Stéphane Tailland
c5d17d1d04
Preferring the event's figure over the read existed only because the catalog gateway cached reads for 60 seconds. That cache has been removed at the source, so the read is current and there is no second source of truth to arbitrate. The crossing context is now appended only while the reference is still below the threshold — an entry outlives the condition it describes. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
289 lines
12 KiB
JSON
289 lines
12 KiB
JSON
{
|
|
"name": "Approvisionnement \u2014 check_availability",
|
|
"nodes": [
|
|
{
|
|
"parameters": {
|
|
"httpMethod": "POST",
|
|
"path": "check-availability",
|
|
"responseMode": "responseNode",
|
|
"options": {}
|
|
},
|
|
"id": "webhook",
|
|
"name": "Webhook",
|
|
"type": "n8n-nodes-base.webhook",
|
|
"typeVersion": 2,
|
|
"position": [
|
|
0,
|
|
0
|
|
],
|
|
"webhookId": "check-availability"
|
|
},
|
|
{
|
|
"parameters": {
|
|
"method": "POST",
|
|
"url": "https://keycloak.sttlab.local/realms/classic-models/protocol/openid-connect/token",
|
|
"sendBody": true,
|
|
"contentType": "form-urlencoded",
|
|
"bodyParameters": {
|
|
"parameters": [
|
|
{
|
|
"name": "grant_type",
|
|
"value": "urn:ietf:params:oauth:grant-type:token-exchange"
|
|
},
|
|
{
|
|
"name": "client_id",
|
|
"value": "classic-models-agent-approvisionnement"
|
|
},
|
|
{
|
|
"name": "client_secret",
|
|
"value": "={{ $env.APPROVISIONNEMENT_CLIENT_SECRET }}"
|
|
},
|
|
{
|
|
"name": "subject_token",
|
|
"value": "={{ $('Webhook').item.json.headers['x-subject-token'] }}"
|
|
},
|
|
{
|
|
"name": "subject_token_type",
|
|
"value": "urn:ietf:params:oauth:token-type:access_token"
|
|
},
|
|
{
|
|
"name": "scope",
|
|
"value": "openid mcp-catalog-audience token-exchange-broker-audience"
|
|
}
|
|
]
|
|
},
|
|
"options": {}
|
|
},
|
|
"id": "exchange-token",
|
|
"name": "Exchange token",
|
|
"type": "n8n-nodes-base.httpRequest",
|
|
"typeVersion": 4.2,
|
|
"position": [
|
|
220,
|
|
0
|
|
]
|
|
},
|
|
{
|
|
"parameters": {
|
|
"method": "POST",
|
|
"url": "https://catalog-dev.sttlab.local/catalog-mcp",
|
|
"sendHeaders": true,
|
|
"headerParameters": {
|
|
"parameters": [
|
|
{
|
|
"name": "Authorization",
|
|
"value": "=Bearer {{ $json.access_token }}"
|
|
},
|
|
{
|
|
"name": "Accept",
|
|
"value": "application/json, text/event-stream"
|
|
}
|
|
]
|
|
},
|
|
"sendBody": true,
|
|
"specifyBody": "json",
|
|
"jsonBody": "{\"jsonrpc\": \"2.0\", \"id\": 1, \"method\": \"initialize\", \"params\": {\"protocolVersion\": \"2025-06-18\", \"capabilities\": {}, \"clientInfo\": {\"name\": \"approvisionnement\", \"version\": \"0.1.0\"}}}",
|
|
"options": {
|
|
"response": {
|
|
"response": {
|
|
"fullResponse": true
|
|
}
|
|
}
|
|
}
|
|
},
|
|
"id": "mcp-initialize",
|
|
"name": "MCP initialize",
|
|
"type": "n8n-nodes-base.httpRequest",
|
|
"typeVersion": 4.2,
|
|
"position": [
|
|
440,
|
|
0
|
|
]
|
|
},
|
|
{
|
|
"parameters": {
|
|
"method": "POST",
|
|
"url": "https://catalog-dev.sttlab.local/catalog-mcp",
|
|
"sendHeaders": true,
|
|
"headerParameters": {
|
|
"parameters": [
|
|
{
|
|
"name": "Authorization",
|
|
"value": "=Bearer {{ $('Exchange token').item.json.access_token }}"
|
|
},
|
|
{
|
|
"name": "Accept",
|
|
"value": "application/json, text/event-stream"
|
|
},
|
|
{
|
|
"name": "mcp-session-id",
|
|
"value": "={{ $json.headers['mcp-session-id'] }}"
|
|
}
|
|
]
|
|
},
|
|
"sendBody": true,
|
|
"specifyBody": "json",
|
|
"jsonBody": "={{ JSON.stringify({ jsonrpc: '2.0', id: 2, method: 'tools/call', params: { name: 'get-product', arguments: { path_productcode: $('Decide the product').item.json.productcode } } }) }}",
|
|
"options": {
|
|
"response": {
|
|
"response": {
|
|
"neverError": true
|
|
}
|
|
}
|
|
}
|
|
},
|
|
"id": "read-stock",
|
|
"name": "Read stock",
|
|
"type": "n8n-nodes-base.httpRequest",
|
|
"typeVersion": 4.2,
|
|
"position": [
|
|
660,
|
|
0
|
|
],
|
|
"alwaysOutputData": true
|
|
},
|
|
{
|
|
"parameters": {
