diff --git a/DECISIONS.md b/DECISIONS.md
new file mode 100644
index 0000000..0a5876c
--- /dev/null
+++ b/DECISIONS.md
@@ -0,0 +1,38 @@
+# DECISIONS.md — ADR log
+
+Decisions inside the set architecture. D-NNN, never renumbered.
+
+- **D-001** — SDD+BDD+TDD adopted (2026-07-13). SPEC-system port:
+  numbered requirements in `specs/`, coverage classes
+  feature/test/manual, `tools/trace.py` enforcement in `make check`.
+  Process is binding — see SPEC-000.
+- **D-002** — BDD runs at the responder seam, not against live
+  services. `FakeModelResponder` scripts model output; Discord-event
+  behavior is unit-tested with mocked discord.py objects. Rationale:
+  Discord ToS forbids test-account automation and LLM output is
+  nondeterministic — a live-BDD lane would be flaky by construction.
+- **D-003** — Packaging = uv + pyproject only (2026-07-13). setup.py,
+  requirements.txt and pytest.ini removed; single source of truth,
+  locked via uv.lock. Python `>=3.11` floor keeps the kitchen host
+  (py3.11) deployable until FDB-016 lands.
+- **D-004** — openai SDK pinned `<2` (1.109.x). The v2 SDK migration
+  happens together with the FDB-005 envelope rewrite (structured
+  outputs / Responses API) — one breaking change, one test cycle,
+  instead of two.
+- **D-005** — `--strict-markers` stays on; requirement tags from
+  `.feature` files are registered as pytest markers dynamically in
+  `tests/conftest.py`.
+- **D-006** — FDB-005 stays on chat.completions + structured outputs;
+  the Responses API migration is deferred to FDB-007, where history
+  handling gets redesigned anyway — one conversation-state reshape
+  instead of two.
+- **D-007** — openai SDK bumped to 2.x together with the envelope
+  rewrite (supersedes the D-004 pin). `multiline` dependency dropped —
+  strict schema output made relaxed-JSON parsing dead code.
+- **D-008** — Operator runtime flags (pause/images/tasks/quiet) are
+  in-memory only; a restart resets to config defaults. Persistence
+  arrives with the FDB-011 task store if staff practice demands it.
+- **D-009** — `translate()` still keys off `fix-model` although the
+  repair path is gone; the whole translate-before-draw step dies in
+  FDB-009 (gpt-image-2 is multilingual). Not worth a config rename
+  for one phase.
diff --git a/features/envelope.feature b/features/envelope.feature
new file mode 100644
index 0000000..4454723
--- /dev/null
+++ b/features/envelope.feature
@@ -0,0 +1,61 @@
+Feature: Response envelope handling
+  The responder parses the model's JSON envelope and decides what the
+  bot says, where, and whether staff is alerted. (SPEC-001)
+
+  Background:
+    Given a responder with history limit 10
+
+  @ENV-01
+  Scenario: Model answer reaches the user
+    Given the model answers with answer "Hei! Velkommen." and answer_needed "true"
+    When user "alice" sends "Hei bot" in channel "chat"
+    Then the response answer contains "Hei! Velkommen."
