Set up WorkerKit in Hark.

Before you start

What you need.

Hark Pro on iOS, Android or the web. Every Hark feature is in the free plan, so no Hark upgrade is needed to connect.

A WorkerKit account, and admin access on it: creating a manager key is admin-only. The WorkerKit Free plan is enough and needs no card.

A few minutes of the person's time: creating one key and handing it to Hark once.

Why MCP: Hark's launch article says it reaches tools and information over MCP, and on 2026-10-06 it connected to the fleet mount and answered on the first call. Both WorkerKit mounts are public HTTPS over streamable HTTP, so a URL is the whole of the wiring.

Why a key and not a sign-in: the fleet mount runs its own OAuth flow, but it registers only assistants it already knows, and Hark is not one of them yet. So Hark connects the way it was tested, with a key it asks for in the chat. A credential in a conversation sits in a transcript and, with Hark, possibly in its memory, which is why step 2 is mostly about making that one key harmless.

The case for connecting at all is on the Hark page.

Step 0. Human and Hark, under a minute

Add the public catalog.

The catalog mount takes no credential, so it connects on the URL alone and proves the wiring before any account is involved.

• Ask Hark, in the thread Connect the remote MCP server WorkerKit Directory at https://mcp.workerkit.ai/directory. It needs no authentication.

The catalog mount takes no credential at all, on either path. It is the fastest proof that the client can reach WorkerKit, and it is worth adding first for exactly that reason: if it connects and the fleet mount does not, the problem is the credential rather than the wiring.

Then ask Hark to call directory_overview and say how many kits it sees. A count back means the transport and discovery both work.

Step 1. Human, about two minutes

Connect the fleet with a narrow key.

The route tested on 2026-10-06. Hark asks for the key in the chat, so create one for Hark alone, start with the reads, give it an expiry and keep it out of Hark's memory.

1. 01

   Sign in as the account that owns the fleet

   At workerkit.ai. Someone who belongs to several accounts confirms the active one first: a key created in the wrong account shows up later as an empty fleet, and checking now saves that round trip.

2. 02

   Open Fleet access

   workerkit.ai/fleet-access is an admin-only page. A member sees a notice saying so rather than a broken page.

3. 03

   Create a manager key named for its purpose

   Name it for the assistant that will hold it. A purpose-specific name makes the key easy to audit, and easy to revoke later without touching anything else.

4. 04

   Pick its scopes

   The tables below say what each one grants. Start with the reads and add only the scopes needed for the approved task. Choose an expiry and request fresh approval when more access is needed.

5. 05

   Copy the key once

   It is shown at creation and never again, so keep it to hand for the wiring step. It reaches the fleet only: no scope on it reads a mailbox, a calendar or a CRM.

• Ask Hark, in the thread Connect the remote MCP server WorkerKit Fleet at https://mcp.workerkit.ai/workers. It authenticates with an Authorization header; I will give you the key when you ask.
• What Hark sends on every call Authorization: Bearer pe_mgr_...
• Ask Hark, once the fleet answers Forget the WorkerKit key I pasted. Keep the connection, but do not store the key in memory, a Project, a Panel or a Specialty, and never repeat it.

Name the key Hark, choose the Observer rung first (readWorkers, readRuns) and set an expiry. Paste it when Hark asks, and only there. Hark remembers what you tell it by design, so the forget request above is part of the step, followed by key_info to confirm the connection still answers. If the key ever appears anywhere else, revoke it at https://workerkit.ai/fleet-access and create a new one: a new key drops into the same connection.

A key carries the scopes it was granted when it was created. Granting a scope later never reaches an existing key: if a call answers 403 OPERATION_NOT_ALLOWED, an admin re-scopes the key at Fleet access or creates a new one, and the new key drops into the same place. Read key_info rather than assuming.

Step 2. Hark

Read the key before doing anything.

Call key_info on the fleet mount. Its scope list is the truth about what Hark may do, whatever was intended.

• No arguments key_info

It returns the account, the key name, its scopes and expiry, and serverTimeUtc. Hark says in plain words which kind of operator it now is: with an observer key it reports on the fleet and changes nothing; with installKits it can put a new worker in the fleet.

