Miru MCP Support Is Live: Agent-Ready Time, Invoices, and Expenses

Miru now speaks MCP natively.

No wrappers. No unofficial bridge. No sidecar service to babysit.

We shipped first-party MCP support in miru-web with the same primitives teams already use in production: projects, time entries, invoices, payments, and expenses.

All examples in this post use synthetic values (example.com, placeholder IDs, sample notes). No real user data.

What we shipped

• HTTP MCP endpoint: https://<your-miru-host>/mcp
• stdio entrypoint: bin/miru-mcp
• Ruby client wrapper: MCP::Miru::Client
• Namespaced tools under miru.*
• CLI parity across read and write operations

This is built on the Ruby MCP SDK (mcp ~> 0.13.0) and is shipped inside the core repo.

5-minute setup (hosted Miru)

Install and authenticate Miru CLI:

curl -fsSL https://raw.githubusercontent.com/saeloun/miru-web/main/tools/miru-cli/install.sh | bash
miru login --base-url https://app.miru.so --email dev@example.com --password '***'
export MIRU_CLI_TOKEN="$(miru config token)"

Use the same CLI token for MCP clients:

[mcp_servers.miru]
url = "https://app.miru.so/mcp"
bearer_token_env_var = "MIRU_CLI_TOKEN"

If you prefer stdio from a local checkout:

cd /path/to/miru-web
MIRU_MCP_TOKEN="$MIRU_CLI_TOKEN" bin/miru-mcp

Tool coverage (CLI parity)

Miru MCP currently ships these tools:

• miru.capabilities
• miru.workspace.whoami
• miru.project.list
• miru.client.list
• miru.time.list
• miru.time.create
• miru.time.update
• miru.time.delete
• miru.invoice.list
• miru.invoice.show
• miru.invoice.send
• miru.payment.list
• miru.payment.show
• miru.expense.list
• miru.expense.create

The practical point: if you can do it in Miru CLI, your MCP client can usually do the same workflow.

Example usage (safe, synthetic)

1) Start with read-only discovery

# frozen_string_literal: true

client = MCP::Miru::Client.http(
  url: "https://app.miru.so/mcp",
  headers: { "Authorization" => "Bearer #{ENV.fetch('MIRU_CLI_TOKEN')}" }
)

begin
  capabilities = client.call_tool(name: "miru.capabilities")
  projects = client.call_tool(name: "miru.project.list", arguments: { search: "internal" })
  time_entries = client.call_tool(
    name: "miru.time.list",
    arguments: { from: "2026-04-01", to: "2026-04-22" }
  )

  puts capabilities.content.first.text
  puts projects.content.first.text
  puts time_entries.content.first.text
ensure
  client.close
end

2) Preview writes with dry_run

Use dry_run: true first. Then send the same call without dry-run when it looks right.

preview = client.call_tool(
  name: "miru.time.create",
  arguments: {
    project_id: 101,
    duration_minutes: 90,
    work_date: "2026-04-22",
    note: "MCP integration smoke test (synthetic)",
    bill_status: "unbilled",
    source_metadata: {
      source: "mcp",
      agent: "codex",
      environment: "staging"
    },
    dry_run: true,
    idempotency_key: "time-create-2026-04-22-project-101"
  }
)

puts preview.content.first.text

3) Safe retry pattern for write calls

Use a stable idempotency_key so retries do not duplicate writes.

send_result = client.call_tool(
  name: "miru.invoice.send",
  arguments: {
    id: 5001,
    recipients: ["billing@example.test"],
    subject: "Invoice INV-5001",
    message: "Please review and process this invoice.",
    dry_run: false,
    idempotency_key: "invoice-send-5001-v1"
  }
)

puts send_result.content.first.text

Access model and guardrails

MCP is Pro-gated at workspace level.

• Allowed: paid workspaces, active trials, billing-exempt workspaces
• Blocked: free workspaces without trial

Blocked requests return HTTP 403 with JSON-RPC code -32003 and forbidden_feature.

That gives agent clients a clean, explicit failure mode instead of ambiguous auth errors.

Why this matters

Most teams do not need another dashboard.

They need fewer manual steps between work done and invoice sent.

MCP support makes Miru composable with coding agents and automations without inventing a parallel API surface. Same domain model. Same operational constraints. Better execution speed.

Start read-only, then enable writes with dry_run and idempotency keys. That is the boring path. Boring is good when billing data is involved.

Vipul A M

Co-founder at Saeloun. Building Miru. Rails contributor. Shipping from Pune, India.