+    And the response is marked as needed
+
+  @ENV-02
+  Scenario: Suppressed answer stays silent
+    Given the model answers with answer "irrelevant musing" and answer_needed "false"
+    When user "alice" sends "talking to bob" in channel "chat"
+    Then the response is not marked as needed
+
+  @ENV-03
+  Scenario: Staff note forces delivery
+    Given the model answers with answer "Et oyeblikk!" and staff note "Guest at table 4 needs a waiter"
+    When user "guest" sends "Can somebody help us?" in channel "chat"
+    Then the response staff note is "Guest at table 4 needs a waiter"
+    And the response is marked as needed
+
+  @ENV-04
+  Scenario: Direct messages are always answered
+    Given the model answers with answer "Svar." and answer_needed "false"
+    When user "alice" sends "hei" directly to the bot
+    Then the response is marked as needed
+
+  @ENV-05
+  Scenario: Short-path rules skip the model
+    Given a short-path rule for channels "spam.*" and users "bob.*"
+    When user "bobby" sends "noise noise" in channel "spam-corner"
+    Then the model was not called
+    And the response is empty
+    And the history contains the message from "bobby"
+
+  @ENV-07
+  Scenario: History is trimmed to the limit
+    Given a responder with history limit 4
+    And 6 prior history entries in channel "chat"
+    And the model answers with answer "ok" and answer_needed "true"
+    When user "alice" sends "hei" in channel "chat"
+    Then the history length is at most 4
+
+  @ENV-08
+  Scenario: Markdown links are unwrapped
+    Given the model answers with answer "Se [menyen](https://fjerkroa.example/meny) her" and answer_needed "true"
+    When user "alice" sends "meny?" in channel "chat"
+    Then the response answer contains "https://fjerkroa.example/meny"
+    And the response answer does not contain "[menyen]"
+
+  @ENV-09
+  Scenario: Missing channel falls back to the message channel
+    Given the model answers with answer "ok" and no channel
+    When user "alice" sends "hei" in channel "kitchen-talk"
+    Then the response channel is "kitchen-talk"
diff --git a/manual-verification.md b/manual-verification.md
new file mode 100644
index 0000000..42ab789
--- /dev/null
+++ b/manual-verification.md
@@ -0,0 +1,11 @@
+# Manual verification log
+
+Rows for requirements with `coverage: manual` (see SPEC-000). Newest
+first. A manual requirement is only "covered" when it has a row here
+with date + result.
+
+| ID | Date | Result |
+| --- | --- | --- |
+
+_No manual-coverage requirements declared yet — DEP-NN arrives with
+FDB-017._
diff --git a/specs/SPEC-000-process.md b/specs/SPEC-000-process.md
new file mode 100644
index 0000000..d8f7045
--- /dev/null
+++ b/specs/SPEC-000-process.md
@@ -0,0 +1,69 @@
+# SPEC-000 — Development process (binding)
+
+This repo is developed spec-driven + behaviour-driven + test-driven.
+
+## The three loops
+
+1. **Spec-driven**: every behavior exists first as a numbered
+   requirement (`<AREA>-NN`) in `specs/SPEC-NNN-*.md`. No code without
+   a requirement. Requirements are never deleted — a dead requirement
+   is marked `(withdrawn: <successor or reason>)` in its title line
+   and keeps its ID forever.
+2. **Behaviour-driven**: every *user-visible* requirement gets at
+   least one Gherkin scenario tagged `@<ID>` in `features/*.feature`,
+   executed by pytest-bdd.
+3. **Test-driven**: implementation starts at a red test. Unit tests
+   cover the non-visible requirements (arithmetic, invariants,
+   parsing).
+
+Change flow: spec change → feature/test red → implementation green →
+refactor.
+
+## Requirement format
+
+```
+### ENV-01 — Model answer reaches the user (coverage: feature)
+
+Normative statement first. Rationale after.
+```
+
+Coverage classes:
+
+- `feature` — needs an `@<ID>` tag in some `.feature` file.
+- `test` — the ID must appear in a test file (docstring or comment
+  of the covering test).
+- `manual` — needs a row in `manual-verification.md` with date and
+  result before the increment demo.
+
+## Enforcement
+
+`tools/trace.py` (stdlib-only) runs in `make check` (and `make
+trace`). It fails the build when a declared requirement lacks its
+coverage class artifact, when a feature tag references an undeclared
+ID, or when an ID is declared twice. Code fences in spec files are
+ignored by trace (the example above does not declare ENV-01).
+
+## Test substrate
+
+BDD scenarios run against the **responder seam**: a
+`FakeModelResponder` subclass with scripted model output — no live
+Discord, no live OpenAI (see DECISIONS.md D-002). Discord-event
+behavior is covered by unit tests with mocked discord.py objects.
