docs(prd): add PRD for egress control plane

Out-of-band egress enforcement & cost-control plane: meter token usage
at the egress proxy, evaluate budgets with agent→bottle→parent→global
precedence, and force cutoff/freeze/kill without the agent in the loop.
Introduces a host-level SQLite ledger behind a thin repository API and a
host-only TUI dashboard. Closes the design discussion on #251.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NkwFXLFff9PYPy4wgVBJp9

bot_bottle/manifest.py

@@ -62,15 +62,25 @@ from dataclasses import dataclass, field, replace
 from pathlib import Path
 from typing import Mapping
 
+from .log import warn
 from .manifest_util import ManifestError, as_json_object
 from .manifest_agent import ManifestAgent, ManifestAgentProvider
+from .manifest_bottle import ManifestBottle
 from .manifest_egress import (
     EGRESS_AUTH_SCHEMES,
     ManifestEgressConfig,
     ManifestEgressRoute,
 )
-from .manifest_git import ManifestGitEntry, ManifestGitUser, ManifestKeyConfig, parse_git_gate_config
-from .manifest_schema import BOTTLE_KEYS
+from .manifest_extends import merge_bottles_runtime, resolve_bottles
+from .manifest_git import ManifestGitEntry, ManifestGitUser, ManifestKeyConfig
+from .manifest_loader import (
+    check_stale_json,
+    load_bottle_chain_from_dir,
+    scan_agent_names,
+    scan_bottle_names,
+)
+from .manifest_schema import validate_agent_frontmatter_keys
+from .yaml_subset import YamlSubsetError, parse_frontmatter
 
 # Re-export everything that callers currently import from this module.
 __all__ = [
@@ -89,10 +99,6 @@ __all__ = [
 ]
 
 
-def _empty_str_dict() -> dict[str, str]:
-    return {}
-
-
 def _section_dict(value: object, label: str) -> dict[str, object]:
     """Like as_json_object but treats absent/null as an empty section."""
     if value is None:
@@ -100,107 +106,6 @@ def _section_dict(value: object, label: str) -> dict[str, object]:
     return as_json_object(value, label)
 
