diff --git a/README.md b/README.md
index c4cb690..a821208 100644
--- a/README.md
+++ b/README.md
@@ -47,12 +47,16 @@ Remember, the recent chat content is just a rolling prompt concatenated to the e
 - Repeat penalty.
   - `/repeat_penalty 1.2` sets the repeated token penalty.
   - `/repeat_window 20` penalizes the most recent 20 tokens from being generated.
+  - `/frequency_penalty 0.1` sets the frequency penalty. (0.0 is default, off)
+  - `/presence_penalty 0.1` sets presence penalty. (0.0 is default, off)
   - `/less= some unwanted words` adds extra tokens to be penalized.
   - `/dropless` clears the extra penalized tokens list.
 - Generation parameters.
   - `/temp 0.7` sets the temperature.
   - `/top_k 40` sets the `top_k` parameter.
   - `/top_p 0.9` sets the `top_p` parameter.
+  - `/tfs_z 0.9` sets Tail Free Sampling cutoff. (1.0 is default, off)
+  - `/typical_p 0.9` sets the Locally Typical Sampling cutoff. (1.0 is default, off)
 - Execution parameters.
   - `/thread_count 8` sets the number of threads.
   - `/batch_count 8` sets the batch size.
diff --git a/src/chat/chat.cc b/src/chat/chat.cc
index dab1f99..21cc1ee 100644
--- a/src/chat/chat.cc
+++ b/src/chat/chat.cc
@@ -105,6 +105,22 @@ rendezllama::augment_chat_input(
   }
 }
 
+static
+  llama_token
+temperature_based_sample(
+    llama_token_data_array* candidates_data,
+    struct llama_context* ctx,
+    const rendezllama::ChatOptions& opt)
+{
+  const unsigned keep_one = 1;
+  llama_sample_top_k(ctx, candidates_data, opt.top_k, keep_one);
+  llama_sample_tail_free(ctx, candidates_data, opt.tfs_z, keep_one);
+  llama_sample_typical(ctx, candidates_data, opt.typical_p, keep_one);
+  llama_sample_top_p(ctx, candidates_data, opt.top_p, keep_one);
+  llama_sample_temperature(ctx, candidates_data, opt.temp);
+  return llama_sample_token(ctx, candidates_data);
+}
+
   llama_token
 rendezllama::generate_next_token(
     struct llama_context* ctx,
@@ -141,18 +157,20 @@ rendezllama::generate_next_token(
       i, logits[i], 0.0f,
     };
   }
-  llama_token_data_array candidates_data = {
+  llama_token_data_array candidates_data[1] = {{
     candidates.data(), candidates.size(), false,
-  };
+  }};
 
   llama_sample_repetition_penalty(
-      ctx, &candidates_data,
+      ctx, candidates_data,
       penalized_tokens.data(), penalized_tokens.size(),
       opt.repeat_penalty);
-  llama_sample_top_k(ctx, &candidates_data, opt.top_k);
-  llama_sample_top_p(ctx, &candidates_data, opt.top_p);
-  llama_sample_temperature(ctx, &candidates_data, opt.temp);
-  llama_token token_id= llama_sample_token(ctx, &candidates_data);
+  llama_sample_frequency_and_presence_penalties(
+      ctx, candidates_data,
+      penalized_tokens.data(), penalized_tokens.size(),
+      opt.frequency_penalty, opt.presence_penalty);
+
+  llama_token token_id = temperature_based_sample(candidates_data, ctx, opt);
 
   // If the improbable happens, just use a newline token.
   if (token_id == llama_token_eos()) {
diff --git a/src/chat/opt.cc b/src/chat/opt.cc
index 4970d87..7b60a8d 100644
--- a/src/chat/opt.cc
+++ b/src/chat/opt.cc
@@ -57,6 +57,25 @@ parse_quoted_string(FildeshX* in)
   return s;
 }
 
+static
+  bool
+maybe_parse_bool_option(
+    bool* b, FildeshX* in,
+    const char* name)
+{
+  int tmp_b = 0;
+  if (!skipstr_FildeshX(in, name)) {
+    return false;
+  }
+  if (parse_int_FildeshX(in, &tmp_b)) {
+    *b = (tmp_b != 0);
+  }
+  else {
+    fildesh_log_warning("Need a 1 or 0.");
+  }
+  return true;
+}
+
 static
   bool
 parse_options_sxproto(
@@ -178,6 +197,11 @@ parse_options_sxproto(
       opt.transcript_sibling_filename = filename;
       opt.transcript_filename = parse_quoted_string(&slice);
     }
+    else if (
+        maybe_parse_bool_option(&opt.mlock_on, &slice, "mlock_on") ||
+        maybe_parse_bool_option(&opt.mmap_on, &slice, "mmap_on")) {
+      // Success!