+
+## ADRs
+
+Decisions inside the set architecture go to `DECISIONS.md` as
+`D-NNN — title — one-paragraph rationale`. The stack itself is not
+re-litigated there.
+
+## Spec map
+
+- SPEC-000 process (this file, no IDs)
+- SPEC-001 responder + envelope — ENV-NN
+- SPEC-002 memory — MEM-NN (lands with FDB-007)
+- SPEC-003 safety/privacy/abuse — SAF-NN (lands with FDB-014)
+- SPEC-004 images — IMG-NN (lands with FDB-009/010)
+- SPEC-005 self-tasking — TSK-NN (lands with FDB-011)
+- SPEC-006 staff/operator controls — OPS-NN (lands with FDB-005)
+- SPEC-007 deploy/hosts — DEP-NN (lands with FDB-017, mostly manual)
+- SPEC-008 config — CFG-NN
diff --git a/specs/SPEC-001-responder-envelope.md b/specs/SPEC-001-responder-envelope.md
new file mode 100644
index 0000000..5f5ad30
--- /dev/null
+++ b/specs/SPEC-001-responder-envelope.md
@@ -0,0 +1,133 @@
+# SPEC-001 — Responder + response envelope
+
+Characterization of the current (v2) responder contract in
+`fjerkroa_bot/ai_responder.py`. The model answers with a JSON
+envelope: `answer`, `answer_needed`, `channel`, `staff`, `picture`,
+`picture_edit`, `hack`. FDB-005 will replace the transport of this
+contract (structured outputs); the *behavioral* requirements below
+survive that change unless marked otherwise.
+
+### ENV-01 — Model answer reaches the user (coverage: feature)
+
+When the model envelope carries a non-empty `answer` and
+`answer_needed` is true, `AIResponder.send()` returns an `AIResponse`
+with that answer text and `answer_needed == True`. This is the core
+loop: user talks, bot answers.
+
+### ENV-02 — Suppressed answer stays silent (coverage: feature)
+
+When the model envelope sets `answer_needed` to false (and the
+message is not direct, mentions nobody, and no staff note is set),
+the returned `AIResponse` has `answer_needed == False`. The bot may
+observe without butting in.
+
+### ENV-03 — Staff note forces delivery (coverage: feature)
+
+When the envelope carries a non-null `staff` text and a non-null
+`answer`, the returned response preserves the staff text and has
+`answer_needed == True`. Staff alerts must never be silently
+dropped.
+
+### ENV-04 — Direct messages are always answered (coverage: feature)
+
+When the incoming `AIMessage` is marked `direct` and the model
+returns a non-null answer, `answer_needed` is forced to `True`
+regardless of the model's own `answer_needed`. A user addressing the
+bot directly gets a reply.
+
+### ENV-05 — Short-path rules skip the model (coverage: feature)
+
+When a configured `short-path` `[channel-regex, user-regex]` pair
+matches the message, `send()` appends the message to history, trims
+history to the limit, persists it, and returns an empty response
+(answer `None`, `answer_needed False`) **without calling the model**.
+Cheap archival of noisy channels.
+
+### ENV-06 — Malformed model output is repaired (coverage: withdrawn — successor ENV-18)
+
+Withdrawn 2026-07-13 with FDB-005: strict structured outputs make the
+repair model obsolete. Malformed output now counts as a failed
+attempt — see ENV-18.
+
+### ENV-07 — History is trimmed to the limit (coverage: feature)
+
+After a completed exchange, `len(history) <= history-limit` holds.
+Trimming happens both before the model call and after appending the
+new question/answer pair.
+
+### ENV-08 — Markdown links are unwrapped (coverage: feature)
+
+In the final answer text, `[label](url)` becomes `url` and
+`@[label](url)` becomes `label`. Discord renders raw URLs; markdown
+link syntax from the model reads as noise.
+
+### ENV-09 — Missing channel falls back to the message channel (coverage: feature)
+
+When the envelope `channel` is null/none/empty, the response channel
+is the channel the message came from.
