,14 @@ struct json_stream *json_stream_success(struct command *cmd UNNEEDED)
 { fprintf(stderr, "json_stream_success called!\n"); abort(); }
 /* Generated stub for json_tok_address_scriptpubkey */
 enum address_parse_result json_tok_address_scriptpubkey(const tal_t *ctx UNNEEDED,
-			      const struct chainparams *chainparams UNNEEDED,
-			      const char *buffer UNNEEDED,
-			      const jsmntok_t *tok UNNEEDED, const u8 **scriptpubkey UNNEEDED)
+			     const struct chainparams *chainparams UNNEEDED,
+			     const char *buffer UNNEEDED,
+			     const jsmntok_t *tok UNNEEDED, const u8 **scriptpubkey UNNEEDED)
 { fprintf(stderr, "json_tok_address_scriptpubkey called!\n"); abort(); }
-/* Generated stub for json_tok_array */
-bool json_tok_array(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		    const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		    const jsmntok_t **arr UNNEEDED)
-{ fprintf(stderr, "json_tok_array called!\n"); abort(); }
-/* Generated stub for json_tok_bool */
-bool json_tok_bool(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		   const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		   bool **b UNNEEDED)
-{ fprintf(stderr, "json_tok_bool called!\n"); abort(); }
 /* Generated stub for json_tok_channel_id */
 bool json_tok_channel_id(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
 			 struct channel_id *cid UNNEEDED)
 { fprintf(stderr, "json_tok_channel_id called!\n"); abort(); }
-/* Generated stub for json_tok_escaped_string */
-bool json_tok_escaped_string(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-			     const char * buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-			     const char **str UNNEEDED)
-{ fprintf(stderr, "json_tok_escaped_string called!\n"); abort(); }
-/* Generated stub for json_tok_label */
-bool json_tok_label(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		    const char * buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		    struct json_escaped **label UNNEEDED)
-{ fprintf(stderr, "json_tok_label called!\n"); abort(); }
-/* Generated stub for json_tok_loglevel */
-bool json_tok_loglevel(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		       const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		       enum log_level **level UNNEEDED)
-{ fprintf(stderr, "json_tok_loglevel called!\n"); abort(); }
-/* Generated stub for json_tok_msat */
-bool json_tok_msat(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		   const char *buffer UNNEEDED, const jsmntok_t * tok UNNEEDED,
-		   u64 **msatoshi_val UNNEEDED)
-{ fprintf(stderr, "json_tok_msat called!\n"); abort(); }
-/* Generated stub for json_tok_number */
-bool json_tok_number(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		     const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		     unsigned int **num UNNEEDED)
-{ fprintf(stderr, "json_tok_number called!\n"); abort(); }
-/* Generated stub for json_tok_pubkey */
-bool json_tok_pubkey(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		     const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		     struct pubkey **pubkey UNNEEDED)
-{ fprintf(stderr, "json_tok_pubkey called!\n"); abort(); }
-/* Generated stub for json_tok_short_channel_id */
-bool json_tok_short_channel_id(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-			       const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-			       struct short_channel_id **scid UNNEEDED)
-{ fprintf(stderr, "json_tok_short_channel_id called!\n"); abort(); }
-/* Generated stub for json_tok_string */
-bool json_tok_string(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		     const char * buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		     const char **str UNNEEDED)
-{ fprintf(stderr, "json_tok_string called!\n"); abort(); }
-/* Generated stub for json_tok_tok */
-bool json_tok_tok(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		  const char *buffer UNNEEDED, const jsmntok_t * tok UNNEEDED,
-		  const jsmntok_t **out UNNEEDED)
-{ fprintf(stderr, "json_tok_tok called!\n"); abort(); }
-/* Generated stub for json_tok_u64 */
-bool json_tok_u64(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		  const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		  uint64_t **num UNNEEDED)
-{ fprintf(stderr, "json_tok_u64 called!\n"); abort(); }
 /* Generated stub for json_to_pubkey */
 bool json_to_pubkey(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
 		    struct pubkey *pubkey UNNEEDED)
@@ -305,6 +245,72 @@ void opening_peer_no_active_channels(struct peer *peer UNNEEDED)
 bool param(struct command *cmd UNNEEDED, const char *buffer UNNEEDED,
 	   const jsmntok_t params[] UNNEEDED, ...)
 { fprintf(stderr, "param called!\n"); abort(); }
+/* Generated stub for param_array */
+struct command_result *param_array(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				   const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				   const jsmntok_t **arr UNNEEDED)
+{ fprintf(stderr, "param_array called!\n"); abort(); }
+/* Generated stub for param_bool */