 
-@dataclass(frozen=True)
-class ManifestBottle:
-    env: Mapping[str, str] = field(default_factory=_empty_str_dict)
-    agent_provider: ManifestAgentProvider = field(default_factory=ManifestAgentProvider)
-    git: tuple[ManifestGitEntry, ...] = ()
-    # Per-bottle git identity (issue #86). Empty default — bottles
-    # that don't set `git-gate.user:` in the manifest skip the
-    # `git config --global` step entirely. A bottle can declare a user
-    # identity without any git-gate.repos upstreams, and vice versa.
-    git_user: ManifestGitUser = field(default_factory=ManifestGitUser)
-    egress: ManifestEgressConfig = field(default_factory=ManifestEgressConfig)
-    # Per-bottle stuck-recovery sidecar (PRD 0013). When true (the
-    # default, issue #249), the launch step brings up a supervise
-    # sidecar that exposes egress MCP tools to the agent. Set
-    # `supervise: false` to skip the sidecar.
-    supervise: bool = True
-
-    @classmethod
-    def from_dict(cls, name: str, raw: object) -> "ManifestBottle":
-        d = as_json_object(raw, f"bottle '{name}'")
-
-        if "runtime" in d:
-            raise ManifestError(
-                f"bottle '{name}' has a 'runtime' field, which is no longer "
-                f"supported. gVisor (runsc) is now auto-detected by the "
-                f"backend; remove the 'runtime' field from the bottle "
-                f"definition."
-            )
-
-        if "ssh" in d:
-            raise ManifestError(
-                f"bottle '{name}' has an 'ssh' field, which has been removed "
-                f"(PRD 0009). Declare upstreams under 'git-gate.repos' with "
-                f"url + identity + host_key; the git-gate sidecar (PRD 0008) "
-                f"holds the credential and gitleaks-scans pushes."
-            )
-
-        if "git" in d:
-            raise ManifestError(
-                f"bottle '{name}' uses 'git' which has been replaced by "
-                f"'git-gate' (PRD 0047). Move git.user → git-gate.user "
-                f"and git.remotes → git-gate.repos (fields: url, identity, host_key)."
-            )
-
-        if "git_user" in d:
-            raise ManifestError(
-                f"bottle '{name}' has a 'git_user' field, which has been "
-                f"removed. Move it under 'git-gate.user'."
-            )
-
-        unknown = set(d.keys()) - BOTTLE_KEYS
-        if unknown:
-            allowed = ", ".join(sorted(BOTTLE_KEYS))
-            raise ManifestError(
-                f"bottle '{name}' has unknown key(s) {sorted(unknown)}; "
-                f"allowed keys are {allowed}."
-            )
-
-        env: dict[str, str] = {}
-        env_raw = d.get("env")
-        if env_raw is not None:
-            env_dict = as_json_object(env_raw, f"bottle '{name}' env")
-            for var, value in env_dict.items():
-                if not isinstance(value, str):
-                    raise ManifestError(
-                        f"env entry {var} in bottle '{name}' must be a JSON string "
-                        f"(was {type(value).__name__}). Use \"?<message>\" for prompt-at-runtime."
-                    )
-                env[var] = value
-
-        git: tuple[ManifestGitEntry, ...] = ()
-        git_user = ManifestGitUser()
-        git_raw = d.get("git-gate")
-        if git_raw is not None:
-            git, git_user = parse_git_gate_config(name, git_raw)
-
-        agent_provider = (
-            ManifestAgentProvider.from_dict(name, d["agent_provider"])
-            if "agent_provider" in d
-            else ManifestAgentProvider()
-        )
-
-        egress = (
-            ManifestEgressConfig.from_dict(name, d["egress"])
-            if "egress" in d
-            else ManifestEgressConfig()
-        )
-
-        supervise_raw = d.get("supervise", True)
-        if not isinstance(supervise_raw, bool):
-            raise ManifestError(
-                f"bottle '{name}' supervise must be a boolean "
-                f"(was {type(supervise_raw).__name__})"
-            )
-
-        return cls(
-            env=env, agent_provider=agent_provider, git=git,
-            git_user=git_user, egress=egress, supervise=supervise_raw,
-        )
-
-
 def _merge_git_user(
     agent_user: ManifestGitUser, base_user: ManifestGitUser
 ) -> ManifestGitUser:
@@ -237,8 +142,6 @@ def _resolve_effective_bottle_eager(
 
     When bottle_names is non-empty they are merged in order. When empty, falls
     back to agent.bottle. Raises ManifestError when neither is set."""
-    from .manifest_extends import merge_bottles_runtime
-
     if bottle_names:
         resolved: list[ManifestBottle] = []
         for bn in bottle_names:
@@ -270,9 +173,6 @@ def _resolve_effective_bottle_lazy(
     When bottle_names is non-empty they are resolved from disk and merged in
     order. When empty, falls back to agent_bottle. Raises ManifestError when
     neither is set."""
-    from .manifest_extends import merge_bottles_runtime
-    from .manifest_loader import load_bottle_chain_from_dir
-
     if bottle_names:
         resolved = [load_bottle_chain_from_dir(bn, bottles_dir) for bn in bottle_names]
         return merge_bottles_runtime(resolved)
@@ -358,8 +258,6 @@ class ManifestIndex:
         home_md = home_dir / ".bot-bottle"
         cwd_md = cwd_dir / ".bot-bottle"
 
-        from .manifest_loader import check_stale_json
-
         check_stale_json(home_dir, home_md, "$HOME")
         if cwd_dir.resolve() != home_dir.resolve():
             check_stale_json(cwd_dir, cwd_md, "$CWD")
@@ -399,7 +297,6 @@ class ManifestIndex:
                 files = sorted(stale_bottles.glob("*.md"))
                 if files:
                     names = ", ".join(p.name for p in files)
-                    from .log import warn
                     warn(
                         f"ignoring bottle file(s) under "
                         f"{stale_bottles}: {names}. Bottles can only "
@@ -421,7 +318,6 @@ class ManifestIndex:
         raw_bottles: dict[str, dict[str, object]] = {}
         for n, b in raw_bottles_obj.items():
             raw_bottles[n] = as_json_object(b, f"bottle '{n}'")
-        from .manifest_extends import resolve_bottles
 
         bottles = resolve_bottles(raw_bottles)
 
