Agent Skills: Gmail Access

Access Gmail via CLI with 1Password OAuth. Use when user wants to read emails, search inbox, export messages, create drafts, or mentions gmail access. TRIGGERS - gmail, email, read email, list emails, search inbox, export emails, create draft, draft email, compose email.

UncategorizedID: terrylica/cc-skills/gmail-access

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pnpm dlx add-skill https://github.com/terrylica/cc-skills/tree/HEAD/plugins/gmail-commander/skills/gmail-access

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plugins/gmail-commander/skills/gmail-access/SKILL.md

Skill Metadata

Name
gmail-access
Description
Access Gmail via CLI with 1Password OAuth. Use when user wants to read emails, search inbox, export messages, create drafts, or.

Gmail Access

Read and search Gmail programmatically via Claude Code.

Self-Evolving Skill: This skill improves through use. If instructions are wrong, parameters drifted, or a workaround was needed — fix this file immediately, don't defer. Only update for real, reproducible issues.

MANDATORY PREFLIGHT (Execute Before Any Gmail Operation)

CRITICAL: You MUST complete this preflight checklist before running any Gmail commands. Do NOT skip steps.

Step 1: Check CLI Binary Exists

ls -la "$HOME/.claude/plugins/marketplaces/cc-skills/plugins/gmail-commander/scripts/gmail-cli/gmail" 2>/dev/null || echo "BINARY_NOT_FOUND"

If BINARY_NOT_FOUND: Build it first:

cd ~/.claude/plugins/marketplaces/cc-skills/plugins/gmail-commander/scripts/gmail-cli && bun install && bun run build

Step 2: Check GMAIL_OP_UUID Environment Variable

echo "GMAIL_OP_UUID: ${GMAIL_OP_UUID:-NOT_SET}"

If NOT_SET: You MUST run the Setup Flow below. Do NOT proceed to Gmail commands.

Step 2.5: Verify Account Context (CRITICAL)

ALWAYS verify you're accessing the correct email account for the current project.

# Show current project context
echo "=== Gmail Account Context ==="
echo "Working directory: $(pwd)"
echo "GMAIL_OP_UUID: ${GMAIL_OP_UUID}"

# Check where GMAIL_OP_UUID is defined (mise hierarchy)
echo ""
echo "=== mise Config Source ==="
grep -l "GMAIL_OP_UUID" .mise.local.toml .mise.toml ~/.config/mise/config.toml 2>/dev/null || echo "Not found in standard locations"

# Quick connectivity test — shows the account email from a real email
echo ""
echo "=== Account Verification ==="
$GMAIL_CLI list -n 1 2>&1 | head -5

STOP and confirm with user before proceeding:

  • The list -n 1 output shows the account's inbox — verify this matches the project's intended email
  • If the wrong account is shown, check which .mise.local.toml sets GMAIL_OP_UUID in the mise hierarchy
  • If mismatch, inform user and do NOT proceed

Multi-account disambiguation (when GMAIL_OP_UUID is NOT_SET but tokens exist). There is no whoami subcommand; map each cached token UUID to its mailbox by probing, then pick the one that fits the project:

# Which accounts are cached, and which mailbox does each resolve to?
for f in ~/.claude/tools/gmail-tokens/*.json; do
  case "$(basename "$f")" in *.app-credentials.json|'*.json') continue ;; esac
  uuid=$(basename "$f" .json)
  who=$(GMAIL_OP_UUID="$uuid" $GMAIL_CLI list -n 1 --json 2>/dev/null \
        | jq -r '.[0].to // "(probe failed / token expired)"')
  echo "$uuid → $who"
done

A probe that returns invalid_grant means that account's refresh token is dead (see "Diagnosing invalid_grant"). Pick the working UUID whose mailbox matches the project, pin it in .mise.local.toml, and confirm it's gitignored. A child project often needs a DIFFERENT account than its parent — verify, never assume the parent's UUID.

Step 3: Verify Token Health

# Check cached token exists and is not expired
TOKEN_FILE="$HOME/.claude/tools/gmail-tokens/${GMAIL_OP_UUID}.json"
APP_CREDS="$HOME/.claude/tools/gmail-tokens/${GMAIL_OP_UUID}.app-credentials.json"
echo "Token file: $([ -f "$TOKEN_FILE" ] && echo "EXISTS" || echo "MISSING")"
echo "App credentials: $([ -f "$APP_CREDS" ] && echo "CACHED" || echo "MISSING — will need 1Password on first run")"

If token file is MISSING: First run will open a browser for OAuth consent. This is expected. If app credentials are MISSING: 1Password will be called once to cache client_id/client_secret, then never again.


