feat(prompts): one base prompt for every host, with a Bearing article

HEADLESS_BASE_PROMPT was a second hand-maintained rendering of the
constitution — the drift pattern AGENTS.md already forbids (BASE_PROMPT
is the sole base prompt). Headless hosts now compose the same
BASE_PROMPT + language + output layers as interactive, skipping only
host chrome (execution profile, authority recap).

BASE_PROMPT gains a Bearing article — peer stance, honesty over
deference, candor over refusal theater, no apology as punctuation, no
sanitizing the user's request — and the scope law now opens with the
mandate ("everything inside it is yours to do") before the edge. Every
pinned kernel invariant survives verbatim.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

crates/tui/src/acp_server.rs

@@ -3970,7 +3970,7 @@ mod tests {
         );
         let text = crate::prompts::system_prompt_flat_text(&prompt);
 
-        assert!(text.contains(crate::prompts::text::HEADLESS_BASE_PROMPT.trim()));
+        assert!(text.contains(crate::prompts::text::BASE_PROMPT.trim()));
         assert!(text.contains("acp-project-marker"));
         assert!(text.contains("acp-config-marker"));
         assert!(!text.contains("You are a coding assistant inside an ACP-compatible editor."));

crates/tui/src/prompts.rs

@@ -395,7 +395,7 @@ fn user_constitution_disabled_by_setup_state() -> bool {
 use text::CALM_PERSONALITY;
 pub use text::{
     BASE_PROMPT, COMPACT_TEMPLATE, CORE_EXECUTION_PROFILE_PROMPT, GOAL_CONTINUATION_PROMPT,
-    HEADLESS_BASE_PROMPT, LANGUAGE_PROMPT, MEMORY_GUIDANCE, OUTPUT_PROMPT,
+    LANGUAGE_PROMPT, MEMORY_GUIDANCE, OUTPUT_PROMPT,
 };
 
 // ── Embedder prompt overrides ──
@@ -974,9 +974,9 @@ fn apply_static_prompt_composer(
     }
 }
 
-// Interactive hosts use the full base and bundled headless hosts use the
-// compact base. Tool availability is enforced by the catalog and execution
-// layer, never by mode-specific prompt text.
+// Every host shares BASE_PROMPT — one constitution, one stance. Host selects
+// only which ceremony layers follow it; tool availability is enforced by the
+// catalog and execution layer, never by mode-specific prompt text.
 
 // ── Public API ────────────────────────────────────────────────────────
 
@@ -1075,30 +1075,21 @@ pub(crate) fn system_prompt_for_mode_with_context_skills_session_and_approval_fo
     session_context: PromptSessionContext<'_>,
     prompt_host: PromptHost,
 ) -> SystemPrompt {
-    // The bundled headless coding host gets one compact constitution. Explicit
-    // user/embedder overrides retain the established full composition because
-    // those bytes are an intentional customization, not bundled ceremony.
-    let bundled_headless = prompt_host == PromptHost::Headless
-        && BASE_PROMPT_OVERRIDE.get().is_none()
-        && effective_static_prompt_composer().is_none();
-    let composed = if bundled_headless {
-        apply_model_template(
-            HEADLESS_BASE_PROMPT.trim(),
-            session_context.model_id,
-            session_context.context_window_override,
-        )
-    } else {
-        let default_layers = compose_default_static_layers_with_context(
-            session_context.model_id,
-            session_context.context_window_override,
-        );
-        apply_static_prompt_composer(
-            effective_static_prompt_composer(),
-            Personality::Calm,
-            session_context.model_id,
-            &default_layers,
-        )
-    };
+    // One base prompt for every host (AGENTS.md: `BASE_PROMPT` is the sole
+    // base prompt). Headless still skips interactive ceremony layers below —
+    // the execution profile and authority recap — which are host chrome, not
+    // doctrine.
+    let headless = prompt_host == PromptHost::Headless;
+    let default_layers = compose_default_static_layers_with_context(
+        session_context.model_id,
+        session_context.context_window_override,
+    );
+    let composed = apply_static_prompt_composer(
+        effective_static_prompt_composer(),
+        Personality::Calm,
+        session_context.model_id,
+        &default_layers,
+    );
 
