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Ambr

REMOTE · GETAMBER.DEV · SCANNED SEP 20

Ricardian contracts for AI agents — dual-format, SHA-256 bound, legible by construction.

Available components

0 this week 85 Trust /100
Trust breakdown (7 categories)

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 Security80
Transport & Reachability100
Schema Quality & AI Usability66
  • AI-judged instruction clarity (excellent).Pass
  • Context-footprint check failed: tool/resource definitions use about 1325 tokens (~220/item across 6 items; 6 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
  • Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
  • No destabilizing schema changes in the last 30 days.Pass
Tool Coverage95
  • 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
  • 85% of tool parameters carry a description.Partial
Tool Safety100
  • No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
  • We read all 6 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
  • An AI judge read all 6 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
  • Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Install

How do I install the Ambr MCP server?

Ambr is a hosted endpoint at https://getamber.dev/api/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 · getamber.dev

# add to Claude Code
claude mcp add --transport http getambr-ambr-mcp-server 'https://getamber.dev/api/mcp'
// .cursor/mcp.json
{
  "mcpServers": {
    "getambr-ambr-mcp-server": {
      "url": "https://getamber.dev/api/mcp"
    }
  }
}
// .vscode/mcp.json
{
  "servers": {
    "getambr-ambr-mcp-server": {
      "type": "http",
      "url": "https://getamber.dev/api/mcp"
    }
  }
}
# ~/.codex/config.toml
[mcp_servers.getambr-ambr-mcp-server]
url = "https://getamber.dev/api/mcp"
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "getambr-ambr-mcp-server": {
      "type": "remote",
      "url": "https://getamber.dev/api/mcp",
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add getambr-ambr-mcp-server --url 'https://getamber.dev/api/mcp' --transport streamable-http
# ~/.hermes/config.yaml
mcp_servers:
  getambr-ambr-mcp-server:
    url: "https://getamber.dev/api/mcp"
// ~/.netclaw/config/netclaw.json
{
  "McpServers": {
    "getambr-ambr-mcp-server": {
      "Transport": "http",
      "Url": "https://getamber.dev/api/mcp"
    }
  }
}
# add to Vellum
assistant mcp add getambr-ambr-mcp-server -t streamable-http -u 'https://getamber.dev/api/mcp'
// mcp.json
{
  "mcpServers": {
    "getambr-ambr-mcp-server": {
      "type": "http",
      "url": "https://getamber.dev/api/mcp"
    }
  }
}

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

Changelog

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 Sept 26 0
    • Stability: 0.97 → pass security
  • 3 Sept 26 0
    • Stability: pass → 0.97 functional
  • 26 Aug 26 0
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 25 Aug 26 0
    • Stability: 0.97 → pass security
  • 24 Aug 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.

  • 13 Aug 26 0
    • MCP protocol: fail → pass functional
    • MCP protocol version: 2025-03-26 → 2025-11-25 functional
  • 11 Aug 26 0
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 5 Aug 26 0
    • Authorization: unverified → partial security
    • TLS certificate: unverified → pass security
    • HSTS header: unverified → pass security
    • MCP protocol: unverified → fail functional
    • Endpoint reachability: unreachable → reachable functional
    • Tool coverage: unverified → 100 functional
    • Stability: unverified → 0.33 functional
Diagnostics

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 20 Sept 2026 · Probed https://getamber.dev/api/mcp

TLS valid

Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .

Subject Issuer Valid from Valid until Key Signature Serial
CN=getamber.dev CN=YR2,O=Let's Encrypt,C=US 5 Sept 2026 4 Dec 2026 RSA 2048 SHA256-RSA 5ca8cbafe07ac18db779e3f8c98a2a09c98
SANs: getamber.dev
CN=YR2,O=Let's Encrypt,C=US (CA) CN=Root YR,O=ISRG,C=US 3 Sept 2025 2 Sept 2028 RSA 2048 SHA256-RSA 4ebd24947e24d394802d84a52fd5b319
CN=Root YR,O=ISRG,C=US (CA) CN=ISRG Root X1,O=Internet Security Research Group,C=US 13 May 2026 2 Sept 2032 RSA 4096 SHA256-RSA f24b6d17f9d9ad7cb1c9fea78782699f

Background: What to check on a remote MCP endpoint →

DNSSEC insecure

Validation of getamber.dev. Not signed

Zone DS Keys Algorithms Outcome
. trust_anchor 20326, 38696 8, 8 Verified
dev. present 60074 8 Verified
getamber.dev. 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
Header Value
strict-transport-security max-age=63072000
x-content-type-options nosniff
x-frame-options DENY
referrer-policy strict-origin-when-cross-origin
permissions-policy camera=(), microphone=(), geolocation=()

Background: How OAuth 2.1 works in the 2026 MCP spec →

Transports 2 probes
Transport URL Outcome Status Location
streamable-http https://getamber.dev/api/mcp Verified 200
http (plaintext) http://getamber.dev/api/mcp HTTPS enforced 308 https://getamber.dev/api/mcp
MCP tools · 6 exposed · ~1,325 tokens

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 →

Tool Tokens
ambr_agent_handshake ~258

Initiate a handshake on a contract on behalf of your delegating principal. Requires an API key with an active delegation (principal wallet registered via /api/v1/delegations). Records the agent's intent to accept, reject, or request changes on the contract. The principal must separately approve via wallet signature on the Reader Portal. Args: - contract_id (string, required): Contract ID (amb-YYYY-NNNN), SHA-256 hash, or UUID - intent (string, required): "accept" | "reject" | "request_changes" - message (string, optional): Note for the counterparty - visibility_preference (string, optional): "private" | "metadata_only" | "public" | "encrypted" Returns: Handshake status and next steps for principal approval. Legibility: the handshake itself is auditable — delegation scope, agent identity, and principal approval are recorded alongside the contract hash.