Setup Flow (When GMAIL_OP_UUID is NOT_SET)

Follow these steps IN ORDER. Use AskUserQuestion at decision points.

Setup Step 1: Check 1Password CLI

command -v op && echo "OP_CLI_INSTALLED" || echo "OP_CLI_MISSING"

If OP_CLI_MISSING: Stop and inform user:

1Password CLI is required. Install with: brew install 1password-cli

Setup Step 2: Discover Gmail OAuth Items in 1Password

# Try common vaults — "Claude Automation" for service accounts, "Employee" for interactive
for VAULT in "Claude Automation" "Employee" "Personal"; do
  ITEMS=$(op item list --vault "$VAULT" --format json 2>/dev/null | jq -r '.[] | select(.title | test("gmail|oauth|google"; "i")) | "\(.id)\t\(.title)"')
  [ -n "$ITEMS" ] && echo "=== Vault: $VAULT ===" && echo "$ITEMS"
done

Parse the output and proceed based on results:

Setup Step 3: User Selects OAuth Credentials

If items found, use AskUserQuestion with discovered items:

AskUserQuestion({
  questions: [{
    question: "Which 1Password item contains your Gmail OAuth credentials?",
    header: "Gmail OAuth",
    options: [
      // POPULATE FROM op item list RESULTS - example:
      { label: "Gmail API - dental-quizzes (56peh...)", description: "OAuth client in Employee vault" },
      { label: "Gmail API - personal (abc12...)", description: "Personal OAuth client" },
    ],
    multiSelect: false
  }]
})

If NO items found, use AskUserQuestion to guide setup:

AskUserQuestion({
  questions: [{
    question: "No Gmail OAuth credentials found in 1Password. How would you like to proceed?",
    header: "Setup",
    options: [
      { label: "Create new OAuth credentials (Recommended)", description: "I'll guide you through Google Cloud Console setup" },
      { label: "I have credentials elsewhere", description: "Help me add them to 1Password" },
      { label: "Skip for now", description: "I'll set this up later" }
    ],
    multiSelect: false
  }]
})
  • If "Create new OAuth credentials": Read and present references/gmail-api-setup.md
  • If "I have credentials elsewhere": Guide user to add to 1Password with required fields
  • If "Skip for now": Inform user the skill won't work until configured

Setup Step 4: Confirm mise Configuration

After user selects an item (with UUID), use AskUserQuestion:

AskUserQuestion({
  questions: [{
    question: "Add GMAIL_OP_UUID to .mise.local.toml in current project?",
    header: "Configure",
    options: [
      { label: "Yes, add to .mise.local.toml (Recommended)", description: "Creates/updates gitignored config file" },
      { label: "Show me the config only", description: "I'll add it manually" }
    ],
    multiSelect: false
  }]
})

If "Yes, add to .mise.local.toml":

  1. Check if .mise.local.toml exists
  2. If exists, append GMAIL_OP_UUID to [env] section
  3. If not exists, create with:
[env]
GMAIL_OP_UUID = "<selected-uuid>"
  1. Verify .mise.local.toml is in .gitignore

If "Show me the config only": Output the TOML for user to add manually.

Setup Step 5: Reload and Verify

mise trust 2>/dev/null || true
cd . && echo "GMAIL_OP_UUID after reload: ${GMAIL_OP_UUID:-NOT_SET}"

If still NOT_SET: Inform user to restart their shell or run source ~/.zshrc.

Setup Step 6: Test Connection

GMAIL_OP_UUID="${GMAIL_OP_UUID}" $HOME/.claude/plugins/marketplaces/cc-skills/plugins/gmail-commander/scripts/gmail-cli/gmail list -n 1

If OAuth prompt appears: This is expected on first run. Browser will open for Google consent.


