feat(agent): add configurable coding_instructions

agent.coding_instructions (a string or list) is appended to the coding brief as
its own stable system block, so users can pin project-wide workflow rules
without editing the shipped brief. Coding-posture only and cache-safe (resolved
once per session; takes effect next session). Empty by default.

agent/coding_context.py

@@ -353,6 +353,29 @@ def _coding_mode(config: Optional[dict[str, Any]]) -> str:
     return "auto"
 
 
+def _coding_instructions(config: Optional[dict[str, Any]]) -> str:
+    """Standing operator instructions for the coding posture (config).
+
+    ``agent.coding_instructions`` — a string or list of strings appended to the
+    coding brief as an extra stable system block, so a user can pin project-wide
+    coding-workflow rules (e.g. "for UI work don't run tsc/lint until I approve;
+    clean the diff before committing") without editing the shipped brief.
+    Cache-safe: resolved once per session into the stable system-prompt tier,
+    like the rest of the posture.
+    """
+    if config is None:
+        try:
+            from hermes_cli.config import load_config
+
+            config = load_config()
+        except Exception:
+            config = {}
+    raw = ((config or {}).get("agent", {}) or {}).get("coding_instructions", "")
+    if isinstance(raw, (list, tuple)):
+        return "\n".join(str(item).strip() for item in raw if str(item).strip())
+    return str(raw or "").strip()
+
+
 def _resolve_cwd(cwd: Optional[str | Path]) -> Path:
     if cwd:
         return Path(cwd).expanduser()
@@ -459,6 +482,9 @@ class RuntimeMode:
     # only to steer edit-format guidance toward the model's family — see
     # ``_edit_format_line``. Fixed for the session, so cache-safe.
     model: Optional[str] = None
+    # Standing operator instructions (``agent.coding_instructions``), appended
+    # as an extra stable system block. Empty unless the user configures it.
+    instructions: str = ""
 
     @property
     def kind(self) -> str:
@@ -505,6 +531,10 @@ class RuntimeMode:
         workspace = build_coding_workspace_block(self.cwd)
         if workspace:
             blocks.append(workspace)
+        # Operator instructions ride their own block so the brief (block 0) stays
+        # byte-stable and cache-keyed independently of user config.
+        if self.instructions:
+            blocks.append(f"Operator instructions (from config):\n{self.instructions}")
         return blocks
 
     def compact_skill_categories(self) -> frozenset[str]:
@@ -557,6 +587,7 @@ def resolve_runtime_mode(
         cwd=resolved_cwd,
         config_mode=mode,
         model=model,
+        instructions=_coding_instructions(config),
     )
 
 

cli-config.yaml.example

@@ -646,6 +646,14 @@ agent:
   # force it on or off; the HERMES_VERIFY_ON_STOP env var (1/0) takes precedence.
   # verify_on_stop: auto
 
+  # Standing operator instructions for the coding posture (when Hermes is in a
+  # code workspace). Appended to the coding brief as an extra system block, so
+  # you can pin project-wide workflow rules without editing the shipped brief.
+  # Accepts a string or a list of strings. Takes effect next session.
+  # coding_instructions:
+  #   - "For UI work, don't run tsc/lint until I approve the look."
+  #   - "Clean the diff before you commit and push."
+
   # When verify-on-stop finds edited code without fresh verification evidence,
   # append guidance for creative UI work (avoid broad tsc/lint/test before visual
   # approval) and clean-diff expectations. Set false to keep that nudge terse.

hermes_cli/config.py

@@ -999,6 +999,13 @@ DEFAULT_CONFIG = {
         #   "on"             — force the prompt posture everywhere.
         #   "off"            — disable entirely.
         "coding_context": "auto",
+        # Standing operator instructions for the coding posture. A string (or
+        # list of strings) appended to the coding brief as an extra stable
+        # system block — pin project-wide workflow rules here instead of editing
+        # the shipped brief, e.g. "For UI work, don't run tsc/lint until I
+        # approve. Clean the diff before you commit and push." Cache-safe:
+        # takes effect next session. Empty by default.
+        "coding_instructions": "",
         # When verify-on-stop finds edited code without fresh verification
         # evidence, append guidance for creative UI work (avoid broad
         # tsc/lint/test before visual approval) and clean-diff expectations.

tests/agent/test_coding_context.py

@@ -353,6 +353,39 @@ class TestRuntimeMode:
         assert any("coding agent" in b for b in blocks)
         assert any("Workspace" in b for b in blocks)
 
+    def test_coding_instructions_append_their_own_block(self, tmp_path):
+        _git_init(tmp_path)
+        cfg = {
+            "agent": {
+                "coding_context": "on",
+                "coding_instructions": "Clean the diff before commit.",
+            }
+        }
+        mode = cc.resolve_runtime_mode(platform="cli", cwd=tmp_path, config=cfg)
+        blocks = mode.system_blocks()
+        # The brief stays block 0 (byte-stable, cache-keyed independently); the
+        # operator instructions ride a separate trailing block.
+        assert blocks[0] == cc.CODING_AGENT_GUIDANCE
+        assert any("Clean the diff before commit." in b for b in blocks[1:])
+
+    def test_coding_instructions_accept_a_list(self, tmp_path):
+        _git_init(tmp_path)
+        cfg = {
+            "agent": {
+                "coding_context": "on",
+                "coding_instructions": ["No tsc/lint on UI.", "Clean the diff."],
+            }
+        }
+        mode = cc.resolve_runtime_mode(platform="cli", cwd=tmp_path, config=cfg)
+        instr_block = mode.system_blocks()[-1]
+        assert "No tsc/lint on UI." in instr_block
+        assert "Clean the diff." in instr_block
+
+    def test_no_instructions_block_when_unset(self, tmp_path):
+        _git_init(tmp_path)
+        mode = cc.resolve_runtime_mode(platform="cli", cwd=tmp_path, config={"agent": {"coding_context": "on"}})
+        assert not any("Operator instructions" in b for b in mode.system_blocks())
+
     def test_toolset_selection_gated_on_focus(self, tmp_path):
         _git_init(tmp_path)
         focus = cc.resolve_runtime_mode(platform="cli", cwd=tmp_path, config={"agent": {"coding_context": "focus"}})