# Kanban tutorial

A walkthrough of the four use-cases the Hermes Kanban system was designed for, with the dashboard open in a browser. If you haven't read the [Kanban overview](./kanban) yet, start there — this assumes you know what a task, run, assignee, and dispatcher are.

## Setup

```bash
hermes kanban init           # optional; first `hermes kanban <anything>` auto-inits
hermes dashboard             # opens http://127.0.0.1:9119 in your browser
# click Kanban in the left nav
```

The dashboard is the most comfortable place to learn the system. Everything you see here is also available via `hermes kanban <verb>` on the CLI — the two surfaces share the same SQLite database at `~/.hermes/kanban.db`.

## The board at a glance

![Kanban board overview](/img/kanban-tutorial/01-board-overview.png)

Six columns, left to right:

- **Triage** — raw ideas, a specifier will flesh out the spec before anyone works on them.
- **Todo** — created but waiting on dependencies, or not yet assigned.
- **Ready** — assigned and waiting for the dispatcher to claim.
- **In progress** — a worker is actively running the task. With "Lanes by profile" on (the default), this column sub-groups by assignee so you can see at a glance what each worker is doing.
- **Blocked** — a worker asked for human input, or the circuit breaker tripped.
- **Done** — completed.

The top bar has filters for search, tenant, and assignee, plus a `Lanes by profile` toggle and a `Nudge dispatcher` button that runs one dispatch tick right now instead of waiting for the daemon's next interval. Clicking any card opens its drawer on the right.

### Flat view

If the profile lanes are noisy, toggle "Lanes by profile" off and the In Progress column collapses to a single flat list ordered by claim time:

![Board with lanes by profile off](/img/kanban-tutorial/02-board-flat.png)

## Story 1 — Solo dev shipping a feature

You're building a feature. Classic flow: design a schema, implement the API, write the tests. Three tasks with parent→child dependencies.

```bash
SCHEMA=$(hermes kanban create "Design auth schema" \
    --assignee backend-dev --tenant auth-project --priority 2 \
    --body "Design the user/session/token schema for the auth module." \
    --json | jq -r .id)

API=$(hermes kanban create "Implement auth API endpoints" \
    --assignee backend-dev --tenant auth-project --priority 2 \
    --parent $SCHEMA \
    --body "POST /register, POST /login, POST /refresh, POST /logout." \
    --json | jq -r .id)

hermes kanban create "Write auth integration tests" \
    --assignee qa-dev --tenant auth-project --priority 2 \
    --parent $API \
    --body "Cover happy path, wrong password, expired token, concurrent refresh."
```

Because `API` has `SCHEMA` as its parent, and `tests` has `API` as its parent, only `SCHEMA` starts in `ready`. The other two sit in `todo` until their parents complete. This is the dependency promotion engine doing its job — no other worker will pick up the test-writing until there's an API to test.

Claim the schema task, do the work, hand off:

```bash
hermes kanban claim $SCHEMA

# (you design the schema, commit, etc.)

hermes kanban complete $SCHEMA \
    --summary "users(id, email, pw_hash), sessions(id, user_id, jti, expires_at); refresh tokens stored as sessions with type='refresh'" \
    --metadata '{
        "changed_files": ["migrations/001_users.sql", "migrations/002_sessions.sql"],
        "decisions": ["bcrypt for hashing", "JWT for session tokens", "7-day refresh, 15-min access"]
    }'
```

When `SCHEMA` hits `done`, the dependency engine promotes `API` to `ready` automatically. The API worker, when it picks up, will read `SCHEMA`'s summary and metadata in its context — so it knows the schema decisions without re-reading a long design doc.

Click the completed schema task on the board and the drawer shows everything:

![Solo dev — completed schema task drawer](/img/kanban-tutorial/03-drawer-schema-task.png)

The Run History section at the bottom is the key addition. One attempt: outcome `completed`, worker `@backend-dev`, duration, timestamp, and the handoff summary in full. The metadata blob (`changed_files`, `decisions`) is stored on the run too and surfaced to any downstream worker that reads this parent.

On the CLI:

```bash
hermes kanban show $SCHEMA
hermes kanban runs $SCHEMA
# #  OUTCOME       PROFILE       ELAPSED  STARTED
# 1  completed     backend-dev        0s  2026-04-27 19:34
#     → users(id, email, pw_hash), sessions(id, user_id, jti, expires_at); refresh tokens ...
```

## Story 2 — Fleet farming

You have three workers (a translator, a transcriber, a copywriter) and a pile of independent tasks. You want all three pulling in parallel and making visible progress. This is the simplest kanban use-case and the one the original design optimized for.