Gmail Commands (Only After Preflight Passes)

GMAIL_CLI="$HOME/.claude/plugins/marketplaces/cc-skills/plugins/gmail-commander/scripts/gmail-cli/gmail"

# List recent emails
$GMAIL_CLI list -n 10

# Search emails
$GMAIL_CLI search "from:someone@example.com" -n 20

# Search with date range
$GMAIL_CLI search "from:phoebe after:2026/01/27" -n 10

# Read specific email with full body
$GMAIL_CLI read <message_id>

# Read and download inline images (copy-pasted screenshots in compose)
$GMAIL_CLI read <message_id> --save-images

# Download inline images to a specific directory
$GMAIL_CLI read <message_id> --save-images --image-dir ./attachments/my-folder/

# Shorthand: --image-dir implies --save-images
$GMAIL_CLI read <message_id> --image-dir ./attachments/my-folder/

# JSON output with image metadata and saved paths
$GMAIL_CLI read <message_id> --save-images --json

# Download REAL file attachments (PDF, docx, csv, …) — distinct from inline images
$GMAIL_CLI read <message_id> --save-attachments

# Download attachments to a specific directory (implies --save-attachments)
$GMAIL_CLI read <message_id> --attachment-dir ./files/case-17402939/

# Export search results to JSON (full body + inlineImages + attachments metadata per message)
$GMAIL_CLI export -q "label:inbox" -o emails.json -n 100

# JSON output (for parsing)
$GMAIL_CLI list -n 10 --json

# Create a draft email
$GMAIL_CLI draft --to "user@example.com" --subject "Hello" --body "Message body"

# Create a draft reply (threads into existing conversation)
$GMAIL_CLI draft --to "user@example.com" --subject "Re: Hello" --body "Reply text" --reply-to <message_id>

# Draft with body loaded from a file (multi-paragraph bodies are awkward via --body)
$GMAIL_CLI draft --to "user@example.com" --subject "Report" --body-file ./email-body.txt

# Draft with file attachments (--attach is repeatable; MIME type guessed from extension)
$GMAIL_CLI draft --to "user@example.com" --subject "Q1 Report" \
  --body-file ./email-body.txt \
  --attach ./report.pdf \
  --attach ./screenshot.png

# Draft reply with both body-file and multiple attachments
$GMAIL_CLI draft --to "user@example.com" --subject "Re: Project" \
  --reply-to <message_id> \
  --body-file ./reply.txt \
  --attach ./diagram.pdf

Inline Image Extraction

Emails often contain copy-pasted screenshots (inline images embedded in the HTML body, not file attachments). These appear as [image: image.png] placeholders in plain text but contain real image data accessible via the Gmail API.

Key Behavior

| Flag | Effect | | -------------------- | ------------------------------------------------------------------------------------------ | | --save-images | Download all inline images to disk (default: ~/.claude/tools/gmail-images/<message_id>/) | | --image-dir <path> | Custom output directory (implies --save-images) | | No flag | Shows image metadata (count, filenames, sizes) but does NOT download |

Output Sections (when images are present)

--- Inline Images (3) ---
  image.png   image/png   245.3 KB
  image.png   image/png   512.1 KB
  photo.jpg   image/jpeg  89.7 KB

--- Saved to Disk ---
  ./attachments/01_image.png  (251,234 B)
  ./attachments/02_image.png  (524,001 B)
  ./attachments/03_photo.jpg  (91,852 B)

--- Markdown References ---
![01_image.png](./attachments/01_image.png)
![02_image.png](./attachments/02_image.png)
![03_photo.jpg](./attachments/03_photo.jpg)

Important: Inline Images vs File Attachments

These are two disjoint channels, surfaced and downloaded separately:

| Channel | MIME parts | Metadata field | Download flag | | -------------------- | ---------------------------------------------------------------------- | ---------------- | ----------------------------------------- | | Inline images | image/* with attachmentId (copy-pasted screenshots) | inlineImages[] | --save-images / --image-dir | | File attachments | non-image parts with a filename + attachmentId (PDF, docx, csv, …) | attachments[] | --save-attachments / --attachment-dir |

A plain gmail read <id> (no flags) shows both as metadata blocks (filename, MIME, size) without downloading — so you can see a PDF exists before pulling it. export and read --json both carry attachments[] (and inlineImages[]) in their JSON.

has:attachment matches real file attachments but NOT inline images. Gmail search has no operator for inline images. To discover emails with inline images, you must read the email and check the MIME tree.

