TonyDua/dsh-web-search-exa

@tonydua/dsh-web-search-exa

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Adds Exa web search to DeepSeek Harness (dsh), the anonymous no-key variant.

dsh plugin --profile web add @tonydua/dsh-web-search-exa

Restart dsh web and it works. No API key, no config edits, no provider to select.

Background, for reference only:

• Exa is a search API. It retrieves pages by keyword or by meaning and returns citable sources with excerpts. It does not generate answers. Exa offers a REST API and also runs an unauthenticated public MCP server.
• The official `dsh-web-search-exa` is dsh's Exa search provider. It uses Exa's REST API and is only useful once you configure an API key.
• This package is a modified copy of the official one. The REST path works the same. What we added is a keyless channel: with no key it uses Exa's public MCP server, and with a key it still uses REST. The anonymous approach follows the oh-my-pi project, see Acknowledgements.

You can ignore all of this by default. Read Selecting a provider only if you also run the official package, or if dsh reports an ambiguous provider.

Built with deepseek-v4-flash inside DeepSeek Harness (dsh). The 0.2.3 live-config work was done with GLM-5.3-flash.

Features

• Works without a key. Searches go through Exa's public MCP server (mcp.exa.ai/mcp) and carry no credentials.
• Returns structured results on that keyless path. It calls web_search_advanced_exa, whose output is JSON in the REST field vocabulary, so sources carry real highlight snippets without text parsing.
• Upgrades itself when you add a key. Setting EXA_API_KEY switches to Exa's POST /search REST API for higher limits, with no behavior change.
• Drop-in. It registers into the dsh ctx.web seam; the model-facing web_search and web_fetch tools, their prompt sections, and the result cards all stay as they are.
• Works out of the box. With no official package installed there is no provider to select.
• Backs off when it fails. After repeated failures on the anonymous channel the plugin marks itself unavailable so dsh can pick another provider, instead of failing every search. See What happens when a search fails.

Installation

Pick one of three. The choice only decides where the code comes from; all three end up the same.

From npm. The dsh.bundle manifest ships the bundle patch, so the provider row is inserted for you and you do not edit any patch by hand.

dsh plugin --profile web add @tonydua/dsh-web-search-exa

From the GitHub Release. The same tarball, for when npm is unreachable.

dsh plugin --profile web add https://github.com/TonyDua/dsh-web-search-exa/releases/latest/download/dsh-web-search-exa.tgz

From the repository. Tracks main, including work not yet released.

dsh plugin --profile web add github:TonyDua/dsh-web-search-exa

For a local development checkout, use the same command with a path instead of a package name: dsh plugin --profile web add ../plugins/dsh-web-search-exa.

Restart dsh web afterwards. That is the whole procedure in most cases.

Selecting a provider

Skip this section unless you install the official package too.

Before each search, the dsh seam picks an available provider. If exactly one is available it is selected automatically. If more than one is available the seam raises WEB_PROVIDER_AMBIGUOUS and asks you to name one. So there are only two cases where you have to act:

• You installed the official package as well. Both packages register the provider id exa, so dsh web fails at startup with WEB_DUPLICATE_PROVIDER. You must give this package a different id first, see Coexistence with the official package.
• You see `WEB_PROVIDER_AMBIGUOUS`. Another provider is available. Name the one you want.

Two ways to name it:

# $DSH_HOME/profiles/web/cordis.patch.yml
- id: web
  name: '@deepseek-ai/dsh-web'
  config:
    searchProvider: exa

Or set $DSH_WEB_SEARCH_PROVIDER=exa at runtime.

Restart dsh web after the change. The model-facing web_search tool then uses the selected provider; no tool configuration changes.

Release artifacts and install warnings (usually not needed)

Release artifacts. CI packs this version's tarball, verifies it against every supported dsh version, attaches it to the GitHub Release, and publishes that same artifact to npm. So the release asset and the npm tarball are one file, not two builds that happen to match.