Create the work:

```bash
for lang in Spanish French German; do
    hermes kanban create "Translate homepage to $lang" \
        --assignee translator --tenant content-ops
done
for i in 1 2 3 4 5; do
    hermes kanban create "Transcribe Q3 customer call #$i" \
        --assignee transcriber --tenant content-ops
done
for sku in 1001 1002 1003 1004; do
    hermes kanban create "Generate product description: SKU-$sku" \
        --assignee copywriter --tenant content-ops
done
```

Start the gateway and walk away — it hosts the embedded dispatcher
that picks up all three specialist profiles' tasks on the same
kanban.db:

```bash
hermes gateway start
```

Now filter the board to `content-ops` (or just search for "Transcribe") and you get this:

![Fleet view filtered to transcribe tasks](/img/kanban-tutorial/07-fleet-transcribes.png)

Two transcribes done, one running, two ready waiting for the next dispatcher tick. The In Progress column is grouped by profile (the "Lanes by profile" default) so you see each worker's active task without scanning a mixed list. The dispatcher will promote the next ready task to running as soon as the current one completes. With three daemons working on three assignee pools in parallel, the whole content queue drains without further human input.

**Everything Story 1 said about structured handoff still applies here.** A translator worker completing a call can pass `--summary "translated 4 pages, style matched existing marketing voice"` and `--metadata '{"duration_seconds": 720, "tokens_used": 2100}'` — useful for analytics and for any downstream task that depends on this one.

## Story 3 — Role pipeline with retry

This is where Kanban earns its keep over a flat TODO list. A PM writes a spec. An engineer implements it. A reviewer rejects the first attempt. The engineer tries again with changes. The reviewer approves.

The dashboard view, filtered by `auth-project`:

![Pipeline view for a multi-role feature](/img/kanban-tutorial/08-pipeline-auth.png)

Three-stage chain visible at once: `Spec: password reset flow` (DONE, pm), `Implement password reset flow` (DONE, backend-dev), `Review password reset PR` (READY, reviewer). Each has its parent in green at the bottom and children as dependencies.

The interesting one is the implementation task, because it was blocked and retried:

```bash
# PM completes the spec with acceptance criteria in metadata
hermes kanban complete $SPEC \
    --summary "spec approved; POST /forgot-password sends email, GET /reset/:token renders form, POST /reset applies new password" \
    --metadata '{"acceptance": [
        "expired token returns 410",
        "reused last-3 password returns 400 with message",
        "successful reset invalidates all active sessions"
    ]}'

# Engineer claims + implements, but review blocks it for missing strength check
hermes kanban claim $IMPL
hermes kanban block $IMPL "Review: password strength check missing, reset link isn't single-use (can be replayed within 30min)"

# Engineer iterates, resolves, completes
hermes kanban unblock $IMPL
hermes kanban claim $IMPL
hermes kanban complete $IMPL \
    --summary "added zxcvbn strength check, reset tokens are now single-use (stored + deleted on success)" \
    --metadata '{
        "changed_files": ["auth/reset.py", "auth/tests/test_reset.py", "migrations/003_single_use_reset_tokens.sql"],
        "tests_run": 11,
        "review_iteration": 2
    }'
```

Click the implementation task. The drawer shows **two attempts**:

![Implementation task with two runs — blocked then completed](/img/kanban-tutorial/04b-drawer-retry-history-scrolled.png)

- **Run 1** — `blocked` by `@backend-dev`. The review feedback sits right under the outcome: "password strength check missing, reset link isn't single-use (can be replayed within 30min)".
- **Run 2** — `completed` by `@backend-dev`. Fresh summary, fresh metadata.

Each run is a row in `task_runs` with its own outcome, summary, and metadata. Retry history is not a conceptual afterthought layered on top of a "latest state" task — it's the primary representation. When a retrying worker opens the task, `build_worker_context` shows it the prior attempts, so the second-pass worker sees why the first pass was blocked and addresses those specific findings instead of re-running from scratch.

The reviewer picks up next. When they open `Review password reset PR`, they see:

![Reviewer's drawer view of the pipeline](/img/kanban-tutorial/09-drawer-pipeline-review.png)

The parent link is the completed implementation. When the reviewer's worker calls `build_worker_context`, it pulls the parent's most-recent-completed-run summary + metadata — so the reviewer reads "added zxcvbn strength check, reset tokens are now single-use" and has the list of changed files in hand before looking at a diff.

## Story 4 — Circuit breaker and crash recovery

Real workers fail. Missing credentials, OOM kills, transient network errors. The dispatcher has two lines of defense: a **circuit breaker** that auto-blocks after N consecutive failures so the board doesn't thrash forever, and **crash detection** that reclaims a task whose worker PID went away before its TTL expired.