+    }
     else if (rendezllama::maybe_parse_option_command(opt, &slice, nullout)) {
       // Success!
     }
@@ -353,15 +377,23 @@ rendezllama::parse_options(rendezllama::ChatOptions& opt, int argc, char** argv)
       opt.command_prefix_char = argv[argi][0];
     }
     else if (0 == strcmp("--thread_count", argv[argi])) {
+      int n = 0;
       argi += 1;
-      if (!fildesh_parse_int(&opt.thread_count, argv[argi]) || opt.thread_count <= 0) {
+      if (fildesh_parse_int(&n, argv[argi]) && n >= 0) {
+        opt.thread_count = n;
+      }
+      else {
         fildesh_log_error("--thread_count needs positive arg");
         exstatus = 64;
       }
     }
     else if (0 == strcmp("--batch_count", argv[argi])) {
+      int n = 0;
       argi += 1;
-      if (!fildesh_parse_int(&opt.batch_count, argv[argi]) || opt.batch_count <= 0) {
+      if (fildesh_parse_int(&n, argv[argi]) && n >= 0) {
+        opt.batch_count = n;
+      }
+      else {
         fildesh_log_error("--batch_count needs positive arg");
         exstatus = 64;
       }
@@ -389,79 +421,19 @@ rendezllama::parse_options(rendezllama::ChatOptions& opt, int argc, char** argv)
       }
     }
     else if (0 == strcmp("--context_token_limit", argv[argi])) {
+      int n = 0;
       argi += 1;
-      if (!fildesh_parse_int(&opt.context_token_limit, argv[argi])) {
-        fildesh_log_error("--context_token_limit needs int");
-        exstatus = 64;
-      }
-      else if (opt.context_token_limit > 2048) {
-        fildesh_log_warning("--context_token_limit is above 2048. Expect poor results.");
-      }
-    }
-    else if (0 == strcmp("--sentence_limit", argv[argi])) {
-      argi += 1;
-      if (!fildesh_parse_int(&opt.sentence_limit, argv[argi])) {
-        fildesh_log_error("--sentence_limit needs int");
-        exstatus = 64;
-      }
-    }
-    else if (0 == strcmp("--sentence_token_limit", argv[argi])) {
-      argi += 1;
-      if (!fildesh_parse_int(&opt.sentence_token_limit, argv[argi])) {
-        fildesh_log_error("--sentence_token_limit needs int");
-        exstatus = 64;
-      }
-    }
-    // Original stuff.
-    else if (0 == strcmp("--repeat_last_n", argv[argi]) ||
-             0 == strcmp("--repeat_window", argv[argi]))
-    {
-      argi += 1;
-      if (!fildesh_parse_int(&opt.repeat_last_count, argv[argi])) {
-        fildesh_log_error("--repeat_window needs int");
-        exstatus = 64;
-      }
-    }
-    else if (0 == strcmp("--repeat_penalty", argv[argi])) {
-      argi += 1;
-      double f = 0;
-      if (!fildesh_parse_double(&f, argv[argi])) {
-        fildesh_log_error("--repeat_penalty needs float");
-        exstatus = 64;
-      }
-      else {
-        opt.repeat_penalty = f;
-      }
-    }
-    else if (0 == strcmp("--temp", argv[argi])) {
-      argi += 1;
-      double f = 0;
-      if (!fildesh_parse_double(&f, argv[argi])) {
-        fildesh_log_error("--temp needs float");
-        exstatus = 64;
+      if (fildesh_parse_int(&n, argv[argi]) && n > 0) {
+        opt.context_token_limit = n;
+        if (opt.context_token_limit > 2048) {
+          fildesh_log_warning("--context_token_limit is above 2048. Expect poor results.");
+        }
       }
       else {
-        opt.temp = f;
-      }
-    }
-    else if (0 == strcmp("--top_k", argv[argi])) {
-      argi += 1;
-      if (!fildesh_parse_int(&opt.top_k, argv[argi])) {
-        fildesh_log_error("--top_k needs int");
+        fildesh_log_error("--context_token_limit needs positive arg");
         exstatus = 64;
       }
     }
-    else if (0 == strcmp("--top_p", argv[argi])) {
-      argi += 1;
-      double f = 0;
-      if (!fildesh_parse_double(&f, argv[argi])) {
-        fildesh_log_error("--top_p needs float");
-        exstatus = 64;
-      }
-      else {
-        opt.top_p = f;
-      }
-    }
     else {
       exstatus = 64;
     }
@@ -496,150 +468,111 @@ rendezllama::parse_options(rendezllama::ChatOptions& opt, int argc, char** argv)
   return exstatus;
 }
 
+static
   bool