@@ -439,7 +335,6 @@ class ManifestIndex:
         filenames without reading their content. In eager mode (from
         from_json_obj) it returns the pre-parsed bottles' names."""
         if self.home_md is not None:
-            from .manifest_loader import scan_bottle_names
             return scan_bottle_names(self.home_md / "bottles")
         return sorted(self.bottles.keys())
 
@@ -451,7 +346,6 @@ class ManifestIndex:
         filenames without reading their content. In eager mode (from
         from_json_obj) it returns the pre-parsed agents' names."""
         if self.home_md is not None:
-            from .manifest_loader import scan_agent_names
             home_names = set(scan_agent_names(self.home_md / "agents").keys())
             cwd_names: set[str] = set()
             if self.cwd_md is not None:
@@ -509,10 +403,6 @@ class ManifestIndex:
         """Lazy path (resolve/from_md_dirs): read and parse the agent file and
         its bottle chain from disk for the first time here."""
         assert self.home_md is not None  # guaranteed by load_for_agent dispatch
-        from .manifest_loader import scan_agent_names
-        from .manifest_schema import validate_agent_frontmatter_keys
-        from .yaml_subset import YamlSubsetError, parse_frontmatter
-
         # Locate the agent file; cwd wins over home on name collision.
         home_agents = scan_agent_names(self.home_md / "agents")
         cwd_agents: dict[str, Path] = {}

bot_bottle/manifest_bottle.py

@@ -0,0 +1,129 @@
+"""The `ManifestBottle` value type.
+
+Split out of `manifest.py` so the `extends:`/loader resolvers can import it
+without a circular dependency: `manifest.py` imports those resolvers, while
+they only need this value type. Everything here depends on leaf modules
+(`manifest_util`, `manifest_agent`, `manifest_egress`, `manifest_git`,
+`manifest_schema`), so this module sits at the bottom of the manifest layer.
+
+`manifest.py` re-exports `ManifestBottle`, so existing
+`from .manifest import ManifestBottle` callers are unaffected.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from typing import Mapping
+
+from .manifest_util import ManifestError, as_json_object
+from .manifest_agent import ManifestAgentProvider
+from .manifest_egress import ManifestEgressConfig
+from .manifest_git import ManifestGitEntry, ManifestGitUser, parse_git_gate_config
+from .manifest_schema import BOTTLE_KEYS
+
+__all__ = ["ManifestBottle"]
+
+
+def _empty_str_dict() -> dict[str, str]:
+    return {}
+
+
+@dataclass(frozen=True)
+class ManifestBottle:
+    env: Mapping[str, str] = field(default_factory=_empty_str_dict)
+    agent_provider: ManifestAgentProvider = field(default_factory=ManifestAgentProvider)
+    git: tuple[ManifestGitEntry, ...] = ()
+    # Per-bottle git identity (issue #86). Empty default — bottles
+    # that don't set `git-gate.user:` in the manifest skip the
+    # `git config --global` step entirely. A bottle can declare a user
+    # identity without any git-gate.repos upstreams, and vice versa.
+    git_user: ManifestGitUser = field(default_factory=ManifestGitUser)
+    egress: ManifestEgressConfig = field(default_factory=ManifestEgressConfig)
+    # Per-bottle stuck-recovery sidecar (PRD 0013). When true (the
+    # default, issue #249), the launch step brings up a supervise
+    # sidecar that exposes egress MCP tools to the agent. Set
+    # `supervise: false` to skip the sidecar.
+    supervise: bool = True
+
+    @classmethod
+    def from_dict(cls, name: str, raw: object) -> "ManifestBottle":
+        d = as_json_object(raw, f"bottle '{name}'")
+
+        if "runtime" in d:
+            raise ManifestError(
+                f"bottle '{name}' has a 'runtime' field, which is no longer "
+                f"supported. gVisor (runsc) is now auto-detected by the "
+                f"backend; remove the 'runtime' field from the bottle "
+                f"definition."
+            )
+
+        if "ssh" in d:
+            raise ManifestError(
+                f"bottle '{name}' has an 'ssh' field, which has been removed "
+                f"(PRD 0009). Declare upstreams under 'git-gate.repos' with "
+                f"url + identity + host_key; the git-gate sidecar (PRD 0008) "
+                f"holds the credential and gitleaks-scans pushes."
+            )
+
+        if "git" in d:
+            raise ManifestError(
+                f"bottle '{name}' uses 'git' which has been replaced by "
+                f"'git-gate' (PRD 0047). Move git.user → git-gate.user "
+                f"and git.remotes → git-gate.repos (fields: url, identity, host_key)."
+            )
+
+        if "git_user" in d:
+            raise ManifestError(
+                f"bottle '{name}' has a 'git_user' field, which has been "
+                f"removed. Move it under 'git-gate.user'."
+            )
+
+        unknown = set(d.keys()) - BOTTLE_KEYS
+        if unknown:
+            allowed = ", ".join(sorted(BOTTLE_KEYS))
+            raise ManifestError(
+                f"bottle '{name}' has unknown key(s) {sorted(unknown)}; "
+                f"allowed keys are {allowed}."
+            )
+
+        env: dict[str, str] = {}
+        env_raw = d.get("env")
+        if env_raw is not None:
+            env_dict = as_json_object(env_raw, f"bottle '{name}' env")
+            for var, value in env_dict.items():
+                if not isinstance(value, str):
+                    raise ManifestError(
+                        f"env entry {var} in bottle '{name}' must be a JSON string "
+                        f"(was {type(value).__name__}). Use \"?<message>\" for prompt-at-runtime."
+                    )
+                env[var] = value
+
+        git: tuple[ManifestGitEntry, ...] = ()
+        git_user = ManifestGitUser()
+        git_raw = d.get("git-gate")
+        if git_raw is not None:
+            git, git_user = parse_git_gate_config(name, git_raw)
+
+        agent_provider = (
+            ManifestAgentProvider.from_dict(name, d["agent_provider"])
+            if "agent_provider" in d
+            else ManifestAgentProvider()
+        )
+
+        egress = (
+            ManifestEgressConfig.from_dict(name, d["egress"])
+            if "egress" in d
+            else ManifestEgressConfig()
+        )
+
+        supervise_raw = d.get("supervise", True)
+        if not isinstance(supervise_raw, bool):
+            raise ManifestError(
+                f"bottle '{name}' supervise must be a boolean "
+                f"(was {type(supervise_raw).__name__})"
+            )
+
+        return cls(
+            env=env, agent_provider=agent_provider, git=git,
+            git_user=git_user, egress=egress, supervise=supervise_raw,
+        )

