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Early access

TheCompaniesAPI MCP server

Resolve a company name or domain and find prospects matching explicit firmographic conditions. Access is gated: request enablement for your organization before connecting.

Request early accessSee 7 actions ↓
SalesAPI keyMCP + RESTthecompaniesapi.com
AUDIT LOG · THECOMPANIESAPIPOLICY: acme-support
09:41:07 · claude · u_8f2read
thecompaniesapi.list_lists
List saved company lists✓ allowed · 212ms
09:41:08 · claude · u_8f2read
thecompaniesapi.get_company
Get company✓ allowed · 164ms
ILLUSTRATIVE POLICY TRACE · NOT A LIVE RECEIPT
01 · USE CASES

Agent workflows for TheCompaniesAPI.

01

Get company

Use when a known company domain needs its name and firmographics. Costs 1 credit for a match; no match is free. A timed-out call may still be charged; retrying may spend again.

02

Search companies

Use when company prospects must match explicit industry, size, country or technology conditions. Up to 25 credits per page. A timed-out call may still be charged.

03

Search companies by name

Use when a company name is known but its domain is not. Defaults to 1 result and exact-word matching. Costs at most the requested size in credits (max 25); a timed-out call may still be charged.

02 · ACTIONS

7 TheCompaniesAPI actions, graded by risk.

These actions come from the Arc0 registry. Your identity, provider permissions and Arc0 policies determine which actions can run.

read

7

Look things up, subject to your permissions.

  • thecompaniesapi.get_company
    Get company

    Use when a known company domain needs its name and firmographics. Costs 1 credit for a match; no match is free. A timed-out call may still be charged; retrying may spend again.

  • thecompaniesapi.search_companies
    Search companies

    Use when company prospects must match explicit industry, size, country or technology conditions. Up to 25 credits per page. A timed-out call may still be charged.

  • thecompaniesapi.search_by_name
    Search companies by name

    Use when a company name is known but its domain is not. Defaults to 1 result and exact-word matching. Costs at most the requested size in credits (max 25); a timed-out call may still be charged.

  • thecompaniesapi.similar_companies
    Find similar companies

    Use when finding businesses similar to known company domains for market comparison. Up to 25 credits per page; a timed-out call may still be charged.

  • thecompaniesapi.count_companies
    Count matching companies

    Use when estimating the size of a company segment before spending credits retrieving its members. This count endpoint is free.

  • thecompaniesapi.list_lists
    List saved company lists

    Use when finding existing saved company lists and checking whether they are dynamic or currently processing. This endpoint is free.

  • thecompaniesapi.get_account
    Get account context and credit balance

    Use when checking the user, current team and available team credits before a paid search. Both account and team reads are free. A user without a current team returns team: null.

write

0

Create and change things. Allow, or ask the user first.

  • No write actions.

destructive

0

Delete, cancel or archive. Ask first, or deny outright.

  • No destructive actions.
03 · POLICIES AND AUDIT

Control access to TheCompaniesAPI.

After early access is enabled, connect the intended TheCompaniesAPI account, authorize your AI client and set policies for its tools.

Provider permissions and Arc0 policy both apply. Allow reads, require approval for selected writes, or deny destructive actions. The audit log records execution decisions.

Configure policies and approvals

Example policy choices

  • Read actions: allow where authorized

Arc0 MCP endpoint: https://api.arc0.ai/mcp

04 · AUTH AND DATA

How TheCompaniesAPI connects.

Connect TheCompaniesAPI using API key. OAuth grants the provider scopes shown during consent; API keys and other credentials retain the permissions configured at the provider. Arc0 stores credentials in its encrypted vault and does not pass them to the model. Disconnect to remove access through Arc0; revoke a key at the provider to invalidate it there. Token refresh and provider-side revocation depend on the authentication lane and provider.

The connection serves authorized calls through Arc0 MCP and REST. How Arc0 handles credentials →

AUTH
API key
CREDENTIALS
Per-tenant encrypted vault
MODEL SEES
Results only, never credentials
AUDIT LOG
Every call, on every plan
05 · AI CLIENTS

Use TheCompaniesAPI with your AI client.

Request access to TheCompaniesAPI first. An Arc0 administrator must enable it for your organization before these actions appear. Then authorize your AI client separately. It only receives tools and accounts allowed for that identity.