+
+### ENV-10 — System prompt template substitution (coverage: test)
+
+`message()` substitutes `{date}` (YYYY-MM-DD), `{time}`, `{memory}`
+(current memory string) in the system prompt; `{news}` is replaced
+with the news file content when the configured file exists and stays
+literal when it does not.
+
+### ENV-11 — Per-channel history shrink prefers busy channels (coverage: test)
+
+`shrink_history_by_one()` removes the oldest entry whose channel has
+more than `history-per-channel` (default 3) entries; when no channel
+exceeds the cap, the oldest entry overall is removed.
+
+### ENV-12 — Exhausted retries raise, attempts are spaced (coverage: test)
+
+When the model returns no usable answer three times in a row,
+`send()` raises `RuntimeError`. Consecutive attempts are separated by
+an exponential-backoff sleep — failures never hammer the API
+back-to-back (D1).
+
+### ENV-13 — Reaction-clear events are recorded (coverage: test)
+
+`on_reaction_clear(message, reactions)` — the discord.py signature —
+records the clearing in the channel's memory. (D7: the previous
+handler declared `(reaction, user)` and crashed on dispatch.)
+
+### ENV-14 — update_memory persists its argument (coverage: test)
+
+`update_memory(memory)` sets the responder's memory to the passed
+value and persists that value. (D12: the argument was ignored.)
+
+### ENV-15 — retry-model is used after a rate limit (coverage: test)
+
+After a rate-limited attempt, the next `chat()` attempt uses the
+configured `retry-model` instead of `model`; a successful attempt
+switches back. (D2: the fallback was assigned to a local and never
+took effect.)
+
+### ENV-16 — Model calls are never served from a disk cache (coverage: test)
+
+`openai_chat`/`openai_image` call the client every time. The pickle
+response cache (`openai_chat.dat`) is a test-era artifact and must
+not exist in the production path (D3/D4).
+
+### ENV-17 — IGDB tool execution runs in a worker thread (coverage: test)
+
+`_execute_igdb_function` executes the synchronous IGDB library off
+the event loop (worker thread), returning identical results. The
+event loop keeps serving Discord events during lookups (D5).
+
+### ENV-18 — Malformed or refused output is a failed attempt (coverage: test)
+
+Model output is requested as schema-validated JSON (strict structured
+outputs). Output that still fails to parse, or a model refusal,
+counts as a failed attempt (backoff + retry per ENV-12) — there is no
+repair model, no `fix()` path, no relaxed-JSON fallback. Replaces
+ENV-06.
+
+### ENV-19 — The envelope schema is pinned (coverage: test)
+
+Every chat call carries `response_format` = strict JSON schema named
+`envelope` with exactly the fields `answer`, `answer_needed`,
+`channel`, `staff`, `picture`, `picture_edit`, `hack` — all required,
+`additionalProperties: false`, nullable where the protocol allows
+null. Tool-followup calls carry the same format.
diff --git a/specs/SPEC-008-config.md b/specs/SPEC-008-config.md
new file mode 100644
index 0000000..2c8e7ba
--- /dev/null
+++ b/specs/SPEC-008-config.md
@@ -0,0 +1,23 @@
+# SPEC-008 — Configuration
+
+TOML config per deployment (`kroa.toml`, `ggg.toml` — both untracked;
+`config.toml` in the repo is the placeholder sample). Loaded by
+`FjerkroaBot.load_config`, hot-reloaded by a watchdog observer
+(defect D9 — reload race — is tracked in FDB-004 and will refine
+these requirements).
+
+### CFG-01 — TOML config loads into a plain dict (coverage: test)
+
+`FjerkroaBot.load_config(path)` parses the TOML file and returns its
+top-level table as a dict; responders read raw keys from it.
+
+### CFG-02 — Per-channel system prompt override (coverage: test)
+
+A responder bound to channel `X` uses `config["X"]` as its system
+prompt when that key exists, else `config["system"]`. One deployment
+can speak differently per channel.