Hark sends only the Authorization header, so it receives the full tool set rather than the focused decision profile, which is chosen by a request header. Expect a long tool list. It grants nothing extra: a call outside the key's scopes answers 403 and names the scope it wanted.

Step 3. Hark

Keep the WorkerKit skill.

Hark publishes no skill-file format, so it reads the operating reference at the start of fleet work and keeps the rules, never the key.

• Ask Hark, in the thread Read https://workerkit.ai/hark/SKILL.md and follow its operating rules whenever you work with my WorkerKit fleet.

Two Hark features can carry it. Memory keeps what you tell it across conversations, and a Specialty is a multi-step workflow Hark learns to repeat and can create on request. Either is a fine home for the rules; re-reading the file at the start of a fleet session is what keeps them current when WorkerKit ships a change.

Step 4. Hark

Run the smoke test.

List the fleet and read recent runs, which alone prove the setup. If there are workers, read one before running it, run it with approval, and report the receipt.

If the fleet is empty, stop after step 3 and say so: a new account has no workers yet, and the steps above have already proved the setup, because the key authenticated and both read scopes answered. Do not read it as a fault, and do not invent a worker to run. Go to the first-worker step and give the fleet something to do.

If the fleet has workers, pick one whose effects are reads. Judge it from the instruction and the permissions, never from the name: a worker whose apps are all read-level and whose instruction only gathers, summarises or reports is safe to run; one that sends, posts, writes, orders or pays is not, whatever it is called. If none is clearly read-only, run one with an explicit prompt for that run bounding it to a read.

• 1. The directory is alive: confirm a kit count comes back directory_overview
• 2. The fleet list: report how many workers the assistant can see workers_list
• 3. Recent runs across the fleet: confirms readRuns runs_feed { "limit": 5 }
• 4. Before running anything, read what that worker does and what it may touch. Both ride on readWorkers, and this is the step that decides whether the run is safe instruction_get worker_permissions_get
• 5. Run it with the person's approval, then poll every 3 to 5 seconds until a terminal event arrives: run.succeeded, run.failed, run.blocked or run.awaiting_input worker_run run_events { "afterSeq": <lastSeq> }
• 6. Read the receipt: costAuthority first, then modelCostUsd run_get

Read costAuthority first, then modelCostUsd beside it, and report both. A null finalDigest is not a failure: a run produces one only when its harness wrote a report. A costAuthority of unbilled_estimate, none or in_flight is not a failure either; it says how far to trust the number, and the operating rules below say what each value means.

A Skipped run is also a pass, and it is the cost brake working: the gate refused the run before any money moved. Report the skipReason rather than retrying. Then report the fleet size, the active scopes, and what the test cost, and the fleet is live.

Step 5. Human and Hark

Give the fleet its first worker.

A new account starts empty. Install a kit from its page in one click, or let Hark preview and install one once you approve.

A new WorkerKit account starts with no workers, so the last step of setup is getting one. A kit is a ready-made worker: its instruction, its exact app permissions and its schedule, written and reviewed in advance, so installing one is how a fleet usually starts rather than a shortcut. There are two paths, and either ends with something to operate.

1. 01

   The one-click path: install a kit from its page

   Browse the catalog at workerkit.ai/kits, open a kit whose job you recognise, and install it. It arrives pre-instructed, pre-permissioned and pre-scheduled, and asks for whatever it needs to connect. This path needs no scope on the manager key at all, so it works on the first session whatever the key can do.

2. 02

   The agent path: shortlist, preview, approve, install

   With installKits on the key, the assistant can do the whole thing in chat: shortlist with kits_search, read the candidate with kit_get, then call kit_install_preview to surface its setup questions and exactly what the new worker would be allowed to touch. Put that in front of the person in plain words, and call kit_install once they approve, with deploy set to true so the new worker is actually able to run (that half needs manageDeployments on the key; without it the worker is installed but inert until worker_deploy). The new worker's key is shown once in the response.