|
|
"jsCode": "// Pull the product code out of the question.\n//\n// Deliberately loose on the part after the underscore: a reference that\n// looks like one but does not exist must reach the catalog and come back\n// as \"no such product\". Rejecting it here would answer \"you named no\n// product\", which is false and sends the caller looking in the wrong place.\n//\n// A regex rather than a model: this agent's critical path is rules, and putting\n// an LLM on it would make a nightly job both slower and less predictable. If the\n// question does not name a product, the agent escalates instead of guessing \u2014\n// an autonomous agent that meets an ambiguity must hand it back, never resolve\n// it on its own.\nconst question = $('Webhook').first().json.body?.question ?? '';\nconst match = question.match(/\\bS\\d+_[A-Za-z0-9]+\\b/);\nif (!match) {\n return [{ json: { productcode: null, question } }];\n}\nreturn [{ json: { productcode: match[0], question } }];\n"
|
|
},
|
|
"id": "decide-the-product",
|
|
"name": "Decide the product",
|
|
"type": "n8n-nodes-base.code",
|
|
"typeVersion": 2,
|
|
"position": [
|
|
220,
|
|
180
|
|
]
|
|
},
|
|
{
|
|
"parameters": {
|
|
"jsCode": "// Turn the MCP reply into a decision.\n//\n// An A2A call returns an answer, not data: the caller learns whether the stock\n// covers what it asked about, and never receives the stock table. That is what\n// keeps this agent from becoming a read proxy onto the catalog domain.\nconst THRESHOLD = 50; // below this, a reorder is due before promising anything\n\nconst decided = $('Decide the product').first().json;\nif (!decided.productcode) {\n return [{ json: {\n answer: 'No product reference in the question. Name one as S10_1949 and ask again.',\n escalate: true,\n }}];\n}\n\nconst item = $('Read stock').first();\nif (!item) {\n return [{ json: {\n answer: `The catalog returned nothing for ${decided.productcode}. It may not exist.`,\n escalate: true,\n }}];\n}\nconst raw = item.json ?? {};\nconst body = typeof raw === 'string' ? raw : (raw.data ?? JSON.stringify(raw));\n\n// The endpoint answers as an SSE event, so the JSON sits on a `data:` line.\nconst line = String(body).split('\\n').find((l) => l.startsWith('data:'));\nif (!line) {\n return [{ json: {\n answer: `Could not read the catalog's reply for ${decided.productcode}.`,\n escalate: true,\n }}];\n}\n\nlet rpc;\ntry {\n rpc = JSON.parse(line.slice(5).trim());\n} catch (e) {\n return [{ json: {\n answer: `The catalog's reply for ${decided.productcode} could not be read.`,\n escalate: true,\n }}];\n}\n\n// A JSON-RPC `error` is a protocol failure \u2014 a malformed call, a session gone.\nif (rpc.error) {\n return [{ json: {\n answer: `The catalog refused the read for ${decided.productcode}: ${rpc.error.message}.`,\n escalate: true,\n }}];\n}\n\n// A *tool* failure is not that. MCP reports it as a perfectly successful result\n// carrying `isError: true`, with the reason as text \u2014 so a client that only\n// checks `error` reads a failure as data and tries to parse \"HTTP call failed\n// with status 404\" as a product. Which is exactly what this did.\nconst text = rpc.result?.content?.[0]?.text ?? '';\nif (rpc.result?.isError) {\n const missing = text.includes('404');\n return [{ json: {\n answer: missing\n ? `There is no product ${decided.productcode} in the catalog.`\n : `The catalog could not answer for ${decided.productcode}: ${text}`,\n escalate: true,\n }}];\n}\n\nlet product;\ntry {\n product = JSON.parse(text);\n} catch (e) {\n return [{ json: {\n answer: `The catalog returned something unreadable for ${decided.productcode}.`,\n escalate: true,\n }}];\n}\nconst stock = Number(product.quantityinstock);\nconst available = stock >= THRESHOLD;\n\n// What the reactive half noticed, if anything. `product.stock_changed` is\n// consumed as it happens, so a crossing that occurred twenty minutes ago is\n// known here \u2014 and \"it fell below this afternoon, under demand\" is a different\n// decision from \"it has been sitting below for a month\".