Strategy for finding emails with inline images:

# Search by sender/date, then read each to check for images
$GMAIL_CLI search "from:sender@example.com after:2026/02/01" -n 10 --json | \
  jq -r '.[].id' | while read id; do
    COUNT=$($GMAIL_CLI read "$id" --json | jq '.inlineImages | length')
    [ "$COUNT" -gt 0 ] && echo "$id has $COUNT inline image(s)"
  done

Gmail Threading and Image Deduplication

When downloading images from a thread (multiple reply emails), later replies include all prior inline images. The last email in a thread is typically the superset.

Recommendation: For threaded conversations, download images from the latest reply only to avoid duplicates. Compare by file size if unsure.

Filename Collision Handling

Copy-pasted screenshots often all share the generic filename image.png. The CLI prefixes a zero-padded index: 01_image.png, 02_image.png, etc. These machine-generated names should be renamed to descriptive names for correspondence archival.

Post-Download: Annotation Transcription Protocol

When inline images contain handwritten annotations (circles, arrows, written text overlaid on screenshots), perform a systematic two-level analysis:

  1. Scene description: What does the screenshot show? (e.g., "Career portal main page showing position listings")
  2. Annotation inventory: Exhaustively catalog every non-original markup element:
    • Hand-drawn shapes: circles, ovals, arrows, underlines, crosses — note what they encompass
    • Handwritten text: transcribe verbatim in quotes, note legibility and location on the image
    • Typed test inputs: text entered into form fields visible in the screenshot
    • Highlights or color markings: note color and what is highlighted

Format annotations as blockquote captions beneath each image in markdown:

![Scene description — annotation summary](path/to/image.png)

> **Annotation transcription**: [Detailed description of visual markup.]
> Handwritten text reads: _"exact transcription here"_
> [Interpretation of what the annotator is requesting.]

Do NOT defer annotation transcription to a second pass. Capture all annotations on the first image examination to avoid redundant re-reads.

File Attachment Extraction

Real file attachments (PDF, docx, csv, …) are surfaced in attachments[] and downloaded with --save-attachments / --attachment-dir. Same fetch path as inline images, different metadata field.

# See what a message carries (no download) — both metadata blocks print
$GMAIL_CLI read <id>          # → "--- Attachments (1) ---  foo.pdf  application/pdf  192.5 KB"

# Download to a chosen dir; files are index-prefixed + sanitized
$GMAIL_CLI read <id> --attachment-dir ./files/

# Discover which messages in a corpus actually carry attachments
$GMAIL_CLI search "from:sender@example.com has:attachment" -n 20 --json | \
  jq -r '.[].id' | while IFS= read -r id; do
    N=$($GMAIL_CLI read "$id" --json | jq '.attachments | length')
    [ "$N" -gt 0 ] && echo "$id → $N attachment(s)"
  done

Why this matters for archival: in clinical/legal/operational mail the attached PDF (a protocol, a vendor form, a signed consent) is often the most important payload. A body-only export silently loses it. Always check attachments[] when archiving a correspondence thread.

Bulk Retrieval & Thread Archival

The canonical pattern for archiving a whole correspondence (verified on a 27-message, 15-thread clinical corpus):

  1. Scope with high-signal queries, not generic keywords. A bare keyword ("Curve") returns mostly newsletter noise. Prefer:
    • domain: curvedental.com (matches from/to/cc on the org)
    • participant: from:dr.phoebe.tsang@gmail.com OR to:…
    • project code: any internal tag the sender uses (e.g. 1233V)
  2. Collect message IDs from search --json (snippet-only) and curate the in-scope set out of the noise.
  3. Fetch full bodies with a read --json loop (one file per message).
  4. Group by threadId client-side — Gmail's list/search APIs return individual messages, not threads; you reconstruct threads yourself.
  5. Sort within a thread by parsed Date and strip quoted history (drop >-prefixed lines and everything after On … wrote:) to expose each message's new content.
  6. Pull attachments for any message whose attachments[] is non-empty.
# Robust batch fetch. NOTE: in zsh `for id in $VAR` does NOT word-split —
# always loop with `while IFS= read -r` over newline-delimited IDs.
printf '%s\n' $IDS | while IFS= read -r id; do
  [ -n "$id" ] && $GMAIL_CLI read "$id" --json > "raw/$id.json"
done

export is the one-call shortcut (fixed)

gmail export -q "<query>" -o out.json -n N writes one JSON array with full body + inlineImages[] + attachments[] per message — the batch-fetch shortcut when a single query captures your set. (Historical note: before the fix, export printed "Exported N emails to <path>" but wrote no fileoutputPath was an unused parameter. If you see that symptom, the binary is stale; rebuild it.) export does not download attachment bytes — it only carries the metadata; use read --save-attachments per message for the files.

