Lob MCP by usefulapi
REMOTE · LOB.USEFULAPI.IO
Verify US & international addresses and send physical mail (postcards, letters, checks) via Lob.
Available components
Last scanned (2 hours ago)
Scores higher than 4% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Documents and Files
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. How we score → Why this is hard to score →
Endpoint Security46
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not yet verified: we couldn't confirm whether this endpoint requires it. View diagnostics → Unverified
- HTTPS enforcement could not be verified: the plaintext port redirected somewhere other than https, so enforcement is unproven. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability0
- Transport check failed: declared streamable-http, but the endpoint redirected instead of responding directly. See how to fix → View diagnostics → Fail
Schema Quality & AI Usability0
- Schema not yet verified: we couldn't read the endpoint's schema, or could read only part of its tool list.Unverified
Stability & Change Management0
- Stability not yet verified: not enough scan history yet (needs a 30-day window).Unverified
Tool Coverage0
- Tool coverage not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.Unverified
Tool Safety0
- Tool safety not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.Unverified
Capabilities0
- Capabilities not yet verified: we couldn't read the endpoint's capabilities.Unverified
Unverified: 5 categories
Categories scored 0 because we could not verify them: authentication we do not have, an unreachable endpoint, or not enough scan history. We only credit what we can confirm.
Checks we ran (4)
- TLS certificate
- HSTS header
- DNSSEC
- Transport
Checks we could not complete (7)
These are gaps on our side, not findings about this hosted endpoint. We only credit what we can confirm, so a category made up entirely of them scores 0.
- Authorization in Endpoint SecurityAuthorisation not yet verified: we couldn't confirm whether this endpoint requires it.
- HTTPS in Endpoint SecurityHTTPS enforcement could not be verified: the plaintext port redirected somewhere other than https, so enforcement is unproven.
- Schema quality in Schema Quality & AI Usability (scores 0 for this)Schema not yet verified: we couldn't read the endpoint's schema, or could read only part of its tool list.
- Stability in Stability & Change Management (scores 0 for this)Stability not yet verified: not enough scan history yet (needs a 30-day window).
- Tool coverage in Tool Coverage (scores 0 for this)Tool coverage not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- Tool safety in Tool Safety (scores 0 for this)Tool safety not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- Capabilities in Capabilities (scores 0 for this)Capabilities not yet verified: we couldn't read the endpoint's capabilities.
Does not apply to this hosted endpoint (2)
- Supply Chain SecurityScored on package channels only. This is a hosted endpoint, so there is nothing to install or inspect.
- Provenance & TransparencyScored on package channels only. This is a hosted endpoint, so there is nothing to install or inspect.
The score does not measure everything. What the score does not measure →
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 2 Nov 26 −59
- Endpoint reachability: reachable → not serving MCP ▼ security
- Tool safety: pass → unverified ▼ security
- Stability: 0.87 → unverified ▼ security
- Authorization: pass → unverified ▼ security
- Schema quality: 100 → unverified ▼ functional
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- 31 Oct 26 +3
- Authorization: partial → pass ▲ security
- MCP protocol: fail → pass ▲ functional
- New prompt “cancel_a_scheduled_postcard_before_it_is_mailed” functional
- New prompt “check_if_a_us_or_international_address_is_deliverable” functional
- New prompt “complete_an_address_or_look_up_a_zip_code” functional
- New prompt “review_sent_postcards_and_letters_and_their_status” functional
- New prompt “save_an_address_and_send_a_postcard_or_letter” functional
- MCP protocol version: 2025-06-18 → 2025-11-25 functional
- Server version: 1.32.0 → 1.34.0 functional
- Server version: 1.31.0 → 1.32.0 functional
- Server version: 1.30.2 → 1.31.0 functional
- 30 Oct 26 +1
- Server version: 1.30.1 → 1.30.2 functional
- Server version: 1.30.0 → 1.30.1 functional
- 29 Oct 26 0
- Server version: 1.29.0 → 1.30.0 functional
- Server version: 1.28.0 → 1.29.0 functional
- 28 Oct 26 +1
- Server version: 1.26.0 → 1.28.0 functional
- 27 Oct 26 0
- Server version: 1.25.0 → 1.26.0 functional
- 26 Oct 26 −5
- Tool “lob_create_letter” rewrote its description, which is the text the model reads security
- Stability: pass → 0.67 functional
- Server version: 1.24.0 → 1.25.0 functional
- “lob_create_letter” added an optional parameter “extra_service” cosmetic
- “lob_create_letter” added an optional parameter “mail_type” cosmetic
- “lob_create_letter” added an optional parameter “use_type” cosmetic
- “lob_create_postcard” added an optional parameter “use_type” cosmetic
- 25 Oct 26 0
- Server version: 1.23.0 → 1.24.0 functional
- Server version: 1.22.0 → 1.23.0 functional
- Server version: 1.21.3 → 1.22.0 functional
- Server version: 1.21.0 → 1.21.3 functional
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 5 Nov 2026 · Probed https://lob.usefulapi.io/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=usefulapi.io | CN=WE1,O=Google Trust Services,C=US | 13 Sept 2026 | 12 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | d9be3287b0fde9630e825ba1f79bff3f |
| SANs: usefulapi.io, *.usefulapi.io | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of lob.usefulapi.io. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | Trust anchor | 20326, 38696 | 8, 8 | Verified |
| io. | DS published | 38690 | 8 | Verified |
| usefulapi.io. | No DS | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication Inconclusive
We could not reach the endpoint well enough to judge its authorisation posture.