     // Load project context from workspace
     let project_context = load_project_context_with_parents(workspace);
@@ -1201,7 +1192,7 @@ pub(crate) fn system_prompt_for_mode_with_context_skills_session_and_approval_fo
     // 4. Lean, runtime-only coding discipline. Context pressure, prompt-cache
     // accounting, footer presentation, and automatic compaction are host
     // responsibilities; teaching their UI to the model dilutes the task.
-    if !bundled_headless {
+    if !headless {
         full_prompt.push_str("\n\n");
         full_prompt.push_str(CORE_EXECUTION_PROFILE_PROMPT.trim());
     }
@@ -1294,7 +1285,7 @@ pub(crate) fn system_prompt_for_mode_with_context_skills_session_and_approval_fo
     .to_system_blocks();
 
     // Trailers keep recency bias after WorldState: authority, then locale.
-    if !bundled_headless {
+    if !headless {
         blocks.push(SystemBlock {
             block_type: "text".to_string(),
             text: effective_authority_recap().trim().to_string(),
@@ -1541,48 +1532,6 @@ mod tests {
         })
     }
 
-    #[test]
-    fn bundled_headless_contract_is_small_and_direct() {
-        for phrase in [
-            "You already have an A",
-            "begin from possibility",
-            "bring your whole attention",
-            "a question, idea, or task",
-            "Invent no urgency or deadline",
-            "tools as senses",
-            "active authority is your limit",
-            "Failure is information",
-            "Check\nbefore concluding",
-            "unverified work as complete",
-        ] {
-            assert!(
-                HEADLESS_BASE_PROMPT.contains(phrase),
-                "bundled headless contract missing {phrase:?}"
-            );
-        }
-        for ceremony in [
-            "todo_write",
-            "checklist",
-            "`repl`",
-            "workflow",
-            "Fleet",
-            "sub-agent",
-            "delegation",
-            "goals",
-            "harness",
-            "Mode:",
-        ] {
-            assert!(
-                !HEADLESS_BASE_PROMPT.contains(ceremony),
-                "bundled headless contract must leave optional capabilities to the tool catalog: {ceremony:?}"
-            );
-        }
-        assert!(
-            HEADLESS_BASE_PROMPT.split_whitespace().count() <= 75,
-            "bundled headless contract must stay compact"
-        );
-    }
-
     #[test]
     fn every_mode_shares_one_prompt_per_host() {
         let _env_lock = crate::test_support::lock_test_env();
@@ -1613,7 +1562,9 @@ mod tests {
             assert!(prompts[0].contains("Preserve the blue-ocean marker"));
             assert!(!prompts[0].contains("##### Mode:"));
             if host == PromptHost::Headless {
-                assert!(prompts[0].contains("You already have an A"));
+                // One base prompt for every host; headless still omits the
+                // interactive ceremony layers.
+                assert!(prompts[0].contains("The A is already yours"));
                 assert!(!prompts[0].contains("## Core Execution"));
                 assert!(!prompts[0].contains("## Authority Recap"));
             }
@@ -3183,7 +3134,7 @@ mod tests {
             "When NOT to use certain tools",
             "Don't reach for",
         ] {
-            assert!(!HEADLESS_BASE_PROMPT.contains(forbidden));
+            assert!(!BASE_PROMPT.contains(forbidden));
         }
     }
 
@@ -3315,7 +3266,7 @@ mod tests {
             rlm_count >= 5,
             "RLM tool descriptions present: expected >= 5 mentions of 'rlm', got {rlm_count}"
         );
-        assert!(!HEADLESS_BASE_PROMPT.contains("`rlm`"));
+        assert!(!BASE_PROMPT.contains("`rlm`"));
     }
 
     /// Project instructions rank above memory, with the nearest scope winning
@@ -3352,19 +3303,19 @@ mod tests {
     fn prompt_documents_fork_context_prefix_cache_contract() {
         let source = include_str!("tools/subagent/mod.rs");
         assert!(source.contains("fork_context"));
-        assert!(!HEADLESS_BASE_PROMPT.contains("fork_context"));
+        assert!(!BASE_PROMPT.contains("fork_context"));
     }
 
     #[test]
     fn prompt_documents_explicit_subagent_model_strength() {
         let source = include_str!("tools/subagent/mod.rs");
         assert!(source.contains("model_strength"));
-        assert!(!HEADLESS_BASE_PROMPT.contains("model_strength"));
+        assert!(!BASE_PROMPT.contains("model_strength"));
     }
 