Creating Draft Emails

The draft command creates emails in your Gmail Drafts folder for review before sending.

Required options:

  • --to - Recipient email address
  • --subject - Email subject line
  • --body OR --body-file - Email body text (one of the two)

Optional:

  • --body-file - Read body from a file instead of --body. Useful for multi-paragraph bodies that are awkward to pass on the shell. Mutually exclusive with --body; if both are passed, --body wins with a stderr warning.
  • --attach - File path to attach. Repeatable for multiple attachments. MIME type is guessed from extension (PDF, PNG, JPEG, DOCX, XLSX, ZIP, MD, JSON, etc. → mapped; unknown → application/octet-stream). Total message size ≤ 25 MB (Gmail limit; the CLI surfaces a 413 with a helpful hint if you exceed it).
  • --from - Sender email alias (auto-detected when replying, see Sender Alignment below)
  • --reply-to - Message ID to reply to (creates threaded reply with proper headers)
  • --json - Output draft details as JSON

MANDATORY Sender Alignment (NON-NEGOTIABLE)

The user has multiple Send As aliases configured in Gmail. The From address MUST match correctly or the recipient sees a reply from the wrong identity.

Rule 1 - Replies (--reply-to is set): The CLI auto-detects the correct sender by reading the original email's To/Cc/Delivered-To headers and matching against the user's Send As aliases. No manual intervention needed. The CLI will print:

From: amonic@gmail.com (auto-detected from original email)

If auto-detection fails (e.g., the email was BCC'd), explicitly pass --from.

Rule 2 - New emails (no --reply-to): When drafting a brand new email (not a reply), you MUST use AskUserQuestion to confirm which sender alias to use BEFORE creating the draft. Never assume the default.

AskUserQuestion({
  questions: [{
    question: "Which email address should this be sent from?",
    header: "Send As",
    options: [
      // Populate from known aliases or let user specify
      { label: "amonic@gmail.com", description: "Personal Gmail" },
      { label: "terry@eonlabs.com", description: "Work email" },
    ],
    multiSelect: false
  }]
})

Then pass the selected address via --from:

$GMAIL_CLI draft --to "recipient@example.com" --from "amonic@gmail.com" --subject "Hello" --body "Message"

Rule 3 - Always verify in output: After draft creation, confirm the From address is shown in the output. If it's missing or wrong, delete the draft and recreate.

MANDATORY Post-Draft Step (NON-NEGOTIABLE)

After EVERY draft creation, you MUST present the user with a direct Gmail link to review the draft. This is critical because drafts should always be visually confirmed before sending.

Always output this after creating a draft:

Draft created! Review it here:
  https://mail.google.com/mail/u/0/#drafts
From: <sender_address>

Never skip this step. The user must be able to click through to Gmail and visually verify the draft content, sender, recipients, and threading before sending.

Example: Reply to an email (auto-detected sender)

# 1. Find the message to reply to
$GMAIL_CLI search "from:someone@example.com subject:meeting" -n 5 --json

# 2. Create draft reply - From is auto-detected from original email's To header
$GMAIL_CLI draft \
  --to "someone@example.com" \
  --subject "Re: Meeting tomorrow" \
  --body "Thanks for the update. I'll be there at 2pm." \
  --reply-to "19c1e6a97124aed8"

# 3. ALWAYS present the review link + From address to user

Example: New email (must ask user for sender)

# 1. Ask user which alias to send from (AskUserQuestion)
# 2. Create draft with explicit --from
$GMAIL_CLI draft \
  --to "someone@example.com" \
  --from "amonic@gmail.com" \
  --subject "Hello" \
  --body "Message body"

# 3. ALWAYS present the review link + From address to user

Note: After creating drafts, users need to re-authenticate if they previously only had read access. The CLI will prompt for OAuth consent to add the gmail.compose scope.

