feat(claude): add forward_host_credentials support

Reads the host's Claude OAuth session key from ~/.claude.json at launch
and forwards it only to the egress sidecar (never to the agent), placing
a placeholder CLAUDE_CODE_OAUTH_TOKEN in the agent env so Claude Code
starts without seeing the real credential.

Mirrors the existing Codex forward_host_credentials flow (PRD 0029).
Adds claude_auth.py to extract and validate the sessionKey, a
CLAUDE_HOST_CREDENTIAL_TOKEN_REF constant in egress.py, and updates
manifest_agent.py to allow the flag for both 'codex' and 'claude'
templates. Also adds a mutual-exclusion check that rejects setting
both auth_token and forward_host_credentials together.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bot_bottle/agent_provider.py

@@ -45,6 +45,10 @@ PROVIDER_TEMPLATES = frozenset({PROVIDER_CLAUDE, PROVIDER_CODEX, PROVIDER_PI})
 # forward_host_credentials is enabled. Pipelock must pass these through
 # (no TLS MITM) or its header DLP blocks the injected JWT.
 CODEX_HOST_CREDENTIAL_HOSTS = ("api.openai.com", "chatgpt.com")
+
+# Host that egress injects the host Claude bearer on when Claude
+# forward_host_credentials is enabled.
+CLAUDE_HOST_CREDENTIAL_HOSTS = ("api.anthropic.com",)
 PromptMode = Literal[
     "append_file",
     "read_prompt_file",

bot_bottle/contrib/claude/agent_provider.py

@@ -23,8 +23,9 @@ from ...agent_provider import (
     provider_startup_args,
 )
 from ...backend.docker import util as docker_mod
-from ...egress import EgressRoute
+from ...egress import CLAUDE_HOST_CREDENTIAL_TOKEN_REF, EgressRoute
 from ...log import die, info, warn
+from .claude_auth import claude_host_access_token
 
 
 if TYPE_CHECKING:
@@ -115,7 +116,6 @@ class ClaudeAgentProvider(AgentProvider):
         color: str = "",
         provider_settings: dict[str, object] | None = None,
     ) -> AgentProvisionPlan:
-        del forward_host_credentials, host_env
         resolved_guest_env = dict(guest_env or {})
         startup_args = provider_startup_args(provider_settings)
         guest_home = self.guest_home
@@ -177,13 +177,24 @@ class ClaudeAgentProvider(AgentProvider):
                 claude_settings,
                 f"{guest_home}/.claude/settings.json",
             ))
+        provisioned_env: dict[str, str] = {}
+        if forward_host_credentials:
+            _host_env = host_env or dict(os.environ)
+            provisioned_env[CLAUDE_HOST_CREDENTIAL_TOKEN_REF] = (
+                claude_host_access_token(_host_env)
+            )
+
+        cred_token_ref = (
+            CLAUDE_HOST_CREDENTIAL_TOKEN_REF if forward_host_credentials
+            else auth_token
+        )
         egress_routes = (EgressRoute(
             host="api.anthropic.com",
-            auth_scheme="Bearer" if auth_token else "",
-            token_ref=auth_token,
+            auth_scheme="Bearer" if (auth_token or forward_host_credentials) else "",
+            token_ref=cred_token_ref,
         ),)
         hidden_env_names: frozenset[str] = frozenset()
-        if auth_token:
+        if auth_token or forward_host_credentials:
             env_vars["CLAUDE_CODE_OAUTH_TOKEN"] = "egress-placeholder"
             hidden_env_names = frozenset({"CLAUDE_CODE_OAUTH_TOKEN"})
 
@@ -205,6 +216,7 @@ class ClaudeAgentProvider(AgentProvider):
             files=tuple(files),
             egress_routes=egress_routes,
             hidden_env_names=hidden_env_names,
+            provisioned_env=provisioned_env,
         )
 
     def provision_skills(self, plan: "BottlePlan", bottle: "Bottle") -> None:

bot_bottle/contrib/claude/claude_auth.py

@@ -0,0 +1,76 @@
+"""Host Claude auth helpers.
+
+Reads the host's Claude Code auth state and returns only the
+session key needed by egress. Does not expose refresh tokens
+or raw auth payloads.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+from datetime import datetime, timezone
+from pathlib import Path
+
+from ...log import die
+
+
+def claude_auth_path(host_env: dict[str, str] | None = None) -> Path:
+    env = os.environ if host_env is None else host_env
+    home = env.get("HOME")
+    if home:
+        return Path(home) / ".claude.json"
+    return Path.home() / ".claude.json"
+
+
+def claude_host_access_token(
+    host_env: dict[str, str] | None = None,
+    *,
+    now: datetime | None = None,
+) -> str:
+    path = claude_auth_path(host_env)
+    if not path.is_file():
+        die(
+            f"claude host credentials: auth file missing at {path}. "
+            "Run `claude login` on the host or disable "
+            "agent_provider.forward_host_credentials."
+        )
+    try:
+        raw = json.loads(path.read_text())
+    except (OSError, json.JSONDecodeError) as e:
+        die(f"claude host credentials: could not read valid JSON at {path}: {e}")
+    if not isinstance(raw, dict):
+        die(f"claude host credentials: {path} must contain a JSON object")
+
+    oauth = raw.get("oauthAccount")
+    if not isinstance(oauth, dict):
+        die(
+            f"claude host credentials: {path} is missing oauthAccount. "
+            "Run `claude login` on the host or disable "
+            "agent_provider.forward_host_credentials."
+        )
+
+    session_key = oauth.get("sessionKey")
+    if not isinstance(session_key, str) or not session_key:
+        die(
+            f"claude host credentials: {path} oauthAccount.sessionKey is missing "
+            "or empty. Run `claude login` on the host and restart the bottle."
+        )
+
+    expires_at = oauth.get("expiresAt")
+    if isinstance(expires_at, (int, float)):
+        check_now = now or datetime.now(timezone.utc)
+        exp_dt = datetime.fromtimestamp(float(expires_at), timezone.utc)
+        if exp_dt <= check_now:
+            die(
+                "claude host credentials: host Claude session token is expired. "
+                "Run `claude login` on the host and restart the bottle."
+            )
+
+    return session_key
+
+
+__all__ = [
+    "claude_auth_path",
+    "claude_host_access_token",
+]

bot_bottle/egress.py

@@ -29,6 +29,7 @@ if TYPE_CHECKING:
     from .manifest import ManifestBottle
 
 CODEX_HOST_CREDENTIAL_TOKEN_REF = "BOT_BOTTLE_CODEX_HOST_ACCESS_TOKEN"
+CLAUDE_HOST_CREDENTIAL_TOKEN_REF = "BOT_BOTTLE_CLAUDE_HOST_ACCESS_TOKEN"
 
 EGRESS_HOSTNAME = "egress"
 
@@ -397,6 +398,7 @@ class Egress(ABC):
         )
 
 __all__ = [
+    "CLAUDE_HOST_CREDENTIAL_TOKEN_REF",
     "CODEX_HOST_CREDENTIAL_TOKEN_REF",
     "EGRESS_HOSTNAME",
     "EGRESS_ROUTES_FILENAME",

bot_bottle/manifest_agent.py

@@ -25,8 +25,9 @@ class ManifestAgentProvider:
     header, and sets a placeholder CLAUDE_CODE_OAUTH_TOKEN in the agent
     so the Claude Code CLI starts.
 
-    `forward_host_credentials` forwards the host Codex auth token into
-    the egress sidecar (Codex only).
+    `forward_host_credentials` forwards the host provider auth token into
+    the egress sidecar (Codex and Claude). For Codex this reads
+    `~/.codex/auth.json`; for Claude it reads `~/.claude.json`.
     """
 
     template: str = "claude"
@@ -92,10 +93,15 @@ class ManifestAgentProvider:
                 f"is only supported for built-in templates "
                 f"({', '.join(sorted(PROVIDER_TEMPLATES))})"
             )
-        if forward_host_credentials and template != "codex":
+        if forward_host_credentials and template not in {"codex", "claude"}:
             raise ManifestError(
                 f"bottle '{bottle_name}' agent_provider.forward_host_credentials "
-                "is currently only supported for template 'codex'"
+                "is only supported for templates 'codex' and 'claude'"
+            )
+        if forward_host_credentials and auth_token:
+            raise ManifestError(
+                f"bottle '{bottle_name}' agent_provider.forward_host_credentials "
+                "and auth_token both set; use one or the other"
             )
         settings = _parse_provider_settings(bottle_name, template, d.get("settings"))
         return cls(