-rendezllama::maybe_parse_option_command(
-    rendezllama::ChatOptions& opt,
-    FildeshX* in,
-    std::ostream& eout)
+maybe_parse_float(
+    float* f, FildeshX* in, std::ostream& out,
+    const char* name,
+    const char* command_delim_chars)
 {
-  if (skipstr_FildeshX(in, "repeat_last_n") ||
-      skipstr_FildeshX(in, "repeat_last_count") ||
-      skipstr_FildeshX(in, "repeat_window"))
-  {
-    int n = -1;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "repeat_window=" << opt.repeat_last_count << '\n'; eout.flush();
-    }
-    else if (parse_int_FildeshX(in, &n) && n >= 0) {
-      opt.repeat_last_count = n;
-    }
-    else {
-      fildesh_log_warning("Need an int.");
-    }
+  double tmp_f = 0;
+  if (!skipstr_FildeshX(in, name)) {
+    return false;
   }
-  else if (skipstr_FildeshX(in, "repeat_penalty")) {
-    double f = 0;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "repeat_penalty=" << opt.repeat_penalty << '\n'; eout.flush();
-    }
-    else if (parse_double_FildeshX(in, &f) && f >= 0) {
-      opt.repeat_penalty = f;
-    }
-    else {
-      fildesh_log_warning("Need a float.");
-    }
+  if (!skipchrs_FildeshX(in, command_delim_chars)) {
+    out << name << "=" << *f << '\n'; out.flush();
   }
-  else if (skipstr_FildeshX(in, "temp")) {
-    double f = 0;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "temp=" << opt.temp << '\n'; eout.flush();
-    }
-    else if (parse_double_FildeshX(in, &f) && f >= 0) {
-      opt.temp = f;
-    }
-    else {
-      fildesh_log_warning("Need a float.");
-    }
+  else if (parse_double_FildeshX(in, &tmp_f) && tmp_f >= 0) {
+    *f = (float) tmp_f;
   }
-  else if (skipstr_FildeshX(in, "top_k")) {
-    int n = -1;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "top_k=" << opt.top_k << '\n'; eout.flush();
-    }
-    else if (parse_int_FildeshX(in, &n) && n > 0) {
-      opt.top_k = n;
-    }
-    else {
-      fildesh_log_warning("Need an int.");
-    }
+  else {
+    fildesh_log_warning("Need a float.");
   }
-  else if (skipstr_FildeshX(in, "top_p")) {
-    double f = 0;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "top_p=" << opt.top_p << '\n'; eout.flush();
-    }
-    else if (parse_double_FildeshX(in, &f) && f >= 0) {
-      opt.top_p = f;
-    }
-    else {
-      fildesh_log_warning("Need a float.");
-    }
+  return true;
+}
+
+static
+  bool
+maybe_parse_nat(
+    unsigned* n, FildeshX* in, std::ostream& out,
+    const char* name,
+    const char* command_delim_chars)
+{
+  int tmp_n = 0;
+  if (!skipstr_FildeshX(in, name)) {
+    return false;
   }
-  else if (skipstr_FildeshX(in, "thread_count")) {
-    int n = -1;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "thread_count=" << opt.thread_count << '\n'; eout.flush();
-    }
-    else if (parse_int_FildeshX(in, &n) && n > 0) {
-      opt.thread_count = n;
-    }
-    else {
-      fildesh_log_warning("Need a positive int.");
-    }
+  if (!skipchrs_FildeshX(in, command_delim_chars)) {
+    out << name << "=" << *n << '\n'; out.flush();
   }
-  else if (skipstr_FildeshX(in, "batch_count")) {
-    int n = -1;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "batch_count=" << opt.batch_count << '\n'; eout.flush();
-    }
-    else if (parse_int_FildeshX(in, &n) && n > 0) {
-      opt.batch_count = n;
-    }
-    else {
-      fildesh_log_warning("Need a positive int.");
-    }
+  else if (parse_int_FildeshX(in, &tmp_n) && tmp_n >= 0) {
+    *n = (unsigned) tmp_n;
   }
-  else if (skipstr_FildeshX(in, "mlock_on")) {
-    int n = 0;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "mlock_on=" << (opt.mlock_on ? 1 : 0) << '\n'; eout.flush();
-    }
-    else if (parse_int_FildeshX(in, &n)) {
-      opt.mlock_on = (n != 0);
-    }
-    else {
-      fildesh_log_warning("Need a 1 or 0.");
-    }
+  else {
+    fildesh_log_warning("Need a non-negative int.");
   }
-  else if (skipstr_FildeshX(in, "mmap_on")) {
-    int n = 0;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "mmap_on=" << (opt.mmap_on ? 1 : 0) << '\n'; eout.flush();
