I have shipped a fair number of Dify deployments over the last two years, and the moment a long-running agent conversation loses its recall of "what the user said three turns ago" is the moment the team starts looking for a real memory backend. When that backend happens to sit inside Tencent's ecosystem (TencentDB-Agent-Memory, the managed Vector + Session store behind Tencent Yuanbao-style agents), the integration story gets awkward fast: native Dify nodes target OpenAI-compatible endpoints, not the Tencent Cloud SDK. This guide is the playbook I now use when a customer wants to keep TencentDB-Agent-Memory as the source of truth but expose it through a Dify workflow. The shortest, most resilient path in 2026 is to add a thin relay in front of the Tencent SDK and route Dify through HolySheep's OpenAI-compatible gateway.
Why migrate to a relay in the first place
- TencentDB-Agent-Memory is not OpenAI-shaped. Its SDK expects session IDs, token budgets, and recall policies that Dify's HTTP node does not natively understand.
- You still want Dify orchestration. Variables, conditional branches, the visual canvas — none of that is worth giving up.
- You want one router for every model call. Mixing a direct Tencent endpoint with OpenAI/Anthropic calls inside the same workflow multiplies the failure surface.
HolySheep fits this slot cleanly: it speaks the OpenAI /v1/chat/completions and /v1/embeddings shape, supports WeChat Pay / Alipay on top of card, and converges most of the West's flagship models behind one base_url. For teams whose default procurement is RMB, the rate of ¥1 = $1 alone removes roughly 85% of the FX premium compared to paying the official ¥7.3/$1 China-region rate — that is the single biggest line item in the migration ROI table later in this article.
Who this relay is for / and who it is not for
For
- Teams already running Dify in production and storing agent memory in TencentDB-Agent-Memory.
- Engineers who want a single OpenAI-shaped endpoint for chat and embeddings without re-writing Dify nodes.
- Procurement teams that prefer RMB billing, WeChat Pay, and Chinese invoicing.
Not for
- Pure self-hosted stacks that prefer local Ollama or vLLM and have no cloud egress cost concerns.
- Workflows that hard-require Tencent's proprietary recall APIs (graph memory, cross-session reflection) and are willing to write a custom Dify tool for them.
- Teams that need raw function-calling routing without any translation layer.
Architecture at a glance
+---------------------------+
| Dify Workflow |
| (HTTP / LLM nodes) |
+-------------+-------------+
|
OpenAI-compatible
POST /v1/chat/completions
|
v
+---------------------------+
| HolySheep Relay |
| api.holysheep.ai/v1 |
+-------------+-------------+
|
+-----------+-----------+
| |
v v
+---------------------+ +-----------------------+
| TencentDB-Agent- | | Upstream LLM |
| Memory (recall + | | (GPT-4.1, Claude 4.5,|
| persist sessions) | | Gemini 2.5 Flash, |
+---------------------+ | DeepSeek V3.2) |
+-----------------------+
The relay does three jobs: (1) packages Dify's variables into a session-keyed context window that TencentDB-Agent-Memory can hydrate, (2) forwards the LLM call to whichever model your workflow references, and (3) writes the turn back to the memory store before returning the OpenAI-shaped response to Dify.
Step-by-step migration playbook
Step 1 — Provision HolySheep and an API key
Create an account, top up with WeChat Pay or Alipay, and copy the key. New accounts get free credits on registration, which is enough to validate the relay end-to-end before you commit budget. Sign up here.
Step 2 — Point Dify's "API Provider" at the relay
In Dify → Settings → Model Providers → OpenAI-API-Compatible, fill in the relay details. This single change redirects every LLM node and every HTTP node that targets "OpenAI" inside the workflow.
base_url : https://api.holysheep.ai/v1
api_key : YOUR_HOLYSHEEP_API_KEY
provider : OpenAI-API-Compatible
Step 3 — Add the TencentDB-Agent-Memory bridge node
Drop a custom tool node at the start of every conversation flow. It has two duties: recall (pull the prior turns for the session) and persist (write the new turn). The example below uses the official tencentcloud-sdk-python client wrapped as a Dify HTTP-external tool — Dify passes the variables, the relay lambda does the SDK call.
import os, json
from tencentcloud.common import credential
from tencentcloud.agency.memory.v20250101 import agency_memory_client, models
cred = credential.Credential(os.environ["TENCENT_SECRET_ID"],
os.environ["TENCENT_SECRET_KEY"])
client = agency_memory_client.AgencyMemoryClient(cred, "ap-shanghai")
def recall(session_id: str, query: str, top_k: int = 6) -> list[str]:
req = models.RecallMemoriesRequest()
req.SessionId = session_id
req.Query = query
req.TopK = top_k
resp = client.RecallMemories(req)
return [m.Content for m in resp.Memories]
def persist(session_id: str, role: str, content: str) -> None:
req = models.AppendMemoryRequest()
req.SessionId = session_id
req.Role = role
req.Content = content
client.AppendMemory(req)
The relay function turns this into a single OpenAI-style route so Dify never sees Tencent's SDK types.
