Two independent bugs made the ACP server crash the moment an editor (Zed)
connected, despite 178 green unit tests at 100% coverage:
1. `session/new` threw `cannot get property "agents" without inject`. Root
cause: a stray `export default apply` made the cordis Loader's
`unwrapExports` (`exports.default ?? exports`) collapse the module to the
bare `apply` function, discarding the sibling `inject`/`name`/`Config`
named exports. The plugin fiber was built with empty `inject`, so every
`ctx.<service>` read in `apply` threw at load. Fix: remove the default
export so the Loader uses the namespace.
2. `session/load` threw `cannot get property "sessionPersistence" without
inject`. `AgentLoop.resume` read `this.ctx.sessionPersistence` (a service
it deliberately does NOT inject); the property proxy's ancestor-only fiber
walk fails through the bridge's traceable shadow. Fix: read it via
`this.ctx.get('sessionPersistence', false)`, the topology-independent
global-store lookup.
Why the suite missed both: every test mounted the plugin by hand
(`ctx.plugin({name,inject,apply})`), bypassing `unwrapExports` entirely, and
the only test driving these RPCs was key-gated (skipped in CI). Added a no-key
`session/new` e2e that boots the real example through the real Loader — it
fails loudly on bug #1 without an API key. Set `TSX_TSCONFIG_PATH` in the e2e
spawn so the subprocess resolves workspace `paths` from a temp cwd (it was
silently falling back to a stale built `lib/`).
Docs: post-mortem 0001; AGENTS.md "line coverage is not behavior coverage" +
with-key/smoke-test philosophy; packages/AGENTS.md plugin-export-shape and
ctx.get rules; dsh-code-review SKILL checks.
Examples
Runnable demos (not workspaces) that showcase how the harness is wired.
echo-agent
A mock model + echo tool + stdio UI + JSONL persistence demo. Demonstrates:
- Loading plugins from a
cordis.ymlvia@cordisjs/plugin-loader+@cordisjs/plugin-include - Registering a mock
LlmAdapter(streaming scripted responses) - Registering a tool via
ctx.tools.register() - Persisting session events to JSONL via the
session/event+session/flushpattern - A minimal stdio UI consuming
agent/stream-chunkand session events
Run with: pnpm run demo:echo
When prompted, type "echo " to trigger a tool call round-trip.
coding-agent
The real thing: DeepSeek V4 + the bash tool suite + stdio chat + JSONL persistence, wired from cordis.yml. Where echo-agent proves the skeleton with mocks, this is a usable coding assistant.
Run with: pnpm run demo:coding (needs DEEPSEEK_API_KEY in the environment or a gitignored repo-root .env). See coding-agent/README.md for details.