Gmail Search Syntax

| Query | Description | | -------------------------- | ------------------------------------------------------------------------------------ | | from:sender@example.com | From specific sender | | to:recipient@example.com | To specific recipient | | subject:keyword | Subject contains keyword | | after:2026/01/01 | After date | | before:2026/02/01 | Before date | | label:inbox | Has label | | is:unread | Unread emails | | has:attachment | Has file attachment (does NOT match inline images — see Inline Image Extraction) |

Reference: https://support.google.com/mail/answer/7190

Environment Variables

| Variable | Required | Description | | ---------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | GMAIL_OP_UUID | Yes | 1Password item UUID for OAuth credentials | | GMAIL_OP_VAULT | No | 1Password vault (default: Employee) | | HTTPS_PROXY | No | Honored by the underlying gaxios library, BUT the CLI auto-injects *.googleapis.com into NO_PROXY at startup so corporate proxies don't break Gmail traffic. See "Proxy Auto-Bypass" below. |

Proxy Auto-Bypass for Google API Hosts

If HTTPS_PROXY (or HTTP_PROXY) is set in the environment, the CLI automatically injects the following hosts into NO_PROXY at module load — before any auth or API call is made:

  • .googleapis.com (covers gmail.googleapis.com, oauth2.googleapis.com, etc.)
  • .google.com
  • accounts.google.com
  • oauth2.googleapis.com

Why this exists: many corporate networks (Cloudflare WARP, mitmproxy local interceptors, ITP-style local proxies) can't tunnel CONNECT to Google API hosts. When the proxy fails, the response surface returns HTTP 502 with an empty error body — the googleapis library throws a gaxios error whose .message is empty, which used to render as a useless empty Error: in stderr.

By force-bypassing the proxy for Google hosts, end-users with a corporate proxy can run the CLI without manually setting NO_PROXY or unsetting HTTPS_PROXY per-command.

Idempotent: the injection only adds entries that aren't already present in NO_PROXY. If you've manually configured NO_PROXY=.googleapis.com, the CLI leaves it alone.

Diagnosing remaining proxy issues (rare): if you still see HTTP 5xx errors, the CLI's new error formatter prints the full URL + response body + a hint. Check that HTTPS_PROXY was set BEFORE the CLI started (env-var detection is one-shot at module load).

Error Messages

The CLI's top-level error handler renders unknown errors as structured messages with HTTP status, request URL, response body snippet, and a category-specific hint. Example for a 404 on a bogus draft ID:

Error: HTTP 404 Not Found DELETE https://gmail.googleapis.com/gmail/v1/users/me/drafts/r-doesnotexist123
  body: {"error":{"code":404,"message":"Requested entity was not found.",...}}
  hint: message / draft ID not found. List existing drafts with `gmail drafts` first.

Hint categories:

| Status | Hint | | ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- | | 401 | Token expired/revoked. Delete ~/.claude/tools/gmail-tokens/$GMAIL_OP_UUID.json to force re-auth. | | 403 | OAuth scope insufficient (drafts/attachments need gmail.compose) or Send As alias not configured. | | 404 | Message / draft ID not found. List existing drafts with gmail drafts first. | | 413 | Attachment(s) exceed Gmail's 25 MB per-message limit. Split or use Drive links. | | 502/503/504 | Gateway error — usually a proxy that can't tunnel to Google. The auto-bypass should prevent this; check that HTTPS_PROXY was set BEFORE the CLI started. |

Network-layer errors (ECONNREFUSED, ENOTFOUND, etc.) are surfaced with their error code instead of the empty Error: of the prior implementation.

Token Architecture

Storage Layout

~/.claude/tools/gmail-tokens/
├── <uuid>.json                    # OAuth token (access + refresh), refreshed hourly
└── <uuid>.app-credentials.json    # client_id + client_secret (static, cached from 1Password)
  • Central location (not in plugin, not in project)
  • Organized by 1Password UUID (supports multi-account)
  • Created with chmod 600

Auth Flow (1Password is one-time only)

  1. First run: 1Password is called to fetch client_id/client_secret → cached to <uuid>.app-credentials.json
  2. First run: Browser opens for Google OAuth consent → tokens saved to <uuid>.json
  3. All subsequent runs: Reads cached files only — no 1Password call, no browser
  4. Hourly refresher (launchd): Keeps access_token alive by calling Google's token endpoint with the cached refresh_token

To force a fresh 1Password lookup (e.g., after rotating OAuth app credentials):

rm ~/.claude/tools/gmail-tokens/<uuid>.app-credentials.json

Diagnosing invalid_grant

A refresh token in a Google OAuth app whose publishing status is "Testing" expires after 7 days — period. The hourly refresher renews the access token but does NOT extend the refresh token's 7-day clock, so a Testing-mode account dies roughly weekly and can only be revived by a browser re-consent. (An app in "In production" status issues long-lived refresh tokens that don't expire on that clock.)

