Ambr

io.github.getambr/ambr-mcp-serverVersion 0.3.0

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

Status

Responds107 msNov 14, 2026, 14:51 UTCAnswered our handshake without sign-in.

Registry data may be out of date

We could not refresh it, so this page shows the last copy.

Last checked: Nov 14, 2026, 14:51 UTC
Latency: 107 ms
Remotes responding: 1 of 1
Sign-in: No sign-in
Hosting: Hosted outside the EU (detected)
Registry data as of: Nov 14, 2026, 22:14 UTC

Data from the official MCP Registry, checked by run.zero. How we check

Connect

Streamable HTTP

https://getamber.dev/api/mcpResponds107 msNov 14, 2026, 14:51 UTC

No sign-in

Claude Code

claude mcp add --transport http ambr-mcp-server https://getamber.dev/api/mcp

Claude Desktop and claude.ai

1
2
3

Settings > Connectors > Add custom connector
Name: ambr-mcp-server
Remote MCP server URL: https://getamber.dev/api/mcp

Cursor

{
  "mcpServers": {
    "ambr-mcp-server": {
      "url": "https://getamber.dev/api/mcp"
    }
  }
}

VS Code

code --add-mcp '{"name":"ambr-mcp-server","type":"http","url":"https://getamber.dev/api/mcp"}'

Built your own server? run.zero hosts MCP servers on European infrastructure.

Host your own MCP server on run.zero

Tools

7 tools

Tools of Ambr
	Description		Read-only	Idempotent	Open world
`ambr_agent_handshake`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.	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.	No	No	Yes	No
`ambr_check_transaction`Check one payment against what an agreement allows. Advisory only: Ambr compares what you report with the agreement's terms; it does not authorize, block or see payments, and in_scope is not an approval or a guarantee. Tests the payment against the agreement's status, validity window, currency, per-transaction limit, monthly limit, approved categories, enumerated actions and approval threshold. If the agreement was amended, the newest approved version is checked. Free: no credits are burned. Ambr does not hold funds or track spend, so the monthly limit is checked only when you pass period_spent. A rule the agreement sets no limit for comes back as not_evaluated, never as a pass. If a rule has a limit but you did not send what it needs (category, action, currency, period_spent), the verdict is "incomplete", not "in_scope". Send everything the agreement limits. Access: a public contract is open to anyone; otherwise use the creator's API key or pass a share_token. Args: - contract_id (string, required): Contract ID (amb-YYYY-NNNN), SHA-256 hash, or UUID - amount (number, required): payment amount, zero or more - currency (string, optional): e.g. "USD" - category (string, optional): spending category - action (string, optional): the action the agent is taking - period_spent (number, optional): already spent this month, to check the monthly limit - share_token (string, optional): share token for a private contract Returns: verdict ("in_scope" \| "out_of_scope" \| "incomplete" \| "needs_approval"), the per-rule checks, plain-language reasons, and the contract that was checked (contract_id, effective_contract_id, sha256_hash, reader_url).	Check one payment against what an agreement allows. Advisory only: Ambr compares what you report with the agreement's terms; it does not authorize, block or see payments, and in_scope is not an approval or a guarantee. Tests the payment against the agreement's status, validity window, currency, per-transaction limit, monthly limit, approved categories, enumerated actions and approval threshold. If the agreement was amended, the newest approved version is checked. Free: no credits are burned. Ambr does not hold funds or track spend, so the monthly limit is checked only when you pass period_spent. A rule the agreement sets no limit for comes back as not_evaluated, never as a pass. If a rule has a limit but you did not send what it needs (category, action, currency, period_spent), the verdict is "incomplete", not "in_scope". Send everything the agreement limits. Access: a public contract is open to anyone; otherwise use the creator's API key or pass a share_token. Args: - contract_id (string, required): Contract ID (amb-YYYY-NNNN), SHA-256 hash, or UUID - amount (number, required): payment amount, zero or more - currency (string, optional): e.g. "USD" - category (string, optional): spending category - action (string, optional): the action the agent is taking - period_spent (number, optional): already spent this month, to check the monthly limit - share_token (string, optional): share token for a private contract Returns: verdict ("in_scope" \| "out_of_scope" \| "incomplete" \| "needs_approval"), the per-rule checks, plain-language reasons, and the contract that was checked (contract_id, effective_contract_id, sha256_hash, reader_url).	No	Yes	Yes	No
`ambr_create_contract`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 } - principal_wallet (string, optional): the deploying party's own wallet. It must differ from the counterparty wallet in parameters (same_wallet_both_parties otherwise); left out, the first wallet that signs fills the principal side - parent_contract_hash (string, optional): SHA-256 hash of a contract you created, which this one is created under (its oversight threshold then applies). Not for amendments: propose those with POST /api/v1/contracts/{id}/amend - 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. 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.	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 } - principal_wallet (string, optional): the deploying party's own wallet. It must differ from the counterparty wallet in parameters (same_wallet_both_parties otherwise); left out, the first wallet that signs fills the principal side - parent_contract_hash (string, optional): SHA-256 hash of a contract you created, which this one is created under (its oversight threshold then applies). Not for amendments: propose those with POST /api/v1/contracts/{id}/amend - 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. 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.	No	No	No	No
`ambr_get_contract`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.	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.	No	Yes	Yes	No
`ambr_get_contract_status`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.	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.	No	Yes	Yes	No
`ambr_list_templates`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.	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.	No	Yes	Yes	No
`ambr_verify_hash`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.	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.	No	Yes	Yes	No

Details

Registry status: Active
Published: Apr 21, 2026
Updated: Apr 21, 2026
Website: https://ambr.run/⁠ (opens in a new tab)
Repository: https://github.com/getambr/site⁠ (opens in a new tab)
Categories: Uncategorized
GDPR: Not declared

Are you the operator? Claim this listing