-    }
-    else if (parse_int_FildeshX(in, &n)) {
-      opt.mmap_on = (n != 0);
-    }
-    else {
-      fildesh_log_warning("Need a 1 or 0.");
-    }
+  return true;
+}
+
+static
+  bool
+maybe_parse_positive(
+    unsigned* n, FildeshX* in, std::ostream& out,
+    const char* name,
+    const char* command_delim_chars)
+{
+  int tmp_n = 0;
+  if (!skipstr_FildeshX(in, name)) {
+    return false;
   }
-  else if (skipstr_FildeshX(in, "sentence_limit")) {
-    int n = -1;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "sentence_limit=" << opt.sentence_limit << '\n'; eout.flush();
-    }
-    else if (parse_int_FildeshX(in, &n) && n >= 0) {
-      opt.sentence_limit = n;
-    }
-    else {
-      fildesh_log_warning("Need a non-negative int.");
-    }
+  if (!skipchrs_FildeshX(in, command_delim_chars)) {
+    out << name << "=" << *n << '\n'; out.flush();
   }
-  else if (skipstr_FildeshX(in, "sentence_token_limit"))
-  {
-    int n = -1;
-    if (!skipchrs_FildeshX(in, opt.command_delim_chars)) {
-      eout << "sentence_token_limit=" << opt.sentence_token_limit << '\n'; eout.flush();
-    }
-    else if (parse_int_FildeshX(in, &n) && n >= 0) {
-      opt.sentence_token_limit = n;
-    }
-    else {
-      fildesh_log_warning("Need a non-negative int.");
-    }
+  else if (parse_int_FildeshX(in, &tmp_n) && tmp_n > 0) {
+    *n = (unsigned) tmp_n;
+  }
+  else {
+    fildesh_log_warning("Need a positive int.");
+  }
+  return true;
+}
+
+  bool
+rendezllama::maybe_parse_option_command(
+    rendezllama::ChatOptions& opt,
+    FildeshX* in,
+    std::ostream& out)
+{
+  const char* const delims = opt.command_delim_chars;
+  if (
+      maybe_parse_float(&opt.frequency_penalty, in, out, "frequency_penalty", delims) ||
+      maybe_parse_float(&opt.presence_penalty, in, out, "presence_penalty", delims) ||
+      maybe_parse_float(&opt.repeat_penalty, in, out, "repeat_penalty", delims) ||
+      maybe_parse_nat(&opt.repeat_last_count, in, out, "repeat_window", delims) ||
+      maybe_parse_nat(&opt.repeat_last_count, in, out, "repeat_last_n", delims) ||
+      maybe_parse_nat(&opt.repeat_last_count, in, out, "repeat_last_count", delims)) {
+    // Success!
+  }
+  else if (
+      maybe_parse_positive(&opt.top_k, in, out, "top_k", delims) ||
+      maybe_parse_float(&opt.top_p, in, out, "top_p", delims) ||
+      maybe_parse_float(&opt.tfs_z, in, out, "tfs_z", delims) ||
+      maybe_parse_float(&opt.typical_p, in, out, "typical_p", delims) ||
+      maybe_parse_float(&opt.temp, in, out, "temp", delims)) {
+    // Success!
+  }
+  else if (
+      maybe_parse_positive(&opt.thread_count, in, out, "thread_count", delims) ||
+      maybe_parse_positive(&opt.batch_count, in, out, "batch_count", delims)) {
+    // Success!
+  }
+  else if (
+      maybe_parse_nat(&opt.sentence_limit, in, out, "sentence_limit", delims) ||
+      maybe_parse_nat(&opt.sentence_token_limit, in, out, "sentence_token_limit", delims)) {
+    // Success!
   }
   else if (skipstr_FildeshX(in, "opt")) {
-    print_options(eout, opt);
+    print_options(out, opt);
   }
   else {
     return false;
diff --git a/src/chat/opt.hh b/src/chat/opt.hh
index 194517f..fbd1495 100644
--- a/src/chat/opt.hh
+++ b/src/chat/opt.hh
@@ -33,16 +33,20 @@ struct ChatOptions {
   char command_prefix_char = '/';
   const char command_delim_chars[5] = ":=! ";
 
-  int thread_count = 1;
-  int sentence_limit = 3;
-  int sentence_token_limit = 50;
-  int top_k = 1000;
+  unsigned thread_count = 1;
+  unsigned sentence_limit = 3;
+  unsigned sentence_token_limit = 50;
+  unsigned top_k = 1000;
   float top_p = 0.95;
   float temp = 0.7;
+  float tfs_z = 1.0;
+  float typical_p = 1.0;
+  float frequency_penalty = 0.0;
+  float presence_penalty = 0.0;
   float repeat_penalty = 1.2;
-  int repeat_last_count = 20;
-  int context_token_limit = 2048;
-  int batch_count = 8;
+  unsigned repeat_last_count = 20;
+  unsigned context_token_limit = 2048;
+  unsigned batch_count = 8;
   int seed;
   bool mlock_on = false;
   bool mmap_on = true;