\n//\n// Read from the watchlist, and absent if the watchlist could not be read: an\n// availability answer must not depend on it.\nlet movement = null;\ntry {\n const watch = $('Recent movement').first()?.json ?? {};\n movement = (watch.entries ?? []).find((e) => e.productcode === product.productcode) ?? null;\n} catch (e) {\n movement = null;\n}\n\n// Only while the reference is still low. An entry stays on the watchlist until\n// a human clears it, so a reference that has since been restocked still has\n// one \u2014 and \"300 in stock \u2026 it crossed the threshold, from 68\" reads as a\n// contradiction even though both halves are true.\nlet context = '';\nif (movement && !available) {\n const when = movement.last_movement_at ?? movement.observed_at;\n const driver = movement.driver === 'demand'\n ? 'driven by orders'\n : 'a stock correction, not demand';\n context = movement.stock_out\n ? ` It ran out at ${when} (${driver}).`\n : ` It crossed the threshold at ${when} (${driver}), from ${movement.was}.`;\n}\n\n// Stock on hand only. Quantities already committed on unshipped orders are\n// NOT deducted, and the answer says so rather than implying a certainty it does\n// not have: the sales API cannot be filtered by product code, so working it out\n// would mean paging the whole orderdetails table on every question \u2014 sixty\n// pages, for one answer. See the backlog note in CLAUDE.md.\nconst basis = 'stock on hand; quantities committed on open orders are not deducted';\n\nreturn [{ json: {\n answer: available\n ? `Yes \u2014 ${product.productname} (${product.productcode}) can be promised: `\n + `${stock} in stock, above the reorder threshold of ${THRESHOLD}. `\n + `Basis: ${basis}.${context}`\n : `No \u2014 ${product.productname} (${product.productcode}) is down to ${stock}, `\n + `below the reorder threshold of ${THRESHOLD}. A reorder is due before it can be promised. `\n + `Basis: ${basis}.${context}`,\n escalate: false,\n}}];\n"
|
|
},
|
|
"id": "answer",
|
|
"name": "Answer",
|
|
"type": "n8n-nodes-base.code",
|
|
"typeVersion": 2,
|
|
"position": [
|
|
880,
|
|
0
|
|
]
|
|
},
|
|
{
|
|
"parameters": {
|
|
"respondWith": "json",
|
|
"responseBody": "={{ JSON.stringify($json) }}",
|
|
"options": {}
|
|
},
|
|
"id": "respond",
|
|
"name": "Respond",
|
|
"type": "n8n-nodes-base.respondToWebhook",
|
|
"typeVersion": 1.1,
|
|
"position": [
|
|
1100,
|
|
0
|
|
]
|
|
},
|
|
{
|
|
"parameters": {
|
|
"method": "GET",
|
|
"url": "http://n8n.n8n.svc.cluster.local/webhook/stock-watchlist",
|
|
"options": {
|
|
"timeout": 5000
|
|
}
|
|
},
|
|
"type": "n8n-nodes-base.httpRequest",
|
|
"typeVersion": 4.2,
|
|
"position": [
|
|
1100,
|
|
0
|
|
],
|
|
"id": "recent-movement",
|
|
"name": "Recent movement",
|
|
"onError": "continueRegularOutput",
|
|
"alwaysOutputData": true
|
|
}
|
|
],
|
|
"connections": {
|
|
"Webhook": {
|
|
"main": [
|
|
[
|
|
{
|
|
"node": "Decide the product",
|
|
"type": "main",
|
|
"index": 0
|
|
}
|
|
]
|
|
]
|
|
},
|
|
"Decide the product": {
|
|
"main": [
|
|
[
|
|
{
|
|
"node": "Exchange token",
|
|
"type": "main",
|
|
"index": 0
|
|
}
|
|
]
|
|
]
|
|
},
|
|
"Exchange token": {
|
|
"main": [
|
|
[
|
|
{
|
|
"node": "MCP initialize",
|
|
"type": "main",
|
|
"index": 0
|
|
}
|
|
]
|
|
]
|
|
},
|
|
"MCP initialize": {
|
|
"main": [
|
|
[
|
|
{
|
|
"node": "Read stock",
|
|
"type": "main",
|
|
"index": 0
|
|
}
|
|
]
|
|
]
|
|
},
|
|
"Read stock": {
|
|
"main": [
|
|
[
|
|
{
|
|
"node": "Recent movement",
|
|
"type": "main",
|
|
"index": 0
|
|
}
|
|
]
|
|
]
|
|
},
|
|
"Answer": {
|
|
"main": [
|
|
[
|
|
{
|
|
"node": "Respond",
|
|
"type": "main",
|
|
"index": 0
|
|
}
|
|
]
|
|
]
|
|
},
|
|
"Recent movement": {
|
|
"main": [
|
|
[
|
|
{
|
|
"node": "Answer",
|
|
"type": "main",
|
|
"index": 0
|
|
}
|
|
]
|
|
]
|
|
}
|
|
},
|
|
"settings": {
|
|
"executionOrder": "v1"
|
|
}
|
|
}
|