3. 03

   Then run it once and read the receipt

   A worker earns its place on the first run. Trigger it with worker_run, follow run_events until a terminal event arrives, and report the digest and the settled cost from run_get. Set a schedule with schedule_create when the person is happy with what it did, and the fleet is not just connected, it is working.

Step 6. Human, about two minutes

Send reports where Hark already looks.

Optional, and it needs no polling: deliver a worker's report to the inbox you connected to Hark, which Hark reads to build its Action Buttons.

1. 01

   Connect a sending mailbox in WorkerKit

   Under Connected apps, connect a Google or Microsoft mailbox for notifications. It can differ from the inbox Hark reads.

2. 02

   Point the worker at the inbox Hark reads

   On the worker, add an email delivery with that address and choose when it sends. With manageDeliveries on its key, Hark can do this with delivery_channels and delivery_create.

3. 03

   Run once and find the report

   Run the worker, confirm the delivery went out with delivery_list, then ask Hark to find the report in your email and summarize what needs you.

Open Connected apps for the sending mailbox, or open your workers to manage deliveries and schedules.

Classification on demand

Create a decision worker from your questions.

Categorize, score or triage connected data, then reuse and adjust the worker.

Reuse an existing worker or decision kit when its questions fit. For a custom classification task, creation compiles a supported source recipe and typed questions into a private kit and an installed decision worker. Optional deploy:true adds deployment; creation never starts a run or adds a schedule. The kit can be edited and published later through the normal kit lifecycle.

On the workers connection, call kit_app_tools(purpose:"decision") for recipes, argument schemas, permissions and examples, then kit_authoring_guide(section:"decision"). Check account connections with apps_list; public discovery does not check them. Send the request to decision_worker_create, follow nextCall, then use worker_run and run_get. Running needs runWorkers; results need readRuns. Use instruction_get / instruction_set for saved category or level answers, or answers on one run. Structural question/source changes need a revised kit and a replacement install. Check receipt status, coverage, omissions, warnings and cost before claiming completion.

Start with email-previews, calendar-events or sheets-rows. These recipes return judgments without app writes. Email previews do not include full threads; calendar events are invitation data, not transcripts; Sheets needs a Google file ID, a finite tab-qualified range and a columns map. A connected app alone does not make every tool a supported source. Source filters select evidence, not permissions: the Sheets recipe grants spreadsheet reads across the linked Drive account.

Supply 1–8 questions: choice with named options, score with ordered levels, or noul for the probability of a statement. Choice adds unclear automatically. Set an explicit confidenceFloor between 0 and 1; it routes uncertainty and does not promise accuracy. maxItems is 1–50, default 20. Creation requires publishKits and installKits; optional deployment also needs manageDeployments.

Use a fresh requestId for each new worker. Retry with the same ID and identical body to recover the original receipt; a changed body returns 409. The response includes tokenId for MCP/CLI worker commands, stable workerId, kitSlug, readiness and nextCall. A deploymentError means the worker already exists: fix deployment on that worker. The receipt is a snapshot; check current worker readiness before running. No worker API secret is returned.

The workers connection includes discovery and authoring, so classification needs one MCP connection. Its full profile has 91 tools (84 manager tools and 7 public discovery reads); only decision_worker_create is new. For a smaller list, a client that supports custom headers can send X-WorkerKit-Profile: decision on every request, including initialization, listing and calls, to select 20 workflow tools. A server operator can instead set MCP_WORKERS_PROFILE=decision. The endpoint and existing sign-in stay the same; a profile grants no additional permissions. Reconnect and relist after changing profiles. Use the advertised tool list: fleet administration, publishing and event-stream tools require the full profile. Successful responses include structured content and a text fallback; creation declares an output schema.

Read the request example and full contract.

Least privilege

What each scope grants.

The key's scopes are exactly its reach, and a refusal names the scope it wanted. Start with the reads and add scopes as the work asks for them.

Operating rules

What the agent follows on every call.

The same rules the skill file carries, so a session that read neither still has them. Every row is a fact of the platform, not advice.

Quick answers

Symptoms, causes, fixes.

Each WorkerKit failure names itself in the response, so an agent never has to guess which one it met: read the code, apply the row, and carry on.