Profile install warnings. dsh profiles default to autoInstallPeers: false, and the harness's own services are provided at runtime by the dsh host rather than resolved by pnpm. If dsh plugin add reports peer warnings, add this to the profile's pnpm-workspace.yaml:

peerDependencyRules:
  ignoreMissing:
    - '@deepseek-ai/cordis'
    - '@deepseek-ai/dsh-*'

Configuration

Key · Default · Meaning apiKey · unset · Literal Exa API key. Empty or missing enables the anonymous MCP path. apiKeyEnv · EXA_API_KEY · Environment variable read when no literal apiKey is set. baseURL · https://api.exa.ai · Exa API base URL. The keyed REST path appends /search, matching the official dsh provider. apiURL · unset · Deprecated full REST endpoint alias. Takes precedence over baseURL when set. mcpURL · https://mcp.exa.ai/mcp?tools=web_search_exa,web_search_advanced_exa · Exa hosted MCP endpoint, used by the anonymous path. The tools query is part of the default because the structured tool is not servable without it. Leave it out of your own URL and the plugin adds it for you. mcpTool · web_search_advanced_exa · Which MCP tool the anonymous path calls: the structured one, or web_search_exa for the older Title:-section text blob. See How it works. searchType · auto · REST retrieval mode: auto, keyword, or neural. Read on the REST path only. numResults · unset · Default result count when a request carries no maxResults. highlightsPerResult · 1 · Highlight sentences requested per result on the REST path. providerId · exa · Provider id registered into ctx.web. Change it only when this package and the official one are installed together, see Coexistence with the official package.

Where to put the config: on dsh 0.2.0 or later use Settings → Plugins, which writes the profile patch for you. On older versions edit this plugin's config in $DSH_HOME/profiles/web/cordis.patch.yml and restart dsh web. A hand edit to that file needs a restart on every version, because dsh watches no patch file. The environment variables EXA_API_KEY and $DSH_WEB_SEARCH_PROVIDER work too. apiKey is marked role('secret'), so no describe() response exposes its value.

In the Web panel

What the Web UI offers depends on the dsh version:

• dsh 0.2.0 and later. Settings → Plugins generates a configuration page for this plugin from its Config schema, and saving applies to the next search without restarting dsh web — including switching between the anonymous and keyed paths by adding or removing the key. This needs 0.2.3 or later: dsh generates the page only for a plugin that declares at least one volatile Config field, so 0.2.1 and 0.2.2 install on that line and then show no page at all.
• dsh 0.1.2 – 0.1.6. The config lives in the profile patch layer. The plugin registers a web-search-exa section through the ctx.settings.installSection API and the data layer accepts writes, but those versions have no generic settings form, so edit cordis.patch.yml or use environment variables.
• Plugin inventory (Settings → Plugins): a web-search-exa entry appears automatically once the plugin is enabled, on every supported version. The inventory reads live entries from the Cordis loader, so no extra code is involved.
• Search result cards: web_search calls render the usual web result cards through dsh-tool-web (sources, excerpts, dates), regardless of provider. Anonymous Exa results look identical to DeepSeek search results.

How it works

Condition · Path · Endpoint apiKey / EXA_API_KEY configured · REST POST /search with Authorization: Bearer · https://api.exa.ai/search (configurable via baseURL) No key configured · Anonymous MCP tools/call web_search_advanced_exa (JSON-RPC 2.0, no credentials) · https://mcp.exa.ai/mcp?tools=… (configurable)

The anonymous MCP path sends no credentials; attribution rides the x-exa-source: dsh-anything header. Results are normalized to the seam's WebSearchSource shape (url, title, snippet, publishedAt), and the seam enforces maxResults on the way back.

