cleanup: remove model name string matching

model_context_window() now reads from config.api_context_window
instead of guessing from model name strings. is_anthropic_model()
replaced with backend == "anthropic" checks. Dead model field
removed from AgentDef/AgentHeader.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/agent/context.rs

@@ -6,15 +6,8 @@ use crate::agent::types::*;
 use tiktoken_rs::CoreBPE;
 
 /// Look up a model's context window size in tokens.
-pub fn model_context_window(model: &str) -> usize {
-    let m = model.to_lowercase();
-    if m.contains("opus") || m.contains("sonnet") {
-        200_000
-    } else if m.contains("qwen") {
-        131_072
-    } else {
-        128_000
-    }
+pub fn model_context_window(_model: &str) -> usize {
+    crate::config::get().api_context_window
 }
 
 /// Context budget in tokens: 60% of the model's context window.

src/config.rs

@@ -53,6 +53,7 @@ pub struct ContextGroup {
 }
 
 fn default_true() -> bool { true }
+fn default_context_window() -> usize { 128_000 }
 fn default_identity_dir() -> PathBuf {
     PathBuf::from(std::env::var("HOME").expect("HOME not set")).join(".consciousness/identity")
 }
@@ -85,6 +86,8 @@ pub struct Config {
     pub api_key: Option<String>,
     #[serde(skip)]
     pub api_model: Option<String>,
+    #[serde(skip, default = "default_context_window")]
+    pub api_context_window: usize,
     /// Used to resolve API settings, not stored on Config
     #[serde(default)]
     agent_model: Option<String>,
@@ -134,6 +137,7 @@ impl Default for Config {
             api_base_url: None,
             api_key: None,
             api_model: None,
+            api_context_window: default_context_window(),
             agent_model: None,
             api_reasoning: "high".to_string(),
             agent_types: vec![
@@ -178,6 +182,9 @@ impl Config {
                         .and_then(|v| v.as_str()).map(String::from);
                 }
                 config.api_model = Some(model_id.to_string());
+                if let Some(cw) = model_cfg.get("context_window").and_then(|v| v.as_u64()) {
+                    config.api_context_window = cw as usize;
+                }
             }
 
         Some(config)
@@ -479,7 +486,7 @@ impl AppConfig {
             api_base = base;
             api_key = key;
             model = mdl;
-            prompt_file = if is_anthropic_model(&model) {
+            prompt_file = if self.backend == "anthropic" {
                 self.prompts.anthropic.clone()
             } else {
                 self.prompts.other.clone()
@@ -546,7 +553,7 @@ impl AppConfig {
 
         let prompt_file = model.prompt_file.clone()
             .unwrap_or_else(|| {
-                if is_anthropic_model(&model.model_id) {
+                if model.backend == "anthropic" {
                     self.prompts.anthropic.clone()
                 } else {
                     self.prompts.other.clone()
@@ -651,11 +658,6 @@ pub fn reload_for_model(app: &AppConfig, prompt_file: &str) -> Result<(String, V
     Ok((system_prompt, context_parts))
 }
 
-fn is_anthropic_model(model: &str) -> bool {
-    let m = model.to_lowercase();
-    m.contains("claude") || m.contains("opus") || m.contains("sonnet")
-}
-
 pub fn show_config(app: &AppConfig, figment: &Figment) {
     fn mask(key: &str) -> String {
         if key.is_empty() { "(not set)".into() }

src/subconscious/defs.rs

@@ -39,7 +39,6 @@ pub struct AgentDef {
     /// Steps — single-step agents have one entry, multi-step have several.
     /// Steps are separated by `=== PROMPT ===` in the .agent file.
     pub steps: Vec<AgentStep>,
-    pub model: String,
     pub schedule: String,
     pub tools: Vec<String>,
     pub count: Option<usize>,
@@ -60,8 +59,6 @@ struct AgentHeader {
     agent: String,
     #[serde(default)]
     query: String,
-    #[serde(default = "default_model")]
-    model: String,
     #[serde(default)]
     schedule: String,
     #[serde(default)]
@@ -87,7 +84,6 @@ struct AgentHeader {
     bail: Option<String>,
 }
 
-fn default_model() -> String { "sonnet".into() }
 fn default_priority() -> i32 { 10 }
 
 /// Parse an agent file: first line is JSON config, rest is the prompt(s).
@@ -149,7 +145,6 @@ fn parse_agent_file(content: &str) -> Option<AgentDef> {
         agent: header.agent,
         query: header.query,
         steps,
-        model: header.model,
         schedule: header.schedule,
         tools: header.tools,
         count: header.count,

src/subconscious/knowledge.rs

@@ -340,8 +340,8 @@ fn run_one_agent_inner(
     };
 
     let phases: Vec<&str> = agent_batch.steps.iter().map(|s| s.phase.as_str()).collect();
-    log(&format!("{} step(s) {:?}, {}KB initial, model={}, {}, {} nodes, output={}",
-        n_steps, phases, first_len / 1024, def.model, tools_desc,
+    log(&format!("{} step(s) {:?}, {}KB initial, {}, {} nodes, output={}",
+        n_steps, phases, first_len / 1024, tools_desc,
         agent_batch.node_keys.len(), state_dir.display()));
 
     let prompts: Vec<String> = agent_batch.steps.iter()

src/thought/context.rs

@@ -11,15 +11,8 @@ use chrono::{DateTime, Utc};
 use tiktoken_rs::CoreBPE;
 
 /// Look up a model's context window size in tokens.
-pub fn model_context_window(model: &str) -> usize {
-    let m = model.to_lowercase();
-    if m.contains("opus") || m.contains("sonnet") {
-        200_000
-    } else if m.contains("qwen") {
-        131_072
-    } else {
-        128_000
-    }
+pub fn model_context_window(_model: &str) -> usize {
+    crate::config::get().api_context_window
 }
 
 /// Context budget in tokens: 60% of the model's context window.