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.

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.