TheCompaniesAPI with Claude

Claude Desktop + Claude Code

  1. In Claude Desktop, add Arc0 through the remote MCP settings and use OAuth. Follow the generic remote-client steps if your account’s interface differs.
  2. For Claude Code, run the command below. Open /mcp, select Arc0, and authenticate in your browser. Select your workspace and review access.
  3. Check the connection with claude mcp get arc0.
claude mcp add --transport http --scope user arc0 https://api.arc0.ai/mcp
Full MCP setup and troubleshooting
All apps for Claude
TheCompaniesAPI with ChatGPT

ChatGPT on the web

  1. Open Plugins in ChatGPT, select the plus button, then Add custom MCP server.
  2. Name it Arc0, enter the server URL below, and choose OAuth. Use dynamic client registration if asked; no Arc0 API key is needed.
  3. Review the notice and select Create as a plugin. Complete Arc0 sign-in, workspace selection and consent, then install and select the plugin in your conversation. Labels and access vary by account; managed workspaces may require administrator approval.
https://api.arc0.ai/mcp
Full MCP setup and troubleshooting
All apps for ChatGPT
TheCompaniesAPI with OpenAI Codex

Codex app + CLI

  1. Run the registration command below. The app and CLI share ~/.codex/config.toml.
  2. Complete browser OAuth, choose your Arc0 workspace, and review access. If authentication does not start, run codex mcp login arc0.
  3. Check codex mcp list, then open a new Codex chat. Inspect an existing arc0 entry before changing it.
codex mcp add arc0 --url https://api.arc0.ai/mcp
Full MCP setup and troubleshooting
All apps for OpenAI Codex
TheCompaniesAPI with Cursor

Remote MCP setup

  1. Add Arc0 in your client’s remote MCP settings using the server URL below.
  2. Choose OAuth, sign in to Arc0, select the intended workspace and review access.
  3. Confirm the server is connected and start with an allowed read. These are generic remote-MCP steps; consult your client’s settings for its current interface.
https://api.arc0.ai/mcp
Full MCP setup and troubleshooting
All apps for Cursor
TheCompaniesAPI with VS Code

Remote MCP setup

  1. Add a remote HTTP MCP server named Arc0 using the URL below.
  2. Use OAuth and finish Arc0 sign-in, workspace selection and consent.
  3. Confirm discovery succeeds before requesting a read. These are generic remote-MCP steps; client UI and availability may differ.
https://api.arc0.ai/mcp
Full MCP setup and troubleshooting
TheCompaniesAPI with Any MCP client

Streamable HTTP

  1. Use a client that supports remote MCP over Streamable HTTP. Add the server URL below and choose OAuth.
  2. For a client without OAuth, use a self-bound API key with execute permission in the X-API-Key header. Store it in secret storage or an environment variable, outside source control. Never send both an API key and an OAuth bearer token.
  3. Use the MCP clients guide for the SDK transport example and Embedded identity for business-managed end users.
https://api.arc0.ai/mcp
Full MCP setup and troubleshooting

After setup, ask your agent to find an allowed read action, load its schema, and execute it on the intended account. Check Activity for the receipt. A connected MCP client alone does not confirm a successful provider call.

06 · RELATED

More sales apps.

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ALL SALES APPS →
07 · FAQ

TheCompaniesAPI and Arc0, answered.

Q01

Does TheCompaniesAPI work with Claude Desktop and Claude Code?

Yes, after early access is enabled for your organization and you connect the intended account. Use Arc0’s remote MCP endpoint with OAuth. Claude Code has a documented registration command; Desktop uses the generic remote-client setup.

Q02

Can I use TheCompaniesAPI with OpenAI Codex, ChatGPT and Cursor?

Yes, after early access is enabled for your organization and you connect the intended account. Codex and ChatGPT have setup instructions in Arc0’s MCP clients guide. Cursor uses the generic remote-MCP steps. Tool access remains scoped to the authorized identity.

Q03

Is this the official TheCompaniesAPI MCP server?

This is Arc0’s integration page, not a claim of an official TheCompaniesAPI server. Arc0 adds a shared connection, policy and audit experience across apps. Consult TheCompaniesAPI for its own current MCP offerings.

Q04

Which TheCompaniesAPI actions are supported?

7 registry-defined actions: 7 read, 0 write and 0 destructive. Provider permissions, access enablement and Arc0 policy determine what can execute.

Q05

Which permissions does TheCompaniesAPI need?

Connect TheCompaniesAPI using API key. OAuth grants the provider scopes shown during consent; API keys and other credentials retain the permissions configured at the provider. Arc0 stores credentials in its encrypted vault and does not pass them to the model. Disconnect to remove access through Arc0; revoke a key at the provider to invalidate it there. Token refresh and provider-side revocation depend on the authentication lane and provider.

Q06

Can I restrict writes in TheCompaniesAPI?

You can deny write and destructive actions or require approval. Provider scopes and Arc0 action policies are separate controls; a policy does not grant additional provider permissions.

Q07

What does TheCompaniesAPI through Arc0 cost?

See Arc0 pricing for current connectivity plans. The provider may require its own subscription or charge per request. Arc0 plan allowances do not make third-party data or paid actions free.

Get started

Request TheCompaniesAPI access.

TheCompaniesAPI MCP server: 7 actions including get company, search companies, search companies by name. Request early access through Arc0.

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Free to build · MCP + REST · Audit log on every plan

TheCompaniesAPI and its logo are trademarks of their respective owners. Arc0 is not affiliated with or endorsed by TheCompaniesAPI.