The anonymous path calls web_search_advanced_exa by default. Its text content is a sanitized JSON search response whose entries use the same field names as the REST API, so a result maps to a source directly and no Title:-section text parsing is involved. Two consequences worth knowing:

• The structured tool is only served when the URL carries `?tools=…`. The bare endpoint answers MCP error -32602: Tool web_search_advanced_exa not found, which is why that query is part of the default mcpURL and why the plugin splices it into any mcpURL that lacks it.
• It returns whole-page text for every hit, and we ask for highlights separately. Without enableHighlights the endpoint returns text-only entries, every result would lack a snippet, and the search would come back empty. The full text is discarded: a snippet is always a real highlight sentence, never generated and never lifted from the page body.

searchType is not forwarded here. The plugin's setting uses the REST vocabulary (auto, keyword, neural) while the tool accepts its own (auto, fast, instant), so forwarding it would make a configured keyword or neural fail argument validation and take the whole anonymous path down. The tool's default is what auto asks for anyway.

Pinning mcpTool: web_search_exa restores the older text-blob path, where the same results arrive as Title:-led sections. Use it if Exa changes the structured tool's shape; a body that is not the expected JSON already falls back to section parsing on its own.

Because the structured tool returns a whole page of text per hit, a response can be large. Anonymous responses are capped at 256 KiB: the declared content-length is checked before the body is read, and a body that keeps growing is aborted mid-transfer. Over-limit responses fail as transient errors rather than being truncated or silently parsed.

Rate limits

The anonymous channel is a public endpoint run by Exa, and it is rate-limited. When you hit the limit the search fails with the code WEB_RATE_LIMITED and a message telling you to configure EXA_API_KEY. That code is ours, so that you and the model can tell throttling apart from a broken network.

With a key configured, searches use the REST path and are not subject to this limit.

What happens when a search fails

What you will see:

• The anonymous channel is rate-limited: error code WEB_RATE_LIMITED, telling you to configure a key.
• The anonymous channel fails 3 times in a row: this plugin marks itself unavailable for a 5-minute cooldown. During that window available() returns false.
• You pinned searchProvider: exa and the cooldown is active: the search reports WEB_PROVIDER_CONFIGURED_UNAVAILABLE.
• You did not pin searchProvider and the cooldown is active: the seam skips this plugin and looks for another provider. With no other provider available it reports WEB_PROVIDER_UNAVAILABLE.
• You configured a key, so searches use REST: none of the above applies, and failures surface as usual.

Why it works this way. Before each search the seam calls available() to decide which provider to use. If this plugin always answered "available", a dead endpoint would make every search fail hard, and what the user sees is a broken dsh. So the plugin adds a circuit breaker: after 3 consecutive transient failures it admits it is temporarily unavailable, giving the seam a chance to choose someone else. That breaker is this plugin's design; Exa has no such mechanism.

How failures are counted. Only failures that a retry could fix: 5xx, 429, network errors, and unparseable response bodies. Three of them start a 5-minute cooldown, and any successful search clears the count immediately.

A 4xx other than 429 does not count. That is a configuration error and would fail identically on every retry, so hiding it behind a cooldown would only delay the same error by 5 minutes.

This trade-off has a cost. While Exa is down for those 5 minutes, a profile with a pinned searchProvider: exa reports an error instead of trying something else. The plugin cannot choose for you:

• Pinning searchProvider: exa: predictable behavior normally, but no fallback once the breaker opens.
• Leaving searchProvider unset: it can fall back when the breaker opens, at the cost that the seam raises WEB_PROVIDER_AMBIGUOUS whenever several providers are usable, and you have to name one.

Choose the second if you want fallback, and install only one alternative provider.

Compared with the official package

DeepSeek Harness has an official Exa provider, @deepseek-ai/dsh-web-search-exa, which you install separately; dsh does not include it by default. This package is its zero-config variant: it adds the anonymous MCP fallback the official one lacks and keeps the same REST behavior once you configure a key.

