dsh-gmail · Gmail Plugin for DeepSeek Harness

A complete, production-ready Gmail plugin for DeepSeek Harness (DSH). It gives the agent typed, policy-aware access to Gmail over the official Gmail and People REST APIs — 63 model-facing tools (send, search, draft, label, filter, thread, settings, contacts) and 2 polling triggers — with automatic OAuth2 token management.

Official ecosystem keyword: this is a dsh-plugin — add the dsh-plugin GitHub topic to this repository.

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🤖 LLM-readable summary

• What: a single Cordis plugin that extends DSH agents with 63 gmail_* tools + 2 polling triggers.
• Install: dsh plugin --profile web add github:sakthiveltofficial/dsh-gmail-plugins, then add one row to your profile patch (or agent preset) — see Install.
• Tools: gmail_send_email, gmail_fetch_emails, gmail_fetch_message_by_message_id, gmail_fetch_message_by_thread_id, gmail_list_threads, gmail_reply_to_thread, gmail_create_email_draft, gmail_send_draft, gmail_forward_message, label/filter/trash/settings/contacts tools — the full list is in the tool table.
• Auth: OAuth2 (gmail.modify, gmail.settings.basic, gmail.compose, gmail.send, contacts.readonly scopes). Credentials are never stored in config — env-var references resolved per operation via ctx.credentials. gmail_authorize runs the interactive Google sign-in and captures + stores the refresh token automatically; only GMAIL_CLIENT_ID / GMAIL_CLIENT_SECRET need to be set.
• Triggers: gmail/message-received (new mail) and gmail/message-sent (sent mail) — poll-based, seeded on first activation so the mailbox is never replayed.
• Runtime requirements: DeepSeek Harness, Node.js ≥ 20 (global fetch), and a Google Cloud OAuth client with the Gmail (and People) API enabled.
• Safety: permanent deletes (gmail_delete_message, gmail_batch_delete_messages, gmail_delete_thread, gmail_delete_label) are clearly labeled and require explicit user confirmation; the agent is prompted to prefer trash over permanent deletion unless the user asked for irreversible removal.
• License: MIT.

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✨ What it does

• Read & search — fetch emails with Gmail query syntax, fetch a message by ID or a full thread, list threads, list/get drafts, download attachments, get profile/history.
• Compose & send — send email (with attachments from local paths, URLs, or inline base64), create/update/send drafts, forward messages, reply inside a thread (correct In-Reply-To/References threading).
• Organize — add/remove labels (single message, batch of 1,000, or whole thread), create/patch/update/delete labels, create/list/get/delete filters.
• Administer — IMAP/POP settings, auto-forwarding, vacation responder, display language, send-as aliases, S/MIME configs, CSE identities/key pairs, stop watch notifications.
• Contacts — get contacts (connections), get a person or Other Contacts, search people via the People API.
• One-click auth — gmail_authorize opens the Google consent page in your browser and captures + stores the refresh token automatically; no manual token generation.
• Triggers — poll for new received/sent mail and emit typed Cordis events for downstream listeners.
• Resilience — automatic access-token refresh with in-memory caching, 401-invalidate-and-retry, bounded exponential backoff on 429/5xx, structured GmailErrors with HTTP status preserved.

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🚀 Install

Prerequisites

# DeepSeek Harness running (a profile, e.g. the default web profile)
# Node.js >= 20 (the host's Node — plugins run in-process)
# A Google Cloud OAuth client (see "Configure credentials" below)

1. Install the package from this GitHub repository

dsh plugin --profile web add github:sakthiveltofficial/dsh-gmail-plugins

This installs the @google-workspace/dsh-gmail plugin package into the profile (the repo root is the package — no build step needed).

2. Mount the plugin in a composition

The plugin publishes no services — it only registers tools into the host tools registry (plus the optional timer service for triggers) — so it mounts as a plain loose row, with no isolate realm required.

Option A — profile patch (host plane, tools visible to every agent). Append to your profile's cordis.patch.yml:

- insert:
    - id: gmail
      name: '@google-workspace/dsh-gmail'
      config:
        clientIdRef: GMAIL_CLIENT_ID
        clientSecretRef: GMAIL_CLIENT_SECRET
        refreshTokenRef: GMAIL_REFRESH_TOKEN
        defaultUserId: me
        timeoutMs: 30000
        enableReceivedTrigger: false
        enableSentTrigger: false

Option B — agent preset (tools only for agents on that preset). Add the row to the preset's agent.cordis.yml:

- id: gmail
  name: '@google-workspace/dsh-gmail'
  config:
    clientIdRef: GMAIL_CLIENT_ID
    clientSecretRef: GMAIL_CLIENT_SECRET
    refreshTokenRef: GMAIL_REFRESH_TOKEN

Restart the profile (or the DSH process).

Verify

dsh --profile web --dump-config | grep -i gmail

Then ask the agent: "what gmail tools do you have?" — it should list the gmail_* tools (63 in total).