+struct command_result *param_bool(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				  const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				  bool **b UNNEEDED)
+{ fprintf(stderr, "param_bool called!\n"); abort(); }
+/* Generated stub for param_escaped_string */
+struct command_result *param_escaped_string(struct command *cmd UNNEEDED,
+					    const char *name UNNEEDED,
+					    const char *buffer UNNEEDED,
+					    const jsmntok_t *tok UNNEEDED,
+					    const char **str UNNEEDED)
+{ fprintf(stderr, "param_escaped_string called!\n"); abort(); }
+/* Generated stub for param_label */
+struct command_result *param_label(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				   const char * buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				   struct json_escaped **label UNNEEDED)
+{ fprintf(stderr, "param_label called!\n"); abort(); }
+/* Generated stub for param_loglevel */
+struct command_result *param_loglevel(struct command *cmd UNNEEDED,
+				      const char *name UNNEEDED,
+				      const char *buffer UNNEEDED,
+				      const jsmntok_t *tok UNNEEDED,
+				      enum log_level **level UNNEEDED)
+{ fprintf(stderr, "param_loglevel called!\n"); abort(); }
+/* Generated stub for param_msat */
+struct command_result *param_msat(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				  const char *buffer UNNEEDED, const jsmntok_t * tok UNNEEDED,
+				  u64 **msatoshi_val UNNEEDED)
+{ fprintf(stderr, "param_msat called!\n"); abort(); }
+/* Generated stub for param_number */
+struct command_result *param_number(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				    const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				    unsigned int **num UNNEEDED)
+{ fprintf(stderr, "param_number called!\n"); abort(); }
+/* Generated stub for param_pubkey */
+struct command_result *param_pubkey(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				    const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				    struct pubkey **pubkey UNNEEDED)
+{ fprintf(stderr, "param_pubkey called!\n"); abort(); }
+/* Generated stub for param_short_channel_id */
+struct command_result *param_short_channel_id(struct command *cmd UNNEEDED,
+					      const char *name UNNEEDED,
+					      const char *buffer UNNEEDED,
+					      const jsmntok_t *tok UNNEEDED,
+					      struct short_channel_id **scid UNNEEDED)
+{ fprintf(stderr, "param_short_channel_id called!\n"); abort(); }
+/* Generated stub for param_string */
+struct command_result *param_string(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				    const char * buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				    const char **str UNNEEDED)
+{ fprintf(stderr, "param_string called!\n"); abort(); }
+/* Generated stub for param_tok */
+struct command_result *param_tok(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				 const char *buffer UNNEEDED, const jsmntok_t * tok UNNEEDED,
+				 const jsmntok_t **out UNNEEDED)
+{ fprintf(stderr, "param_tok called!\n"); abort(); }
+/* Generated stub for param_u64 */
+struct command_result *param_u64(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				 const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				 uint64_t **num UNNEEDED)
+{ fprintf(stderr, "param_u64 called!\n"); abort(); }
 /* Generated stub for peer_memleak_done */
 void peer_memleak_done(struct command *cmd UNNEEDED, struct subd *leaker UNNEEDED)
 { fprintf(stderr, "peer_memleak_done called!\n"); abort(); }
diff --git a/lightningd/test/run-jsonrpc.c b/lightningd/test/run-jsonrpc.c
index 7b1e787f4..09055b6e3 100644
--- a/lightningd/test/run-jsonrpc.c
+++ b/lightningd/test/run-jsonrpc.c
@@ -21,25 +21,6 @@ const char *feerate_name(enum feerate feerate UNNEEDED)
 /* Generated stub for fmt_wireaddr_without_port */
 char *fmt_wireaddr_without_port(const tal_t *ctx UNNEEDED, const struct wireaddr *a UNNEEDED)
 { fprintf(stderr, "fmt_wireaddr_without_port called!\n"); abort(); }
-/* Generated stub for json_feerate_estimate */
-bool json_feerate_estimate(struct command *cmd UNNEEDED,
-			   u32 **feerate_per_kw UNNEEDED, enum feerate feerate UNNEEDED)
-{ fprintf(stderr, "json_feerate_estimate called!\n"); abort(); }
-/* Generated stub for json_tok_number */
-bool json_tok_number(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		     const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		     unsigned int **num UNNEEDED)
-{ fprintf(stderr, "json_tok_number called!\n"); abort(); }
-/* Generated stub for json_tok_sha256 */
-bool json_tok_sha256(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		     const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		     struct sha256 **hash UNNEEDED)
-{ fprintf(stderr, "json_tok_sha256 called!\n"); abort(); }
-/* Generated stub for json_tok_tok */
-bool json_tok_tok(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		  const char *buffer UNNEEDED, const jsmntok_t * tok UNNEEDED,
-		  const jsmntok_t **out UNNEEDED)
-{ fprintf(stderr, "json_tok_tok called!\n"); abort(); }
 /* Generated stub for log_ */
 void log_(struct log *log UNNEEDED, enum log_level level UNNEEDED, const char *fmt UNNEEDED, ...)
 
