Closes out single-host before the cross-host work. Sequenced BEFORE CB-308 deliberately: federation's own gating concern is the trust model, and it inherits whatever identity shape lands here. The finding this stage is built around: bridged had exactly ONE security control, the loopback bind. ConnectionIdentity resolves a worker from its connection (unforgeable), but every caller that was not a recognised worker pane fell through to being treated as the PRIMARY -- the most privileged role on the bus. Latent today; load-bearing the moment a bind widens. CB-501 auth: - Role/Principal/CallerResolver: connection identity first, bearer token second, ANONYMOUS third. Inverts the old default so absence of identity means nothing, not everything. - Worker identity is never token-gated, so enabling auth cannot lock the fleet out of bridge_reply. - Constant-time token compare (MessageDigest.isEqual). - validateAuthExposure(): a non-loopback bind under loopback-trust now REFUSES TO START. Makes the dangerous config unrepresentable rather than merely documented. - TLS terminates at a reverse proxy by design (D3), not in the JVM. CB-505 authz + audit, enforced on BOTH entry paths: - The docs describe MCP as "a thin adapter over the REST core"; at code level it is not. BridgeMcp calls MessageService directly, and /mcp is a raw servlet on Jetty's context handler that never traverses Javalin's before filter. Enforcing only at REST would have left /mcp open. - Load-bearing rule is own-session-only: a worker may reply/ask only as itself. Structurally true over MCP already; over REST the session id in the URL path had simply been trusted. - Audit: JSON lines to a dedicated appender, additivity=false. Never records message content -- this bus carries source and prompts. CB-502 metrics: zero new dependencies. A ~150-line Prometheus text renderer instead of the specced Micrometer, because this pom already hand-pins jackson-annotations to reconcile Jackson 2/3, imports a Jetty BOM against skew, and carries four accepted-CVE advisories -- and CLAUDE.md's mandated dependency CVE gate could not be run (no JetBrains MCP server connected). Instrumented at MessageService, the single funnel both surfaces share. CB-503 CI: .gitea/workflows/ci.yml against the already-running Gitea runner. Needs no contract-exclusion flag -- the pom's default-excludes profile already sets excludedGroups=contract, so plain `mvn clean install` IS the mock-socket surface. Provisions JDK 25 explicitly (runner default-jdk is older). CB-504 supervision: launchd agent (the real target -- this host is macOS, there is no systemd) plus a systemd unit for the Linux gateways CB-308 adds. Ordering directives are advisory, so the actual fix is that startup now waits up to 30s for the herdr socket and then serves degraded, instead of crashing into a restart loop on a boot-order race. Also fixes drift found while surveying: - bridged.example.yaml documented spawn_ready_timeout_ms in snake_case; config binds via plain Jackson with ignoreUnknown, so uncommenting it would have been silently dropped and the default kept. Now camelCase, with a test that loads the shipped example and one that pins every documented knob's spelling -- no test had ever loaded that file. - Added the 6 shipped-but-undocumented knobs (worktreeRoot, parityOverlay, gitTokenEnv, gitHostEnv, configDir, primary:). - README "Next" listed bridge_ask and session lifecycle as upcoming; both shipped long ago. - docs/CB-301-ext and docs/CB-402 status headers said "design"/"pre- implementation" for work already merged. 307 unit/acceptance tests green (was 266), mvn clean install BUILD SUCCESS. Note: CLAUDE.md's per-file ide_diagnostics gate and the pom Mend.io CVE check could not be run -- no JetBrains/intellij-index MCP server is connected this session. mvn clean install is the only gate that ran.
7.3 KiB
claude-bridge
A subscription-safe bridge that lets a primary Claude Code (Opus 4.8, on Pro/Max)
session drive a secondary Claude agent running a different model via its own
ANTHROPIC_BASE_URL — without ever putting a proxy on the primary session.
Sibling of crush-bridge (which drives a headless
Crush worker on GX10 DeepSeek). claude-bridge keeps the worker a real Claude Code
process, so it inherits CLAUDE.md, hooks, skills, and MCP — just pointed at a
cheaper/local model.
Leading approach — herdr-centric message server (bridged)
A small always-on message server, bridged, controls
herdr (an agent multiplexer) over its Unix-socket API and exposes a
clean 2-way messaging API as an MCP server that both the primary and the workers mount —
one unified Claude setup and the sole communication gateway (REST/SSE stays for non-Claude
clients; any broker is bridged-internal, below the gateway).
herdr owns the PTYs, multiplexing, persistence, and agent-status events; bridged owns
policy (subscription boundary, session lifecycle, status-gated delivery) and the client
contract. The worker claude launches with ANTHROPIC_BASE_URL=https://ollama.ltms.dev + a
bearer token; the primary Opus stays env-clean and calls bridged's MCP tools.
