Replace the legacy cmd/docgardener orchestration (~2400 LOC of Go
spawning subprocess workers via local_command + admin socket) with
three Docker-isolated agents that all reach SynapBus through MCP:
doc-coordinator — Gemini Pro, triages goal, calls create_goal +
propose_task_tree + send_message via MCP
docs-inspector — Gemini Flash, fetches docs, installs mcpproxy,
shells out to verify, reports findings via MCP
docs-critic — Gemini Flash, independent reviewer with its
own MCP API key + config_hash, audits the
inspector's evidence and DMs the owner
Every agent runs inside synapbus-agent:latest with --cap-drop=ALL,
--security-opt=no-new-privileges, --read-only root + tmpfs /tmp,
--pids-limit, memory + CPU quotas. The container reaches the
SynapBus MCP server on the host at host.docker.internal:18089
because the docker harness rewrites .gemini/settings.json URLs
from 127.0.0.1 automatically.
Wrapper baked into the image at /usr/local/bin/synapbus-agent-wrapper.sh
so configs don't need to mount or template a per-example wrapper.
The harness's default no longer overrides docker CMD — the image's
baked entry script is used unless docker.command is set explicitly.
start.sh changes:
- Preflight: docker daemon, GEMINI_API_KEY (or ~/.gemini/oauth_creds.json)
- Builds synapbus-agent image lazily on first run
- Mints one MCP API key per agent via `agent revoke-key`
- Templates each config with __PORT__, __*_APIKEY__, __MODEL__,
__GEMINI_API_KEY__, __EXTRA_MOUNTS__
- With OAuth fallback: copies host ~/.gemini → data/agent-home/.gemini
once and bind-mounts the whole agent-home rw at /home/agent so
in-container gemini has a writable HOME without polluting the host
- SYNAPBUS_KEEP_WORKDIR=1 preserves per-run docker workdirs for
debugging
- Sets harness_name=docker explicitly so the resolver picks the
right backend even with empty local_command
stop.sh: best-effort cleanup of lingering synapbus-* containers so a
killed parent doesn't leave bind-mount holders that block the next
start.sh from re-mounting the same paths.
run_task.sh: snapshot-baseline pattern (only watches replies newer
than the max msg id at send time), 600s deadline, treats any reply
from doc-coordinator that isn't DELEGATED:/REVISING: as terminal,
plus FINAL:/CANNOT: from any sender.
cmd/docgardener slimmed from 7 files / 2580 LOC to 3 files / ~370 LOC.
The remaining binary only renders the HTML report (queries goals +
goal_tasks + traces + harness_runs from the SynapBus DB read-only).
agent.go, channels.go, flow.go, gemini_tree.go all deleted.
Verified end-to-end against gemini-2.5-pro coordinator + gemini-2.5-flash
workers (with OAuth fallback mount):
./run_task.sh "what does this demo do?"
→ coordinator TRIVIAL: replies directly via MCP send_message
./run_task.sh "Verify the CLI commands on docs.mcpproxy.app/cli/command-reference"
→ coordinator calls create_goal (slug verify-mcpproxy-cli-...),
propose_task_tree (3-node tree: coordinator/plan,
doc-gardener/scan, doc-gardener/audit) and send_message to
docs-inspector
→ inspector container runs ~10 minutes inside the sandbox:
installs mcpproxy from real release URL (linux-arm64), curls
the docs page, falls back from BeautifulSoup → grep when
python3-venv is missing, debugs its own f-string syntax, writes
extract_flags.py, runs `mcpproxy --help` for ground truth
→ real multi-agent iteration loop: critic REVISE: → inspector
retry → critic REVISE: with new feedback
The agents discovered real environment quirks (tmpfs noexec on /tmp,
externally-managed Python, missing python3-venv) and worked around
them inside the sandbox without touching the host.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
SynapBus examples
Runnable demos of SynapBus features. Each example is self-contained under its own directory, launches an isolated synapbus instance on a distinct port, and cleans up after itself.
| Example | Feature | Real LLM? | Port |
|---|---|---|---|
cold-topic-explainer/ |
Reactive agent triggers + subprocess harness — three Gemini agents (decomposer → writer → critic) collaborate via DMs to produce a 3-paragraph explainer, with real LLM calls end-to-end. | ✅ yes (gemini CLI) |
18088 |
doc-gardener/ |
Dynamic agent spawning (spec 018) — a coordinator meta-agent decomposes a goal into a task tree, spawns specialists with config_hash-rooted trust + delegation-cap enforcement, runs them through the state machine, generates a rich HTML report. |
❌ v1 is synthetic (primitives demo); real LLM coordinator is a follow-up PR | 18089 |
Quick start
Pick an example, cd into it, and follow its README. In general:
cd examples/<name>
./start.sh # rebuild + launch an isolated synapbus instance
./run_task.sh # drive the demo flow
./report.sh # (where applicable) render an HTML report
./stop.sh # shut down
Both examples use the same layout for consistency:
examples/<name>/
├── start.sh # build & launch
├── run_task.sh # execute the demo flow
├── stop.sh # shut down
├── report.sh # (doc-gardener only) render HTML report
├── bin/
│ ├── synapbus # built from the current checkout
│ └── <helper> # example-specific driver binary
├── configs/ # per-agent JSON configs (harness_config, prompts, etc.)
├── data/ # isolated SQLite DB + attachment store + sockets
├── synapbus.log # server stdout+stderr
└── README.md # example-specific docs
What each example proves
- cold-topic-explainer proves that the SynapBus reactor + subprocess harness can drive a real multi-agent loop with three distinct LLMs, with depth and budget guards, OpenTelemetry tracing, and harness_runs accounting.
- doc-gardener proves that the dynamic-agent-spawning data primitives —
goals,goal_taskswith denormalized ancestry, atomic optimistic-lock claim,config_hash-keyed reputation ledger, delegation-cap enforcement, per-billing-code cost rollup — work end-to-end against real SQLite, and feed a rich HTML report.
The two examples are complementary: cold-topic-explainer exercises the runtime path (reactor → harness → LLM → DMs), doc-gardener exercises the work-tracking path (goals → tasks → trust → report). A future example will combine them into a full LLM-driven coordinator loop.
Global prereqs
- Go 1.25+
sqlite3,curl,jqon$PATH- A free TCP port per example (see table above)
- For
cold-topic-explaineronly:geminiCLI authenticated viagemini auth login
Troubleshooting
- Port already in use: set
SYNAPBUS_PORT=18090 ./start.sh(each example honors the env var). - Web UI is blank: rebuild the embedded Svelte SPA with
make webfrom the repo root once, then re-run./start.sh. - Stale binary: delete the example's
bin/directory and rerun./start.shto force a rebuild.