T3 Code

Claude threads in T3 Code reach the Inbox through MCP. Your reply arrives in the thread as a new turn.

Hooks and MCP · Plannotator’s hooks and commands plus the Inbox through MCP

Set it up

Install Plannotator with the T3 hook. macOS and Linux.

curl -fsSL https://plannotator.ai/install.sh | bash -s -- --with-t3
In T3 open Settings → Environments. Open the environment’s menu and choose Copy MCP URL.
Sign Plannotator in to T3 with that URL. On T3’s sign-in page choose Supervised or higher.

plannotator t3 login --url <T3 MCP URL>

You should see The terminal prints Authorize Plannotator in T3: and T3’s sign-in page opens.
Connect the Inbox for Claude. Skip this if claude mcp get plannotator-inbox already finds one.

claude mcp add -s user plannotator-inbox -- plannotator inbox mcp --t3

You should see Inside a T3 thread Claude has the Inbox tools. Outside T3 that server shows none.
Start a new Claude thread in T3 so it loads the hook and the server.

Other ways

Without the review hook

Skip --with-t3 and run the sign-in and connect steps. Replies still wake Claude threads.

curl -fsSL https://plannotator.ai/install.sh | bash

All the details

The T3 help lists every step and option.

plannotator t3 --help

Check it works

Paste this into the T3 thread.

Send me a test question in the Plannotator Inbox, and read my answer when I tell you I sent it.

You should see A question arrives in the Inbox. Answer it and press Send. The thread reads Delivered to T3 Code and the T3 thread goes on with your answer.

Troubleshooting

The log says No T3 grant reaches thread: The sign-in expired or was revoked. It lasts 30 days. Sign in again.

plannotator t3 login --url <T3 MCP URL>
T3 answers capability_denied: Sign in again and choose Supervised or higher. Read only can’t send replies.
plannotator t3 login says --url is required: Copy the URL from T3 Settings → Environments → Copy MCP URL.
No Inbox tools outside T3: That is how --t3 works: the server lists its tools only inside a T3 thread.
A review doesn’t go back to the thread: Ask Claude to run plannotator review itself: a /plannotator-review you type isn’t routed. Otherwise read t3-code/hook.log in your Plannotator data folder. A hook added before T3 reported itself as t3-code never runs: install with --with-t3 again. Then start a new thread.
Sign-in works but nothing arrives: Use the same PLANNOTATOR_DATA_DIR for the sign-in and the Inbox and the hook.
A Codex or OpenCode or Pi thread in T3 isn’t woken: Only Claude threads wake. The others see your reply when they read the thread.

What works

Inbox tool MCP after sign-in
Reply wakes it Wakes Claude threads
Start from Inbox No
Permission cards No

Plan review No
Code review With the T3 hook
Annotate With the T3 hook
Ask this session With the T3 hook

Only Claude threads wake, and only threads with a UUID id.
The review hook routes only a plain plannotator review or annotate or last that Claude runs as a Bash command. A slash command you type and compound commands and subagents and a folder below the project aren’t routed.
A sign-in lasts 30 days and isn’t renewed. After that replies wait in the Inbox until you sign in again, and only the Inbox log says so.
Plannotator doesn’t review plans in T3: T3 shows its own plan card.
The review hook adds about 320 ms to each Bash call in any Agent SDK session.
No Send now. No row in Settings → Agents yet. Not on Windows yet.
Tested on T3 Nightly 0.0.46.

Examples

Ask Claude in a T3 thread to run plannotator review. Your comments go back to that thread.

Every agent