bot_bottle/manifest_extends.py

@@ -2,11 +2,10 @@
 
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
-
-if TYPE_CHECKING:
-    from .manifest import ManifestBottle
-    from .manifest_egress import ManifestEgressConfig
+from .manifest_bottle import ManifestBottle
+from .manifest_egress import ManifestEgressConfig, validate_egress_routes
+from .manifest_git import ManifestGitUser, parse_git_gate_config
+from .manifest_util import ManifestError, as_json_object
 
 
 def merge_bottles_runtime(bottles: "list[ManifestBottle]") -> "ManifestBottle":
@@ -27,9 +26,6 @@ def merge_bottles_runtime(bottles: "list[ManifestBottle]") -> "ManifestBottle":
 
 
 def _merge_two_bottles_runtime(base: "ManifestBottle", override: "ManifestBottle") -> "ManifestBottle":
-    from .manifest import ManifestBottle, ManifestGitUser
-    from .manifest_egress import ManifestEgressConfig
-
     merged_env = {**base.env, **override.env}
 
     merged_git_user = ManifestGitUser(
@@ -81,8 +77,6 @@ def _resolve_one_bottle(
     repos_cache: dict[str, dict[str, object]],
     seen: tuple[str, ...],
 ) -> ManifestBottle:
-    from .manifest import ManifestBottle, ManifestError
-
     if name in cache:
         return cache[name]
     if name in seen:
@@ -174,11 +168,6 @@ def _fold_two_bottles(
     later_repos_raw: dict[str, object],
 ) -> tuple[ManifestBottle, dict[str, object]]:
     """Combine two resolved parent bottles; later wins over earlier."""
-    from .manifest import ManifestBottle, ManifestGitUser
-    from .manifest_egress import ManifestEgressConfig
-    from .manifest_git import parse_git_gate_config
-    from .manifest_util import as_json_object
-
     merged_env = {**earlier.env, **later.env}
 