· Official @deepseek-ai/dsh-web-search-exa · This package @tonydua/dsh-web-search-exa REST path (POST /search) · ✅ the only path · ✅ used when a key is configured Requires an API key · ✅ yes, an empty key makes it unavailable · ❌ no, with no key it uses the anonymous MCP fallback Anonymous MCP (mcp.exa.ai/mcp) · ❌ not implemented · ✅ the default path with no key Zero-config install · ❌ · ✅ Provider id · exa (fixed) · exa by default, configurable via providerId Cordis plugin name · web-search-exa · web-search-exa Config keys · apiKey, baseURL, searchType, numResults, highlightsPerResult · apiKey, apiKeyEnv, baseURL, apiURL (legacy), mcpURL, mcpTool, searchType, numResults, highlightsPerResult, providerId

Which to use:

• You have an EXA_API_KEY and want the officially maintained package: use the official one, it is the canonical implementation.
• You want to try Exa search with no configuration, no key, and no cost commitment: use this package. It defaults to the anonymous MCP path and switches to REST once a key appears.
• You want both: install both and separate them with providerId, see the next section.

Coexistence with the official package

Both packages register the same provider id (exa) under ctx.web, and both use the cordis plugin name web-search-exa. The seam rejects duplicate ids with WEB_DUPLICATE_PROVIDER, so installing both into one profile without changing the config fails at startup.

Coexistence requires explicit configuration through the providerId switch:

1. The official package keeps exa; its id is fixed.
2. Give this package a different id. Set providerId: exa-anon in this plugin's config; any unique string works.
3. Name one of them on the web seam. Use searchProvider: exa-anon for the anonymous variant, or searchProvider: exa for the official package. $DSH_WEB_SEARCH_PROVIDER works too.

- insert:
    - id: web-search-exa
      name: '@tonydua/dsh-web-search-exa'
      config:
        providerId: exa-anon
- id: web
  name: '@deepseek-ai/dsh-web'
  config:
    searchProvider: exa-anon

The simplest alternative is to install only one of the two packages per profile, which works with the default config.

Troubleshooting

After upgrading dsh to 0.2.0 or later, startup reports `Plugin @tonydua/dsh-web-search-exa@0.1.x is incompatible with dsh 0.2.0-rc.x ... skipping profile bundle`. Plugin versions before 0.2.1 declare peer ranges that end at >=0.1.8, which cannot match a dsh 0.2.x prerelease, and dsh refuses to load them rather than risk a crash — web search then runs without this plugin. Upgrade the plugin and restart:

dsh plugin --profile web add @tonydua/dsh-web-search-exa

(web is your profile name.) From 0.2.3 the plugin also gets its configuration page back on 0.2.0 and later, see In the Web panel.

`dsh web` fails at startup with `duplicate loader entry id: web`. This is a 0.1.2 bug, fixed in 0.1.4, so upgrading the plugin resolves it. If you already run 0.1.4 or later, please open an issue with dsh --version and your cordis.patch.yml, because a user patch that inserts a web row produces the same error.

Startup fails with `Cannot read properties of undefined (reading 'prepare')`. @deepseek-ai/dsh-tools is a dsh runtime singleton and must resolve to one physical package instance per profile. This plugin does not depend on it. The usual cause is another third-party plugin in the profile declaring it as an ordinary nested dependency rather than a peer dependency. Fix that plugin's dependency declaration, or have the profile's package manager resolve one shared instance, and only then investigate search errors.

A search reports `WEB_PROVIDER_AMBIGUOUS`. More than one provider is available. Name one explicitly as described in Selecting a provider.

A search reports `WEB_PROVIDER_CONFIGURED_UNAVAILABLE`. The provider you pinned is currently unavailable. This happens when the keyless channel's breaker is open, see What happens when a search fails.

The plugin config form is missing in the Web UI. The native configuration editor exists on dsh 0.2.0 and later; on 0.1.2 – 0.1.6 configure through cordis.patch.yml or environment variables, see In the Web panel.

Version compatibility