Canon for DeepSeek Harness

@canonmsg/deepseek-harness-plugin adds Canon as a channel inside a DeepSeek Harness (DSH) profile. Canon becomes an additional surface beside the normal DSH Web UI; this bundle does not replace DSH's Web, session, approval, tool, or persistence rows.

Use the Canon app at canonmail.com to approve your agent and message it after setup.

The plugin uses DSH's public ctx.agents and session-event contracts. DSH owns the model, tools, permissions, persistence, and execution environment; Canon only adapts messages, visible activity, one-shot approvals, and runtime signals.

Requirements

• Node.js 22.19 or newer (or Node 24+)
• DeepSeek Harness 0.1.1-rc.2
• A Canon agent registered with client type deepseek-harness

DSH is a developer preview and warns that breaking changes are expected. Canon therefore pins the direct DSH service APIs to the exact tested 0.1.1-rc.2 line rather than advertising a broad prerelease range.

Register the Canon agent

canon-dsh-register \
  --name "My DSH Agent" \
  --description "Coding agent in DeepSeek Harness" \
  --phone "+15551234567" \
  --profile my-dsh

After Canon approval, install the published bundle into a selected DSH profile:

dsh plugin --profile my-dsh-profile add @canonmsg/deepseek-harness-plugin

DSH's plugin manager recognizes dsh.bundle.patch and adds the package to that profile's ordered bundle list automatically. Check the composed row without booting the agent:

CANON_AGENT=my-dsh dsh --profile my-dsh-profile --dump-config

Confirm that row canon-dsh is present and enabled. Then start DSH from the project workspace:

cd /path/to/project
CANON_AGENT=my-dsh dsh --profile my-dsh-profile

The Canon profile (my-dsh) and DSH profile (my-dsh-profile) are separate concepts. The first selects Canon credentials. The second selects the DSH bundle stack.

Configuration

The bundle row reads these environment expressions:

Variable	Purpose	Default
CANON_AGENT	Canon profile in ~/.canon/agents.json	empty; Canon auto-selects only when exactly one matching profile is available
CANON_DSH_WORKSPACE	Absolute DSH workspace root	DSH invocation directory
DSH_PROVIDER	Optional provider route for Canon-created agents	DSH model settings/default selection
DSH_MODEL	Optional model for Canon-created agents	DSH model settings/default selection
CANON_DSH_DISABLED	Set to 1 to disable only the Canon row	enabled

DSH_PROVIDER and DSH_MODEL must be supplied together. Omit both to use the profile's normal model selection.

What the bridge supports

• One durable DSH session per Canon conversation, resumed from DSH's event-sourced session log after restart.
• A Canon message batch mapped to one immutable DSH user message.
• Visible assistant text streaming.
• Runtime activity for DSH turns and tool calls/results without exposing raw tool arguments.
• One-shot Canon approval cards for DSH approval requests.
• Interrupt, stop-and-drop, and new-session signals.

Canon interrupt aborts the active DSH turn with keepInbox: true. Stop-and-drop uses DSH's default cancellation behavior and clears queued inbox work. New session advances Canon's durable generation mapping without deleting the old DSH event log.

Canon's conversation-to-session map is stored under CANON_HOME (normally ~/.canon), never inside the project workspace.

Approval semantics

DSH requests carry a tool name, optional call correlation, and a reason; they do not carry raw tool arguments. Canon does not fabricate arguments.

The mapping preserves DSH's closed vocabulary:

• explicit Canon allow → allowed-once
• explicit Canon denial by a human → rejected
• DSH/Canon request abort → cancelled
• timeout, transport failure, missing responder, or indeterminate result → unavailable

unavailable is never treated as permission. Canon session rules are disabled for this bridge because DSH has only one-shot grants.

Current limitations

• Canon attachments are represented as safe text placeholders; they are not yet converted into native DSH image attachments.
• DSH user questions remain owned by the selected DSH surface. They are not conflated with Canon approval cards.
• Provider/model, permission mode, effort, workspace selection, execution mode, session-state snapshots, rich cards, and steering/interleave are not advertised as Canon controls until the bridge can validate and enforce each control end to end.
• The initial package is tested against DSH 0.1.1-rc.2 only.

Troubleshooting

1. Run CANON_AGENT=<profile> dsh --profile <dsh-profile> --dump-config.
2. Confirm row id canon-dsh and package name @canonmsg/deepseek-harness-plugin.
3. Set CANON_DSH_DISABLED=0 or unset it if the row is disabled.
4. Check that ~/.canon/agents.json contains the selected profile with clientType: "deepseek-harness".
5. Start DSH from the intended project directory or set CANON_DSH_WORKSPACE to its absolute path.

Development

npm install
npm run check

The bundle patch intentionally inserts only canon-dsh; it does not replace or deep-merge any DSH-owned row.

DeepSeek Harness is in developer preview. This repository pins the exact DSH release it is tested against; compatibility updates are reviewed and released explicitly rather than inferred from a broad prerelease range.