     merged_git_user = ManifestGitUser(
@@ -227,10 +216,6 @@ def _merge_bottles(
     name: str,
 ) -> ManifestBottle:
     """Apply PRD 0025 merge rules."""
-    from .manifest import ManifestBottle, ManifestGitUser
-    from .manifest_egress import validate_egress_routes
-    from .manifest_util import as_json_object
-
     # git-gate.repos: when the child declares repos, inject the already
     # name-merged repo set (computed by _resolve_repos_raw) so the child
     # parses with the full inherited+overridden list (issue #237).
@@ -303,8 +288,6 @@ def _resolve_repos_raw(
     inherits the parent's set verbatim; an explicit empty dict clears it.
     Otherwise parent and child unite by name, with same-name entries
     field-merged (parent fields are defaults, child fields win)."""
-    from .manifest_util import as_json_object
-
     if not _child_declares_git_gate_repos(child_raw):
         return parent_repos
     child_repos = _declared_repos_raw(child_raw)
@@ -324,8 +307,6 @@ def _resolve_repos_raw(
 def _declared_repos_raw(child_raw: dict[str, object]) -> dict[str, object]:
     """Return the child's explicitly declared git-gate.repos as raw dicts,
     or an empty dict when none are declared."""
-    from .manifest_util import as_json_object
-
     if not _child_declares_git_gate_repos(child_raw):
         return {}
     git_raw = as_json_object(child_raw.get("git-gate", {}), "child git-gate")
@@ -333,8 +314,6 @@ def _declared_repos_raw(child_raw: dict[str, object]) -> dict[str, object]:
 
 
 def _child_declares_git_gate_repos(child_raw: dict[str, object]) -> bool:
-    from .manifest_util import as_json_object
-
     git_raw = child_raw.get("git-gate")
     if git_raw is None:
         return False
@@ -347,9 +326,6 @@ def _merge_egress(
     child: ManifestEgressConfig,
     child_raw: dict[str, object],
 ) -> ManifestEgressConfig:
-    from .manifest_egress import ManifestEgressConfig
-    from .manifest_util import as_json_object
-
     child_egress_raw = as_json_object(child_raw.get("egress"), "child egress")
     routes = parent.routes + child.routes
     log = child.Log if "log" in child_egress_raw else parent.Log

bot_bottle/manifest_loader.py

@@ -3,9 +3,10 @@
 from __future__ import annotations
 
 from pathlib import Path
-from typing import TYPE_CHECKING
 
 from .log import warn
+from .manifest_bottle import ManifestBottle
+from .manifest_extends import resolve_bottles
 from .manifest_schema import (
     entity_name_from_path,
     validate_bottle_frontmatter_keys,
@@ -13,9 +14,6 @@ from .manifest_schema import (
 from .manifest_util import ManifestError
 from .yaml_subset import YamlSubsetError, parse_frontmatter
 
-if TYPE_CHECKING:
-    from .manifest import ManifestBottle
-
 
 def check_stale_json(dir_path: Path, md_dir: Path, label: str) -> None:
     """Die if `<dir_path>/bot-bottle.json` exists but `md_dir` does
@@ -78,8 +76,6 @@ def load_bottle_chain_from_dir(
 
     Only the files in the extends chain are read — unrelated bottle files
     are never touched. Raises ManifestError on parse or validation failure."""
-    from .manifest_extends import resolve_bottles
-
     raws: dict[str, dict[str, object]] = {}
     to_load = [bottle_name]
     while to_load:

docs/prds/prd-new-egress-control-plane.md

@@ -0,0 +1,247 @@
+# PRD prd-new: Egress control plane — metering, budgets, and forced cutoff
+
+- **Status:** Draft
+- **Author:** didericis
+- **Created:** 2026-06-25
+- **Issue:** #251
+
+## Summary
+
+Add an **out-of-band egress enforcement & observability plane**: meter every
+agent's token usage at the egress proxy, decrement budgets without the agent's
+cooperation, and forcibly cut a bottle's egress when a budget is exhausted —
+either automatically or on command from a host-level dashboard. The trigger
+(usage threshold) and the action (route-drop / freeze / kill) both live in the
+egress plane and run with no agent in the loop. This is distinct from the
+supervise sidecar (PRD 0013), which is agent-initiated and therefore cannot
+enforce a cost cutoff on a runaway agent. State (usage ledger, budgets, audit)
+moves into a host-level SQLite database behind a thin repository API, the first
+SQL store in an otherwise flat-file repo.
+
+## Problem
+
+bot-bottle can't currently do two things the cost-overrun case demands:
+
+1. **Forced egress shutdown on limit.** When an agent crosses a token
+   threshold, kill its egress automatically — no human in the loop.
+2. **Remote (host-level) management.** Drive agents from a single surface:
+   see usage, cut egress, stop bottles, to prevent cost overruns.
+
+The existing supervise sidecar (PRD 0013) is **entirely agent-initiated**: every
+action begins with the agent voluntarily calling an MCP tool and an operator
+approving it. A runaway or expensive agent — exactly the cost-overrun case —
+will never call `egress-block` on itself. Supervision is therefore a
+**collaborative recovery** mechanism, not an **enforcement** mechanism; making
+it mandatory (#249) would not deliver forced cost-cutoff.
+
+The requirement forces a distinction the current design blurs:
+
+- **Plane A — enforcement / observability (this PRD).** System → infrastructure.
+  Meter usage, cut egress on threshold or command, account for cost.
+  Out-of-band; independent of the agent. **Unconditional** — an enforcement
+  plane you can opt out of isn't enforcement.
+- **Plane B — agent-facing recovery (the existing supervise sidecar).**
+  Agent → operator, approval-gated. Useful interactively; meaningless for a
+  headless agent with no operator watching its queue. Remains optional.
+
+This PRD builds Plane A. It reframes the "always-on control" invariant of #249
+as "the egress control plane is always present" — a more defensible property
+than "every agent runs the agent-facing supervisor." Unsupervised
+(headless/CI/ephemeral) agents stay first-class: still subject to the mandatory
+meter + kill switch, they simply lack the agent-facing proposal tools they
+couldn't use anyway.
+
+## Goals / Success Criteria
+
+- The egress proxy meters every request to a metered API host (e.g.
+  `api.anthropic.com`) and records authoritative token usage per bottle and per
+  agent provider, with no agent cooperation.
+- A budget can be set at four scopes with deterministic precedence
+  (**agent → bottle → parent bottle → global host budget**); the
+  most-specific applicable budget governs.
+- When usage crosses a budget, the bottle's configured **cutoff policy**
+  (`cutoff` | `freeze` | `kill`) fires automatically, executed host-side on the
+  egress plane — never via the supervise queue.
+- An operator can, from a single **host-level TUI dashboard**, see live per-bottle
+  usage against budget and command a cutoff/stop on demand.
+- Host budgets, default cutoff policy, and per-provider limits are declared in a
+  new host-level `~/.bot-bottle/settings.yml`, parseable by `yaml_subset.py`.
+- All usage, budget state, and enforcement actions persist in a host-level
+  SQLite DB behind a thin repository API, so the store can later be swapped for
+  a cross-host cloud service.
+
+## Non-goals
+
+- **Remote control / cross-host control plane.** Web + mobile remote control,
+  cross-host budgets, and the authn/transport they require are explicitly
+  deferred. v1 is a **host-only TUI** with no remote surface.
+- **Dollar-denominated budgets.** Budgets are token counts keyed by agent
+  provider, not currency. Price tables are out of scope.
+- **Migrating existing flat-file state into SQLite.** Resume `metadata.json`,
