{"record":{"id":"ebc5201050b9dfd8","repo":"headroomlabs-ai/headroom","slug":"no-toin-pattern-found-with-hash-starting-with-ha","errorCode":null,"errorMessage":"No TOIN pattern found with hash starting with: {hash_prefix}","messagePattern":"No TOIN pattern found with hash starting with: (.+?)","errorType":"http","errorClass":"HTTPException","httpStatus":404,"severity":"info","filePath":"headroom/proxy/server.py","lineNumber":4918,"sourceCode":"        exported = toin.export_patterns()\n        patterns_data = exported.get(\"patterns\", {})\n\n        # Search for pattern with matching hash prefix\n        for sig_hash, pattern_dict in patterns_data.items():\n            if sig_hash.startswith(hash_prefix):\n                # Keep this response aligned with /v1/toin/patterns while\n                # excluding query text, field semantics, and other internal\n                # learning state from the detail endpoint.\n                return {\n                    \"compressions\": pattern_dict.get(\"total_compressions\", 0),\n                    \"retrievals\": pattern_dict.get(\"total_retrievals\", 0),\n                    \"retrieval_rate\": pattern_dict.get(\"retrieval_rate\", 0.0),\n                    \"confidence\": pattern_dict.get(\"confidence\", 0.0),\n                    \"skip_recommended\": pattern_dict.get(\"skip_compression_recommended\", False),\n                    \"optimal_max_items\": pattern_dict.get(\"optimal_max_items\", 20),\n                }\n\n        raise HTTPException(\n            status_code=404, detail=f\"No TOIN pattern found with hash starting with: {hash_prefix}\"\n        )\n\n    @app.get(\"/v1/retrieve/{hash_key}\", dependencies=[Depends(_require_loopback)])\n    async def ccr_retrieve_get(hash_key: str):\n        \"\"\"GET version of CCR retrieve for easier testing.\"\"\"\n        store = get_compression_store()\n        entry_status = store.get_entry_status(hash_key, clean_expired=True)\n\n        if entry_status[\"status\"] != \"available\":\n            raise HTTPException(\n                status_code=404,\n                detail=format_retrieval_miss_detail(entry_status),\n            )\n\n        # Retrieval is by hash: always return the full original content.\n        entry = store.retrieve(hash_key)\n        if entry:","sourceCodeStart":4900,"sourceCodeEnd":4936,"githubUrl":"https://github.com/headroomlabs-ai/headroom/blob/322425c43bffde1ed0b64fecf3cf5951565dd82b/headroom/proxy/server.py#L4900-L4936","documentation":"GET /v1/toin/patterns/{hash_prefix} returns HTTP 404 when no learned TOIN pattern matches the supplied hash prefix. Prefix lookup only matches patterns already collected by the Tool Output Intelligence Network store.","triggerScenarios":"Querying a prefix with no learned patterns, a too-short/ambiguous prefix that matched nothing, or a pattern DB that is empty after a fresh start or reset.","commonSituations":"New deployments before enough tool traffic; querying after the learning store was cleared; environment mismatch between collection and query.","solutions":["Check /v1/toin/stats to confirm patterns exist at all.","Use the exact prefix reported by pattern-listing endpoints.","Run representative tool workloads first so patterns are learned."],"exampleFix":null,"handlingStrategy":"validation","validationCode":"stats = (await client.get(\"/v1/toin/stats\")).json()\nif not stats.get(\"total_patterns\", 0):\n    skip_pattern_lookup(prefix)","typeGuard":null,"tryCatchPattern":"resp = await client.get(f\"/v1/toin/patterns/{prefix}\")\nif resp.status_code == 404:\n    handle_no_pattern(prefix)","preventionTips":["Warm the store with real tool traffic before querying patterns.","Use full or listing-reported prefixes."],"tags":["http","toin","not-found"],"backgroundTag":null,"analyzedSha":"322425c43bffde1ed0b64fecf3cf5951565dd82b","analyzedAt":"2026-08-15T01:03:05.481Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}