@@ -64,6 +45,26 @@ struct oneshot *new_reltimer_(struct timers *timers UNNEEDED,
 bool param(struct command *cmd UNNEEDED, const char *buffer UNNEEDED,
 	   const jsmntok_t params[] UNNEEDED, ...)
 { fprintf(stderr, "param called!\n"); abort(); }
+/* Generated stub for param_feerate_estimate */
+struct command_result *param_feerate_estimate(struct command *cmd UNNEEDED,
+					      u32 **feerate_per_kw UNNEEDED,
+					      enum feerate feerate UNNEEDED)
+{ fprintf(stderr, "param_feerate_estimate called!\n"); abort(); }
+/* Generated stub for param_number */
+struct command_result *param_number(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				    const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				    unsigned int **num UNNEEDED)
+{ fprintf(stderr, "param_number called!\n"); abort(); }
+/* Generated stub for param_sha256 */
+struct command_result *param_sha256(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				    const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				    struct sha256 **hash UNNEEDED)
+{ fprintf(stderr, "param_sha256 called!\n"); abort(); }
+/* Generated stub for param_tok */
+struct command_result *param_tok(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				 const char *buffer UNNEEDED, const jsmntok_t * tok UNNEEDED,
+				 const jsmntok_t **out UNNEEDED)
+{ fprintf(stderr, "param_tok called!\n"); abort(); }
 /* AUTOGENERATED MOCKS END */
 