+  transcripts, Dockerfile overrides, the supervise queue, and audit logs stay on
+  the filesystem. Only the *new* metering/budget/enforcement ledger is SQL.
+- **Making the supervise sidecar (Plane B) mandatory.** Out of scope here; this
+  PRD is the answer to "what should be unconditional" (Plane A), leaving #249's
+  Plane-B question open.
+- **Per-request hard pre-send blocking as the primary mechanism.** The gate is
+  budget-crossing detected at/after metering; a pre-flight estimator (below) is a
+  refinement, not the core enforcement path.
+
+## Design
+
+### Two measurements: gate vs. account
+
+There are two distinct needs, and they want different signals:
+
+- **Account (authoritative).** Decrement the real budget from the API
+  **response**, which already carries authoritative usage (Anthropic
+  `input_tokens` / `output_tokens`, OpenAI `usage`). The egress addon already
+  has a `response(flow)` hook (`bot_bottle/egress_addon.py:460`), so the real
+  number is available with no extra network call. **Caveat:** agent traffic is
+  mostly streaming SSE, so the response path must tail the stream for the final
+  usage event rather than parse a single JSON body — scoped explicitly as work.
+- **Gate (estimate).** To block *before* sending, only the request is available,
+  so an estimator / provider `count_tokens` endpoint is the only option.
+
+Calling `count_tokens` for accounting would be both less accurate *and* an extra
+metered egress call per request, so accounting uses response `usage` and the
+estimator is reserved for the optional pre-flight gate.
+
+### `count_tokens` on agent providers
+
+Add an abstract `count_tokens(request) -> int` to the `AgentProvider`
+abstraction (`bot_bottle/agent_provider.py`):
+
+- **Default** is a good-enough stdlib estimator. Prefer stdlib only; a small
+  pip dependency *for the sidecar* is acceptable for the fallback if stdlib
+  proves too inaccurate (this does not relax the package's stdlib-first stance —
+  it would be a sidecar-only dep, like the bundle already carries).
+- **Built-in `claude`** uses Anthropic's token-counting endpoint;
+  **built-in `codex`** uses OpenAI's. These are exact for the gate but cost a
+  metered call, so they are gate-only; accounting still comes from the response.
+
+### Budgets and precedence
+
+Budgets are token counts keyed by **agent provider name** (the same names
+bottles already use). Four scopes, most-specific wins:
+
+```
+agent  →  bottle  →  parent bottle  →  global (host)
+```
+
+The global host budget is the highest-priority feature to ship (the cross-host
+control plane will eventually consume it); per-agent and per-bottle budgets
+override it for finer control. A budget can also be supplied **at bottle
+launch** (`--budget` or equivalent), overriding the settings.yml defaults for
+that run. Enforcement evaluates the effective budget as the
+nearest-defined scope at decrement time.
+
+### `~/.bot-bottle/settings.yml`
+
+New **host-level** settings file (the `~/.bot-bottle/` root, *not* the per-repo
+`.bot-bottle/` — host budgets must not be committed per-repo). Parsed by
+`yaml_subset.py`, so it must stay within that bounded subset (flat mappings,
+scalars; no anchors, no multi-line block scalars). Shape:
+
+```yaml
+budget:
+  claude: 5000000      # token budget keyed by agent provider
+  codex: 2000000
+shutdown: cutoff       # default cutoff policy: cutoff | freeze | kill
+```
+
+### Forced cutoff and cutoff policy
+
+On budget exhaustion (or an operator command), the configured per-bottle cutoff
+policy fires. The three policies map onto primitives that already exist:
+
+- **`cutoff`** (default) — drop the bottle's `routes.yaml` to empty and reload
+  (or isolate the bottle from the egress network); the agent/bottle keeps
+  running but can no longer reach metered hosts. This is the route-drop already
+  available on the egress plane (`bot_bottle/backend/egress_apply.py`).
+- **`freeze`** — commit/snapshot state, then kill the agent/bottle; resumable
+  later via `bot_bottle/backend/freeze.py`.
+- **`kill`** — tear the bottle down without saving state (backend teardown).
+
+The trigger lives in the metering path and the action in the egress/backend
+plane; **neither touches the supervise proposal queue** (design constraint from
+#251).
+
+### Host-level SQLite store
+
+**Decision: introduce SQLite now, narrowly.**
+
