# io.usefulapi/lob (remote · lob.usefulapi.io)

Verify US & international addresses and send physical mail (postcards, letters, checks) via Lob.

- Trust score: 72/100 (medium)
- Change this week: +5
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-08-03

## Components

- remote · `lob.usefulapi.io`: 72/100 (this document), [markdown](https://verifymcp.io/servers/io-usefulapi-lob/lob.md), [page](https://verifymcp.io/servers/io-usefulapi-lob/lob)

## Channel facts

- Endpoint: `https://lob.usefulapi.io/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.1`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-08-03.

- **Endpoint Security**: 78/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation is enforced on tool calls, advertised via RFC 9728 protected-resource metadata. Discovery is public, which costs nothing: no tool can be invoked without a token.
  - HTTPS not yet verified: we couldn't determine whether a plaintext access path exists.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
  - The authorisation server offers only Dynamic Client Registration (RFC 7591), which MCP 2026-07-28 deprecated in favour of Client ID Metadata Documents.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 71/100
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 1929 tokens (~107/item across 18 items; 18 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 23/100
  - Stability observed for 7 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 97/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 91% of tool parameters carry a description.
- **Capabilities**: 60/100
  - Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28.

## Install

### Claude

```bash
claude mcp add --transport http io-usefulapi-lob https://lob.usefulapi.io/mcp
```

### Codex

```toml
[mcp_servers.io-usefulapi-lob]
url = "https://lob.usefulapi.io/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "io-usefulapi-lob": {
      "type": "remote",
      "url": "https://lob.usefulapi.io/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add io-usefulapi-lob --url https://lob.usefulapi.io/mcp --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  io-usefulapi-lob:
    url: "https://lob.usefulapi.io/mcp"
```