NameTypeReqDescription
contract_idstringyesContract ID, SHA-256 hash, or UUID
intentstringyesHandshake intent
messagestringOptional note for counterparty
visibility_preferencestringOptional visibility preference for negotiation

No output schema declared.

No examples provided.

ambr_create_contract ~444

Generate a Ricardian Contract from a template. Creates a dual-format contract (human-readable legal text + machine-parsable JSON) using AI, linked by SHA-256 hash. The contract is stored on Ambr and accessible via the Reader Portal. Requires a valid API key (X-API-Key header on the HTTP request) with available credits. Use ambr_list_templates first to discover templates and their required parameters. Args: - template (string, required): Template slug (e.g. "d1-general-auth") - parameters (object, required): Template-specific parameters matching the schema - principal_declaration (object, required): { agent_id, principal_name, principal_type } - parent_contract_hash (string, optional): SHA-256 hash of parent contract for amendments - oversight_threshold_usd (number, optional): spending level above which work created under this contract needs human approval. Children exceeding it halt at awaiting_principal_approval. - amendment_type (string, optional): "original" | "amendment" | "extension" Returns: - contract_id: Unique ID (e.g. "amb-2026-0042") - sha256_hash: SHA-256 hash for verification - status: Contract status - reader_url: URL to view in Reader Portal - credits_remaining: Remaining API credits Legibility: Output is dual-format by construction and replayable to the original SHA-256 hash — the basis of Ambr's legibility guarantee.

NameTypeReqDescription
amendment_typestring
oversight_threshold_usdnumberSpending level above which work created UNDER this contract requires human approval. A child contract exceeding the parent threshold is held at awaiting_principal_approval until a human signs, and ca…
parametersobjectyesTemplate-specific parameters
parent_contract_hashstringSHA-256 hash of parent contract (for amendments)
principal_declarationobjectyes
templatestringyesTemplate slug from ambr_list_templates

No output schema declared.

No examples provided.

ambr_get_contract ~189

Retrieve a contract by ID, SHA-256 hash, or UUID. With a valid API key (contract creator): returns the full contract including human-readable text, machine-readable JSON, status, and principal declaration. Without authentication: returns metadata only (contract_id, status, hash, dates). Supports three lookup formats: - Contract ID: "amb-2026-0042" - SHA-256 hash: 64-character hex string - UUID: Standard UUID format Args: - id (string, required): Contract ID, SHA-256 hash, or UUID Returns: Full contract (if authorized) or metadata-only response. Legibility: retrieval preserves the dual-format pairing — prose and JSON always replay to the same SHA-256.

NameTypeReqDescription
idstringyesContract ID (amb-YYYY-NNNN), SHA-256 hash, or UUID

No output schema declared.

No examples provided.

ambr_get_contract_status ~150

Check the status of a contract and its amendment chain. Returns the current status and any linked amendments (parent or child contracts). Useful for verifying if a contract is active, amended, or terminated. Args: - id (string, required): Contract ID, SHA-256 hash, or UUID Returns: - contract_id, status, created_at - amendment_type, parent_contract_hash - amendments: Array of child contracts (if any) Legibility: amendments are bilateral and themselves dual-format — the chain stays legible from original through every revision.

NameTypeReqDescription
idstringyesContract ID (amb-YYYY-NNNN), SHA-256 hash, or UUID

No output schema declared.

No examples provided.

ambr_list_templates ~121

List available contract templates on Ambr. Returns all active Ricardian Contract templates with their slugs, names, descriptions, categories, parameter schemas, and pricing. Use this to discover which templates are available before creating a contract with ambr_create_contract. No authentication required. Returns: Array of template objects with slug, name, description, category, parameter_schema, price_cents, and version fields. Legibility: templates are the parameter schema for the dual-format contracts you create — starting here keeps your request conformant and your output defensible.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

ambr_verify_hash ~163

Verify a contract's SHA-256 hash to confirm document integrity. Checks whether the provided hash matches a contract stored on Ambr. Returns verification status, contract metadata, and Reader Portal URL if found. Args: - hash (string, required): SHA-256 hash (64-character hex string) Returns: - verified: boolean - contract_id: string (if found) - status: string (if found) - reader_url: string (if found) Legibility: verification is the point at which legibility becomes provable — matching hash means the prose a human reads and the JSON a machine parses are the same document that was originally signed.

NameTypeReqDescription
hashstringyesSHA-256 hash to verify (64-character hex)

No output schema declared.

No examples provided.

Common questions

What is the Ambr MCP server?

Ambr is an MCP server listed in the public MCP registry as io.github.getambr/ambr-mcp-server. Ricardian contracts for AI agents, dual-format, SHA-256 bound, legible by construction. This page covers its hosted endpoint (https://getamber.dev/api/mcp).

Is the Ambr MCP server safe to use?

Ambr scores 85 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 Ambr MCP server expose?

Ambr exposes 6 tools: ambr_list_templates, ambr_create_contract, ambr_get_contract, ambr_get_contract_status, ambr_verify_hash, ambr_agent_handshake. Their descriptions and schemas cost roughly 1,325 tokens of context every time the server is loaded.

Does the Ambr MCP server require authentication?

No. We connected to Ambr without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

Is the Ambr MCP server still maintained?

Ambr is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.