+
+### CFG-03 — Missing news file leaves the placeholder untouched (coverage: test)
+
+When `news` points to a non-existent file, the `{news}` placeholder
+stays literal in the system prompt (no crash, no empty substitution).
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..db03d97
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,15 @@
+import re
+from pathlib import Path
+
+FEATURES_DIR = Path(__file__).resolve().parent.parent / "features"
+TAG_RE = re.compile(r"@([A-Z]{2,8}-\d{2,3})\b")
+
+
+def pytest_configure(config):
+    # pytest-bdd turns @ENV-01 tags into markers; register them so
+    # --strict-markers stays enabled (D-005).
+    ids = set()
+    for feature in FEATURES_DIR.glob("**/*.feature"):
+        ids |= set(TAG_RE.findall(feature.read_text(encoding="utf-8")))
+    for req_id in sorted(ids):
+        config.addinivalue_line("markers", f"{req_id}: spec requirement tag")
diff --git a/tests/test_bdd_envelope.py b/tests/test_bdd_envelope.py
new file mode 100644
index 0000000..ee41e44
--- /dev/null
+++ b/tests/test_bdd_envelope.py
@@ -0,0 +1,147 @@
+"""BDD steps for features/envelope.feature (SPEC-001, ENV-01..09).
+
+Scenarios drive AIResponder.send() through a FakeModelResponder with
+scripted model output — no live OpenAI, no live Discord (D-002).
+"""
+
+import asyncio
+import json
+from typing import Any, Dict, List, Optional, Tuple
+
+from pytest_bdd import given, parsers, scenarios, then, when
+
+from fjerkroa_bot.ai_responder import AIMessage, AIResponder
+
+scenarios("../features/envelope.feature")
+
+
+def envelope(answer=None, answer_needed=False, channel="chat", staff=None, picture=None, picture_edit=False, hack=False) -> str:
+    return json.dumps(
+        {
+            "answer": answer,
+            "answer_needed": answer_needed,
+            "channel": channel,
+            "staff": staff,
+            "picture": picture,
+            "picture_edit": picture_edit,
+            "hack": hack,
+        }
+    )
+
+
+class FakeModelResponder(AIResponder):
+    """AIResponder with the model calls scripted away (D-002)."""
+
+    def __init__(self, config: Dict[str, Any], channel: Optional[str] = None) -> None:
+        super().__init__(config, channel)
+        self.scripted: List[str] = []
+        self.chat_calls = 0
+
+    async def chat(self, messages: List[Dict[str, Any]], limit: int) -> Tuple[Optional[Dict[str, Any]], int]:
+        self.chat_calls += 1
+        if not self.scripted:
+            return None, limit
+        return {"role": "assistant", "content": self.scripted.pop(0)}, limit
+
+    async def memory_rewrite(self, memory: str, message_user: str, answer_user: str, question: str, answer: str) -> str:
+        return memory
+
+    async def translate(self, text: str, language: str = "english") -> str:
+        return text
+
+
+@given(parsers.parse("a responder with history limit {limit:d}"), target_fixture="responder")
+def responder(limit):
+    config = {"system": "You are a test bot. {memory}", "history-limit": limit}
+    return FakeModelResponder(config, "chat")
+
+
+@given(parsers.parse('the model answers with answer "{answer}" and answer_needed "{needed}"'))
+def script_answer(responder, answer, needed):
+    responder.scripted.append(envelope(answer=answer, answer_needed=needed == "true"))
+
+
+@given(parsers.parse('the model answers with answer "{answer}" and staff note "{staff}"'))
+def script_staff(responder, answer, staff):
+    responder.scripted.append(envelope(answer=answer, answer_needed=False, staff=staff))
+
+
+@given(parsers.parse('the model answers with answer "{answer}" and channel "{channel}"'))
+def script_channel(responder, answer, channel):
+    responder.scripted.append(envelope(answer=answer, answer_needed=True, channel=channel))
+
+
+@given(parsers.parse('the model answers with answer "{answer}" and no channel'))
+def script_channel_none(responder, answer):