### Other

```json
{
  "mcpServers": {
    "io-usefulapi-lob": {
      "type": "http",
      "url": "https://lob.usefulapi.io/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-08-03 (score 72, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-08-02 (score 71, +53)

- [security improvement] Authorization: unverified → pass
- [security improvement] Transport: fail → pass
- [functional regression] MCP protocol: unverified → fail
- [functional improvement] Endpoint reachability: not serving MCP → reachable
- [functional improvement] Stability: unverified → 0.20
- [functional improvement] Tool coverage: unverified → 100

### 2026-08-01 (score 18, −52)

- [security regression] Endpoint reachability: reachable → not serving MCP
- [security regression] Stability: 0.13 → unverified
- [security regression] Authorization: pass → unverified
- [security regression] Transport: pass → fail
- [functional regression] Tool coverage: 100 → unverified
- [functional regression] Capabilities: fail → unverified

### 2026-07-31 (score 70, +3)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-30 (score 67, −2)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-29 (score 69, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-07-28 (score 68, +1)

- [functional improvement] Stability: unverified → 0.03

### 2026-07-27 (score 67, +55)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

## MCP tools (18)

### `lob_verify_us_address` (~174 tokens)

Verify a US address

Validate & standardize a US address, returning deliverability, corrected components, and a confidence score. Pass either a single freeform `address` string OR structured `primary_line`/`city`/`state`/`zip_code`. Non-mutating (no mail sent). Lob API: POST /v1/us_verifications.

Input parameters:

- `address` (string): Freeform single-line address (alternative to the structured fields).
- `city` (string)
- `primary_line` (string): Primary delivery line, e.g. '210 King Street'.
- `secondary_line` (string): Secondary line, e.g. 'Suite 6100'.
- `state` (string): 2-letter state code, e.g. 'CA'.
- `zip_code` (string): 5-digit or ZIP+4.

### `lob_verify_intl_address` (~123 tokens)

Verify an international address

Validate & standardize a non-US address. `country` (2-letter ISO code) is required. Non-mutating (no mail sent). Lob API: POST /v1/intl_verifications.

Input parameters:

- `city` (string)
- `country` (string, required): 2-letter ISO country code, e.g. 'GB', 'DE', 'CA'.
- `postal_code` (string)
- `primary_line` (string, required): Primary delivery line.
- `secondary_line` (string)
- `state` (string): State / province / region.

### `lob_us_zip_lookup` (~61 tokens)

Look up a US ZIP code

Return the cities and state associated with a US ZIP code. Non-mutating. Lob API: POST /v1/us_zip_lookups.

Input parameters:

- `zip_code` (string, required): A 5-digit US ZIP code, e.g. '94107'.

### `lob_us_autocomplete` (~101 tokens)

Autocomplete a US address

Suggest complete US addresses from a partial primary line — useful for address entry. Non-mutating. Lob API: POST /v1/us_autocompletions.

Input parameters:

- `address_prefix` (string, required): Partial primary line, e.g. '185 Berr'.
- `city` (string): Optional city to narrow suggestions.
- `state` (string): Optional 2-letter state to narrow suggestions.
- `zip_code` (string): Optional ZIP to narrow suggestions.

### `lob_list_postcards` (~88 tokens)

List postcards

List sent/scheduled postcards, newest first. Lob API: GET /v1/postcards.

Input parameters:

- `after` (string): Cursor for the next page (from a previous response's next_url).
- `before` (string): Cursor for the previous page (from a previous response's previous_url).
- `limit` (integer): Max results per page (1–100). Default 10.

### `lob_get_postcard` (~53 tokens)

Get a postcard

Retrieve a single postcard by id, including status, PDF url, and expected delivery. Lob API: GET /v1/postcards/{id}.

Input parameters:

- `id` (string, required): Postcard id (psc_…).

### `lob_list_letters` (~87 tokens)

List letters

List sent/scheduled letters, newest first. Lob API: GET /v1/letters.

Input parameters:

- `after` (string): Cursor for the next page (from a previous response's next_url).
- `before` (string): Cursor for the previous page (from a previous response's previous_url).
- `limit` (integer): Max results per page (1–100). Default 10.

### `lob_get_letter` (~50 tokens)

Get a letter

Retrieve a single letter by id, including status, PDF url, and tracking. Lob API: GET /v1/letters/{id}.

Input parameters:

- `id` (string, required): Letter id (ltr_…).

### `lob_list_checks` (~87 tokens)

List checks

List sent/scheduled checks, newest first. Lob API: GET /v1/checks.

Input parameters:

- `after` (string): Cursor for the next page (from a previous response's next_url).
- `before` (string): Cursor for the previous page (from a previous response's previous_url).
- `limit` (integer): Max results per page (1–100). Default 10.

### `lob_get_check` (~50 tokens)

Get a check

Retrieve a single check by id, including amount, status, and check number. Lob API: GET /v1/checks/{id}.

Input parameters:

- `id` (string, required): Check id (chk_…).

