Manifold Markets

OpenClaw tool plugin + standalone MCP server for Manifold Markets, wrapping the public REST API at https://api.manifold.markets/v0.

This package exposes 40 manifold_-prefixed tools with TypeBox schemas, a shared platform-agnostic HTTP client, and a uniform error shape. Responses pass through verbatim — no mutation, no client-side formatting, no per-tool auth gating beyond what the upstream API enforces.

Table of contents

• Features

• Install for OpenClaw

• Use as an MCP server

• Tool inventory

• Configuration

• Development

• Testing

• Troubleshooting

• Architecture

• License

Related MCP server: Polymarket MCP Server

Features

• OpenClaw plugin — install from npm, configure your API key, call tools by name

• Standalone MCP server — runs over stdio for any MCP-compatible client

• 40 tools covering markets, users, groups, bets, comments, leagues, boosts, authenticated reads, and write actions

• TypeBox schemas required by the OpenClaw SDK

• Shared, platform-agnostic HTTP client used by both the plugin and the MCP server

• Uniform error shape for upstream, auth, network, timeout, and validation errors

• No response mutation — upstream JSON passes through verbatim

Install for OpenClaw

1. Install the plugin

From any shell with the openclaw CLI:

openclaw plugins install npm:openclaw-plugin-manifold-markets@0.2.0

Omit @0.2.0 to use the latest published version. Pinning the version is recommended for reproducible setups.

2. Configure your API key

Get your key from your Manifold profile → edit → refresh API key.

The plugin config schema accepts one field:

{
  "apiKey": "<your-manifold-api-key>"
}

Plugin config lives at plugins.entries.<id>.config in openclaw.json (run openclaw config file to see the file path for your setup). The plugin ID is manifold-markets.

Set the key with the OpenClaw CLI:

openclaw config set plugins.entries.manifold-markets.config.apiKey "<your-manifold-api-key>"

For a hardened setup, use a SecretRef pointing at an env var instead of a literal value:

openclaw config set plugins.entries.manifold-markets.config.apiKey \
  --ref-provider default --ref-source env --ref-id MANIFOLD_API_KEY

Equivalently, edit openclaw.json directly:

{
  "plugins": {
    "entries": {
      "manifold-markets": {
        "enabled": true,
        "config": { "apiKey": "<your-manifold-api-key>" }
      }
    }
  }
}

With no key, only the public read tools work. Authenticated read tools and all write tools return an auth-category 401 error.

3. Verify the install

List installed tools:

openclaw plugins list

Smoke-test a read-only tool:

openclaw tools call manifold_search_markets '{"term": "AI", "limit": 3}'

If you configured an API key, test an authenticated tool:

openclaw tools call manifold_get_me '{}'

Use as an MCP server

Build and run the stdio server with your API key:

npm install
npm run build
MANIFOLD_API_KEY=your-key npm run mcp:start

The server exposes the same 40 tools over stdio. Point any MCP client at node path/to/dist/mcp-server.js.

For example, in Claude Desktop's claude_desktop_config.json:

{
  "mcpServers": {
    "manifold-markets": {
      "command": "node",
      "args": [
        "/path/to/node_modules/openclaw-plugin-manifold-markets/dist/mcp-server.js"
      ],
      "env": {
        "MANIFOLD_API_KEY": "your-key"
      }
    }
  }
}

Tool inventory

All tools are prefixed with manifold_ to avoid collisions with other plugins.

Public read tools (no API key required)

• manifold_search_markets — search markets by term

• manifold_get_market — get a market by ID

• manifold_get_market_by_slug — get a market by slug

• manifold_list_markets — list markets

• manifold_get_market_prob — get probability(ies) for a market

• manifold_get_market_probs — batch-fetch probabilities by market IDs

• manifold_get_market_positions — get market positions/leaderboard

• manifold_get_user — get user by username

• manifold_get_user_lite — get lite user by username

• manifold_get_user_by_id — get user by ID

• manifold_get_user_by_id_lite — get lite user by ID

• manifold_list_users — list users

• manifold_search_users — search users (intentionally excluded from test suite; list_users preferred)

• manifold_get_bets — list bets

• manifold_get_comments — get comments on a market

• manifold_get_groups — list groups

• manifold_get_group — get group by slug

• manifold_get_group_by_id — get group by ID

• manifold_get_leagues — get league cohorts

• manifold_get_boost_history — get boost history

Authenticated read tools (API key required)