+    responder.scripted.append(envelope(answer=answer, answer_needed=True, channel=None))
+
+
+@given(parsers.parse('a short-path rule for channels "{chan_re}" and users "{user_re}"'))
+def short_path_rule(responder, chan_re, user_re):
+    responder.config["short-path"] = [[chan_re, user_re]]
+
+
+@given(parsers.parse('{count:d} prior history entries in channel "{channel}"'))
+def prior_history(responder, count, channel):
+    for i in range(count):
+        responder.history.append({"role": "user", "content": json.dumps({"message": f"old {i}", "channel": channel})})
+
+
+@when(parsers.parse('user "{user}" sends "{text}" in channel "{channel}"'), target_fixture="response")
+def send_message(responder, user, text, channel):
+    return asyncio.run(responder.send(AIMessage(user, text, channel)))
+
+
+@when(parsers.parse('user "{user}" sends "{text}" directly to the bot'), target_fixture="response")
+def send_direct(responder, user, text):
+    return asyncio.run(responder.send(AIMessage(user, text, "chat", direct=True)))
+
+
+@then(parsers.parse('the response answer contains "{text}"'))
+def answer_contains(response, text):
+    assert response.answer is not None and text in response.answer
+
+
+@then(parsers.parse('the response answer does not contain "{text}"'))
+def answer_not_contains(response, text):
+    assert response.answer is not None and text not in response.answer
+
+
+@then("the response is marked as needed")
+def is_needed(response):
+    assert response.answer_needed is True
+
+
+@then("the response is not marked as needed")
+def not_needed(response):
+    assert response.answer_needed is False
+
+
+@then(parsers.parse('the response staff note is "{text}"'))
+def staff_note_is(response, text):
+    assert response.staff == text
+
+
+@then(parsers.parse('the response channel is "{channel}"'))
+def channel_is(response, channel):
+    assert response.channel == channel
+
+
+@then("the model was not called")
+def model_not_called(responder):
+    assert responder.chat_calls == 0
+
+
+@then("the response is empty")
+def response_empty(response):
+    assert response.answer is None and response.answer_needed is False
+
+
+@then(parsers.parse('the history contains the message from "{user}"'))
+def history_has_user(responder, user):
+    assert any(f'"user": "{user}"' in item["content"] for item in responder.history)
+
+
+@then(parsers.parse("the history length is at most {limit:d}"))
+def history_at_most(responder, limit):
+    assert len(responder.history) <= limit
diff --git a/tests/test_spec_cfg.py b/tests/test_spec_cfg.py
new file mode 100644
index 0000000..6d6885e
--- /dev/null
+++ b/tests/test_spec_cfg.py
@@ -0,0 +1,43 @@
+"""Unit coverage for SPEC-008 (CFG-01..03)."""
+
+import unittest
+from unittest.mock import mock_open, patch
+
+import toml
+
+from fjerkroa_bot import FjerkroaBot
+from fjerkroa_bot.ai_responder import AIMessage, AIResponder
+
+
+class TestConfigLoad(unittest.TestCase):
+    def test_load_config_parses_toml(self):
+        """CFG-01: load_config parses the TOML file into a plain dict."""
+        data = {"system": "prompt", "history-limit": 7, "additional-responders": []}
+        with patch("builtins.open", mock_open(read_data=toml.dumps(data))):
+            result = FjerkroaBot.load_config("config.toml")
+        self.assertEqual(result, data)
+
+
+class TestPerChannelPrompt(unittest.TestCase):
+    def test_channel_override_wins(self):
+        """CFG-02: responder bound to a channel uses config[channel] over config['system']."""
+        config = {"system": "Default prompt", "kitchen": "Kitchen prompt", "history-limit": 5}
+        responder = AIResponder(config, "kitchen")
+        system = responder.message(AIMessage("alice", "hei", "kitchen"))[0]["content"]
+        self.assertTrue(system.startswith("Kitchen prompt"))
+
+    def test_fallback_to_system(self):
+        """CFG-02: without a channel key the shared system prompt is used."""