| Result | Inconclusive |
|---|---|
| HTTP status | 302 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://lob.usefulapi.io/mcp | Redirected | 302 | https://usefulapi.io/lob/ |
| http (plaintext) | http://lob.usefulapi.io/mcp | Inconclusive | 302 | http://lob.usefulapi.io/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
lob_cancel_postcard Cancel a scheduled postcard ~64
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}.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Postcard id (psc_…) to cancel. |
No output schema declared.
No examples provided.
lob_create_address Save an address record ~168
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.
| Name | Type | Req | Description |
|---|---|---|---|
| address_city | string | – | – |
| address_country | string | – | 2-letter ISO country code. Defaults to US. |
| address_line1 | string | yes | 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). |
No output schema declared.
No examples provided.
lob_create_letter Send a letter (COSTS MONEY) ~426
⚠️ 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`. Tracked mail: `extra_service` = certified (U.S. addresses: tracking + proof of delivery), certified_return_receipt (certified + the recipient's electronic signature) or registered (international addresses only); extra cost, first class only, not for us_legal size. The tracking number is on the letter (lob_get_letter). Lob API: POST /v1/letters.
| Name | Type | Req | Description |
|---|---|---|---|
| address_placement | string | – | Where the recipient address is placed. |
| color | boolean | yes | true = color printing, false = black & white. |
| description | string | – | Internal label. |
| double_sided | boolean | – | Print on both sides. Default true. |
| extra_service | string | – | Tracked mail (extra cost): certified or certified_return_receipt for U.S. addresses, registered for international ones. Omit for ordinary mail. |
| file | string | yes | Letter body: HTML string, asset/PDF URL, or template id (tmpl_…). |
| from | – | yes | Return address (id or inline object). Required for letters. |
| mail_type | string | – | USPS mail class. Default usps_first_class. extra_service needs first 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. |
| to | – | yes | Either an existing address id (adr_…) or an inline address object. |
| use_type | string | – | Lob mail use type: operational (bills, notices, legal letters) or marketing. Lob requires it unless the account has a default use type (Account Settings). |
No output schema declared.
No examples provided.
lob_create_postcard Send a postcard (COSTS MONEY) ~297
⚠️ 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.
| Name | Type | Req | Description |
|---|---|---|---|
| back | string | yes | Back artwork: HTML string, asset URL, or template id (tmpl_…). |
| description | string | – | Internal label. |
| from | – | – | Return address (id or inline object). Optional. |
| front | string | yes | 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 | – | yes | Either an existing address id (adr_…) or an inline address object. |
| use_type | string | – | Lob mail use type: operational (bills, notices, legal letters) or marketing. Lob requires it unless the account has a default use type (Account Settings). |
No output schema declared.
No examples provided.
lob_get_address Get a saved address ~43
Retrieve a single saved address record by id. Lob API: GET /v1/addresses/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Address id (adr_…). |
No output schema declared.
No examples provided.
lob_get_check Get a check ~50
Retrieve a single check by id, including amount, status, and check number. Lob API: GET /v1/checks/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Check id (chk_…). |
No output schema declared.
No examples provided.
lob_get_letter Get a letter ~50
Retrieve a single letter by id, including status, PDF url, and tracking. Lob API: GET /v1/letters/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Letter id (ltr_…). |
No output schema declared.
No examples provided.
lob_get_postcard Get a postcard ~53
Retrieve a single postcard by id, including status, PDF url, and expected delivery. Lob API: GET /v1/postcards/{id}.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Postcard id (psc_…). |
No output schema declared.