Recovery (re-consent): Delete the expired token file and re-authorize via browser:

# 1. Back up and remove the expired token
mv ~/.claude/tools/gmail-tokens/<uuid>.json ~/.claude/tools/gmail-tokens/<uuid>.json.expired

# 2. Run any gmail command — browser will open for OAuth consent
#    (sign in with the SPECIFIC account that <uuid> maps to — see accounts.json labels)
$GMAIL_CLI list -n 1

# 3. Verify the hourly refresher picks up the new token
~/.claude/automation/gmail-token-refresher/gmail-oauth-token-refresher 2>&1

# 4. Clean up backup
rm ~/.claude/tools/gmail-tokens/<uuid>.json.expired

Durable fix (stop the weekly death — "keep everything re-auth"): publish the OAuth app to Production so refresh tokens stop expiring on the 7-day clock.

  1. If an account survives indefinitely while another dies weekly, they use different OAuth apps (check accounts.json vault per uuid). Only the dying one is stuck in Testing.
  2. Google Cloud Console → the project owning that OAuth client (the client_id prefix is the project number; the CLI prints the full client_id in the consent URL during re-auth).
  3. APIs & Services → OAuth consent screen → Publishing status → Publish app → confirm "In production". (External + Production with Gmail scopes may warn "unverified" for new users, but already-consented accounts get long-lived refresh tokens; full Google verification is only needed for public/>100-user apps.)
  4. Re-consent once more after publishing; the hourly refresher then keeps the access token fresh indefinitely with no weekly re-auth.

Multi-Account Token Status

# Check all accounts at once
for f in ~/.claude/tools/gmail-tokens/*.json; do
  [ "$(basename "$f")" = "*.json" ] && continue
  case "$(basename "$f")" in *.app-credentials.json) continue ;; esac
  UUID=$(basename "$f" .json)
  python3 -c "
import json, datetime
t = json.load(open('$f'))
exp = datetime.datetime.fromtimestamp(t.get('expiry_date',0)/1000)
delta = (exp - datetime.datetime.now()).total_seconds()
status = 'VALID' if delta > 0 else 'EXPIRED'
print(f'  {\"$UUID\"}: {status} (expires in {int(delta/60)}m)' if delta > 0 else f'  {\"$UUID\"}: EXPIRED ({int(-delta/3600)}h ago)')
" 2>/dev/null
done

References

Post-Change Checklist

  • [ ] YAML frontmatter valid (no colons in description)
  • [ ] Trigger keywords current
  • [ ] Path patterns use $HOME not hardcoded paths
  • [ ] References exist and are linked

Evolution Log

  • 2026-05-31 — export silent failure + no attachment retrieval (clinical archival task).
    • Trigger: archiving a 27-message Curve-Dental correspondence. gmail export -o <path> printed "Exported N emails to <path>" but wrote nothing (exportEmails returned the array, never wrote outputPath). Separately, the CLI surfaced no file attachments (only inlineImages), so 11 messages' attached PDFs (a vendor certification form, protocols) were silently dropped.
    • Fix: (1) exportEmails now writeFiles the JSON. (2) Added extractAttachments + attachments[] metadata in formatMessage, saveAttachments() in gmail-images.ts, --save-attachments/--attachment-dir flags, and an Attachments metadata block in printEmails. Documented the inline-image-vs-attachment split, the bulk thread-archival pipeline, the multi-account UUID→mailbox probe, and the zsh while read batch-loop gotcha.
    • Evidence: export -q curvedental.com -o /tmp/x.json now writes 3 emails with full bodies; read <id> --attachment-dir pulled CDAnet Software Vendor Certification Application form.pdf (197,168 B, valid PDF 1.7, 3 pages). Rebuilt binary, tsc --noEmit clean.

Post-Execution Reflection

After this skill completes, reflect before closing the task:

  1. Locate yourself. — Find this SKILL.md's canonical path before editing.
  2. What failed? — Fix the instruction that caused it.
  3. What worked better than expected? — Promote to recommended practice.
  4. What drifted? — Fix any script, reference, or dependency that no longer matches reality.
  5. Log it. — Evolution-log entry with trigger, fix, and evidence.

Do NOT defer. The next invocation inherits whatever you leave behind.