Ambr

io.github.getambrPublished by GitHub account getambrv0.3.0Updated Oct 25, 2026

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

VerifiedStreamable HTTPWeb executableFinanceBusiness & Commerce

Overview

AI-generated overview

Ambr lets an assistant list contract templates, generate and retrieve Ricardian contracts, check status and amendments, verify SHA-256 hashes, and record agent-

What you can do
List available Ricardian Contract templates with slugs, names, descriptions, categories, parameter schemas and pricing, then generate a dual-format contract (human-readable legal text plus machine-parsable JSON) bound by a SHA-256 hash and stored on Ambr. Retrieve a contract by ID, hash or UUID, with full content for the authenticated creator and metadata only otherwise. Check a contract's status and its amendment chain, and verify a SHA-256 hash to confirm document integrity. Record an agent's intent to accept, reject or request changes on a contract on behalf of a delegating principal.
When to use it
Useful when an assistant needs to draft, look up or verify Ricardian contracts on Ambr, or when an agent acting for a registered principal must signal acceptance or rejection of a contract. Less relevant if you do not work with Ambr contracts.
Requirements
Remote endpoint at getamber.dev over streamable HTTP; no local runtime. Creating contracts and full retrieval need an API key sent in the X-API-Key header. The handshake tool needs an API key tied to an active delegation, with the principal's wallet registered via the delegations API.
Before you install
Contract creation and the handshake write data to Ambr and are tied to an API key; keep that key private. The handshake only records the agent's intent, and the principal must approve separately. Contracts are stored on Ambr's servers, so contract content leaves your machine. Templates carry pricing, so check costs before creating contracts.

Installation

In SourceWeft

  1. Open Ambr in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.getambr%2Fambr-mcp-server/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "ambr": {
      "type": "http",
      "url": "https://getamber.dev/api/mcp"
    }
  }
}

README

This repository has no README.

Tools

6

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.

Takes no parameters.

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 } - 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.

Parameterstemplaterequiredparametersrequiredamendment_typeparent_contract_hashprincipal_declarationrequiredoversight_threshold_usd

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.

Parametersidrequired

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.

Parametersidrequired

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.

Parametershashrequired

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.

Parametersintentrequiredmessagecontract_idrequiredvisibility_preference

Version history

1
  1. v0.3.0LatestSep 16, 2026

Score

75% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts

    Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.

  • License10 pts

    Declare a license in the repository or the registry entry.