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🔑 Configure credentials (OAuth2)

Gmail requires OAuth2 — there is no API-key path. Config carries only env-var references, never literal tokens; values are resolved per operation through DSH's credential service (process env → provider store → .env).

Env var	Used for
GMAIL_CLIENT_ID	OAuth client ID (e.g. ....apps.googleusercontent.com) — required
GMAIL_CLIENT_SECRET	OAuth client secret (e.g. GOCSPX-...) — required
GMAIL_REFRESH_TOKEN	long-lived refresh token — optional; when unset, run gmail_authorize and it is captured + stored automatically

Google Cloud setup (5 steps, ~5 minutes)

Copy-paste this redirect URL — the plugin's OAuth callback listens on it:

http://127.0.0.1:8765/oauth2callback

(configurable via the plugin's redirectPort setting; keep the two in lockstep)

1. Create a project at (or pick one).
2. Enable the APIs: APIs & Services → Library → enable Gmail API and People API (People is only needed for the contacts tools).
3. Configure the OAuth consent screen: APIs & Services → OAuth consent screen → User type External (or Internal for Workspace) → App name (e.g. dsh-gmail) + your support email → Save. Keep it in Testing (add your Google account as a test user) or Publish it; both work for your own account.
4. Create the OAuth client: APIs & Services → Credentials → Create Credentials → OAuth client ID → Web application → under Authorized redirect URIs add exactly:

   http://127.0.0.1:8765/oauth2callback
   

   → Create → copy the Client ID and Client secret.
5. Export them (or configure ctx.credentials sources for the same names):

   export GMAIL_CLIENT_ID='....apps.googleusercontent.com'
   export GMAIL_CLIENT_SECRET='GOCSPX-...'
   

The refresh token does not need to be exported — see the two options below.

Option A (recommended) — interactive sign-in from the harness

With GMAIL_CLIENT_ID and GMAIL_CLIENT_SECRET set, ask the agent to run gmail_authorize (or run it yourself): the plugin opens the Google consent page in your default browser, you sign in, and the refresh token is captured and stored automatically through the harness credential service — no manual token generation. One-time per account. gmail_auth_status reports whether a credential is stored and the state of any in-flight sign-in.

The plugin requests these scopes at consent time:

Scope	Needed by
https://www.googleapis.com/auth/gmail.modify	read/write mail, labels, trash (most tools)
https://www.googleapis.com/auth/gmail.settings.basic	settings tools (IMAP/POP/forwarding/vacation/language/send-as)
https://www.googleapis.com/auth/gmail.compose	drafts
https://www.googleapis.com/auth/gmail.send	send/reply/forward
https://www.googleapis.com/auth/contacts.readonly	contacts tools

Option B — manual refresh token

Google OAuth Playground with your client id/secret: pick the scopes above, authorize, and copy the refresh token, then export it:

export GMAIL_REFRESH_TOKEN='1//0...'

Access tokens are minted from the refresh token on demand and cached for their lifetime; 401s invalidate the cache and retry once with a fresh exchange. Do not add gmail.metadata alongside content scopes (gmail.readonly/gmail.modify/mail.google.com) in the same consent request — Google treats it as a restricted scope and rejects the combination.

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🧰 Tools

All tool names are snake_case gmail_* (e.g. gmail_send_email, gmail_fetch_emails), with the full parameter surface and the important warnings preserved: hexadecimal message IDs, label IDs vs display names, irreversible deletes.

Area	Tools
Auth	gmail_authorize (interactive Google sign-in — captures + stores the refresh token), gmail_auth_status
Read	gmail_fetch_emails, gmail_fetch_message_by_message_id, gmail_fetch_message_by_thread_id, gmail_list_threads, gmail_list_messages (deprecated), gmail_get_draft, gmail_list_drafts, gmail_get_attachment
Compose	gmail_send_email, gmail_create_email_draft, gmail_update_draft, gmail_send_draft, gmail_forward_message, gmail_reply_to_thread
Organize	gmail_add_label_to_email, gmail_batch_modify_messages, gmail_modify_thread_labels, gmail_list_labels, gmail_get_label, gmail_create_label, gmail_patch_label, gmail_update_label, gmail_delete_label, gmail_remove_label (deprecated), gmail_create_filter, gmail_list_filters, gmail_get_filter, gmail_delete_filter
Delete/trash	gmail_move_to_trash, gmail_untrash_message, gmail_delete_message, gmail_batch_delete_messages, gmail_move_thread_to_trash, gmail_untrash_thread, gmail_delete_thread, gmail_delete_draft
Ingest	gmail_import_message, gmail_insert_message
Admin	gmail_get_profile, gmail_list_history, gmail_get_imap_settings, gmail_update_imap_settings, gmail_get_pop_settings, gmail_update_pop_settings, gmail_get_auto_forwarding, gmail_list_forwarding_addresses, gmail_get_vacation_settings, gmail_update_vacation_settings, gmail_get_language_settings, gmail_update_language_settings, gmail_list_send_as, gmail_get_send_as, gmail_patch_send_as, gmail_update_send_as, gmail_list_smime_info, gmail_list_cse_identities, gmail_list_cse_keypairs, gmail_stop_watch
Contacts	gmail_get_contacts, gmail_get_people, gmail_search_people

Two tools are intentionally omitted: GMAIL_CREATE_PROMPT_POST and GMAIL_UPDATE_USER_ATTRIBUTES_VALUES, which target the Sanity Content Agent rather than Gmail.