+- **The dependency objection doesn't apply.** `sqlite3` is in the Python stdlib,
+  so it does not break the AGENTS.md stdlib-first / no-runtime-pip stance — same
+  category as the hand-rolled `yaml_subset.py`, except the stdlib already ships
+  the whole engine.
+- **It fits the problem.** A *global* token budget decremented concurrently by N
+  egress sidecars (today `~/.bot-bottle/` already has `state/`, `audit/`,
+  `queue/` written by parallel bottles) is a read-modify-write race. Over JSON
+  that means hand-rolled file locking; SQLite gives atomic transactions + WAL for
+  free. The per-agent/per-bottle precedence rollup plus "sum across all bottles"
+  is a `GROUP BY`, not an N-directory rescan.
+- **It rehearses the cloud swap.** "Wrap operations in an API so we can swap to a
+  cloud service" maps directly onto a thin repository/DAO over SQLite → Postgres
+  later. A JSON-file store is a worse rehearsal than SQL.
+
+**Costs (real but bounded):** a new paradigm in a flat-file repo needs a
+`schema_version` table + idempotent startup migrations; SQLite serializes
+writers, so WAL mode + `busy_timeout` are required (a non-issue at a handful of
+bottles); test fixtures need temp DBs.
+
+**Scope of the store:** one DB at `~/.bot-bottle/bot-bottle.db` behind a thin
+repository API. Only the **new** metering/budget/enforcement-audit ledger lives
+there. Existing per-bottle blobs (resume `metadata.json`, transcripts,
+Dockerfile overrides, supervise queue) stay on the filesystem — migrating them
+now is churn for no benefit and they lack the concurrency/aggregation problem.
+
+### Host-level controller + dashboard
+
+A single **host-level controller** owns the meter, budget evaluation, and the
+cutoff actions across all bottles (cf. `bot_bottle/cli/supervise.py`'s
+cross-bottle view), rather than a per-bottle daemon. v1 ships one host-level
+**TUI dashboard** that reads live usage-vs-budget from the SQLite store and
+offers on-demand cutoff/stop. The existing supervisor UI should eventually fold
+into this same dashboard; this PRD lays the host-level surface it will move to.
+
+## Implementation chunks
+
+Ordered, individually mergeable:
+
+1. **SQLite repository foundation.** `~/.bot-bottle/bot-bottle.db`, schema +
+   `schema_version` migrations, WAL + `busy_timeout`, thin repository API,
+   temp-DB test fixtures. No behavior wired yet.
+2. **Metering at the egress proxy.** Parse authoritative response `usage`
+   (including SSE final-usage tailing) in the egress addon `response` hook;
+   write per-bottle / per-provider usage rows to the ledger.
+3. **`settings.yml` + budget model.** Host-level `~/.bot-bottle/settings.yml`
+   parsed by `yaml_subset.py`; budget precedence (agent → bottle → parent →
+   global) and the `--budget` launch flag.
+4. **Forced cutoff + cutoff policy.** Wire the threshold trigger to the
+   `cutoff` / `freeze` / `kill` primitives on the egress/backend plane; record
+   enforcement actions to the audit ledger.
+5. **Host-level TUI dashboard.** Live usage-vs-budget view + on-demand
+   cutoff/stop, reading the store.
+6. **`count_tokens` pre-flight gate (optional refinement).** Abstract method +
+   stdlib estimator default; Anthropic/OpenAI endpoints for built-in
+   claude/codex; optional pre-send block.
+
+## Open questions
+
+- **SSE usage tailing robustness.** Buffering streamed responses to extract the
+  final usage event without breaking the agent's own stream consumption — how
+  much of the body must the addon hold, and what's the failure mode if the
+  stream is interrupted mid-flight?
+- **Crossing mid-request.** A single response can push usage past budget only
+  *after* it's already been delivered. Is post-hoc cutoff (next request blocked)
+  sufficient, or is a pre-flight estimator gate (chunk 6) required for v1?
+- **Provider name ↔ metered host mapping.** How does the proxy attribute a
+  flow to an agent-provider budget key — by destination host, by bottle
+  identity, or both?
+- **Parent-bottle budget semantics.** For `bottle extends` (PRD 0025 / 0065)
+  chains, does "parent bottle" mean the manifest parent, the launching bottle,
+  or the full ancestry summed?
+- **Dashboard ↔ controller transport (even host-only).** In-process, a local
+  socket, or polling the SQLite store directly? Picks the seam the future remote
+  control plane will extend.