@viztor/dsh-opencode

OpenCode on DeepSeek Harness

Free OpenCode models, working inside DeepSeek Harness. Zen (muse-spark-1.3-contributor-free, space-bunny-free) and Go (deepseek-v4.1-flash) — no 403 FreeTierError, no 400 MissingSessionID.

OpenCode's gateways expect three things DSH doesn't send by default: a valid x-opencode-session on every call, CLI origin proof on Zen (User-Agent, client headers, ses_…-shaped IDs), and read/bash tool definitions on free-tier calls. DSH strips the user agent, identifies sessions with UUIDs the gateways reject, and can send tool-less requests — so the calls fail. This plugin restores exactly what's missing at the network layer, and only for OpenCode traffic (opencode / opencode-go routes, zen/v1 / zen/go/v1 URLs). DeepSeek, OpenAI, GitHub, and every other request pass through byte-for-byte untouched.

Install

From npm:

dsh plugin --profile web add @viztor/dsh-opencode

Or pin it in your profile's package.json:

{
  "dependencies": {
    "@viztor/dsh-opencode": "^0.5.0"
  },
  "dsh": {
    "profile": {
      "bundles": [
        "@deepseek-ai/dsh-base",
        "@deepseek-ai/dsh-web-app",
        "@viztor/dsh-opencode"
      ]
    }
  }
}

Then pnpm install in the profile directory.

Configure

DSH Web → Settings → Plugins → OpenCode Integration. Flip toggles, Save:

Setting	Default	Effect
Inject User-Agent	on	Restores the OpenCode CLI User-Agent DSH strips
User-Agent Override	empty	Custom string instead of the canonical CLI one
Inject Origin Headers	on	Adds x-opencode-client: cli + x-opencode-project: global
Inject Core Tools	on	Adds fallback read/bash schemas to free-tier /responses calls
Providers	opencode, opencode-go	Which route IDs get the treatment
Debug Logging	off	Logs each header-injected call via ctx.logger
Debug File	empty	Appends JSONL stream-debug entries to a server-side path

Defaults live in code and show in the labels, so an empty field always means "the default". Settings resolve in layers — built-in defaults, then cordis.patch.yml, then anything saved here — and saving writes only what you edited. The Overridden badge marks UI-saved fields; Reset drops a field back to the file value.

Headless config

For servers or cordis.patch.yml overlays (all optional — omitting everything yields the defaults above):

- id: dsh-opencode
  name: "@viztor/dsh-opencode"
  config:
    providers: [opencode, opencode-go]
    injectUserAgent: true
    userAgent: ""
    injectOriginHeaders: true
    injectCoreTools: true
    debug: false

Types and debugFile are documented in cordis.patch.yml.

Troubleshooting

Symptom	Likely cause	Fix
403 FreeTierError on free models	Headers stripped or tools missing	Keep the three inject toggles on
400 MissingSessionID	No session header attached	Plugin must be in bundles and activated — check boot logs
Anything else misbehaving	Shouldn't be us — non-OpenCode traffic is never touched	File an issue with a redacted log

Compatibility

Last verified: 2026-10-01 — refreshed on every release (see Contributing).

Component	Verified version
Plugin	@viztor/dsh-opencode@0.5.1 (npm + GitHub Packages)
Host	DSH Web profile (dsh-profile-web, patchReload: live)
Runtime	Node 24+
Gateways	zen/v1 (/responses + chat completions), zen/go/v1 (chat completions)
Models	muse-spark-1.3-contributor-free, space-bunny-free, deepseek-v4.1-flash (Go)
Gates	vp check clean, 49 deterministic tests green, registry install resolves

Links

• Contributing — setup, conventions, release process
• Changelog — per-version record
• License — MIT (nobu121 & viztor)

Attribution

Evolved from nobu121/dsh-opencode-session by @nobu121, which pioneered the x-opencode-session approach for OpenCode Go. This project extends it to Zen free-tier compatibility, deterministic session hashing, configurable headers, and a Web settings UI.