No examples provided.
lob_list_addresses List saved addresses ~86
List saved address records, newest first. Lob API: GET /v1/addresses.
| Name | Type | Req | Description |
|---|---|---|---|
| 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. |
No output schema declared.
No examples provided.
lob_list_checks List checks ~87
List sent/scheduled checks, newest first. Lob API: GET /v1/checks.
| Name | Type | Req | Description |
|---|---|---|---|
| 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. |
No output schema declared.
No examples provided.
lob_list_letters List letters ~87
List sent/scheduled letters, newest first. Lob API: GET /v1/letters.
| Name | Type | Req | Description |
|---|---|---|---|
| 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. |
No output schema declared.
No examples provided.
lob_list_postcards List postcards ~88
List sent/scheduled postcards, newest first. Lob API: GET /v1/postcards.
| Name | Type | Req | Description |
|---|---|---|---|
| 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. |
No output schema declared.
No examples provided.
lob_list_self_mailers List self-mailers ~92
List sent/scheduled self-mailers, newest first. Lob API: GET /v1/self_mailers.
| Name | Type | Req | Description |
|---|---|---|---|
| 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. |
No output schema declared.
No examples provided.
lob_list_templates List templates ~88
List saved HTML templates usable as postcard/letter artwork. Lob API: GET /v1/templates.
| Name | Type | Req | Description |
|---|---|---|---|
| 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. |
No output schema declared.
No examples provided.
lob_us_autocomplete Autocomplete a US address ~101
Suggest complete US addresses from a partial primary line — useful for address entry. Non-mutating. Lob API: POST /v1/us_autocompletions.
| Name | Type | Req | Description |
|---|---|---|---|
| address_prefix | string | yes | 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. |
No output schema declared.
No examples provided.
lob_us_zip_lookup Look up a US ZIP code ~61
Return the cities and state associated with a US ZIP code. Non-mutating. Lob API: POST /v1/us_zip_lookups.
| Name | Type | Req | Description |
|---|---|---|---|
| zip_code | string | yes | A 5-digit US ZIP code, e.g. '94107'. |
No output schema declared.
No examples provided.
lob_verify_intl_address Verify an international address ~123
Validate & standardize a non-US address. `country` (2-letter ISO code) is required. Non-mutating (no mail sent). Lob API: POST /v1/intl_verifications.
| Name | Type | Req | Description |
|---|---|---|---|
| city | string | – | – |
| country | string | yes | 2-letter ISO country code, e.g. 'GB', 'DE', 'CA'. |
| postal_code | string | – | – |
| primary_line | string | yes | Primary delivery line. |
| secondary_line | string | – | – |
| state | string | – | State / province / region. |
No output schema declared.
No examples provided.
lob_verify_us_address Verify a US address ~174
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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. |
No output schema declared.
No examples provided.
How do I install the Lob MCP by usefulapi server?
Lob MCP by usefulapi is a hosted endpoint at https://lob.usefulapi.io/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · lob.usefulapi.io
claude mcp add --transport http io-usefulapi-lob 'https://lob.usefulapi.io/mcp'
What is the Lob MCP by usefulapi server?
Lob MCP by usefulapi is listed in the public MCP registry as io.usefulapi/lob. Verify US & international addresses and send physical mail (postcards, letters, checks) via Lob. This page covers its hosted endpoint (https://lob.usefulapi.io/mcp).
Is the Lob MCP by usefulapi server safe to use?
Lob MCP by usefulapi scores 18 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the Lob MCP by usefulapi server expose?
Lob MCP by usefulapi exposes 18 tools: lob_verify_us_address, lob_verify_intl_address, lob_us_zip_lookup, lob_us_autocomplete, lob_list_postcards, and 13 more. Their descriptions and schemas cost roughly 2,138 tokens of context every time the server is loaded.
Does the Lob MCP by usefulapi server require authentication?
Its publisher declares no required credentials for Lob MCP by usefulapi. We have not been able to confirm that against the live endpoint, and a server can require authorisation without declaring it here.
Is the Lob MCP by usefulapi server still maintained?
Lob MCP by usefulapi is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.
What did VerifyMCP test on the Lob MCP by usefulapi server?
VerifyMCP ran 4 checks on Lob MCP by usefulapi, covering TLS certificate, HSTS header, DNSSEC and Transport. 7 items could not be completed, a gap on our side rather than a finding about Lob MCP by usefulapi: Authorization, HTTPS, Schema quality, Stability and 3 more. 5 categories score 0 for that reason, because we only credit what we can confirm. Supply Chain Security and Provenance & Transparency do not apply to a hosted endpoint, so they were not tested. The score does not measure everything, and the scoring documentation lists what it leaves out.