• manifold_get_me — current user

• manifold_get_portfolio — portfolio metrics

• manifold_get_portfolio_history — portfolio history over time

• manifold_get_contract_metrics — per-user per-market metrics

• manifold_get_transactions — transaction history for the authenticated user

Write tools (API key required)

• manifold_place_bet — place a bet

• manifold_place_multi_bet — place a multi-answer bet

• manifold_cancel_bet — cancel a limit bet

• manifold_create_market — create a market

• manifold_resolve_market — resolve a market

• manifold_sell_shares — sell shares

• manifold_close_market — update market close time

• manifold_add_liquidity — add liquidity

• manifold_add_answer — add an answer to a multi-choice market

• manifold_market_group — add/remove a market from a group

• manifold_rebalance — rebalance a multi-choice position

• manifold_add_bounty — add a bounty

• manifold_award_bounty — award a bounty

• manifold_send_mana — send mana to another user

• manifold_create_comment — create a comment

Configuration

The plugin accepts a single optional apiKey:

{
  "apiKey": "string"
}

If you call an authenticated tool without a key, the upstream API returns a 401, which is surfaced as an auth-category error. The plugin never logs or exposes the key beyond sending it in the Authorization: Key <apiKey> header over HTTPS.

Development

npm install
npm run build          # compile TypeScript to dist/
npm test               # run the live-API Vitest suite
npm run plugin:validate # manifest sync + validation

Repository layout

src/
  api-client.ts      # Shared HTTP client
  errors.ts          # Uniform ManifoldError shape
  index.ts           # OpenClaw plugin entry
  mcp-server.ts      # Standalone MCP server entry
  tool-builder.ts    # makeGetTool / makePostTool helpers
  tools/             # Tool definitions by domain
  index.test.ts      # Vitest live-API suite
specs/               # Speckit spec, checklists, and planning docs
scripts/             # Development helpers (e.g. create-test-market.ts)
openclaw.plugin.json # OpenClaw plugin manifest

Testing

npm test exercises most tools against the live Manifold API.

Opt-in write tests

Write tests are disabled by default because they spend mana. To run them with a single API key:

export MANIFOLD_API_KEY=your-key
export MANIFOLD_RUN_WRITE_TESTS=1
npm test

Default write-test cost is ~M$3 (place bet, comment, add liquidity, then recover via sell_shares). cancel_bet, market_group, and close_market are net-zero.

manifold_send_mana requires a second API key (MANIFOLD_API_KEY2) and costs M$10. If the key is absent, the test skips cleanly.

Troubleshooting

Architecture

• Thin wrapper: the plugin performs zero response transformation. Every tool returns the exact JSON the upstream API returns.

• Shared client: api-client.ts is the only module that knows about HTTP, headers, base URL, and error wrapping. Both the OpenClaw plugin and MCP server use it.

• Rely-on-upstream auth: there is no per-tool auth-required metadata. The plugin sends requests with whatever key is configured (including none) and lets the upstream 401/403 surface as an auth or upstream error.

• Uniform errors: every failure is wrapped in ManifoldError with { category: "upstream"\|"auth"\|"network"\|"timeout"\|"validation", message, status?, body? }.

CI/CD

GitHub Actions workflows live in .github/workflows/:

• CI (.github/workflows/ci.yml) — runs on every push to main and every PR. Builds the plugin, validates the manifest, and runs the test suite on Node 22. Live integration tests hit the Manifold API; authed tests skip without MANIFOLD_API_KEY.

• Release (.github/workflows/release.yml) — triggered when a GitHub Release is published. Runs the full build + test suite, then publishes to npm with provenance. Requires the NPM_TOKEN repository secret.

Releasing a new version

1. Bump version in package.json and openclaw.plugin.json

2. Commit: git commit -am "v0.3.0"

3. Tag: git tag v0.3.0 && git push origin v0.3.0

4. Create the release: gh release create v0.3.0 --generate-notes

The Release workflow publishes to npm automatically. Provenance is enabled — the published package links back to the workflow run that built it.

Dependabot

.github/dependabot.yml opens weekly PRs for npm dependencies and GitHub Actions. Updates are grouped (TypeScript type defs, Vitest, GitHub Actions) to reduce PR noise.

License

MIT — see LICENSE.