Expose top_k / min_p / presence_penalty / frequency_penalty sampling options

README.md

@@ -194,6 +194,23 @@ This should return a JSON response listing available models. If you get a connec
 
 > For a complete list of all available configuration options with comments and defaults, see `mod-ollama-chat.conf.dist` included in this repository.
 
+### Key Inference / Sampling Parameters
+
+These options control how the Ollama model generates text. All are set in `mod-ollama-chat.conf`:
+
+| Option | Default | Description |
+|---|---|---|
+| `OllamaChat.NumPredict` | `40` | Max tokens to generate. `0` = unlimited. |
+| `OllamaChat.Temperature` | `0.8` | Output randomness. Lower = more focused; higher = more creative. |
+| `OllamaChat.TopP` | `0.95` | Nucleus sampling threshold. |
+| `OllamaChat.RepeatPenalty` | `1.1` | Penalizes repeated tokens. `1.0` = no penalty. |
+| `OllamaChat.TopK` | `0` | Limits sampling to the top K tokens. `0` = unset (model default, typically 40). |
+| `OllamaChat.MinP` | `0.0` | Min-p sampling: keeps tokens with prob >= MinP × top-token prob. `0.0` = unset (model default). Alternative to TopP. |
+| `OllamaChat.PresencePenalty` | `0.0` | Penalizes tokens that have already appeared, encouraging new topics. `0.0` = unset (model default / no penalty). |
+| `OllamaChat.FrequencyPenalty` | `0.0` | Penalizes tokens proportionally to how often they have appeared, reducing repetition. `0.0` = unset (model default / no penalty). |
+
+These four parameters (`TopK`, `MinP`, `PresencePenalty`, `FrequencyPenalty`) default to `0` / `0.0`, which means they are **not sent** to Ollama and the model uses its own defaults. Behavior is unchanged unless an operator explicitly sets a non-zero value.
+
 ## Text Commands
 
 The module provides several in-game text commands for administrators (Game Masters) to manage and monitor the Ollama chat functionality. All commands require **SEC_ADMINISTRATOR** security level (GM level 3 or higher).

conf/mod_ollama_chat.conf.dist

@@ -84,6 +84,34 @@ OllamaChat.TopP = 0.95
 #     Default:     1.1
 OllamaChat.RepeatPenalty = 1.1
 
+# OllamaChat.TopK
+#     Description: Limits sampling to the top K most likely tokens. Higher = more diverse.
+#                  0 = unset (uses the model default, typically 40). Typical: 40.
+#     Example:     OllamaChat.TopK = 40
+#     Default:     0
+OllamaChat.TopK = 0
+
+# OllamaChat.MinP
+#     Description: Min-p sampling: keep tokens with probability >= MinP * (top token prob).
+#                  An alternative to TopP. 0.0 = unset (model default). Typical: 0.05.
+#     Example:     OllamaChat.MinP = 0.05
+#     Default:     0.0
+OllamaChat.MinP = 0.0
+
+# OllamaChat.PresencePenalty
+#     Description: Penalizes tokens that have already appeared, encouraging new topics.
+#                  0.0 = unset (model default / no penalty). Typical: 0.1-0.5.
+#     Example:     OllamaChat.PresencePenalty = 0.2
+#     Default:     0.0
+OllamaChat.PresencePenalty = 0.0
+
+# OllamaChat.FrequencyPenalty
+#     Description: Penalizes tokens proportionally to how often they have appeared,
+#                  reducing repetition. 0.0 = unset (model default / no penalty). Typical: 0.1-0.5.
+#     Example:     OllamaChat.FrequencyPenalty = 0.2
+#     Default:     0.0
+OllamaChat.FrequencyPenalty = 0.0
+
 # OllamaChat.NumCtx
 #     Description: Maximum context length (in tokens) sent to the model.
 #                  0 = model default. Use a value only if you want to restrict or expand context.

src/mod-ollama-chat_api.cpp

@@ -70,6 +70,22 @@ std::string QueryOllamaAPI(const std::string& prompt)
         options["repeat_penalty"] = g_OllamaRepeatPenalty;
         hasOptions = true;
     }
+    if (g_OllamaTopK > 0) {
+        options["top_k"] = g_OllamaTopK;
+        hasOptions = true;
+    }
+    if (g_OllamaMinP != 0.0f) {
+        options["min_p"] = g_OllamaMinP;
+        hasOptions = true;
+    }
+    if (g_OllamaPresencePenalty != 0.0f) {
+        options["presence_penalty"] = g_OllamaPresencePenalty;
+        hasOptions = true;
+    }
+    if (g_OllamaFrequencyPenalty != 0.0f) {
+        options["frequency_penalty"] = g_OllamaFrequencyPenalty;
+        hasOptions = true;
+    }
     if (g_OllamaNumCtx > 0) {
         options["num_ctx"] = g_OllamaNumCtx;
         hasOptions = true;

src/mod-ollama-chat_config.cpp

@@ -46,6 +46,10 @@ uint32_t    g_OllamaNumPredict = 40;
 float       g_OllamaTemperature = 0.8f;
 float       g_OllamaTopP = 0.95f;
 float       g_OllamaRepeatPenalty = 1.1f;
+uint32_t    g_OllamaTopK = 0;
+float       g_OllamaMinP = 0.0f;
+float       g_OllamaPresencePenalty = 0.0f;
+float       g_OllamaFrequencyPenalty = 0.0f;
 uint32_t    g_OllamaNumCtx = 0;
 uint32_t    g_OllamaNumThreads = 0;
 std::string g_OllamaStop = "";
@@ -390,6 +394,10 @@ void LoadOllamaChatConfig()
     g_OllamaTemperature               = sConfigMgr->GetOption<float>("OllamaChat.Temperature", 0.8f);
     g_OllamaTopP                      = sConfigMgr->GetOption<float>("OllamaChat.TopP", 0.95f);
     g_OllamaRepeatPenalty             = sConfigMgr->GetOption<float>("OllamaChat.RepeatPenalty", 1.1f);
+    g_OllamaTopK                      = sConfigMgr->GetOption<uint32_t>("OllamaChat.TopK", 0);
+    g_OllamaMinP                      = sConfigMgr->GetOption<float>("OllamaChat.MinP", 0.0f);
+    g_OllamaPresencePenalty           = sConfigMgr->GetOption<float>("OllamaChat.PresencePenalty", 0.0f);
+    g_OllamaFrequencyPenalty          = sConfigMgr->GetOption<float>("OllamaChat.FrequencyPenalty", 0.0f);
     g_OllamaNumCtx                    = sConfigMgr->GetOption<uint32_t>("OllamaChat.NumCtx", 0);
     g_OllamaNumThreads                = sConfigMgr->GetOption<uint32_t>("OllamaChat.NumThreads", 0);
     g_OllamaStop                      = sConfigMgr->GetOption<std::string>("OllamaChat.Stop", "");

src/mod-ollama-chat_config.h

@@ -47,6 +47,11 @@ extern uint32_t    g_OllamaNumPredict;
 extern float       g_OllamaTemperature;
 extern float       g_OllamaTopP;
 extern float       g_OllamaRepeatPenalty;
+// additional Ollama sampling parameters (0 / 0.0 = unset, not sent -> model default)
+extern uint32_t    g_OllamaTopK;
+extern float       g_OllamaMinP;
+extern float       g_OllamaPresencePenalty;
+extern float       g_OllamaFrequencyPenalty;
 extern uint32_t    g_OllamaNumCtx;
 extern uint32_t    g_OllamaNumThreads;
 extern std::string g_OllamaStop;