### Circuit breaker — permanent-looking failure

A deploy task that can't spawn its worker because `AWS_ACCESS_KEY_ID` isn't set in the profile's environment:

```bash
hermes kanban create "Deploy to staging (missing creds)" \
    --assignee deploy-bot --tenant ops
```

The dispatcher tries to spawn the worker. Spawn fails (`RuntimeError: AWS_ACCESS_KEY_ID not set`). The dispatcher releases the claim, increments a failure counter, and tries again next tick. After three consecutive failures (the default `failure_limit`), the circuit trips: the task goes to `blocked` with outcome `gave_up`. No more retries until a human unblocks it.

Click the blocked task:

![Circuit breaker — 2 spawn_failed + 1 gave_up](/img/kanban-tutorial/11-drawer-gave-up.png)

Three runs, all with the same error on the `error` field. The first two are `spawn_failed` (retryable), the third is `gave_up` (terminal). The event log above shows the full sequence: `created → claimed → spawn_failed → claimed → spawn_failed → claimed → gave_up`.

On the terminal:

```bash
hermes kanban runs t_ef5d
# #   OUTCOME        PROFILE        ELAPSED  STARTED
# 1   spawn_failed   deploy-bot          0s  2026-04-27 19:34
#       ! AWS_ACCESS_KEY_ID not set in deploy-bot env
# 2   spawn_failed   deploy-bot          0s  2026-04-27 19:34
#       ! AWS_ACCESS_KEY_ID not set in deploy-bot env
# 3   gave_up        deploy-bot          0s  2026-04-27 19:34
#       ! AWS_ACCESS_KEY_ID not set in deploy-bot env
```

If Telegram / Discord / Slack is wired in, a gateway notification fires on the `gave_up` event so you hear about the outage without having to check the board.

### Crash recovery — worker dies mid-flight

Sometimes the spawn succeeds but the worker process dies later — segfault, OOM, `systemctl stop`. The dispatcher polls `kill(pid, 0)` and detects the dead pid; the claim releases, the task goes back to `ready`, and the next tick gives it to a fresh worker.

The example in the seed data is a migration that was running out of memory:

```bash
# Worker claims, starts scanning 2.4M rows, OOM kills it at ~2.3M
# Dispatcher detects dead pid, releases claim, increments attempt counter
# Retry with a chunked strategy succeeds
```

The drawer shows the full two-attempt history:

![Crash and recovery — 1 crashed + 1 completed](/img/kanban-tutorial/06-drawer-crash-recovery.png)

Run 1 — `crashed`, with the error `OOM kill at row 2.3M (process 99999 gone)`. Run 2 — `completed`, with `"strategy": "chunked with LIMIT + WHERE id > last_id"` in its metadata. The retrying worker saw the crash of run 1 in its context and picked a safer strategy; the metadata makes it obvious to a future observer (or postmortem writer) what changed.

## Structured handoff — why `--summary` and `--metadata` matter

In every story above, workers passed `--summary` and `--metadata` on completion. That's not decoration — it's the primary handoff channel between stages of a workflow.

When a worker on task B reads its context, it gets:

- B's **prior attempts** (previous runs: outcome, summary, error, metadata) so a retrying worker doesn't repeat a failed path.
- **Parent task results** — for each parent, the most-recent completed run's summary and metadata — so downstream workers see why and how the upstream work was done.

This replaces the "dig through comments and the work output" dance that plagues flat kanban systems. A PM writes acceptance criteria in the spec's metadata, and the engineer's worker sees them structurally. An engineer records which tests they ran and how many passed, and the reviewer's worker has that list in hand before opening a diff.

The bulk-close guard exists because this data is per-run. `hermes kanban complete a b c --summary X` is refused — copy-pasting the same summary to three tasks is almost always wrong. Bulk close without the handoff flags still works for the common "I finished a pile of admin tasks" case.

## Inspecting a task currently running

For completeness — here's the drawer of a task still in flight (the API implementation from Story 1, claimed by `backend-dev` but not yet complete):

![Claimed, in-flight task](/img/kanban-tutorial/10-drawer-in-flight.png)

Status is `Running`. The active run appears in the Run History section with outcome `active` and no `ended_at`. If this worker dies or times out, the dispatcher closes this run with the appropriate outcome and opens a new one on the next claim — the attempt row never disappears.

## Next steps

- [Kanban overview](./kanban) — the full data model, event vocabulary, and CLI reference.
- `hermes kanban --help` — every subcommand, every flag.
- `hermes kanban watch --kinds completed,gave_up,timed_out` — live stream terminal events across the whole board.
- `hermes kanban notify-subscribe <task> --platform telegram --chat-id <id>` — get a gateway ping when a specific task finishes.