 bool deprecated_apis;
diff --git a/wallet/test/run-wallet.c b/wallet/test/run-wallet.c
index 4cc7d5cd3..255933802 100644
--- a/wallet/test/run-wallet.c
+++ b/wallet/test/run-wallet.c
@@ -257,11 +257,6 @@ void json_object_start(struct json_stream *ks UNNEEDED, const char *fieldname UN
 /* Generated stub for json_stream_success */
 struct json_stream *json_stream_success(struct command *cmd UNNEEDED)
 { fprintf(stderr, "json_stream_success called!\n"); abort(); }
-/* Generated stub for json_tok_bool */
-bool json_tok_bool(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		   const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		   bool **b UNNEEDED)
-{ fprintf(stderr, "json_tok_bool called!\n"); abort(); }
 /* Generated stub for json_tok_channel_id */
 bool json_tok_channel_id(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
 			 struct channel_id *cid UNNEEDED)
@@ -272,31 +267,6 @@ const char *json_tok_full(const char *buffer UNNEEDED, const jsmntok_t *t UNNEED
 /* Generated stub for json_tok_full_len */
 int json_tok_full_len(const jsmntok_t *t UNNEEDED)
 { fprintf(stderr, "json_tok_full_len called!\n"); abort(); }
-/* Generated stub for json_tok_loglevel */
-bool json_tok_loglevel(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		       const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		       enum log_level **level UNNEEDED)
-{ fprintf(stderr, "json_tok_loglevel called!\n"); abort(); }
-/* Generated stub for json_tok_number */
-bool json_tok_number(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		     const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		     unsigned int **num UNNEEDED)
-{ fprintf(stderr, "json_tok_number called!\n"); abort(); }
-/* Generated stub for json_tok_pubkey */
-bool json_tok_pubkey(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		     const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		     struct pubkey **pubkey UNNEEDED)
-{ fprintf(stderr, "json_tok_pubkey called!\n"); abort(); }
-/* Generated stub for json_tok_short_channel_id */
-bool json_tok_short_channel_id(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-			       const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-			       struct short_channel_id **scid UNNEEDED)
-{ fprintf(stderr, "json_tok_short_channel_id called!\n"); abort(); }
-/* Generated stub for json_tok_tok */
-bool json_tok_tok(struct command *cmd UNNEEDED, const char *name UNNEEDED,
-		  const char *buffer UNNEEDED, const jsmntok_t * tok UNNEEDED,
-		  const jsmntok_t **out UNNEEDED)
-{ fprintf(stderr, "json_tok_tok called!\n"); abort(); }
 /* Generated stub for json_to_pubkey */
 bool json_to_pubkey(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
 		    struct pubkey *pubkey UNNEEDED)
@@ -349,6 +319,40 @@ void outpointfilter_remove(struct outpointfilter *of UNNEEDED,
 bool param(struct command *cmd UNNEEDED, const char *buffer UNNEEDED,
 	   const jsmntok_t params[] UNNEEDED, ...)
 { fprintf(stderr, "param called!\n"); abort(); }
+/* Generated stub for param_bool */
+struct command_result *param_bool(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				  const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				  bool **b UNNEEDED)
+{ fprintf(stderr, "param_bool called!\n"); abort(); }
+/* Generated stub for param_loglevel */
+struct command_result *param_loglevel(struct command *cmd UNNEEDED,
+				      const char *name UNNEEDED,
+				      const char *buffer UNNEEDED,
+				      const jsmntok_t *tok UNNEEDED,
+				      enum log_level **level UNNEEDED)
+{ fprintf(stderr, "param_loglevel called!\n"); abort(); }
+/* Generated stub for param_number */
+struct command_result *param_number(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				    const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				    unsigned int **num UNNEEDED)
+{ fprintf(stderr, "param_number called!\n"); abort(); }
+/* Generated stub for param_pubkey */
+struct command_result *param_pubkey(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				    const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+				    struct pubkey **pubkey UNNEEDED)
+{ fprintf(stderr, "param_pubkey called!\n"); abort(); }
+/* Generated stub for param_short_channel_id */
+struct command_result *param_short_channel_id(struct command *cmd UNNEEDED,
+					      const char *name UNNEEDED,
+					      const char *buffer UNNEEDED,
+					      const jsmntok_t *tok UNNEEDED,
+					      struct short_channel_id **scid UNNEEDED)
+{ fprintf(stderr, "param_short_channel_id called!\n"); abort(); }
+/* Generated stub for param_tok */
+struct command_result *param_tok(struct command *cmd UNNEEDED, const char *name UNNEEDED,
+				 const char *buffer UNNEEDED, const jsmntok_t * tok UNNEEDED,
+				 const jsmntok_t **out UNNEEDED)
+{ fprintf(stderr, "param_tok called!\n"); abort(); }
 /* Generated stub for parse_onionpacket */
 struct onionpacket *parse_onionpacket(
 	const tal_t *ctx UNNEEDED,
diff --git a/wallet/walletrpc.c b/wallet/walletrpc.c
index e2410c7e0..63f9199b9 100644
--- a/wallet/walletrpc.c
+++ b/wallet/walletrpc.c
@@ -95,22 +95,26 @@ static void json_withdraw(struct command *cmd,
 	u32 *feerate_per_kw;
 	struct bitcoin_tx *tx;
 	enum address_parse_result addr_parse;
+	struct command_result *res;
 