+        config = {"system": "Default prompt", "history-limit": 5}
+        responder = AIResponder(config, "kitchen")
+        system = responder.message(AIMessage("alice", "hei", "kitchen"))[0]["content"]
+        self.assertTrue(system.startswith("Default prompt"))
+
+
+class TestNewsFileMissing(unittest.TestCase):
+    def test_missing_news_file_keeps_placeholder(self):
+        """CFG-03: nonexistent news file -> {news} placeholder stays literal, no crash."""
+        config = {"system": "N: {news}", "history-limit": 5, "news": "/nonexistent/news.txt"}
+        responder = AIResponder(config, "chat")
+        system = responder.message(AIMessage("alice", "hei"))[0]["content"]
+        self.assertIn("{news}", system)
diff --git a/tests/test_spec_env.py b/tests/test_spec_env.py
new file mode 100644
index 0000000..7383b2c
--- /dev/null
+++ b/tests/test_spec_env.py
@@ -0,0 +1,56 @@
+"""Unit coverage for SPEC-001 test-class requirements (ENV-10..12)."""
+
+import json
+import time
+import unittest
+
+from fjerkroa_bot.ai_responder import AIMessage, AIResponder
+
+from .test_bdd_envelope import FakeModelResponder
+
+
+def entry(channel: str, text: str = "x"):
+    return {"role": "user", "content": json.dumps({"message": text, "channel": channel})}
+
+
+class TestSystemPromptTemplate(unittest.TestCase):
+    def test_template_substitution(self):
+        """ENV-10: {date}/{memory} substituted; missing news file leaves {news} literal."""
+        config = {"system": "Date {date} memory {memory} news {news}", "history-limit": 5, "news": "/nonexistent/news.txt"}
+        responder = AIResponder(config, "chat")
+        responder.memory = "MEMSTR"
+        messages = responder.message(AIMessage("alice", "hei"))
+        system = messages[0]["content"]
+        self.assertIn(time.strftime("%Y-%m-%d"), system)
+        self.assertIn("MEMSTR", system)
+        self.assertIn("{news}", system)  # left literal — file does not exist
+
+
+class TestHistoryShrink(unittest.TestCase):
+    def test_shrink_prefers_busy_channel(self):
+        """ENV-11: entry from the channel exceeding history-per-channel is removed first."""
+        config = {"system": "s", "history-limit": 4}
+        responder = AIResponder(config, "chat")
+        responder.history = [entry("a", "a0"), entry("a", "a1"), entry("a", "a2"), entry("a", "a3"), entry("b", "b0")]
+        responder.shrink_history_by_one()
+        self.assertEqual(len(responder.history), 4)
+        self.assertNotIn("a0", responder.history[0]["content"])  # oldest busy-channel entry gone
+
+    def test_shrink_falls_back_to_oldest(self):
+        """ENV-11: when no channel exceeds the cap, the oldest entry overall is removed."""
+        config = {"system": "s", "history-limit": 4}
+        responder = AIResponder(config, "chat")
+        responder.history = [entry("a", "a0"), entry("b", "b0"), entry("c", "c0")]
+        responder.shrink_history_by_one()
+        self.assertEqual(len(responder.history), 2)
+        self.assertNotIn("a0", responder.history[0]["content"])
+
+
+class TestRetriesExhausted(unittest.IsolatedAsyncioTestCase):
+    async def test_send_raises_after_three_failures(self):
+        """ENV-12: three model failures -> RuntimeError (revision pending in FDB-004/D1)."""
+        responder = FakeModelResponder({"system": "s", "history-limit": 5}, "chat")
+        # scripted list empty -> chat() returns None every attempt
+        with self.assertRaises(RuntimeError):
+            await responder.send(AIMessage("alice", "hei", "chat"))
+        self.assertEqual(responder.chat_calls, 3)
diff --git a/tools/trace.py b/tools/trace.py
new file mode 100644
index 0000000..cfe67aa
--- /dev/null
+++ b/tools/trace.py
@@ -0,0 +1,86 @@
+#!/usr/bin/env python3
+"""trace.py — enforce spec requirement coverage (SPEC-000).