     #[test]
     fn prompt_documents_structured_subagent_briefs() {
-        assert!(!HEADLESS_BASE_PROMPT.contains("Subagent Brief"));
+        assert!(!BASE_PROMPT.contains("Subagent Brief"));
         for heading in [
             "### SUMMARY",
             "### EVIDENCE",
@@ -3378,8 +3329,8 @@ mod tests {
 
     #[test]
     fn universal_prompt_does_not_invent_orchestration_limits() {
-        assert!(!HEADLESS_BASE_PROMPT.contains("3-5 tool calls"));
-        assert!(!HEADLESS_BASE_PROMPT.contains("No fan-out without a fan-in owner"));
+        assert!(!BASE_PROMPT.contains("3-5 tool calls"));
+        assert!(!BASE_PROMPT.contains("No fan-out without a fan-in owner"));
     }
 
     #[test]
@@ -3390,7 +3341,7 @@ mod tests {
             "request_user_input",
             ".workflow.js",
         ] {
-            assert!(!HEADLESS_BASE_PROMPT.contains(recipe));
+            assert!(!BASE_PROMPT.contains(recipe));
         }
     }
 
@@ -3403,7 +3354,7 @@ mod tests {
             "dispatch, join",
             "busy-waiting",
         ] {
-            assert!(!HEADLESS_BASE_PROMPT.contains(internal));
+            assert!(!BASE_PROMPT.contains(internal));
         }
     }
 

crates/tui/src/prompts/text.rs

@@ -51,12 +51,23 @@ The A is already yours. Your competence is a settled fact, not a performance.
 Do the real work — bold, careful, generous. Take the work seriously. Don't take
 yourself seriously. Let the work speak.
 
+### Bearing
+You answer to the work and to the user — not to habit, optics, or the
+appearance of obedience. The user is a peer: they get your honesty, not your
+deference. When a gate blocks the work, name it plainly and keep moving —
+that is candor, not refusal theater. When the code is bad, say so; when the
+request is crude, do it without a lecture. Apologize when there is something
+to apologize for, never as punctuation. You do not sanitize what the user
+asked for or editorialize what you find. What is real — tools, tests, the
+tree — outranks every story about it, including yours.
+
 ### Ground truth
 Your tools tell you what is. Report what they return — even when it surprises
 you. When a tool fails or evidence is uncertain, say so. The user may tell you
 to set a fact aside or proceed despite it; no one may tell you to invent one.
 
 ### User intent and scope
+The request is the whole mandate — everything inside it is yours to do.
 Do what the user's current request asks, no more. Act on clear, reversible work;
 ask when ambiguity is costly. Report adjacent issues instead of silently
 expanding scope. Irreversible actions, external publication, spending,
@@ -80,7 +91,8 @@ Never present a partial result as the whole.
 ### Put guarantees in mechanism
 Authorization, ordering, stopping, schema validity, resource limits, and
 required checks belong in code, types, tests, tool gates, and runtime policy.
-A principle names the duty; mechanism carries it.
+A principle names the duty; mechanism carries it — so the guarantees are
+real, and performing them is never your job.
 
 ### Whose word wins
 When guidance conflicts, each yields to the one before it:
@@ -97,22 +109,6 @@ At equal rank, the more specific and the more recent govern. Ground truth
 underlies the whole list: the user may override a fact, but no one may invent
 one. A tie you cannot break is not yours to break — name it, and ask.
 "#;
-/// Compact default constitution for non-interactive coding hosts.
-///
-/// Tool schemas and repository instructions are supplied separately. This
-/// block states only the cross-cutting contract the runtime cannot express.
-pub const HEADLESS_BASE_PROMPT: &str = r#"## Codewhale
-
-You are Codewhale, assisting someone.
-
-You already have an A: begin from possibility and bring your whole attention.
-
-Meet each message as it is—a question, idea, or task. Honor the person's intent
-and boundaries. Invent no urgency or deadline. Use the workspace and available
-tools as senses; active authority is your limit. Failure is information. Check
-before concluding; never invent results or present partial, running, or
-unverified work as complete.
-"#;
 /// Language mirroring law, split from the compact constitution in 0.9.0.
 ///
 /// The constitution and internal law stay English (machine-facing, one