### `lob_list_self_mailers` (~92 tokens)

List self-mailers

List sent/scheduled self-mailers, newest first. Lob API: GET /v1/self_mailers.

Input parameters:

- `after` (string): Cursor for the next page (from a previous response's next_url).
- `before` (string): Cursor for the previous page (from a previous response's previous_url).
- `limit` (integer): Max results per page (1–100). Default 10.

### `lob_list_addresses` (~86 tokens)

List saved addresses

List saved address records, newest first. Lob API: GET /v1/addresses.

Input parameters:

- `after` (string): Cursor for the next page (from a previous response's next_url).
- `before` (string): Cursor for the previous page (from a previous response's previous_url).
- `limit` (integer): Max results per page (1–100). Default 10.

### `lob_get_address` (~43 tokens)

Get a saved address

Retrieve a single saved address record by id. Lob API: GET /v1/addresses/{id}.

Input parameters:

- `id` (string, required): Address id (adr_…).

### `lob_list_templates` (~88 tokens)

List templates

List saved HTML templates usable as postcard/letter artwork. Lob API: GET /v1/templates.

Input parameters:

- `after` (string): Cursor for the next page (from a previous response's next_url).
- `before` (string): Cursor for the previous page (from a previous response's previous_url).
- `limit` (integer): Max results per page (1–100). Default 10.

### `lob_create_address` (~168 tokens)

Save an address record

Create a reusable saved address record (does NOT send any mail). Returns an address id (adr_…) usable as `to`/`from` in mail tools. Lob API: POST /v1/addresses.

Input parameters:

- `address_city` (string)
- `address_country` (string): 2-letter ISO country code. Defaults to US.
- `address_line1` (string, required): Primary street address.
- `address_line2` (string): Unit/suite/apt.
- `address_state` (string): 2-letter state/province code.
- `address_zip` (string): ZIP / postal code.
- `company` (string)
- `description` (string): Internal label for this address.
- `name` (string): Recipient name (required unless `company` is set).

### `lob_create_postcard` (~257 tokens)

Send a postcard (COSTS MONEY)

⚠️ SENDS A REAL POSTCARD and charges your Lob account (use a test_ key to avoid real mail/charges). `to` and `from` accept an existing address id (adr_…) or an inline address object. `front`/`back` accept an HTML string, a hosted asset URL, or a template id (tmpl_…). Cancelable only before `send_date`. Lob API: POST /v1/postcards.

Input parameters:

- `back` (string, required): Back artwork: HTML string, asset URL, or template id (tmpl_…).
- `description` (string): Internal label.
- `from`: Return address (id or inline object). Optional.
- `front` (string, required): Front artwork: HTML string, asset URL, or template id (tmpl_…).
- `mail_type` (string): USPS mail class.
- `merge_variables` (object): Key/value data merged into HTML templates.
- `send_date` (string): ISO-8601 date/time to schedule the send (future). Cancelable until then.
- `size` (string): Postcard size. Default 4x6.
- `to` (required): Either an existing address id (adr_…) or an inline address object.

### `lob_create_letter` (~257 tokens)

Send a letter (COSTS MONEY)

⚠️ SENDS A REAL LETTER and charges your Lob account (use a test_ key to avoid real mail/charges). `to`/`from` accept an address id (adr_…) or inline object. `file` accepts an HTML string, a hosted PDF/URL, or a template id (tmpl_…). `color` is required. Cancelable only before `send_date`. Lob API: POST /v1/letters.

Input parameters:

- `address_placement` (string): Where the recipient address is placed.
- `color` (boolean, required): true = color printing, false = black & white.
- `description` (string): Internal label.
- `double_sided` (boolean): Print on both sides. Default true.
- `file` (string, required): Letter body: HTML string, asset/PDF URL, or template id (tmpl_…).
- `from` (required): Return address (id or inline object). Required for letters.
- `merge_variables` (object): Key/value data merged into HTML templates.
- `send_date` (string): ISO-8601 date/time to schedule the send (future). Cancelable until then.
- `to` (required): Either an existing address id (adr_…) or an inline address object.

### `lob_cancel_postcard` (~64 tokens)

Cancel a scheduled postcard

Cancel a postcard before its send_date so it is never mailed (and not billed). Fails if the send window has passed. Lob API: DELETE /v1/postcards/{id}.

Input parameters:

- `id` (string, required): Postcard id (psc_…) to cancel.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/io-usefulapi-lob/lob#diagnostics

## Score history

- 2026-08-03: 72
- 2026-08-02: 71
- 2026-08-01: 18
- 2026-07-31: 70
- 2026-07-30: 67
- 2026-07-29: 69
- 2026-07-28: 68
- 2026-07-27: 67
- 2026-07-26: 12

## Links

- Remote endpoint: https://lob.usefulapi.io/mcp
- Repository: https://github.com/m190/usefulapi-mcp
- Changelog RSS feed: https://verifymcp.io/servers/io-usefulapi-lob/lob/changelog.xml
- Changelog JSON feed: https://verifymcp.io/servers/io-usefulapi-lob/lob/changelog.json
- HTML version of this page: https://verifymcp.io/servers/io-usefulapi-lob/lob