+
+Stdlib only. Collects declared requirement IDs from specs/SPEC-*.md
+headers (code fences stripped), @ID tags from features/*.feature, ID
+mentions from tests/**/*.py, and rows from manual-verification.md.
+Fails when a declared requirement lacks its coverage artifact, when a
+feature tag or manual row references an undeclared ID, or when an ID
+is declared twice.
+"""
+
+import re
+import sys
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+ID_PATTERN = r"[A-Z]{2,8}-\d{2,3}"
+HEADER_RE = re.compile(rf"^###\s+({ID_PATTERN})\s+[—–-]+\s+.*\(coverage:\s*(feature|test|manual|withdrawn[^)]*)\)", re.M)
+FENCE_RE = re.compile(r"^```.*?^```", re.M | re.S)
+TAG_RE = re.compile(rf"@({ID_PATTERN})\b")
+MANUAL_ROW_RE = re.compile(rf"^\|\s*({ID_PATTERN})\s*\|", re.M)
+
+
+def collect():
+    declared = {}
+    errors = []
+    for spec in sorted((ROOT / "specs").glob("SPEC-*.md")):
+        text = FENCE_RE.sub("", spec.read_text(encoding="utf-8"))
+        for req_id, coverage in HEADER_RE.findall(text):
+            if req_id in declared:
+                errors.append(f"{req_id}: declared twice")
+            declared[req_id] = coverage
+
+    feature_tags = set()
+    features_dir = ROOT / "features"
+    if features_dir.exists():
+        for feature in features_dir.glob("**/*.feature"):
+            feature_tags |= set(TAG_RE.findall(feature.read_text(encoding="utf-8")))
+
+    test_ids = set()
+    for test_file in (ROOT / "tests").glob("**/*.py"):
+        test_ids |= set(re.findall(ID_PATTERN, test_file.read_text(encoding="utf-8")))
+
+    manual_ids = set()
+    manual_file = ROOT / "manual-verification.md"
+    if manual_file.exists():
+        manual_ids = set(MANUAL_ROW_RE.findall(manual_file.read_text(encoding="utf-8")))
+
+    return declared, feature_tags, test_ids, manual_ids, errors
+
+
+def coverage_errors(declared, feature_tags, test_ids, manual_ids):
+    errors = []
+    for req_id, coverage in sorted(declared.items()):
+        if "withdrawn" in coverage:
+            continue
+        if coverage == "feature" and req_id not in feature_tags:
+            errors.append(f"{req_id}: coverage 'feature' but no @{req_id} tag under features/")
+        elif coverage == "test" and req_id not in test_ids and req_id not in feature_tags:
+            errors.append(f"{req_id}: coverage 'test' but not mentioned under tests/ or features/")
+        elif coverage == "manual" and req_id not in manual_ids:
+            errors.append(f"{req_id}: coverage 'manual' but no row in manual-verification.md")
+    errors += [f"@{tag}: tagged under features/ but not declared in specs/" for tag in sorted(feature_tags - set(declared))]
+    errors += [f"{mid}: manual-verification.md row without spec declaration" for mid in sorted(manual_ids - set(declared))]
+    return errors
+
+
+def main() -> int:
+    declared, feature_tags, test_ids, manual_ids, errors = collect()
+    errors += coverage_errors(declared, feature_tags, test_ids, manual_ids)
+
+    if errors:
+        print("trace: FAIL")
+        for error in errors:
+            print(f" - {error}")
+        return 1
+
+    by_class = {c: sum(1 for v in declared.values() if v == c) for c in ("feature", "test", "manual")}
+    print(
+        f"trace: OK — {len(declared)} requirements ({by_class['feature']} feature / {by_class['test']} test / {by_class['manual']} manual)"
+    )
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())