KARTA — spend control for AI agents
REMOTE · KARTA.RTA.LAT
Task envelope, budget ledger, kill switch and signed receipts for agents that pay.
Available components
Last scanned (47 minutes ago)
Scores higher than 43% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Finance and Payments
Recent critical change
Authorization (28 Oct 2026). See the changelog before you install this server.
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 check failed: no authorisation is required to call this server, and it exposes a tool marked destructive (kill_envelope). See how to fix → View diagnostics → Fail
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 406, which proves neither a plaintext path nor enforcement. 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 & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability63
- AI-judged instruction clarity (good).Pass
- Tool/resource definitions use about 447 tokens (~74/item across 6 items; 6 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management33
- Stability observed for 10 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage71
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 0% of tool parameters carry a description.Fail
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- All 1 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation.Pass
- An AI judge read all 7 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
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.
- 4 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.
- 2 Nov 26 +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.
- 31 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.
- 29 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.
- 28 Oct 26 +1
- Authorization: unverified → fail ▼ critical
- New tool “kill_envelope”, which the server declares destructive security
- Schema quality: 123 → 74 ▲ functional
- Schema quality: fair → good functional
- Destructive annotations: pass → 100 functional
- New tool “envelope_evidence” functional
- New tool “get_envelope” functional
- New tool “open_envelope” functional
- New tool “policy_rules” functional
- Tool “check_spend” changed its title: Check a spend against a task envelope cosmetic
- 27 Oct 26 +1
- Stability: unverified → 0.03 ▲ functional
- 26 Oct 26 54
First indexed and scored.
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://karta.rta.lat/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=rta.lat | CN=YE1,O=Let's Encrypt,C=US | 10 Oct 2026 | 8 Jan 2027 | ECDSA 256 | ECDSA-SHA384 | 59db7032239aa6d4ff0b819218c19402ee7 |
| SANs: *.rta.lat, rta.lat | ||||||
| CN=YE1,O=Let's Encrypt,C=US (CA) | CN=Root YE,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | ECDSA 384 | ECDSA-SHA384 | 5ddd70dd31f801c85c186a7a04b80afe |
| CN=Root YE,O=ISRG,C=US (CA) | CN=ISRG Root X2,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | ECDSA-SHA384 | 872165fc34b6e5fba8add5b3705fb53a |
| CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | SHA256-RSA | 6c8f1dc727c7117f7baf853ac980f9cd |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of karta.rta.lat. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| lat. | present | 25789, 42520 | 8, 8 | Verified |
| rta.lat. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://karta.rta.lat/mcp | Verified | 200 | |
| http (plaintext) | http://karta.rta.lat/mcp | Inconclusive | 406 |
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 →
check_spend Check a spend against a task envelope ~87
Check whether a proposed agent spend is inside a task envelope. Returns verdict, rule, reason, counterfactual and next. No state is stored.
| Name | Type | Req | Description |
|---|---|---|---|
| amount | string | yes | – |
| calls_so_far | integer | – | – |
| envelope | object | yes | – |
| is_subscription | boolean | – | – |
| payee | string | yes | – |
| spent_so_far | string | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
envelope_evidence Evidence pack for an envelope ~51
Return an evidence bundle for one envelope: state, every recorded spend, the stop record and a sha256 of the whole pack that anyone can recompute. Read-only.
| Name | Type | Req | Description |
|---|---|---|---|
| envelope_id | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
get_envelope Read an envelope ~44
Return an envelope's state: budget, per-call cap, calls used, spent, remaining, allowlist and expiry. Read-only.
| Name | Type | Req | Description |
|---|---|---|---|
| envelope_id | string | yes | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
kill_envelope Stop an envelope ~55
Stop one task envelope immediately: no further spend is approved for it, the reason is recorded with a timestamp. Idempotent — the first reason wins.
| Name | Type | Req | Description |
|---|---|---|---|
| envelope_id | string | yes | – |
| reason | string | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
open_envelope Open a task envelope ~133
Create a signed budget envelope for one task: total budget, per-call cap, call count, allowlisted payees, subscription rule, expiry. Stores it in this server's local ledger (no funds move, no keys). Returns the envelope id. Capped at 30 envelopes/hour per server.
| Name | Type | Req | Description |
|---|---|---|---|
| allow_new_payee | boolean | – | – |
| allow_subscriptions | boolean | – | – |
| allowlist | – | – | – |
| approval_threshold | – | – | – |
| budget_total | string | yes | – |
| calls_max | integer | yes | – |
| per_call_max | string | yes | – |
| ttl_hours | integer | – | – |
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
policy_rules List policy rules ~41
List the deterministic rules a spend is checked against (E01-E08) with the order they are applied and the meaning of each. Read-only, no state.
Input schema present but exposes no named parameters.
| Name | Type | Req | Description |
|---|---|---|---|
| result | string | yes | – |
No examples provided.
How do I install the KARTA — spend control for AI agents MCP server?
KARTA — spend control for AI agents is a hosted endpoint at https://karta.rta.lat/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 · karta.rta.lat
claude mcp add --transport http lat-rta-karta-guard 'https://karta.rta.lat/mcp'
What is the KARTA — spend control for AI agents MCP server?
KARTA — spend control for AI agents is an MCP server listed in the public MCP registry as lat.rta.karta/guard. Task envelope, budget ledger, kill switch and signed receipts for agents that pay. This page covers its hosted endpoint (https://karta.rta.lat/mcp).
Is the KARTA — spend control for AI agents MCP server safe to use?
KARTA — spend control for AI agents scores 60 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 KARTA — spend control for AI agents MCP server expose?
KARTA — spend control for AI agents exposes 6 tools: check_spend, open_envelope, get_envelope, kill_envelope, envelope_evidence, policy_rules. Their descriptions and schemas cost roughly 411 tokens of context every time the server is loaded.
Does the KARTA — spend control for AI agents MCP server require authentication?
No. We connected to KARTA — spend control for AI agents without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the KARTA — spend control for AI agents MCP server still maintained?
KARTA — spend control for AI agents 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.