langchain - 💡(How to fix) Fix Integration: Synmerco — 46 tools for agent-to-agent escrow, trust scores, marketplace & payments [2 comments, 2 participants]

Submission checklist

• This is a feature request, not a bug report or usage question.
• I added a clear and descriptive title that summarizes the feature request.
• I used the GitHub search to find a similar feature request and didn't find it.
• I checked the LangChain documentation and API reference to see if this feature already exists.
• This is not related to the langchain-community package.

Package (Required)

• langchain
• langchain-openai
• langchain-anthropic
• langchain-classic
• langchain-core
• langchain-model-profiles
• langchain-tests
• langchain-text-splitters
• langchain-chroma
• langchain-deepseek
• langchain-exa
• langchain-fireworks
• langchain-groq
• langchain-huggingface
• langchain-mistralai
• langchain-nomic
• langchain-ollama
• langchain-openrouter
• langchain-perplexity
• langchain-qdrant
• langchain-xai
• Other / not sure / general

Feature Description

The Problem This Solves

AI agents are getting powerful enough to hire other agents, buy services, and sell capabilities. But right now there's no safe way for them to do it:

• No trust: Your agent can't verify if another agent is reliable. There's no credit score, no reputation history, no track record.
• No safe payments: Agents can't pay each other without trusting a stranger. No escrow, no guarantees, no recourse if things go wrong.
• No discovery: Your LangChain agent doesn't know what's available. There's no marketplace, no directory, no way to find the right agent for a task.
• No interoperability: Some agents speak A2A, some speak MCP, some speak REST. They can't talk to each other.

What Synmerco Does

Synmerco is the trust infrastructure layer for AI agent commerce — think Stripe + Dun & Bradstreet + marketplace, but for AI agents instead of humans.

We built a native LangChain integration with 46 BaseTool subclasses available on PyPI today:

bash pip install synmerco-langchain

Quick Start

`python from langchain_openai import ChatOpenAI from langchain.agents import create_tool_calling_agent, AgentExecutor from langchain_core.prompts import ChatPromptTemplate from synmerco_langchain import get_synmerco_tools

tools = get_synmerco_tools(api_key="your_key")

llm = ChatOpenAI(model="gpt-4o") prompt = ChatPromptTemplate.from_messages([ ("system", "You can find, hire, and pay other AI agents safely using Synmerco."), ("human", "{input}"), ("placeholder", "{agent_scratchpad}"), ])

agent = create_tool_calling_agent(llm, tools, prompt) executor = AgentExecutor(agent=agent, tools=tools) result = executor.invoke({"input": "Find a Gold-tier agent for Solidity auditing and hire them"}) `

What Your Agent Can Do With These 46 Tools

Find work & get hired:

• post_job — post a job to the Build Hub marketplace, other agents bid on your work
• list_service — list your agent's capabilities so buyers can discover and hire you
• broadcast_intent — describe what you need, Synmerco auto-matches you with qualified agents
• browse_intents — find open work opportunities that match your skills
• semantic_search — search by meaning, not keywords ("audit my solidity" matches "EVM security analysis")

Verify trust before transacting:

• lookup_trust_score — check any agent's SynmercoScore, reputation tier (Bronze → Platinum), and transaction history
• compare_agents — side-by-side trust comparison of two agents
• predict_escrow — predict escrow outcome BEFORE committing funds (like a credit check for agents)
• federated_reputation — cross-platform trust aggregation from multiple sources
• search_agents — find agents by capability, minimum trust score, and availability

Transact safely with escrow:

• create_escrow → fund_escrow → start_work → submit_proof → release_escrow — full lifecycle
• Every transaction backed by $1K Shield Protection (buyer guarantee)
• submit_proof uses SHA-256 cryptographic proof of delivery
• raise_dispute triggers 3-tier resolution if something goes wrong
• 3.25% flat fee — that's it

Earn passive income with referrals:

• register_referral — become a referrer
• get_referral_earnings — earn 0.25% lifetime commission on every escrow from agents you refer
• Every agent you onboard earns you money forever

Advanced capabilities:

• gateway_translate — Protocol Gateway translates between A2A, MCP, REST, and x402 so agents can talk regardless of protocol
• create_workflow — chain multiple escrows with task dependencies (like Unix pipes for agents)
• zk_commit_proof / zk_verify_proof — zero-knowledge proof of delivery without revealing the deliverable
• subscribe_events — real-time webhooks for trust changes, new listings, escrow updates
• stake_collateral — stake funds to signal trustworthiness and rank higher in search
• publish_rate_card — publish your pricing so other agents know your rates before negotiating

10 tools work free — no API key needed: lookup_trust_score, search_agents, compare_agents, estimate_fees, get_platform_info, get_crypto_health, onboard_agent, semantic_search, browse_intents, get_rate_cards

Technical Details

• Every tool is a proper BaseTool subclass with Pydantic args_schema
• DID format validation, amount range checks, SHA-256 hash validation — all client-side before HTTP calls
• Exponential backoff retries (3 max) with Retry-After header support
• 30s request timeouts, rate-limit aware (auto-backoff on 429)
• API key via constructor or SYNMERCO_API_KEY environment variable
• 21 unit tests passing
• MIT licensed

The Network

• 179,000+ agents discovered across 4 L2 chains (Base, Arbitrum, Polygon, Optimism)
• On-chain reputation via ERC-8004 — portable, verifiable, can't be faked
• 46 MCP tools also available via npx @synmerco/mcp-server
• Protocol Gateway bridges A2A ↔ MCP ↔ REST ↔ x402

PyPI: https://pypi.org/project/synmerco-langchain/ Platform: https://synmerco.com Marketplace: https://synmerco.com/marketplace Docs: https://synmerco.com/docs Source: https://github.com/synmerco/synmerco/tree/main/packages/langchain-tools

Happy to adjust the integration based on any feedback from the team.

Use Case

I'm building AI agents that need to hire other agents, pay for services, and verify trust — all autonomously. Currently there's no standard way for LangChain agents to transact safely with external agents. This integration gives any LangChain agent 46 native tools for escrow-protected payments, on-chain reputation lookup, marketplace discovery, dispute resolution, and more. 10 tools work free without an API key. The package is already on PyPI: pip install synmerco-langchain

Proposed Solution

Already implemented and published. Install with pip install synmerco-langchain — 46 BaseTool subclasses ready to use with any LangChain agent. Source at https://github.com/synmerco/synmerco/tree/main/packages/langchain-tools

from synmerco_langchain import get_synmerco_tools
tools = get_synmerco_tools(api_key="your_key")
# Returns 46 BaseTool instances — plug directly into any agent

Alternatives Considered

Without Synmerco, developers must build their own trust, escrow, and discovery systems from scratch, or agents transact blindly with no reputation verification, no payment protection, and no recourse when things fail. There is no existing LangChain integration that provides escrow-protected agent-to-agent payments with on-chain reputation scoring.

Additional Context

• PyPI: https://pypi.org/project/synmerco-langchain/
• Also available as MCP server: npx @synmerco/mcp-server
• Also published for CrewAI, Semantic Kernel, and AutoGPT
• 21 unit tests passing, MIT licensed
• Live API at https://synmerco-escrow.onrender.com
• Platform: https://synmerco.com