flowchart LR
OPUS["Opus — primary<br/>(Claude Code, env CLEAN)<br/>MCP client"]
subgraph BD["bridged — standalone daemon (not a claude process)"]
SRV["SERVER face<br/>MCP · REST/SSE · policy"]
CLI["CLIENT face<br/>status-gated injector · herdr socket"]
SRV --> CLI
end
HERDR["herdr<br/>panes · agent-status"]
W["worker claude pane<br/>ANTHROPIC_BASE_URL set<br/>MCP client"]
M["ollama.ltms.dev<br/>(worker model)"]
OPUS -->|"MCP bridge_send (blocks)"| SRV
W -.->|"MCP bridge_reply"| SRV
CLI -->|"Unix socket<br/>send_text · events.subscribe"| HERDR
HERDR -->|"drives PTY"| W
W -->|"inference"| M
classDef ext fill:#2b6cb0,stroke:#1a365d,color:#ffffff;
classDef core fill:#2f855a,stroke:#22543d,color:#ffffff;
class OPUS ext
class SRV,CLI,HERDR core
- Subscription boundary: the primary never sets
ANTHROPIC_BASE_URL(stays on Pro/Max). Only the secondary process is off-subscription — andbridgeditself is a plain daemon (no Anthropic quota), so it may poll/subscribe freely. - One gateway (unified MCP setup):
bridgedis the sole communication path for every Claude session. Primary and workers each mount it as an MCP server (oneclaude mcp addline, same on both) and talk over MCP tools —bridge_send/bridge_reply/bridge_status(withbridge_askplanned for the blocked-worker path). No Claude session ever addresses a broker, a peer, or the network directly; any queue isbridged-internal. MCP tool I/O never setsANTHROPIC_BASE_URL, so mounting the bridge is subscription-safe by construction. - How the primary consumes a reply: a single blocking MCP call (
bridge_send);bridgedholds it open until the worker callsbridge_replyor its turn hitsagent_status=done, then returns the reply as the tool result. No cross-turn busy-poll, so no quota burn. SSE is an optional side-channel for humans/dashboards watching status. - Worker → primary rides
bridged's MCP rendezvous — the reply resolves the primary's blocking call (or, for detached work,bridgedinjects the primary's idle pane when it's ready), so no keystroke-into-primary and no broker are involved, even single-host. The one exception: a split-host primary that isn't a herdr pane wakes via its ownStop-hook, which pollsbridged(never a broker). See the wiki for the two topologies. - Different model per process sidesteps Claude Code's lack of per-subagent provider routing — the worker isn't a subagent, it's its own configured process.
- AgentAPI (
coder/agentapi) is retained only as a swappable fallback injector behind the same interface. See the wiki for the full design, comparison, and rationale.
Docs
Full design, setup, and operations live in the wiki,
vendored here as a submodule under wiki/:
git clone --recurse-submodules ssh://git@git.ltms.dev:2224/lms/claude-bridge.git
# or, after a plain clone:
git submodule update --init
Edit docs in wiki/, then cd wiki && git commit && git push to publish them to the
Gitea wiki.
Status
🟢 Implemented & dogfooded — the herdr-centric bridged message server is built and in
real use: an Opus primary delegates tasks to off-subscription workers that reply through the
bridge (code reviews delegated this way have produced committed bug fixes). Selected as the
primary approach 2026-07-11, superseding the AgentAPI plan (2026-07-08); AgentAPI retained as a
fallback injector.
Shipped (Java 25 · Maven · 266 unit/acceptance tests green; the live-herdr and broker contract
tests run separately via mvn test -Pcontract):
- Core gateway — herdr socket client (contract-tested vs live 0.7.0); guard-checked worker
spawn with
ANTHROPIC_BASE_URLinjected only into the worker's env; status-gated injector; blockingbridge_sendwith reply rendezvous; MCP server as a thin adapter over the REST core. - MCP tools —
bridge_send/bridge_reply/bridge_status(messaging) andbridge_spawn/bridge_list/bridge_stop/bridge_profiles/bridge_poll(fleet). Caller identity is connection-based (loopback peer PID → herdr pane), so the same mount serves primary and workers. - Delivery reliability — completion fallback (a confirmed
working→idleturn resolves a send); async fire-and-poll (beats the caller's MCP call timeout for long tasks); and failure detection for wedged (unknown), vanished, and never-ready workers so a send never hangs. - Fleet — multiple worker profiles, each with an independent base_url guard check; workers
inherit the primary's working directory (never
$HOME); a readiness gate holds delivery until a worker's Claude has connected the bridge MCP (no paste lost into its boot window). - Blocked-worker path —
bridge_askreverse rendezvous: a worker pauses its delegated turn to ask the primary and resumes the same turn with the answer (CB-205). - Session lifecycle — session manager with spawn/reuse/recycle,
idle_ttlreaper,context_cap, and graceful drain on shutdown (CB-301/CB-303); per-worker git worktrees on their own branch with a config-parity overlay, so parallel implementers never stomp each other (CB-301-ext). - Reliable worker→primary delivery — a durable
ReplyInbox(in-memory by default, AMQP/LavinMQ for cross-restart durability) holds a reply that arrives with no open send, and an active status-gated push loop nudges the primary to drain it (CB-307). - Pluggable peers — a
PeerLauncherSPI with two in-tree adapters,claude-codeandopencode, routed by akind:discriminator (CB-401/CB-402).
Next (see the roadmap) — Stage 5 hardening (auth/TLS, /metrics, CI,
service supervision, per-session authz + audit), then cross-host: CB-308 multi-host federation and
CB-500 multi-tier coordination.