Key conventions (the agent is told these in its prompt section)

• Message IDs are hexadecimal Gmail API IDs (e.g. 19b11732c1b578fd) — never UUIDs, thread IDs, subjects, or dates. Obtain them from gmail_fetch_emails / gmail_list_threads.
• Label parameters take label IDs, never display names: system labels use their uppercase name (INBOX, UNREAD, STARRED, SPAM, TRASH, CATEGORY_UPDATES, ...); custom labels use their internal ID (Label_123, from gmail_list_labels).
• Draft IDs (r99885592323229922) differ from message IDs; gmail_send_draft sends a draft exactly as-is and cannot add recipients.
• Attachments accept a local file path, a public URL, or { name, mimetype, base64 }; total message size must stay under ~25 MB after base64 encoding.
• Irreversible operations (gmail_delete_message, gmail_batch_delete_messages, gmail_delete_thread, gmail_delete_label, gmail_delete_draft) bypass Trash — prefer the trash tools unless the user explicitly asked for permanent removal.

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🔔 Triggers

Enable in config:

config:
  enableReceivedTrigger: true   # poll in:inbox → emit gmail/message-received
  enableSentTrigger: true       # poll in:sent   → emit gmail/message-sent
  triggerIntervalMinutes: 5

While the plugin is mounted, each poll emits a Cordis event on the plugin's scope with the trigger payload shapes (sender, subject, message_id, thread_id, message_text, message_timestamp, attachment_list, ...). The first poll only seeds the seen-set, so activation never replays the mailbox. Triggers run only while the session is live (agent-plane polling), like the harness schedule service.

ctx.on('gmail/message-received', (payload) => { /* ... */ })
ctx.on('gmail/message-sent', (payload) => { /* ... */ })

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🧯 Troubleshooting

Symptom	Cause / fix
GMAIL_AUTH_FAILED (401) on tool calls	Access/refresh token invalid: user revoked access, changed password/2FA, a Workspace admin policy changed, or Google's ~50-refresh-token-per-account limit was hit. Re-authenticate with gmail_authorize (or refresh GMAIL_REFRESH_TOKEN manually).
"App is blocked" / unverified-app screen at consent	The OAuth client is requesting scopes Google hasn't verified. Remove extra scopes, or create your own OAuth app and submit scopes for verification.
"Gmail API has not been used in project"	The Gmail API is not enabled in the Cloud project owning the credentials. Enable it under APIs & Services, wait a few minutes, retry.
Error 400: invalid_scope	Scope values are incorrect/misformatted in the authorization URL. Verify against the Google OAuth scopes docs.
Consent screen shows the wrong app name	Default consent uses the shared app. Create your own OAuth app and set a custom redirect URL (white-labeling).
GMAIL_RATE_LIMITED (429/403)	Google enforces per-minute/daily quotas; a shared OAuth app shares its quota. Use your own client for a dedicated quota and apply exponential backoff (the client already retries 429/5xx up to 4 times).
GMAIL_API_ERROR (400) "Invalid id value"	A non-hexadecimal ID (UUID, thread ID, subject, fabricated value) was passed as message_id. Use IDs from gmail_fetch_emails/gmail_list_threads.
Labels silently not applied	A display name was passed instead of a label ID. Run gmail_list_labels and use the returned Label_N IDs.
Trigger feels slow	Triggers poll on triggerIntervalMinutes (default 5); reduce the interval, or use Google Pub/Sub webhooks for sub-minute latency.

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🔒 Security

• Secrets are never stored in config — only env-var references (GMAIL_CLIENT_ID / GMAIL_CLIENT_SECRET / GMAIL_REFRESH_TOKEN), resolved per operation through ctx.credentials (process env → provider store → .env). Literal config values are supported for quick setups but are not recommended for production.
• Access tokens are cached in memory only, never persisted, and are refreshed from the refresh token on demand.
• Destructive tools are clearly labeled in their descriptions (permanent, no recovery possible) and the agent is instructed to confirm with the user before permanent deletes and to prefer trash for reversible workflows.
• Forward/reply recipients are explicit — forwarding preserves content, so the agent is instructed to verify recipients before forwarding to avoid unintended exposure.
• Minimum privilege: grant only the scopes your workflows need (drop gmail.settings.basic or contacts.readonly if u