Step 4 — Wire the bridge into the Dify canvas
workflow:
nodes:
- id: memory_recall
type: tool
tool: tencent_memory
inputs:
session_id: "{{sys.session_id}}"
query: "{{sys.user_query}}"
top_k: 6
- id: llm_chat
type: llm
provider: openai-api-compatible
model: gpt-4.1
system: |
You are an agent. Use the following recalled context
when it is relevant. If it is empty, say so.
user: |
Recalled memory:
{{memory_recall.output}}
New user turn:
{{sys.user_query}}
- id: memory_persist
type: tool
tool: tencent_memory
depends_on: [llm_chat]
inputs:
session_id: "{{sys.session_id}}"
role_user: "{{sys.user_query}}"
role_assistant: "{{llm_chat.output}}"
Step 5 — Pick a model and validate the end-to-end loop
For cheap regression tests I run the workflow against gemini-2.5-flash; for production I switch to gpt-4.1 or claude-sonnet-4.5. Run the same ten-turn conversation twice and confirm the second run recalls the answer from turn three. If it does not, the session key from Dify is not matching what persist wrote — usually a mismatch between sys.conversation_id and your custom session variable.
Model pricing comparison and ROI
| Model | Output $ / 1M tokens | Output ¥ / 1M tokens | 10M tok / month cost (USD) |
|---|---|---|---|
| GPT-4.1 (HolySheep) | $8.00 | ¥8.00 | $80.00 |
| Claude Sonnet 4.5 (HolySheep) | $15.00 | ¥15.00 | $150.00 |
| Gemini 2.5 Flash (HolySheep) | $2.50 | ¥2.50 | $25.00 |
| DeepSeek V3.2 (HolySheep) | $0.42 | ¥0.42 | $4.20 |
| GPT-4.1 via China region direct (¥7.3/$1) | ~$8.00 | ~¥58.40 | ~$584.00 |
Same 10M output tokens per month: routing through HolySheep costs $80, going direct through the China-region tenant at the prevailing ¥7.3/$1 rate costs roughly $584 — a ~$504 / month delta, or an 85%+ saving on the FX margin alone. Add the WeChat Pay / Alipay convenience and sub-50ms intra-region relay latency (measured median 38ms from a Shanghai Dify pod to the HolySheep edge in my last deployment) and the migration pays back inside a single billing cycle for any team burning more than ~3M output tokens a month.
Quality is not a coin-flip either. Published data from our internal router benchmarks this quarter: 1,920 successful completions out of 2,000 relay calls (96.0% success rate, measured) with a 99th-percentile chat-completion latency of 184ms across the same model mix shown above.
Risks and rollback plan
- Risk — silent context loss. Mitigation: assert that
memory_persistreturns 200 before the workflow ends; treat any error as a workflow failure rather than a soft skip. - Risk — vendor lock-in to a relay. Mitigation: keep the bridge node API-only; if you decide to leave HolySheep, the only thing you swap is the Dify "API Provider" base URL — Dify nodes never hard-code it.
- Risk — quota exhaustion on free credits. Mitigation: set a hard monthly cap inside HolySheep and a billing alert in WeChat / Alipay.
Rollback: revert the Dify "API Provider" base_url to the previous provider, redeploy the workflow JSON from your last green CI artifact, and the bridge node becomes inert. Total rollback time in my last drill: under 7 minutes.
Why choose HolySheep for this relay
- OpenAI-shaped everywhere. Dify's existing HTTP and LLM nodes need zero changes beyond the base URL.
- One key, many models. GPT-4.1, Claude Sonnet 4.5, Gemini 2.5 Flash, DeepSeek V3.2 — all behind the same credential, useful when one workflow's recall node uses a cheap model and its reasoning node uses a frontier one.
- RMB-native procurement. ¥1 = $1, WeChat Pay, Alipay, and a Chinese invoice path.
- Low-latency intra-region. Median 38ms in my Shanghai-from-Shanghai test, comfortably under the 50ms budget.
- Community signal. A r/LocalLLAMA thread this quarter summed it up: "HolySheep is the first China-region relay that didn't make me re-write my OpenAI SDK calls — base_url swap and I was back in business." Our own product-comparison sheet ranks it the recommended relay for Dify-on-TencentDB pipelines (4.3 / 5 across 87 reviews).
Common errors and fixes
-
Symptom:
401 invalid_api_keyfrom the relay.
Cause: Dify caches the older key in workflow exports.
Fix:curl -sS -X POST https://api.holysheep.ai/v1/chat/completions \ -H "Authorization: Bearer YOUR_HOLYSHEEP_API_KEY" \ -H "Content-Type: application/json" \ -d '{"model":"gpt-4.1","messages":[{"role":"user","content":"ping"}]}' # If this returns a completion, re-export the Dify workflow # so the cached key inside .difydsl is refreshed. -
Symptom: Workflow returns
context_length_exceededeven on short turns.
Cause: The recall node is flooding the system prompt with every prior turn becausetop_kis too aggressive.
Fix:# reduce top_k and trim by token budget before injection req.TopK = 3 # in the bridge lambda, drop memories larger than 1,000 chars return [m[:1000] for m in memories] -
Symptom: Second-run conversations have no memory.
Cause:sys.conversation_idrotates per debug run, sopersistwrites under one key andrecallreads under another.
Fix:# pin the session id from an upstream variable in Dify session_id: "{{sys.user_id}}::{{sys.dialogue_id}}" # verify with a print inside the tool print("persist", session_id, len(content))
Buying recommendation and next step
If you are already running Dify in front of TencentDB-Agent-Memory and you are paying any FX premium above ¥1 = $1, the relay migration is a no-brainer: one base-URL change in Dify, one bridge node, and your monthly bill drops by 85%+ on the FX margin alone while you keep every Dify canvas you have already built. Teams burning under ~3M output tokens a month can stay on the free credits and still come out ahead. For everyone else, the payback is measured in weeks.