 	withdraw->cmd = cmd;
 	wtx_init(cmd, &withdraw->wtx);
 
 	if (!param(cmd, buffer, params,
-		   p_req("destination", json_tok_tok, &desttok),
-		   p_req("satoshi", json_tok_tok, &sattok),
-		   p_opt("feerate", json_tok_feerate, &feerate_per_kw),
+		   p_req("destination", param_tok, &desttok),
+		   p_req("satoshi", param_tok, &sattok),
+		   p_opt("feerate", param_feerate, &feerate_per_kw),
 		   NULL))
 		return;
 
-	if (!json_tok_wtx(&withdraw->wtx, buffer, sattok, -1ULL))
+	res = param_wtx(&withdraw->wtx, buffer, sattok, -1ULL);
+	if (res)
 		return;
 
 	if (!feerate_per_kw) {
-		if (!json_feerate_estimate(cmd, &feerate_per_kw, FEERATE_NORMAL))
+		res = param_feerate_estimate(cmd, &feerate_per_kw,
+					     FEERATE_NORMAL);
+		if (res)
 			return;
 	}
 
@@ -223,23 +227,24 @@ encode_pubkey_to_addr(const tal_t *ctx,
 }
 
 /* Extract a bool indicating "p2sh-segwit" or "bech32" */
-static bool json_tok_newaddr(struct command *cmd, const char *name,
-			     const char *buffer, const jsmntok_t *tok,
-			     bool **is_p2wpkh)
+static struct command_result *param_newaddr(struct command *cmd,
+					    const char *name,
+					    const char *buffer,
+					    const jsmntok_t *tok,
+					    bool **is_p2wpkh)
 {
 	*is_p2wpkh = tal(cmd, bool);
 	if (json_tok_streq(buffer, tok, "p2sh-segwit")) {
 		**is_p2wpkh = false;
-		return true;
+		return NULL;
 	}
 	if (json_tok_streq(buffer, tok, "bech32")) {
 		**is_p2wpkh = true;
-		return true;
+		return NULL;
 	}
-	command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-		     "'%s' should be 'bech32' or 'p2sh-segwit', not '%.*s'",
-		     name, tok->end - tok->start, buffer + tok->start);
-	return false;
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be 'bech32' or 'p2sh-segwit', not '%.*s'",
+			    name, tok->end - tok->start, buffer + tok->start);
 }
 
 static void json_newaddr(struct command *cmd,
@@ -255,7 +260,7 @@ static void json_newaddr(struct command *cmd,
 	char *out;
 
 	if (!param(cmd, buffer, params,
-		   p_opt_def("addresstype", json_tok_newaddr, &is_p2wpkh, true),
+		   p_opt_def("addresstype", param_newaddr, &is_p2wpkh, true),
 		   NULL))
 		return;
 
@@ -314,7 +319,7 @@ static void json_listaddrs(struct command *cmd,
 	u64 *bip32_max_index;
 
 	if (!param(cmd, buffer, params,
-		   p_opt_def("bip32_max_index", json_tok_u64, &bip32_max_index,
+		   p_opt_def("bip32_max_index", param_u64, &bip32_max_index,
 				 db_get_intvar(cmd->ld->wallet->db,
 				 "bip32_max_index", 0)),
 		   NULL))